Monsanto Petition (10-188-01p) for Determination of 

Nonregulated Status of Dicamba Herbicide-resistant 

Soybean (Glycine max) MON 87708 

OECD Unique Identifier: 

MON-877Ø8-9

Plant Pest Risk Assessment 

August 2014

Agency Contact 

Cindy Eck

Biotechnology Regulatory Services

4700 River Road

USDA, APHIS 

Riverdale, MD 20737 

Fax: (301) 734-8669

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Mention of companies or commercial products in this report does not imply recommendation or endorsement by the 

U.S. Department of Agriculture over others not mentioned. USDA neither guarantees nor warrants the standard of any 

product mentioned. Product names are mentioned solely to report factually on available data and to provide specific 

information. 

This publication reports research involving pesticides. All uses of pesticides must be registered by appropriate State 

and/or Federal agencies before they can be recommended. 

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TABLE OF CONTENTS

A. Introduction............................................................................................................. 1

B. Development of MON 87708 Soybean .................................................................... 3

C. Description of Inserted Genetic Material, Its Inheritance and Expression, 

Gene Products, and Changes to Plant Metabolism .................................................. 6

D. Potential Plant Pest and Disease Impacts............................................................... 16

E. Potential Impacts on Nontarget Organisms Beneficial to Agriculture..................... 22

F. Potential for Enhanced Weediness of MON 87708 Soybean .................................. 24

G. Potential Impacts on the Weediness of Any Other Plants with which MON 

87708 Soybean Can Interbreed............................................................................. 29

H. Potential Changes to Agriculture or Cultivation Practices...................................... 32

I. Potential Impacts from Transfer of Genetic Information to Organisms with 

which MON 87708 Soybean Cannot Interbreed.................................................... 36

J. Conclusion ............................................................................................................ 40

K. References............................................................................................................. 41

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A. Introduction

Monsanto Company (hereafter referred to as Monsanto) has petitioned the Animal and 

Plant Health Inspection Service (APHIS) of the United States Department of Agriculture 

(USDA) for a determination that genetically engineered (GE) dicamba herbicideresistant1 soybean event MON 87708 and OECD Unique Identifier MON-87708-9

(hereafter referred to as MON 87708 soybean) is unlikely to pose a plant pest risk and,

therefore, should no longer be a regulated article under APHIS’ 7 Code of Federal 

Regulations (CFR) part 340 (7 CFR part 340). This petition was assigned the number 10-

188-01p and is hereafter referenced as (Monsanto, 2012). APHIS administers 7 CFR part 

340 under the authority of the plant pest provisions of the Plant Protection Act (PPA) of 

2000 (7 U.S.C. 7701 et seq.) 2

. This plant pest risk assessment was conducted to 

determine if MON 87708 soybean is unlikely to pose a plant pest risk.

APHIS regulations in 7 CFR part 340 regulate the introduction (importation, interstate 

movement, or release into the environment) of certain GE organisms and products. A GE 

organism is no longer subject to the plant pest provisions of the PPA or to the regulatory 

requirements of Part 340 when APHIS determines that it is unlikely to pose a plant pest 

risk. A GE organism is considered a regulated article under Part 340 if the donor 

organism, recipient organism, or vector, or vector agent used in engineering the organism 

belongs to any genera or taxa designated in 7 CFR 340.2 and meets the definition of plant 

pest, or is an unclassified organism and/or an organism whose classification is unknown,

or any product which contains such an organism, or any other organism or product 

altered or produced through genetic engineering which the Administrator determines is a 

plant pest or has reason to believe is a plant pest3

. MON 87708 soybean was produced 

by Agrobacterium-mediated transformation, and portions of the inserted genetic material 

were derived from plant pest organisms listed in 7 CFR part 340.2 (i.e., promoter 

sequence from peanut chlorotic streak caulimovirus, leader sequence from Tobacco Etch 

virus, and T-DNA border sequences from Agrobacterium tumefaciens) (Table III-1, p. 

40, Monsanto, 2012). Therefore, the genetically engineered MON 87708 soybean is 

1 Monsanto has described the phenotype of MON 87708 soybean as “herbicide tolerant” and historically 

APHIS has also referred to GE plants with reduced herbicide sensitivity as herbicide tolerant. However, 

the phenotype would fall under the Weed Science Society of America (WSSA) definition of “herbicide 

resistance” since MON 87708 soybean has an “inherited ability to survive and reproduce following 

exposure to a dose of herbicide normally lethal to the wild type”. By the WSSA (1998) definition, 

“resistance (to an herbicide) may be naturally occurring or induced by such techniques as genetic 

engineering or selection of variants produced by tissue culture or mutagenesis.” Herbicide tolerance, by the 

WSSA definition, only applies to plant species with an “inherent ability to survive and reproduce after 

herbicide treatment. This implies that there was no selection or genetic manipulation to make the plant 

tolerant; it is naturally tolerant."

2 Plant Protection Act in 7 U.S.C. 7702 § 403(14) defines plant pest as: “Plant Pest - The term “plant pest” 

means any living stage of any of the following that can directly or indirectly injure, cause damage to, or 

cause disease in any plant or plant product: (A) A protozoan. (B) A nonhuman animal. (C) A parasitic 

plant. (D) A bacterium. (E) A fungus. (F) A virus or viroid. (G) An infectious agent or other pathogen. (H) 

Any article similar to or allied with any of the articles specified in the preceding subparagraphs.”

3 Limited exclusions or exemptions apply for certain engineered microorganisms and for interstate 

movement of some organisms, as in 7 CFR 340.1 and 340.2.(b).

1

 
considered a regulated article under APHIS regulations at 7 CFR part 340. Monsanto has 

conducted field releases of MON 87708 soybean as a regulated article under APHISauthorized permits or acknowledged notifications since 2005 (Appendix Table A-1, pp. 

284-286, Monsanto, 2012), in part, to gather information to support that MON 87708 

soybean is unlikely to pose a plant pest risk. 

Potential impacts in this Plant Pest Risk Assessment are those that pertain to plant pest 

risk associated with MON 87708 soybean and its progeny and their use in the absence of 

confinement relative to the unmodified recipient and/or other appropriate comparators. 

APHIS utilizes data and information submitted by the applicant, in addition to current 

literature, to determine if MON 87708 soybean is unlikely to pose a plant pest risk. 

APHIS regulations in 7 CFR 340.6(c) specify the information needed for consideration in 

a petition for nonregulated status. APHIS will assess information submitted by the 

applicant about MON 87708 soybean related to plant pest risk characteristics; expression 

of the gene product, new enzymes, or changes to plant metabolism; disease and pest 

susceptibilities and indirect plant pest effects on other agricultural products; effects of the 

regulated article on nontarget organisms; weediness of the regulated article; impact on the 

weediness of any other plant with which it can interbreed; changes to agricultural or 

cultivation practices that may impact diseases and pests of plants; and transfer of genetic 

information to organisms with which it cannot interbreed.

APHIS may also consider information relevant to reviews conducted by other agencies 

that are part of the ‘Coordinated Framework for the Regulation of Biotechnology’ (51 FR 

23302, June 26, 1986; 57 FR 22984, May 29, 1992). Under the Coordinated Framework, 

the oversight of biotechnology-derived plants rests with APHIS, the Food and Drug 

Administration (FDA), and the Office of Pesticide Programs of the U.S. Environmental 

Protection Agency (EPA). Depending on its characteristics, certain biotechnologyderived products are subjected to review by one or more of these agencies. 

EPA regulates under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) (7 

U.S.C. 136 et seq.) the distribution, sale, use and testing of pesticidal substances 

produced in plants and microbes, including those pesticides that are produced by an 

organism through techniques of modern biotechnology. EPA also sets tolerance limits 

for residues of pesticides on and in food and animal feed, or establishes an exemption 

from the requirement for a tolerance, under the Federal Food, Drug and Cosmetic Act 

(FFDCA) (21 U.S.C. Chapter 9). Prior to registration for a new use for a new or 

previously registered pesticide, EPA must determine through testing that the pesticide 

does not cause unreasonable adverse effects on humans, the environment, and non-target 

species when used in accordance with label instructions. EPA must also approve the 

language used on the pesticide label in accordance with Data Requirements for Pesticides

(40 CFR part 158). Other applicable EPA regulations include Pesticide Registration and 

Classification Procedures (40 CFR part 152) and Experimental Use Permits (40 CFR part 

172). Dicamba was first registered in 1967 for use as a pesticide (herbicide) in the U.S.

and is currently approved for preplant and preharvest labeled uses on soybean (US-EPA, 

2009; BASF, 2010). However, less than 1% of soybean acreage in 2008 was estimated to 

be treated with dicamba (p. 28, USDA-NASS, 2007; Section VIII.G, p. 198 and Table 

2
VIII-12, p. 199, Monsanto, 2012) due to the high sensitivity of soybean to the herbicide

(BASF, 2010; Appendix C.2, Table C-7, p. 317, Monsanto, 2012). To allow for a wider 

window of application of dicamba on dicamba-resistant MON 87708 soybean, Monsanto 

has submitted an application to amend EPA Registration Number 524-582 to register a 

new use pattern for dicamba on MON 87708 soybean which would allow preemergence 

application up to the day of crop emergence and in-crop postemergence application 

through the early reproductive (R1/R2) growth stage (p. 35, Monsanto, 2012; 75 FR 

51045, August 18, 2010). Monsanto has also requested that EPA amend 40 CFR part 180 

to establish a tolerance for residues of dicamba and its relevant metabolites in or on 

soybean forage at 45 parts per million (ppm) and soybean hay at 70 ppm, which would 

allow for the feeding of dicamba-treated soybean forage and hay to livestock (p. 35, 

Monsanto, 2012; 75 FR 46924, August 4, 2010). EPA is currently reviewing the label 

changes to remove all preemergence planting restrictions (intervals and rainfall) for 

dicamba on MON 87708 soybean and establish tolerances for residues of dicamba on 

soybean forage and hay. EPA’s assessment will analyze risks to non-target organisms to 

determine if the label is sufficient to meet EPA’s standards for registration: “reasonable 

certainty of no harm to humans” and “no unreasonable adverse effects on the 

environment.” If these standards are not met, EPA will apply appropriate risk mitigation 

strategies and propose label modifications to address the specific concerns. After EPA 

has completed its assessments and provided these to APHIS, APHIS will update this 

PPRA if needed.

The FDA under the FFDCA is responsible for ensuring the safety and proper labeling of 

all plant-derived foods and feeds, including those developed through modern 

biotechnology. To help sponsors of foods and feeds derived from genetically engineered 

crops comply with their obligations, the FDA encourages them to participate in its 

comprehensive voluntary consultation process prior to commercial distribution of food or 

feed (57 FR 22984, May 29, 1992). Monsanto initiated a consultation with the FDA 

(Biotechnology Notification File [BNF] No. 125) on the food and feed safety and 

compositional assessment of MON 87708 soybean (p. 34, Monsanto, 2012). Monsanto 

submitted a safety and nutritional assessment summary document to the FDA on 

November 9, 2010 and received a completed consultation letter from the FDA on October 

11, 2011. A copy of the text of this letter responding to BNF 125, as well as a copy of 

the text of FDA’s memorandum summarizing the information in BNF 125, is available 

via the FDA webpage “Biotechnology Consultations on Food from GE Plant Varieties” at

http://www.accessdata.fda.gov/scripts/fdcc/?set=Biocon (US-FDA, 2011).

B. Development of MON 87708 Soybean

For over 50 years, the U.S. has been the world’s largest producer of soybeans 

(FAOSTAT, 2012). In 2011, over 3 billion bushels were produced on 74 million acres 

(USDA-NASS, 2012b) in over 30 states (Figure 1), generating a crop value of $35.8 

billion (USDA-NASS, 2012c). To optimize yield and economic return, growers select 

soybean lines adapted to the local environmental and climatic conditions and grow them 

using appropriate cultivation practices such as seedbed preparation, planting timing and 

3
 Figure 1. Soybean production areas in the U.S. (USDA-NASS, 2012d).

density, and integrated pest management to handle weed and disease pressures (Hoeft et 

al. 2000; OECD 2000).

The presence of weeds in soybean fields can cause greater production losses than either 

insects or diseases (Aref and Pike 1998; Gibson et al. 2005; Oerke 2006). Before the 

development of effective herbicides for the selective control of weeds in soybeans in the 

early 1960’s, cultural practices including tillage, use of weed-free seed, row spacing and 

crop rotation were the only ways to control weeds (Wax 1973). By 1987, over 30 

herbicides were being used on soybeans (Jordan et al. 1987). With the 1996 commercial 

introduction and rapid adoption of glyphosate-resistant soybeans, a major change in 

herbicide usage occurred; glyphosate use increased concurrent with the increase in 

plantings of glyphosate-resistant soybeans, and the use of other soybean herbicides 

decreased (Figure 2; NRC 2010; Young 2006). Consequently, the diversity of herbicides 

used for weed management has declined in soybean (Table 1; Young 2006) resulting in 

weed species shifts (Johnson et al. 2009). 

Repeated and intensive use of herbicides with the same mechanisms of action can rapidly 

select for tolerant, difficult-to-control weeds and for herbicide-resistant weeds, especially 

in the absence of the concurrent use of herbicides with different mechanisms of action 

and/or use of different mechanical or cultural practices for weed control (Vencill et al. 

2012). Currently growers are looking for more options for over-the-top herbicide 

4
Figure 2. Percent planted acres of genetically engineered crops in the U.S. (USDA-ERS 

2012).

applications for their no-till soybean crops to use in conjunction with cultural and 

mechanical best management practices to mitigate the evolution of herbicide-resistant 

weeds, especially glyphosate-resistant weeds (Service 2007). 

Dicamba (3,6-dichloro-2-methoxybenzoic acid) is a selective pre- and post-emergent 

herbicide used to control a wide spectrum of broadleaf weeds and woody plants. It is a 

synthetic auxin herbicide that acts similar to endogenous auxin (indole-3-acetic acid); 

low concentrations induce cellular elongation and turgor as well as cellular differentiation 

and division, while increased concentrations lead to abnormal cell division and growth, 

and higher concentrations inhibit cell division and growth to the point of plant death 

(Bunch et al. 2012; Kelley and Reichers 2007; WSSA 2012). Because dicamba is 

effective on broadleaf weeds which are hard-to-control with glyphosate or are 

glyphosate-resistant, Monsanto intends to commercialize GE soybeans which are 

resistant to both dicamba and glyphosate so that soybean growers have greater weed 

control options using both of these modes of herbicide action. Soybean is normally 

sensitive to dicamba. MON 87708 soybean was developed from A3525, a high-yielding 

soybean variety that was then genetically engineered to be resistant to dicamba by 

expressing a mono-oxygenase gene (dmo) from Strenotrophomonas maltophilia that 

rapidly demethylates dicamba, rendering it inactive. Although the original 

transformation contained a gene for resistance to glyphosate herbicide, subsequent selfpollination and selection with glyphosate herbicide was used identify the segregant which 

is referred to as MON 87708 soybean that lacks this glyphosate resistance gene (as 

5
described in the next section). However, Monsanto intends to stack MON 87708 soybean 

with MON 89788 (glyphosate-resistant Roundup Ready 2 Yield® soybean) utilizing 

traditional breeding methods (p. 33, (Monsanto, 2012)). The near isogenic soybean line 

A3525 was used as a comparator in many of the studies submitted to support the petition.

Table 1. Average (across all states) percent of U.S. soybean acres treated with the listed 

herbicides in 1990, 1995, 2000 and 2006 (USDA-NASS, 2012a).

Herbicide* 1990 1995 2000 2006 Herbicide* 1990 1995 2000 2006

2,4-D 3 10 5 Glyphosate 5 21 62 92

2,4-D, Dimeth 3 Imazamox 6

2,4-D 2-EHE 7 Imazaquin 16 15 4 1

Acifluorfen 3 Imazethapyr 11 44 12 3

Alachlor 13 4 1 Lactofen 1 5 2

Bentazon 16 12 2 Linuron 6 2

Chlorimuron 20 16 10 4 Metolachlor 10 7 2

Clethodim 5 4 3 Metribuzin 19 11 4 2

Clomazone 7 4 Paraquat 2 2 1

Cloransulam 4 1 Pendimethalin 14 26 11 3

Ethalfluralin 5 1 Quizalofop 3 6

Fenoxaprop 6 4 Sethoxydim 4 7 2

Fluazifop 6 10 5 1 Sulfentrazone 4 1

Flumetsulam 2 2 Sulfosate 4 1

Flumioxazin 3 Thifensulfuron 4 12 6 1

Fomesafen 2 4 7 2 Trifluralin 37 20 14 2

* Herbicides used on only 1% or less acreage for all years listed are not included; 2006 was last 

year reported at the time the petition was submitted.

C. Description of Inserted Genetic Material, Its Inheritance and 

Expression, Gene Products, and Changes to Plant Metabolism

To inform the potential hazards resulting from the genetic modification and potential 

routes of exposure related to the inserted DNA and its expression products, APHIS 

assessed data and information presented in the petition related to: the transformation 

process; the source of the inserted genetic material and its function in both the donor 

organism and the GE crop event; and the integrity, stability and mode of inheritance of 

the inserted genetic material through sexual or asexual reproduction based on the location 

of the insertion (e.g. nucleus or organelle) and the number of loci inserted. 

6
APHIS also assessed data presented in the petition on whether the genetic modification 

results in expression of new genes, proteins, or enzymes or changes in plant metabolism 

or composition in the MON 87708 soybean relative to the nontransgenic counterpart 

A3525 soybean or to other reference soybean varieties considered for the composition 

analysis. The assessment encompasses a consideration of the expressed mono-oxygenase 

gene (dmo) from Strenotrophomonas maltophilia and any observed or anticipated effects

on plant metabolism including, e.g. any relevant changes in levels of metabolites, 

antinutrients, or nutrients in harvested seed or forage derived from the MON 87708 

soybean compared to those in the conventional counterpart A3525 soybean or to other 

reference soybean varieties. 

This information is used later in this risk assessment to inform whether there is any 

potential for plant pest vectors or sequences to cause disease or greater plant pest risks in 

the GE crop event; or for expression of inserted DNA, new proteins or enzymes, or 

changes in metabolism to affect plant pest or diseases, nontarget beneficial organisms, 

weediness, agricultural practices that impact pest or diseases or their management, or 

plant pest risks through horizontal gene flow. 

Description of the genetic modification and inheritance of inserted DNA

MON 87708 soybean was developed through Agrobacterium tumefaciens-mediated 

transformation of conventional soybean variety A3525 meristem tissue without 

utilization of callus (Martinell et al. 2002), using plasmid vector PV-GMHT4355. The 

PV-GMHT4355 plasmid vector is a two-T-DNA vector and contained a Transfer DNA 

(T-DNA I) sequence containing the dmo plant expression cassette, a second Transfer 

DNA (T-DNA II) containing the cp4 epsps plant expression cassette, and plasmid 

backbone sequences necessary for maintenance or selection of the plasmid vector in 

bacteria but which are not expected to be transferred to the plant (Figure III-1, p. 39 and 

Table III-1, pp. 40-42, (Monsanto, 2012)), as summarized below:

T-DNA I dmo cassette

• Right Border Sequence: A specific DNA region from A. tumefaciens containing 

the Right Border sequence used for transfer of the T-DNA (Depicker et al. 1982; 

Zambryski et al. 1982).

• PC1SV Promoter Sequence: Promoter for the Full-Length Transcript (FLt) of 

peanut chlorotic streak caulimovirus (Maiti and Shepherd 1998) that directs 

transcription in plant cells.

• TEV Leader Sequence: 5' non-translated region from the Tobacco Etch virus 

genome (Niepel and Gallie 1999) that is involved in regulating gene expression.

• RbcS Targeting Sequence: Sequences encoding the chloroplast transit peptide 

(CTP) and the first 24 amino acids of the mature protein of the Rubisco small 

subunit (RbcS) gene from Pisum sativum (pea) (Fluhr et al. 1986) that directs 

transport of the dicamba mono-oxygenase (DMO) precursor protein to the 

chloroplast.

• dmo Coding Sequence: Coding sequence for dicamba mono-oxygenase (DMO) 

from Stenotrophomonas maltophilia which confers resistance to the herbicide 

dicamba (Herman et al. 2005; Wang et al. 1997). 

7
• RbcS2-E9 Terminator Sequence: 3′ non-translated region from the RbcS2 gene of 

Pisum sativum (pea) encoding the Rubisco small subunit, which functions to 

direct polyadenylation of the mRNA (Coruzzi et al. 1984). 

• Left Border Sequence: A specific DNA region from A. tumefaciens containing 

the Left Border sequence used for transfer of the T-DNA (Barker et al. 1983).

Plasmid Vector Backbone

• oriV Origin of Replication Sequence: Origin of replication from the broad host 

range plasmid RK2 for maintenance of plasmid in Agrobacterium (Stalker et al. 

1981).

• rop Repressor of Primer Coding Sequence: Coding sequence for repressor of 

primer protein derived from the Co1E1 plasmid for maintenance of plasmid copy 

number in Escherichia coli (Giza and Huang 1989).

• ori-pBR322 Origin of Replication Sequence: Origin of replication from pBR322 

for maintenance of plasmid in E. coli (Sutcliffe 1979).

• aadA Promoter-Coding-Terminator Sequence: Bacterial promoter, coding and 3′ 

untranslated region sequences for an aminoglycoside-modifying enzyme,

3' (9)-O-nucleotidyltransferase from transposon Tn7 (Fling et al. 1985) that

confers spectinomycin and streptomycin resistance.

T-DNA II cp4 epsps cassette

• Left Border Sequence: A specific DNA region from A. tumefaciens containing 

the Left Border sequence used for transfer of the T-DNA (Barker et al. 1983).

• RbcS2-E9 Terminator Sequence: 3′ non-translated region from the RbcS2 gene 

of Pisum sativum (pea) encoding the Rubisco small subunit, which functions to 

direct polyadenylation of the mRNA (Coruzzi et al. 1984).

• cp4 epsps Coding Sequence: Codon optimized codon sequence of the aroA gene 

from Agrobacterium spp. strain CP4 encoding CP4 EPSPS which confers 

resistance to the herbicide glyphosate (Barry et al. 1997; Padgette et al. 1996) 

• CTP2 Targeting Sequence: Sequences encoding the chloroplast transit peptide 

region from the shkG gene of Arabidopsis thaliana encoding EPSPS (Herrmann 

1995; Klee et al. 1987) that directs transport of the CP4 ESPS precursor protein to 

the chloroplast.

• DnaK Leader Sequence: 5' non-translated leader sequence from the Petunia x 

hybrida Hsp70 gene (Rensing and Maier 1994) that is involved in regulating gene 

expression.

• FMV Promoter Sequence: Promoter for the 35S RNA from figwort mosaic virus 

(Rogers 2000) that directs transcription in plant cells. 

• Right Border Sequence: A specific DNA region from A. tumefaciens containing 

the Right Border sequence used for transfer of the T-DNA (Depicker et al. 1982; 

Zambryski et al. 1982).

In addition to the above sequences, to facilitate DNA cloning the dmo cassette also 

contained between 1 and 89 base-pair length intervening sequences, the backbone 

8
contained between 86 and 737 base-pair length intervening sequences, and the cp4 epsps

cassette contained between 3 and 171 base-pair length intervening sequences. 

Monsanto provided evidence demonstrating the following:

• During transformation, both T-DNAs were inserted into the soybean genome, but 

through conventional self-pollination to segregate T-DNA I from T-DNA II, 

followed by a sub-lethal glyphosate selection screen, quantitative polymerase 

chain reaction (PCR) analysis and southern blot analysis, a homozygous 

segregant containing only T-DNA I was selected as MON 87708 soybean 

(Section III.B and Figure III-2 on pp. 43-44 and Section IV.B on pp. 58-62, 

(Monsanto, 2012));

• The T-DNA I inserted into the MON 87708 soybean genome is present at a 

single locus, and contains one functional copy of the dmo gene (Section IV.A, 

pp. 52-57, (Monsanto, 2012)); 

• The final product does not contain any of the backbone sequences from the 

plasmid PV-GMHT4355 outside of the T-DNA region or dmo expression

cassette borders as demonstrated through Southern blot analysis (Section IV.C, 

pp. 63-64, (Monsanto, 2012));

• The T-DNA sequence in MON 87708 soybean is identical to the corresponding 

T-DNA I sequence of the original donor plasmid PV-GMHT4355 (as confirmed 

by DNA sequence analysis); however, as expected, both the right and left TDNA border sequences are truncated (Table IV-2, p. 51; Section IV.D, p. 65; and 

Appendix Figure B-1, p. 292, (Monsanto, 2012));

• The inserted dmo expression cassette DNA was stably inherited across four 

breeding generations (Section IV.F, pp. 65-68, (Monsanto, 2012)); and

• The dmo expression cassette in MON 87708 soybean resides at a single locus 

within the soybean genome and is inherited according to Mendelian principles of 

inheritance (as determined by chi-square analysis for three segregating 

populations), consistent with the molecular characterization data that indicate 

MON 87708 soybean contains a single, intact copy of the dmo expression 

cassette that was inserted into the soybean genome at a single locus (Section 

IV.G, pp. 69-72, (Monsanto, 2012)).

Insertion of foreign genetic material tends to induce mutations at sites of insertion 

(generally referred to as insertional mutations) in recipient genomes (Laufs et al. 1999; 

Nacry et al. 1998). Monsanto examined the T-DNA insertion site in MON 87708 

soybean compared to the near isogenic conventional soybean control A3525 using PCR 

and sequence analyses (Appendix B.10, pp. 290-293, (Monsanto, 2012)) and discovered 

that MON 87708 contained transformation induced mutations at the flanking site adjacent 

to 3' and 5' ends of the T-DNA insert (Section IV.E, p. 65, (Monsanto, 2012)). There was 

an 899 base pair deletion and a 128 base pair insertion just 5' of T-DNA I, and a 35 bp 

insertion just 3' of T-DNA I, when the conventional control sequence was compared to 

the genomic DNA sequence flanking the 3' and 5' ends of the T-DNA insert in MON 

87708 soybean. According to Monsanto, the observed insertion and insertion-deletion 

mutation (indel mutation) presumably resulted from double-stranded break repair 

mechanisms in the plant during the Agrobacterium-mediated transformation process 

9
(Salomon and Puchta 1998). As discussed later in this document, none of these 

mutations altered the function of the dmo gene or exhibited deleterious phenotypes in 

MON 87708 soybean.

The plant pest derived vector DNA and the plant pest vector used to insert the DNA do 

not pose a plant pest risk to MON 87708 soybean. The binary plasmid vector PVGMHT4355 proved to be disarmed; the T-DNA inserted into MON 87708 soybean 

contained only the intended sequences as described above along with the typical insertion 

site mutations, and lacked sequences from Tumor-inducing (Ti) plasmids normally 

responsible for the formation of crown gall tumors upon A. tumefaciens infection 

(Hellens et al. 2000; Hoekema et al. 1983). The sequences derived from plant pathogens 

retained in MON 87708 soybean (i.e., promoter sequence from peanut chlorotic streak 

caulimovirus, leader sequence from Tobacco Etch virus, and the T-DNA border 

sequences from Agrobacterium tumefaciens) are non-coding sequences which do not 

cause plant disease. Furthermore, following transformation, the R0 plant tissue was 

treated with the antibiotics carbenicillin, cefotaxime, and ticarcillin/clavulanate acid 

mixture to inhibit the growth of excess Agrobacterium (Hellens et al. 2000; p. 43, 

(Monsanto, 2012)).

Expression of inserted DNA, changes in gene expression, new proteins or metabolism

Dicamba herbicide resistance in MON 87708 soybean is derived from a bacterial 

oxygenase gene (dmo) from Stenotrophomonas maltophilia isolated from a stormwater 

retention pond outside a dicamba manufacturing plant (Krueger et al. 1989). S. 

maltophilia is an aerobic, ubiquitous bacterium that can be found in a variety of 

environments, including associated with plants used as food or feed (pp. 81-82, 

(Monsanto, 2012)), but it is not considered a plant pathogenic bacterium (ISPP 2012). 

Originally classified as Pseudomonas maltophilia, S. maltophilia was also grouped in the 

genus Xanthomonas before eventually becoming the type species of the 

Stenotrophomonas genus in 1993 (Palleroni and Bradbury 1993). The bacterium can 

utilize dicamba as a sole carbon source through the action of a multicomponent 

demethylase system comprised of a reductase, a ferredoxin and an oxygenase 

(Chakraborty et al. 2005) which work together in a redox system similar to many other 

oxygenases to degrade aromatic compounds by catalyzing the incorporation of oxygen 

into organic substrates. In MON 87708 soybean, the reductase and ferredoxin are 

endogenous in the soybean chloroplast where they associate with the transgenic DMO to 

transport electrons from nicotinamide adenine dinucleotide (NADH) to oxygen to 

catalyze the demethylation of dicamba to form the non-herbicidal metabolites DCSA 

(3,6-dichlorosalicyclic acid) and formaldehyde (Figure 3; Behrens et al. 2007; Dumitru et 

al. 2009).

10
Figure 3. Demethylation of dicamba (3,6-dichloro-2-methoxybenzoic acid) catalyzed by

dicamba mono-oxygenase to form the metabolites 3,6-dichlorosalicylic acid and 

formaldehyde (Chakraborty et al. 2005).

DCSA is a known metabolite of dicamba whose safety in soybean, soil, and livestock has 

been evaluated by the EPA (40 CFR part 180.227 [7-1-11 Edition]; US-EPA 2009) and 

whose structure is similar to salicylic acid (2-hydroxybenzoic acid), an endogenous plant 

benzoic acid (Frear 1976; p. 250, (Monsanto, 2012)). Formaldehyde is found naturally in 

plants up to several hundred ppm (Adrian-Romero et al. 1999). Because both endogenous 

salicylic acid compounds and formaldehyde are known to be involved in plant responses 

to stress, including to pests and pathogens (Szabo et al. 2003; Szende and Tyihak 2010; 

Wildermuth 2006), their role will be further discussed in the later section on Plant Pest 

and Disease Impacts. In addition, impacts of the application of the dicamba herbicide 

and/or the metabolites produced as a result of the expression of MON 87708 soybean 

DMO on pest and disease incidence, severity or damage will be discussed in the section 

on Potential Changes to Agriculture or Cultivation Practices.

The physicochemical characteristics and functional activity of the MON 87708 soybean 

DMO were determined using a panel of analytical techniques, including: 1) western blot 

analysis to establish identity and immunoreactivity of MON 87708 DMO using an antiDMO antibody, 2) N-terminal amino acid sequence analysis, 3) matrix-assisted laser

desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to generate a

tryptic peptide map of the MON 87708 DMO, 4) sodium dodecyl sulfate polyacrylamide

gel electrophoresis (SDS-PAGE) to establish the apparent molecular weight of MON 

87708 DMO, 5) glycosylation status of MON 87708 DMO, and 6) MON 87708 DMO 

activity analysis to demonstrate functional activity (Sections V.A and V.B, pp. 74-78 and 

Appendix C, pp. 294 – 322, (Monsanto, 2012)). 

Two forms of mature MON 87708 soybean DMO result from post-translational 

modification of the DMO precursor protein after transport to the chloroplast (Sections V -

V.A.1 and V.B, pp. 74-75 and 77-78, and Appendix C.1, pp. 294-312, (Monsanto, 

2012)): 

• An expected DMO consists of 339 amino acids and lacks the 57 amino acid 

transit peptide and 24 amino acids of the N-terminus of the mature protein 

encoded by the pea RbcS gene, the N-terminal methionine, and three amino acids 

11
encoded by the nine base pair intervening sequence (9521-9529) used for cloning 

purposes (see Table III-1, pp. 40-42 in (Monsanto, 2012)). Unexpectedly, a 

larger DMO consisting of 367 amino acids (referred to as DMO+27) is detected 

with the 57 amino acid CTP portion of the targeting sequence cleaved while the 

24 amino acid N-terminal portion of the pea RbcS is retained along with the 

three amino acids resulting from an intervening sequence (confirmed by western 

blot analysis by probing with an antibody specific for both forms of the MON 

87708 DMO protein, N-terminal sequencing, and peptide analysis; see V.A.1, p. 

75 and Appendices C.1.11 – 1.13, pp. 304-310). 

• The apparent molecular weights of DMO and DMO+27 are 39.8 and 42.0 kDa, 

respectively (Appendix C.1.10, pp. 301-303), and neither are glycosylated 

(Appendix C.1.14, p. 311). 

• The specific activity of purified MON 87708 soybean DMO (naturally expressed 

DMO and DMO+27 mixture) was measured by quantifying the conversion of 

dicamba to DCSA, and it was determined to be 62.21 ± 11 nmoles 

DCSA/min/mg of MON 87708 DMO (Section V.B, p. 78; Appendix C.1.9, p. 

301; and Appendix C.1.15, Table C-4, p. 312). 

Since these studies showed that DMO purified from MON 87708 soybean seed contains a 

mixture of both DMO and DMO+27, and it is known that the active form of DMO 

necessary to demethylate dicamba and confer resistance to the herbicide is a trimer 

comprised of three DMO monomers (Chakraborty et al. 2005), the petitioner refers to 

both forms of the protein (DMO and DMO+27) and all forms of the trimer (DMO, 

DMO+27, or a combination of both) as MON 87708 soybean DMO (Section V, pp. 74-

75). That the active binding pocket of DMO with dicamba occurs through hydrogenbonding and steric interactions at locations not involving the N-terminus of DMO 

(Dumitru 2009) supports the petitioner’s assertion that both forms of DMO and 

DMO+27 are likely involved in the formation of active trimers.

The petitioner provided data on the relative specificity of MON 87708 DMO for dicamba 

and also the herbicide resistance phenotype of MON 87708 soybean (Section V.A.2, pp. 

75-77, and Appendix C.2, pp. 312-321, (Monsanto, 2012)): 

• In addition to dicamba (formulation Clarity®; BASF 2010), a total of 19 

herbicides representing eight families with distinct modes-of-action, some of 

which are approved for use in soybean, were tested under greenhouse conditions 

to compare tolerance levels of MON 87708 soybean and the near isogenic 

conventional soybean control A3525 at rates representative of commercial rates 

needed to control broadleaf weeds at the early vegetative soybean growth stage 

(Table V-1, p. 77). As expected, MON 87708 soybean sprayed over-the-top with 

dicamba exhibited negligible injury whereas the conventional soybean control 

A3525 sustained 100% injury; however compared to the conventional control 

A3525, MON 87708 showed limited but not commercially-acceptable tolerance 

to three other phenoxy synthetic auxin herbicides, 2,4-D (2,4-dichlorophenoxy 

acetic acid), MCPA (2-methyl-4-chlorophenoxy acetic acid) and 2,4-DB (2,4-

dichlorophenoxy butanoic acid), but was similar to the conventional control in 

12
level of tolerance or sensitivity to 16 other herbicides (Appendix Table C-7, pp. 

317-318). 

• Because 2,4-D is the most similar to dicamba of the three phenoxy herbicides 

tested, it was selected for further in vitro experimentation where it was shown 

that conversion of 2,4-D to the predicted, possible DMO oxidative reaction 

product 2,4-DCP occurred in minimal amounts in both the presence or absence 

of an E. coli-produced DMO in the reaction mix, and with a substrate only 

control (Figure C-9, p. 320). The degradation of a dicamba control to form 

DCSA was demonstrated using the E. coli-produced DMO, and supports 

Monsanto's claims that the E. coli-produced DMO is similar in sequence and 

function to MON 87708 DMO, and that therefore it is appropriate to extend 

specificity data generated with the E. coli-produced DMO to MON 87708 DMO 

(Section V.A.2, pp. 75-77; Appendix C.2.1, p. 312; Appendix C.2.7, 

p. 316; Figure C-9, p. 320); however this does not explain the slight difference in 

reduced sensitivity of MON 87708 soybean to the other phenoxy synthetic auxin 

herbicides in the greenhouse assays. 

• The possibility that MON 87708 soybean DMO can metabolize plant 

endogenous substrates structurally similar to dicamba and abundant in soybean 

was also tested in vitro. None of the five potential substrates (o-anisic acid, 

vanillic acid, syringic acid, ferulic acid and sinapic acid; Figure V-2, p. 76) were 

metabolized by the E. coli-produced DMO in vitro (Appendix Figure C-10, p. 

321). 

The DMO protein is expressed in all tissues of MON 87708 soybean (Section V.C, pp. 

78-80, and Appendix D, pp. 323-325, (Monsanto, 2012)):

• The levels of MON 87708 soybean DMO in various tissues collected during the 

2008 growing season from replicated plots from five U.S. field test sites

representative of soybean producing regions were determined based on ELISA 

assays (Appendix D).

• Expression analysis showed that MON 87708 soybean DMO was detected in all 

tissue types from MON 87708 across all five sites ranging from 3.9 – 180 μg/g 

dry weight (dwt). The mean levels across the five sites increased in over-season 

leaf collected during the later developmental stages (from the V3-V4 vegetative 

developmental stage at 17 μg/g dwt to the R5 (beginning seed stage) -V16 

developmental stage at 69 μg/g dwt), but were lower in forage (53 μg/g dwt), 

seed (47 μg/g dwt), and roots (6.1 μg/g dwt) collected at later developmental 

stages (Table V-3, p. 80). 

• MON 87708 soybean DMO makes up only approximately 0.01 to 0.02 % of the 

total protein in seed and forage, respectively, considering that total protein is 

41.17 % and 22.7% of MON 87708 seed and forage dry weight, respectively 

(Table VI-5, p. 122, and Table VI-8, p. 140). As expected, MON 87708 DMO 

was below the limit of quantitation for all tissue types of the conventional 

control.

The results of the petitioner’s DMO characterization studies support the conclusion that 

the functional activity, specificity and expression levels of the MON 87708 soybean 

13
DMO confer the intended phenotype of dicamba resistance to MON 87708 soybean, but 

MON 87708 soybean also has slightly reduced sensitivity to three other phenoxy 

synthetic herbicides compared to the conventional control soybean A3525. The 

implications of the changes in sensitivity to these herbicides with respect to control of 

volunteer soybean will be discussed in the section of this PPRA on the Potential for 

Enhanced Weediness of MON 87708 Soybean.

The petitioner carried out a compositional assessment of forage and seed samples using 

the principles and analytes outlined in the OECD consensus document for soybean 

composition (OECD 2001) to assess whether levels of key nutrients and anti-nutrients in 

MON 87708 soybean were equivalent to levels in the near isogenic conventional control 

soybean A3525, and to the composition of twenty commercial reference varieties 

(Section VI, pp. 86-145, and Appendix E, pp. 326-436, (Monsanto, 2012)). The samples 

for compositional assessment were collected in the 2008 growing season from five 

replicated sites chosen to represent the typical soybean growing regions of the United 

States. In addition to the conventional weed control programs, MON 87708 soybean 

plots were either treated at the V2-V3 growth stage with a dicamba application at the 

target label rate of 0.5 lb acid equivalents per acre (1800 g a.e./ha) or not treated with 

dicamba (Section VI.A, p. 86, (Monsanto, 2012)). Four different commercial reference 

varieties were grown at each of the five replicated sites and their data pooled to generate 

a tolerance interval which the petitioner claims is expected to contain, with 95% 

confidence, 99% of the quantities expressed in the population of commercial reference 

varieties (Section VI.A, p. 87; Appendix Table E-1, p. 326; and Appendix E.6, p. 333, 

Monsanto 2012a). The 99% tolerance interval is meant to define the natural variability of 

each compositional component in soybean varieties that have a history of safe 

consumption, and that were grown concurrently with MON 87708 soybean and the 

conventional control in the same trial (see p. 87, (Monsanto, 2012) for further details 

about data interpretations).

Nutrients assessed included proximates, fiber, amino acids, fatty acids, and vitamin E in 

seed, and proximates and fiber in forage. The anti-nutrients assessed in seed included 

raffinose, stachyose, lectin, phytic acid, trypsin inhibitor and isoflavones (daidzein, 

genistein, and glycitein) (see Appendix E for analytical methods, pp. 327- 333, 

(Monsanto, 2012)). In all, 50 components for dicamba-treated and untreated MON 

87708 soybean were statistically assessed – 35 nutrients and eight anti-nutrients in seed, 

and seven nutrients in forage. The petitioner employed six statistical comparisons on the 

MON 87708 soybean compositional data. One comparison was based on compositional 

data combined across all five field sites (combined-site analysis) and five separate 

comparisons were conducted on data from each of the individual field sites. 

In dicamba-treated MON 87708 soybean, the petitioner’s combined site analysis of both 

seed and forage showed statistically significant differences (α = 0.05) between MON 

87708 and the conventional control for 29 (58%) of the 50 mean value comparisons – 24 

nutrients and four anti-nutrients from the seed analysis and one nutrient from the forage 

analysis (Table VI-1, pp. 98-111, (Monsanto, 2012)). 

14
• Nutrient component differences in seed were observed in mean values for ash, 

carbohydrates, protein and 12 amino acids, five fatty acids, acid detergent fiber 

(ADF), neutral detergent fiber (NDF), crude fiber, and vitamin E. All were of 

relatively small magnitude with respect to the conventional control and, whether 

increased or decreased, ranged from a minimum difference of 1.51% (18:2

linoleic acid) to a maximum difference of 15.13% (Vitamin E). Three of the 

nutrient components in the combined-site analysis (decreased levels of 18:1 oleic 

acid and increased levels of 18:3 linolenic acid and vitamin E) were also 

observed to be statistically different in at least four or more of the five individual 

sites, whereas the other combined-site differences occurred at fewer or none of 

the individual sites.

• Anti-nutrient component differences in seed were observed in mean values for 

phytic acid, raffinose, stachyose, and daidzein. All were of small relative 

magnitude with respect to the conventional control, and ranged from a minimum 

difference of a 6.14% decrease (phytic acid) to maximum difference of an 

11.51% increase (daidzein). None of the anti-nutrient components were 

observed to be statistically different at more than two of the five individual sites.

• The only nutrient difference in forage for the combined-site analysis was 

observed in ADF, and its relative magnitude of difference, with respect to the 

conventional control, was +10.45%. No differences between MON 87708 

soybean and the conventional control ADF mean values were observed at any of 

the five individual sites.

• All 29 of the statistically significant differences between dicamba-treated MON 

87708 soybean components compared to the conventional control were within 

the 99% tolerance interval established from the commercial reference varieties 

grown concurrently and at the same field sites, as well as within ranges in the 

International Life Sciences Institute (ILSI) Crop Composition Database (ILSI 

2012) and the scientific literature (Table VI-9, pp. 142-143, (Monsanto, 2012)).

In dicamba-untreated MON 87708 soybean, the petitioner’s combined site analysis of 

both seed and forage showed statistically significant differences (α = 0.05) between MON 

87708 and the conventional control for 20 (40%) of the 50 mean value comparisons – 17 

nutrients and three anti-nutrients from the seed analysis (Table VI-5, pp. 122-131, 

(Monsanto, 2012)). 

• Nutrient component differences in seed were observed in mean values for protein 

and eight amino acids, five fatty acids, ADF, NDF and vitamin E. All were of 

relatively small magnitude with respect to the conventional control and, whether 

increased or decreased, ranged from a minimum difference of 1.45% (18:2

linoleic acid) to a maximum difference of 18.16% (vitamin E). As in the 

dicamba-treated trials, three of the nutrient components in the combined-site

analysis (decreased levels of 18:1 oleic acid and increased levels of 18:3 

linolenic acid and vitamin E) were also observed to be statistically different in at 

least four of the five individual sites, whereas the other combined-site differences 

occurred at fewer or none of the individual sites. The small relative magnitudes 

of the differences in 18:3 linolenic acid, 18:1 oleic acid and vitamin E compared 

15
to the conventional control, as well as the even broader range of these fatty acids 

and vitamin E present in commercial soybean varieties, suggest that the 

differences are not meaningful to nutritional quality in MON 87708 soybean.

• Anti-nutrient component differences in seed were observed in mean values for 

trypsin inhibitor, daidzein and genistein. All were of small relative magnitude 

with respect to the conventional control, and ranged from increases of 11.59% 

for genistein, 15.37% for trypsin inhibitor and 17.24% for daidzein. None of the 

anti-nutrient components were observed to be statistically different at more than 

one of the five individual sites.

• No nutrient component differences in forage for the combined-site analysis were 

observed.

• All 20 of the statistically significant differences between dicamba-untreated 

MON 87708 soybean components compared to the conventional control were 

within the 99% tolerance interval established from the commercial reference 

varieties grown concurrently and at the same field sites, as well as within ranges 

in the ILSI Crop Composition Database and the scientific literature (Table VI-9, 

pp. 142-143, (Monsanto, 2012)).

Based on the data presented by the petitioner on the composition of key nutrients and 

anti-nutrients in seed and key nutrients in forage for both dicamba-treated and untreated

MON 87708 soybean, it is reasonable to conclude that neither the dicamba tolerance trait 

nor the dicamba herbicide treatment have a meaningful impact on the composition of 

seed or forage derived from MON 87708 soybean compared to other commercial soybean 

varieties. 

Based on all the above noted considerations, APHIS concludes that MON 87708 soybean 

poses no more of a plant pest risk from new gene products, changes to plant metabolism 

or composition than conventional soybean varieties.

D. Potential Plant Pest and Disease Impacts

APHIS assessed whether potential plant pest or disease impacts are likely to result from 

the transformation process, from DNA sequences from plant pests, or from any other 

expression products, new enzymes, proteins or changes in plant metabolism or 

composition in MON 88708 soybean that are known or anticipated to cause disease 

symptoms, or to affect plant pests or diseases or plant defense responses (as identified 

from the previous section). APHIS also assessed or whether MON 88708 soybean is 

likely to have significantly increased disease and pest susceptibility based on data and 

observations from field trials on specific pest and disease damage or incidence and any 

agronomic data that might relate to such damage. Impacts or changes are assessed to 

determine if they would (1) affect the new GE crop and/or result in significant 

introduction or spread of a damaging pest or disease to other plants; (2) result in the 

introduction, spread, and/or creation of a new disease; and/or (3) result in a significant 

exacerbation of a pest or disease for which APHIS has a control program. Any increase 

in pest or disease susceptibility is evaluated with respect to the context of currently 

16
cultivated varieties, the ability to manage the pest or disease, and the potential impact on 

agriculture.

Plant Protection and Quarantine (PPQ) is an APHIS program that safeguards agriculture 

and natural resources from the entry, establishment, and spread of animal and plant pests 

and noxious weeds into the United States of America; and supports trade and exports of 

U.S. agricultural products. PPQ responds to many new introductions of plant pests to 

eradicate, suppress, or contain them through various programs in cooperation with state 

departments of agriculture and other government agencies. These may be emergency or 

longer term domestic programs that target a specific pest. A variety of insect, plant 

disease, mollusk, nematode or weed programs exist (USDA-APHIS 2014a). For instance, 

a PPQ program was initiated for soybean rust prior to its November 2004 discovery in the 

continental US, in order to train diagnosticians to identify the causal organisms and to 

prepare U.S. soybean growers for the arrival of this rapidly spreading disease which 

causes serious crop losses in many parts of the world. Soybean rust is caused by two 

fungal species, Phakopsora pachyrhizi and Phakopsora meibomiae, with P. pachyrhizi

being the more virulent strain in the U.S. for which all currently available commercial 

varieties of soybeans are susceptible (ACES 2012).

Soybean is not a plant pest in the U.S. (7 CFR part 340.2; USDA-NRCS 2012) and the 

Agrobacterium tumefaciens transformed plants used in the generation of MON 87708 

soybean were treated with antibiotics to kill A. tumefaciens cells. The description of the 

introduced genetic elements, expression of the gene products and their functions in MON 

87708 soybean has been summarized above. DNA sequences derived from plant pests 

that were incorporated in MON 87708 soybean do not result in the production of 

infectious agents or disease symptoms in plants, and so it is unlikely that MON 87708 

soybean could pose a plant pest risk. 

MON 87708 soybean was released within confined field trials in the U.S. from 2005 

through 2009 in at least 75 locations across 24 states and territories covering a diverse 

range of environmental conditions representative of where soybeans are currently grown 

and bred, and where MON 87708 is expected to be grown (Appendix A, Table A-1, pp. 

283-286, (Monsanto, 2012)). In addition to the observational data that Monsanto 

annually reported to USDA-APHIS from these product development trials, which would 

have included reports of unusual pest and/or disease incidence, Monsanto also carried out 

a comparative assessment of both dicamba-treated and untreated MON 87708 soybean 

with the near isogenic conventional soybean control A3525 to evaluate environmental 

interactions (i.e., interactions between the crop plants and their receiving environment, 

including responses to abiotic stress, disease damage, arthropod-related damage, and pest 

and beneficial arthropod abundance) (Section VII, pp. 146-169, and Appendix G, pp. 

443-485, (Monsanto, 2012)). The petitioner assessed both treated and untreated MON 

87708 soybean to allow for not only the assessment of the effect of the inserted dmo gene 

on environmental interactions, but also the assessment of the effect of the dicamba 

herbicide treatment which is important for this plant pest risk assessment since the 

reaction products formed in MON 87708 soybean in the presence of dicamba are analogs 

17
of endogenous salicylic acid compounds and formaldehyde which are known to be 

involved in plant responses to stress, including to pests and pathogens.

Environmental interaction data were collected in 2008 on untreated MON 87708 soybean 

at 18 field sites and in 2009 on treated MON 87708 soybean at 8 field sites (Tables VII-3 

and VII-4, pp. 157-158, (Monsanto, 2012)). 

• These 26 locations provided a diverse range of environmental and agronomic 

conditions representative of commercial soybean production areas in North 

America (Appendix G.1, p. 443, and Tables G-3 and G-4 for 2008 and 2009 

trials respectively, pp. 448-450, (Monsanto, 2012)). Multiple commercial 

reference varieties (including some Roundup Ready - glyphosate resistant 

soybeans) were grown concurrently with MON 87708 soybean and the 

conventional A3525 control at each site to establish a range of natural variability 

for the assessed stressors (Tables G-1 and G-2 for 2008 and 2009 field trials, 

respectively, pp. 445-447, (Monsanto, 2012)). 

• The researchers at each field site were expected to be familiar with the growth, 

production, and evaluation of soybean characteristics, and to use well-established 

qualitative and/or quantitative techniques to observe and evaluate environmental 

interactions. They chose abiotic stressors, diseases and arthropod pests that were 

either actively causing injury or were likely to occur in soybean during the given 

observation period. The assessed stressors were present at natural levels, as no 

artificial infestation or imposed abiotic stress was used. 

• For plant responses to abiotic stress, disease damage and arthropod-related 

damage, at least three abiotic stressors, three diseases and three arthropod pests 

were evaluated up to four times during the growing season at all 26 sites. The 

researcher at each field site chose abiotic stressors, diseases, and arthropod pests 

that were either actively causing plant injury in the study area or were likely to 

occur in soybean during the given observation period. Therefore, the stressors 

typically varied between observations at a site or among sites (Appendix G.7, pp. 

451-452, (Monsanto, 2012)).

• Arthropod abundance was measured only in 2008, and only at four of the 18 sites 

which were designed to contain plots suited for the purpose of collecting robust 

arthropod abundance data (Section VII.C.2.4, pp. 162-163; Appendix G.3, pp. 

443-444; and Appendix G.8, p. 453, (Monsanto, 2012)).

• Qualitative categorical data on observations of plant response to abiotic stress 

and disease damage were not statistically analyzed; they were considered 

different on a particular observation date at a site if the range of injury severity to 

MON 87708 soybean did not overlap with the range of injury severity to the 

control across all three replications. Qualitative numerical data for arthropod 

damage and quantitative data for arthropod abundance underwent statistical 

analysis (α = 0.05) (Section VII.C.2.4, pp. 162-163, (Monsanto, 2012)).

• The results of the 2009 study which included only dicamba-treated MON 87708

soybean (not untreated MON 87708) will also be discussed later in the section on 

Potential Changes to Agriculture or Cultivation Practices.

Neither the dicamba tolerance trait nor the dicamba herbicide treatment altered the 

18
assessed environmental interactions of MON 87708 soybean compared to the 

conventional A3525 control (Section VII.C.2.4, pp. 162-166; Appendices G.6-G.11, pp. 

451-454; and Tables G-9 through G-16, pp. 469-484; (Monsanto, 2012)).

Abiotic stressors: 

• In 2008, 193 out of 194 observations between untreated MON 87708 soybean 

and the conventional control showed no meaningful differences in damage from 

12 abiotic stressors (cold, compaction, crusting, drought, excess moisture, 

flooding, frost, hail, heat damage, mineral toxicity, nutrient deficiency and wind) 

(Table G-9, p. 469). Slight damage due to wind was observed on untreated 

MON 87708 soybean compared to the control (no wind damage) for one of the 

four observations at one of the sites, but since the difference was slight and no 

differences were observed in any of the other wind evaluations, the difference is 

not considered biologically meaningful. 

• In 2009, no differences were observed between treated MON 87708 soybean and 

the conventional control for all 89 observations of damage from eight abiotic 

stressors (cold, compaction, drought, flood, frost damage, hail damage, nutrient 

deficiency and wind damage) (Table G-14, p. 481).

Disease damage: 

• In 2008, no differences were observed between untreated MON 87708 soybean 

and the conventional control for all 215 observations for damage from all 22 

diseases evaluated (Alternaria leaf spot, anthracnose, Asian rust, bacterial blight, 

brown stem rot, Cercospora, charcoal rot, downy mildew, frogeye leaf spot, 

Phytophthora, pod and stem blight, powdery mildew, Pythium, Rhizoctonia, 

Septoria brown spot, soybean cyst nematode, soybean mosaic virus, soybean 

rust, stem canker, sudden death syndrome, white mold and yellow mosaic virus) 

(Table G-10, p. 470). 

• In 2009, 92 of 93 observations between treated MON 87708 soybean and the 

conventional control showed no differences in damage for all 18 diseases 

evaluated (anthracnose, bacterial blight, bacterial leaf spot, brown stem rot, 

Cercospora, charcoal rot, downy mildew, frogeye leaf spot, leaf spot, 

Phytophthora root rot, powdery mildew, Pythium, Rhizoctonia, soybean mosaic 

virus, soybean rust, stem canker, sudden death and white mold) (Table G-15, p. 

482). One difference was observed for white mold during a single observation 

(slight on MON 87708 soybean vs. none on the control) which was outside the 

reference range (no white mold was observed in the references), but since the 

difference was slight and no differences were observed in any of the other white 

mold evaluations, the difference is not considered biologically meaningful. 

Arthropod damage: 

• In 2008, 89 out of 95 comparisons between untreated MON 87708 soybean and 

the conventional control showed no significant damage from all 19 arthropods 

assessed (aphid, armyworm, bean leaf beetle, blister beetle, cabbage looper, corn 

rootworm beetle, cutworm, fall armyworm, grasshopper, green cloverworm, 

Japanese beetle, leafhopper, seedcorn maggot, soybean looper, spider mite, stink 

19
bug, thistle caterpillar, thrips and yellow woollybear) (Table G-11, pp. 471-472). 

The six differences in arthropod damage were from four taxa (aphid, blister 

beetle, potato leafhopper and Japanese beetle) and were all small in magnitude 

and not consistent across observations or sites. 

• In 2009, 56 out of 59 comparisons between treated MON 87708 soybean and the 

conventional control showed no significant damage from all 14 arthropods 

assessed (aphids, bean leaf beetle, blister beetle, cabbage looper, corn earworm, 

fall armyworm, grasshopper, green cloverworm, Japanese beetle, potato 

leafhopper, soybean looper, stink bugs, three cornered alfalfa hopper and velvet 

leaf caterpillar) (Table G-16, pp. 483-484). The three differences in arthropod 

damage were from two taxa (leaf beetle and grasshopper) and were small in 

magnitude and/or not consistent across observations or sites.

Arthropod abundance (pests and beneficials): 

• In 2008, 142 out of 151 comparisons between untreated MON 87708 soybean 

and the conventional control showed no significant differences in abundances of 

all eleven pest and seven beneficial arthropod taxa assessed (Tables G-12 and G13, pp. 473-480). Pest arthropods included aphid, bean leaf beetle, grape 

colaspis, garden flea-hopper, green clover-worm, Japanese beetle, potato 

leafhopper, stink bug, tarnished plant bug, velvet-bean caterpillar and woollybear caterpillar. Beneficial arthopods included Araneae (spiders), big eyed bug, 

Carabidae, lacewings, ladybird beetles, micro-parasitic wasps, Nabis spp., 

Opilones, Orius spp. and syrphid larvae. The seven differences detected for 

abundance for three pest taxa (green cloverworm, Japanese beetles and stink 

bugs) and the two differences detected for abundance of beneficial arthropod 

taxa (Aranaea and Nabis spp.) were all small in magnitude and were not detected 

or were not consistent in other collections or sites. 

• No arthropod abundance data were collected from the 2009 field trials between 

treated MON 87708 soybean and the conventional control, so no assessment can 

be made on whether the dicamba herbicide treatment alters arthropod abundance, 

however, impacts of herbicide treatment on nontargets are assessed by the EPA.

Impacts of the herbicide on nontarget organisms are not considered a plant pest 

risk.

The results of the petitioner’s field studies on the assessed environmental interactions 

between MON 87708 soybean and its receiving environment indicate that neither the 

dicamba resistance trait nor the dicamba herbicide treatment alter the response of MON 

87708 to abiotic stress, diseases, or arthropod pests under natural levels of these stressors, 

and nor were pest arthropods more abundant around MON 87708 plots.

Monsanto claims that the DCSA metabolite produced from applications of dicamba on 

DMO-expressing crops such as MON 87708 soybean may actually confer beneficial 

health effects on the crop plants, such as increased resistance against biotic (e.g., insects, 

fungi, viruses, nematodes, and other pathogens) and abiotic stresses (e.g., drought, cold, 

ozone, soil nutrient deficiencies), with resulting increases in yields and improved quality 

of crops. This reported discovery was made by Monsanto during research on a variety of 

20
dicamba-tolerant crops currently under development (corn, cotton as well as soybean) 

and is currently claimed under a pending patent (Bhatti et al. 2010). Endogenous 

salicylic acid is known to be a common and widespread mediator of plant responses to 

biotic and abiotic stress (Vlot et al. 2008; Vlot et al. 2009; Wildermuth 2006). Since 

DCSA is a synthetic analog of salicylic acid, it is not surprising it could play a similar 

role as salicylic acid in plants, but it is also plausible it could interfere with plant defense 

signaling such as other salicylic analogs have been shown to do (Park et al. 2009; 

Silverman et al. 2005). Monsanto’s patent claim indicates they have evidence supporting 

the former; however, as shown above, the beneficial plant health effects described in the 

patent claim are not evident in the data provided in the petition for the determination of 

nonregulated status of MON 87708 soybean.

Formaldehyde, the other breakdown product of dicamba by MON 87708 soybean DMO, 

is found naturally in plants up to several hundred ppm (Adrian-Romero et al. 1999) and is 

incorporated into the one-carbon pool reactions which are essential to all organisms 

(Hanson and Roje 2001). In plants, these reactions supply the C1 units needed to 

synthesize proteins, nucleic acids, pantothenate, and a great variety of methylated 

molecules (Kalasz 2003). C1 pathways are particularly active in tissues that produce 

methylated compounds such as lignin, alkaloids, and betaines because the C1 demands 

for these physiologically and economically important secondary metabolites can dwarf 

those of primary metabolism. C1 transfers are also central to the massive 

photorespiratory fluxes that occur in C3 plants (Hanson and Roje 2001). Formaldehyde 

production in plants has been shown to change in response to abiotic and biotic stress 

(Sardi et al. 1996; Szabo et al. 2003; Szende and Tyihak 2010) although the mechanism 

and function is unclear. In MON 87708 soybean, the dicamba-derived formaldehyde is 

expected to be produced in small amounts; the maximum theoretical amount is estimated 

to be 16.7-37.5 mg/kg based on an assumption that the entire 0.56 kg/ha (0.5 lb/acre) a.e. 

of dicamba application at the V3 to R1 growth stage of MON 87708 soybean is 

intercepted and instantaneously metabolized by the MON 87708 DMO (pp. 251-252, 

(Monsanto, 2012)). This is well within the range of formaldehyde measured in a variety 

of dicot plants (up to several hundred mg/kg) (Adrian-Romero et al. 1999) and 

agricultural commodities (WHO-IPCS 1989), so it is likely that dicamba-produced 

formaldehyde will play a similar role as naturally produced endogenous formaldehyde. 

This is supported by the compositional analysis of seed and forage from dicamba-treated 

MON 87708 soybean vs. dicamba-untreated conventional controls which revealed no 

biologically meaningful differences in nutrients or anti-nutrients; e.g., differences in 

means from the combined site analysis were relatively small, were within the 99% 

tolerance interval established from the commercial reference varieties, and often were not 

consistent across sites. Similarly, the environmental interactions study indicated that the 

dicamba herbicide treatment did not alter the response of MON 87708 soybean to abiotic 

stress, diseases, or arthropod pests under natural levels of these stressors. 

In conclusion, for MON 87708 soybean, no plant pest or disease impacts are expected 

from the plant pest transformation vector or plant pest sequences used in the 

transformation, nor the expression of the new enzyme for dicamba resistance and minor 

changes in composition, nor from the herbicide metabolites produced as a result of 

21
treating MON 87708 soybean with dicamba. Field study observations on the assessed 

environmental interactions between MON 87708 soybean and its receiving environment 

indicate that neither the dicamba resistance trait nor the dicamba herbicide treatment 

(including any metabolites produced as a result) significantly alter the response of MON 

87708 to diseases, or arthropod pests under natural levels of these stressors, and nor were 

pest arthropods more abundant around MON 87708 soybean plots compared to the 

control line. As discussed earlier, there were no significant changes in MON 87708

soybean compositions that would render MON 87708 more susceptible to pests and 

diseases over its control or reference soybean varieties. As presented later in this 

document, the observed agronomic traits also did not reveal any significant changes that 

would indirectly indicate that MON 87708 soybean is or could be relatively more 

susceptible to pests and diseases over control or reference soybean varieties. Thus MON 

87708 is unlikely to be more susceptible to plant pathogens and insect pests than 

conventional soybean. For this reason, MON 87708 soybean is unlikely to differ from 

conventional soybean in its ability to harbor or transmit plant pathogens or pests and 

cause indirect plant pest effects on other agricultural products.

E. Potential Impacts on Nontarget Organisms Beneficial to Agriculture

MON 87708 soybean is not engineered for pest resistance, thus there are no ‘target’ 

species, and thus no ‘nontarget’ species either. APHIS assessed whether exposure or 

consumption of MON 87708 soybean would have a direct or indirect adverse impact on 

species beneficial to agriculture. Organisms considered were representatives of the 

species associated with production of the regulated crop in the agricultural environment. 

The assessment includes an analysis of data and information on MON 87708 soybean

compared to the non-GE counterpart A3525 soybean (or other comparators) for any

biologically relevant changes in the phenotype or substances produced (e.g. the MON 

87708 DMO, nutrients, antinutrients, metabolites, etc.) which may be novel or expressed 

at significantly altered amounts that are associated with impacts on organisms beneficial 

to agriculture, and/or any observations of beneficial organisms associated with the plants. 

APHIS reviewed information Monsanto provided justifying the safety of MON 87708 

soybean (Sections V.D-V.F, pp. 81-85, (Monsanto, 2012)) as well additional literature:

• The donor organism for the dmo gene, S. maltophilia, has been previously 

reviewed as part of a safety and nutritional assessment of MON 87708 soybean 

that Monsanto completed with the FDA (US-FDA 2011). S. maltophilia is an 

aerobic, ubiquitous, environmental, gram-negative bacterium, and although its 

close genetic relatives are plant pathogens, it is not classified as such. APHIS 

examined a recent review of S. maltophilia by Brooke (2012) that indicates that

it has been isolated from soil, water, animals, invertebrates, plant matter

including food, and hospital equipment, and can cause infections in humans, 

particularly immunocompromised and debilitated individuals; but there is no 

indication that the dmo from S. maltophilia plays a role in pathogenicity, 

22
virulence, antibiotic resistance, adhesion or other interactions with human, 

animals or invertebrates. 

• The DMO enzyme present in MON 87708 soybean shares sequence identity and 

many catalytic and domain structural similarities with a wide variety of 

oxygenases found in numerous species of microorganisms widely distributed and 

prevalent in the environment (Chakraborty et al. 2012), and with oxygenases 

such as pheophorbide A oxygenase also found in plants such as rice, maize, 

canola and pea (Rodoni et al. 1997; Yang et al. 2004) that are consumed in a 

variety of food and feed sources which have a history of safe human 

consumption, establishing that plants, animals and humans are extensively 

exposed to these types of enzymes (Section V.E.2, pp. 82-83, (Monsanto, 2012)). 

• Bioinformatics analyses demonstrated that MON 87708 soybean DMO does not 

share amino acid sequence similarities with known allergens, gliadins, glutenins 

or protein toxins which could have adverse effects to human or animal health 

(Section V.D, p. 81, (Monsanto, 2012); US-FDA 2011).

• MON 87708 soybean DMO is readily digestible in simulated gastric and 

intestinal fluids, making it highly unlikely that it would be absorbed in the small 

intestine and have any adverse effects on human or animal health (Section V.E.5, 

p. 84, (Monsanto, 2012)).

• An acute oral toxicity study indicated no adverse effects in mice at the highest 

dose tested (140 mg/kg body weight), and by extrapolation using the Margin of 

Error approach, no meaningful risk to human or animal health from dietary 

exposure to MON 87708 soybean DMO (Section V.E.6, p. 84, (Monsanto, 

2012)).

As indicated earlier in this plant pest risk assessment, the petitioner’s characterization of 

MON 87708 soybean showed nutrient and anti-nutrient levels in seed and forage were 

within the 99% tolerance intervals for commercial reference varieties, and that the MON 

87708 soybean DMO protein makes up only approximately 0.01 to 0.02 % of the total 

protein in seed or forage, respectively, so there is unlikely to be nontarget effects 

resulting from changes in composition or from consumption of MON 87708 DMO. Also 

the study on environmental interactions found that there were no changes in beneficial 

arthropod abundance in field plots of MON 87708 soybean. 

Honeybees were not among the arthropods sampled in the beneficial arthropod study and 

are not essential for soybean pollination, with natural outcrossing rates in cultivated 

soybean often lower than 1% (Table IX-1, p. 259, (Monsanto, 2012)). Monsanto 

examined MON 87708 soybean pollen and found there was no difference in pollen 

viability, size or visual morphology due to the dicamba resistance trait (Section VII.C.3, 

pp.166-167). MON 87708 soybean DMO is targeted to the chloroplast and is not 

expected to be found in nectar. Soybean does not produce a lot of pollen and so would 

not be a significant source of protein for honeybees, however soybean flour can be used 

to provide supplemental protein to bee colonies to support low levels of brood rearing 

during winter months in the South, Southwest, and Southeast when pollen sources are 

low (Standifer et al. 1977). Since the protein has no known toxicity and is present at low 

levels in soybean seed, no adverse effect on honeybees would be expected from such use. 

23
Monsanto also found that the nitrogen-fixing plant-microbe symbiotic relationship 

between MON 87708 soybean and Bradyrhizobiaceae japonicum was unaltered due to 

the introduction of the dicamba resistance trait, as there was no significant difference 

detected in nodule number, nodule dry weight, root dry weight, shoot dry weight and 

shoot total nitrogen (percent and mass) between MON 87708 and the conventional 

control when grown in nitrogen-deficient potting medium from seeds inoculated with a 

solution of the symbiont (Section VII.C.4 and Table VII-8, pp.168-169, (Monsanto, 

2012)).

Therefore, based on the above analysis of Monsanto’s studies on MON 87708 soybean 

food and feed safety, nutrient and anti-nutrient composition, levels of DMO in tissues, 

environmental interactions with beneficial arthropods, pollen characteristics and 

association with symbionts, APHIS concludes exposure to and/or consumption of MON 

87708 soybean are unlikely to have any adverse impacts on organisms beneficial to 

agriculture.

F. Potential for Enhanced Weediness of MON 87708 Soybean

APHIS assessed whether the MON 87708 soybean is likely to become more weedy (i.e.

more prevalent, competitive, damaging or difficult-to-control in situations where it is not 

wanted) than the nontransgenic progenitor from which it was derived, or other varieties 

of the crop currently under cultivation. The assessment considers the basic biology of the 

crop, the situations in which crop volunteers or feral populations are considered weeds, 

and an evaluation of the MON 87708 soybean compared to its nontransgenic progenitor 

A3525 soybean evaluated under field conditions characteristic for the regions of the U.S.

where soybean is grown (and/or under laboratory or greenhouse conditions) for 

characteristics related to establishment, competiveness, reproduction, survival,

persistence and/or spread that could influence weediness and the ability to manage the 

crop as a weed. For soybean, such characteristics include in particular, hard seededness, 

vegetative vigor, harvest seed loss and lodging. The assessment also considers whether 

the engineered trait affects methods of control for the crop in situations where it is 

managed as a weed or volunteer in subsequent crops or in feral populations. 

In the U.S., soybean is not listed as a weed in the major weed references (Crockett 1977; 

Holm et al. 1979; Holm et al. 1997), nor is it designated as a noxious weed by the federal 

government (USDA-APHIS 2012), although it has been mentioned as an agricultural 

weed by the Southern Weed Science Society (USDA-NRCS 2012). Soybean does not 

possess any of the attributes commonly associated with weeds (Baker, 1965), such as 

long persistence of seed in the soil, the ability to disperse, invade, and become a 

dominant species in new or diverse landscapes, or the ability to compete well with native 

vegetation. Furthermore, mature soybean seeds have no innate dormancy; germinating 

seedlings and plants are sensitive to cold, are not expected to survive in freezing winter 

conditions and do not vegetatively reproduce (OECD 2000; Raper Jr. and Kramer 1987). 

Soybeans that volunteer from the previous year’s crop are rarely a management issue, as 

24
crop losses attributable to interference from soybean volunteers are minimal (Owen and 

Zelaya 2005). However, volunteers can be a problem particularly in the South where 

winters are milder, and particularly if weather events lead to soybean seed loss prior to 

harvest (York et al. 2005). 

To test the expectation that MON 87708 soybean has not obtained characteristics that 

would increase its weediness, Monsanto conducted a combination of replicated 

laboratory, greenhouse and multi-site field experiments in 2008 and 2009, similar to the 

design of the compositional and environmental interaction assessments previously 

discussed which compared dicamba-treated or untreated MON 87708 with the

conventional soybean control A3525, to evaluate phenotypic characteristics that may 

impact weediness (e.g., viable hard seed as an indication of seed dormancy, vegetative 

vigor as an indication of competitiveness, pre-harvest seed loss and lodging as indications 

of the potential for seed to occur on the soil following harvest and potentially volunteer 

as a weed in the subsequent crop) (Section VII, pp. 146-169, and Table VII-1, pp. 148-

149, (Monsanto, 2012)). Multiple commercial reference varieties were included in the 

assessment of weediness characteristics to provide a range of comparative values that are 

representative of existing commercial soybean varieties. 

For seed dormancy and germination characteristics, the seed lots for MON 87708

soybean, the conventional control and eight commercial reference varieties were 

produced in replicated field trials during 2008 in Iowa, Illinois and Missouri, which 

represent environmentally relevant conditions for soybean production. In addition to the 

Association of Official Seed Analysts (AOSA 2007) recommended temperature range of 

20/30°C, seed was tested at five additional temperature regimes of 10, 20, 30, 10/20, 

and 10/30°C to assess seed germination properties, following the methods presented in 

Appendix F (pp. 437-442, (Monsanto, 2012)). In a combined site analysis, in which the 

data were pooled among the three seed production sites, none of the significant 

differences detected (α = 0.05) between MON 87708 soybean and the conventional 

control were outside the range of the eight commercial reference varieties nor were they 

in the direction that would increase potential weediness; all were small in magnitude 

(Table VII-2, p. 155, (Monsanto, 2012)): 

• MON 87708 soybean had lower percent germinated seed at 10°C (98.9% vs. 

99.7%) and at 10/30°C (98.6% vs. 99.7%). Concurrently, MON 87708 soybean 

had higher percent dead seed at 10°C (0.8% vs. 0.2%) and 10/30°C (1.4% vs. 

0.3%). These differences are small and would not increase plant weediness; on 

the contrary, there would be lower stand count and less viable seed available for 

seed dispersal or soil seed banking under these temperature regimes, all other 

factors being equal.

• There were no differences for percentages of germinated or dead seed in the

temperature regimes 20, 30, 10/20, and at the optimal temperature range of 

20/30°C.

• There were also no detectable differences for percentages of viable hard seed or 

viable firm-swollen seed in any temperature regime. 

25
For the phenotypic and agronomic characteristics, APHIS evaluated 14 characteristics 

assessed in the field by Monsanto to determine if MON 87708 soybean was likely to be 

more weedy than the conventional control (Section VII, pp. 146-169, and Appendix G, 

pp. 443-468, (Monsanto, 2012)):

• Eleven quantitative characteristics (early stand count, seedling vigor, days to 

50% flowering, plant height, lodging, pod shattering, final stand count, seed 

moisture, 100 seed weight, test weight and yield) underwent statistical analysis 

(α = 0.05), whereas three qualitative characteristics (flower color, plant 

pubescence and plant growth stage) were assessed for categorical differences 

(Table VII-1, pp. 148-149). 

• MON 87708 soybean and the conventional control were grown in the same 

replicated field trials previously described for the environmental interaction 

study described in the section of this PPRA on the Potential Plant Pest and 

Disease Impacts, following the methods presented in Section V.II (V.II.A-VII.B, 

pp. 146-152 and V.II.C.2, pp. 156-158) and Appendix G.1-G.11 (pp. 443-454). 

• Data were collected in 2008 on untreated MON 87708 soybean at 18 field sites 

and in 2009 on dicamba-treated MON 87708 soybean at 8 field sites (Tables VII3 and VII-4, pp. 157-158). 

An evaluation of the data shows that neither the dicamba tolerance trait nor the dicamba 

herbicide treatment altered the weediness potential of MON 87708 soybean compared to 

the conventional control based on the assessed phenotypic and agronomic traits (Section 

VII.C.2.3, pp. 158-162; Appendix G.12, pp. 454-456; Tables G-5 through G-8, pp. 457-

468, (Monsanto, 2012)):

2008 Analysis with Untreated MON 87708 Soybean

• In the combined-site analysis for 2008, no significant differences were detected 

between untreated MON 87708 soybean and the control for 9 of 11 quantitative 

characteristics (e.g., early stand count, seedling vigor, days to 50% flowering, 

lodging, pod shattering, final stand count, seed moisture, test weight and yield). 

For the other two characteristics, untreated MON 87708 soybean had 

significantly taller plants (6% taller, with a plant mean height of 33.5 inches vs. 

31.6 inches) and significantly lighter seeds (3.3% smaller, weighing 15.0 vs. 15.5 

grams per 100 seed weight) (Table VII-5, p. 159). 

• While the differences in plant height and seed weight were small in magnitude, 

an examination of the corresponding individual-site data revealed that the 

differences were consistent; untreated MON 87708 soybean had taller plants at 

16 of the 18 sites with 8 of those significantly taller, and had lighter seeds at 15 

of the 18 sites with 5 of those significantly lighter (Table G-5, pp. 457-459). 

None of these differences were outside the reference ranges (Table VII-5, p. 159) 

calculated from the 18 commercial reference varieties (Table G-1, p. 445) grown 

across the 18 sites. Nevertheless the differences are significant, although 

increased plant height and lower seed weight are not characteristics associated 

with plant weediness for soybean.

• There were 13 other significant differences detected out of 179 comparisons of 

26
quantitative traits at individual sites, but these are not indicative of a consistent 

or biologically meaningful response since no significant differences were 

detected in the corresponding combined-site analyses. 

• Untreated MON 87708 soybean developed similar to the conventional control, as 

indicated by no categorical differences in plant growth stages for 131 out of 132 

observations among all sites (Table G-7, pp. 463-466), and no differences in 

flower color and plant pubescence (Table G-5, p. 457).

2009 Analysis with Dicamba-Treated MON 87708 Soybean

• In the combined-site analysis for 2009, no significant differences were detected 

between treated MON 87708 soybean and the control for 9 of 10 quantitative 

characteristics (e.g., early stand count, seedling vigor, days to 50% flowering, 

plant height, lodging, pod shattering, final stand count, seed moisture and yield). 

The only significant difference was that treated MON 87708 soybean had 

significantly lighter seeds (6.4% smaller, weighing 14.6 vs. 15.6 grams per 100 

seed weight) (Table VII-6, p. 161). 

• While the difference in seed weight was small in magnitude, an examination of 

the corresponding individual-site data revealed that the differences were very 

consistent, with treated MON 87708 soybean having lighter seeds at all 8 

individual sites, with 4 of these significantly lighter (Table G-6, pp. 460-462), 

similar to the 2008 untreated study. Furthermore, the mean 100 seed weight of 

treated MON 87708 soybean (14.6 grams) was slightly below the reference range 

(15.0 – 17.7 grams, Table VII-6, p. 161) calculated from the 14 commercial 

reference varieties (Table G-2, p. 446) grown across the 8 sites, although 

reported ranges of commercial soybean seed weight are as broad as 13 – 20 

grams per 100 seed (Fasoula et al. 2004). While the reduced 100 seed weight did 

not manifest into a significant reduction in yield, nevertheless the reduction is 

significant and so far appears durable across years, sites and herbicide treatment. 

However, while the seed weight reduction has interesting implications for how 

the inserted dmo gene may be ultimately affecting seed weight, for the purposes 

of this plant pest risk assessment, lower seed weight is not a characteristic 

associated with plant weediness for soybean and therefore is not a cause for 

concern by APHIS.

• There were 10 other significant differences detected out of 71 comparisons of 

quantitative traits at individual sites, but these are not indicative of a consistent 

or biologically meaningful response since the 10 differences were distributed 

widely among eight of the 11 characteristics and no significant differences were 

detected in the corresponding combined-site analyses. 

• Treated MON 87708 soybean developed the same as the conventional control, as 

indicated by no categorical differences in plant growth stages for 44 out of 44 

observations among all sites (Table G-8, pp. 467-468) and no differences in 

flower color (Table G-6, p. 460). 

APHIS evaluated information provided in the petition regarding the dicamba herbicide 

use in the U.S. and control of volunteers of MON 87708 soybean in other crops (Sections 

VIII.G.1 – VIII.G.2, pp. 197 – 206, and Section VIII.J, pp. 238-240, (Monsanto, 2012)). 

27
Resistance of MON 87708 soybean volunteers to dicamba would increase its survival 

compared to its conventional control in situations where it is treated with dicamba, e.g., 

in subsequent rotation with dicamba-resistant soybean or in fallow land or another crop 

with a labeled application of dicamba. In crops that are normally treated with dicamba to 

control broadleaf weeds, should volunteers of MON 87708 soybean appear, they could be 

controlled with other effective herbicides or cultural control methods. Since Monsanto 

intends to commercialize MON 87708 soybean as a stack with glyphosate herbicideresistant MON 89788 soybean (Roundup Ready 2 Yield), glyphosate would also not be 

an effective herbicide for volunteer control. As indicated earlier, MON 87708 soybean is 

also reduced in sensitivity to at least three other phenoxy synthetic auxin herbicides: 

2,4-D, MCPA and 2,4-DB.

An analysis of crop rotation practices in soybean and the use of dicamba in crops 

following soybean in rotation by region and by state are summarized in Section VIII.I of 

the petition (pp. 224-237 (Monsanto, 2012), including revised Tables VIII-24 through 

VIII-27 received from Monsanto on October 10, 2012). Crops that follow soybean in 

rotation and soybean volunteer pressure differ depending on the geographical growing 

region. Volunteer soybeans are less of a concern in the Midwest region where the 

majority of soybean in the U.S. is grown, since their lack of innate seed dormancy and 

sensitivity to cold causes soybean seeds or seedlings to be killed by the cold temperatures 

over the winter or in the early spring (Andersson and de Vicente 2010; Carpenter et al. 

2002; OECD 2000); however volunteer soybeans may be more problematic in the 

southern growing regions. According to analysis in the petition, based on 2008 planting 

data compiled from all the regions (Midwest, Southeast, and East Coastal), U.S. soybean 

acreage is most frequently rotated the following year to corn (68.6%), soybean (14.5%), 

wheat (11.2%), cotton (2.1%), rice (1.4%) or sorghum (1.1%) with other minor crops 

making up less than one percent of the estimated rotated acreage (Table VIII-24). Of the 

total soybean acreage rotated, the acreage of the rotational crops (other than soybean) 

treated with dicamba is expected to be a relatively small percentage due to the generally 

low percentage of dicamba use for the other crops typically rotated with soybean, and 

there are expected to be regional and state differences as shown below in Table 2. 

Preplant tillage and/or herbicides can be used to control emerging volunteers of soybean 

in most rotation crops, and additionally flooding can be used as a control measure in rice 

(Carpenter et al. 2002; York et al. 2005). Furthermore, as summarized in Table VIII-28 

(p. 240, (Monsanto, 2012)), excellent ratings are obtained for postemergence control of 

volunteer soybeans in the rotational crops corn, sorghum, wheat, barley, oats, cotton and 

rice for one or more labeled herbicides with different modes of action than the synthetic 

auxins to which MON 87708 soybean has acquired complete or partial resistance 

(Appendix Table C-7, pp. 317-318, (Monsanto, 2012)). Depending on the herbicide 

resistance trait of the rotational crop, additional herbicide options may be possible. 

28
Table 2. The acreage of the rotational crop following soybean that is treated with 

dicamba (Dicamba Acreage) and the percent of the total acreage rotated to the crop that is 

treated with dicamba (% Dicamba Usage), for the U.S. and each region (where available 

or applicable) (summarized from columns H and I, respectively, from revised Tables 

VIII-24 through VIII-27 received from Monsanto on October 10, 2012). 

Major Crop 

Following 

Soybean In 

Rotation1

Dicamba Acreage / (% Dicamba Usage)2

United States Midwest 

Region Southeast Region East Coastal Region

Corn 5053 / ( 9.8) 4591 / ( 9.7) 72 / ( 3.2) 390 / (22.4)

Soybean 4350 / (40.0) 1954 / (40.0) 2299 / (40.0) 97 / (40.0)

Wheat 448 / ( 5.3) 448 / ( 5.5)

Cotton 153 / ( 9.7) 14 / (18.0) 139 / ( 9.4)

1 Those rotation crops that follow soybean for which planted acreage is estimated to exceed 2.0% 

of the total soybean acres planted in the U.S. as compiled in Table VIII-24 Column G. 

2 Acreage expressed as 1000s of acres based on 2008 planting data, during which 75,037,000 

acres of soybean were planted in the US; percent dicamba usage for soybean was based on a 

future market estimate of 40% ((Monsanto, 2012)) and revised Tables VIII-24 through VIII-27 

received from Monsanto on October 10, 2012.

APHIS concludes, based on the agronomic field data and literature survey concerning 

weediness potential of the crop, the there is no indication that MON 87708 soybean 

possesses a selective advantage that would result in increased weediness either in 

cultivated or unmanaged fallow fields. MON 87708 soybean is no more likely to 

establish troublesome volunteer populations than either existing transgenic or 

nontransgenic herbicide-resistant or nontransgenic herbicide sensitive soybean varieties. 

Volunteer populations of MON 87708 soybean, although resistant to dicamba and less 

sensitive to other phenoxy synthetic auxin herbicides, could still be controlled using other 

currently available weed control methods.

G. Potential Impacts on the Weediness of Any Other Plants with which 

MON 87708 Soybean Can Interbreed

Gene flow is a natural biological process with significant evolutionary importance. A 

number of angiosperm taxa are believed to be derived from hybridization or introgression 

between closely related taxa (Grant, 1981; Rieseberg and Wendel, 1993; Soltis et al., 

1993; Grant, 1994; Hegde et al., 2006) and even in the existing floras, the occurrence of 

hybridization or introgression is reported to be widespread (Stace, 1987; Rieseberg and 

Wendel, 1993; Rieseberg 1997; Peterson et al., 2002). It has been a common practice by 

plant breeders to artificially introgress traits from wild relatives into crop plants to 

develop new cultivars (Khoury et al., 2013). However, gene flow from crops to wild 

relatives is also thought of as having a potential to enhance the weediness of wild 

29
relatives, as observed in rice, sorghum, sunflower and a few other crops (see Table 1 in

Ellstrand et al. (1999). By providing fitness-related traits such as resistance to insects, 

diseases, herbicides or harsh growing conditions, gene flow from crops to their wild 

relatives could allow the hybrids to compete better, produce more seeds, and become 

more abundant (Snow 2002). Besides weediness, other concerns are the loss of herbicide 

resistance as a tool to protect crops from closely related weeds (Gepts and Papa 2003). 

This topic is covered in two sections: 1) the potential for gene flow, hybridization and 

introgression from MON 87708 soybean to sexually compatible relatives, including wild, 

weedy, feral or cultivated species in the United States and its territories, and 2) if so, the 

risk potential with respect to weediness of those taxa following introgression, based on 

the phenotypic changes that have been observed in the engineered plants. 

Potential for gene flow, hybridization and gene introgression

Gene flow is unlikely to occur between MON 87708 soybean and other soybean crops 

due to its highly self-pollinating nature. Natural outcrossing rates in soybean are usually 

lower than 1% (Andersson and de Vicente 2010; Table IX-1, p. 259, (Monsanto, 2012)). 

This is predominantly due to soybean flower physiology and anatomy, where the anthers 

mature in the flower buds and directly shed their pollen onto the stigma of the same 

flower before flower opening (Andersson and de Vicente 2010; OECD 2000). 

Pollination typically takes place on the day the flower opens. The soybean flower stigma 

is receptive to pollen approximately 24 hours before anthesis (i.e., the period in which a 

flower is fully open and functional) and remains receptive for 48 hours after anthesis. 

Anthesis normally occurs in late morning, depending on the environmental conditions. 

The pollen usually remains viable for two to four hours, and no viable pollen can be 

detected by late afternoon. Natural or artificial cross-pollination can only take place 

during the short time when the pollen is viable. Additionally, soybean flower orientation 

which reduces its exposure to wind and the clumping and stickiness of soybean pollen 

decreases the dispersion ability of pollen (Yoshimura 2011). The limited potential for 

cross-pollination in soybean is evident in the Federal Seed Act Rules of Practice used by 

growers of Foundation, Registered and Certified soybean seed, which permit an isolation 

distance of zero between fields of different varieties of soybean, with the caveat that there 

also be adequate distance around the field to prevent mechanical mixing with farm 

equipment (7 CFR part 201.76, 2014 Edition). 

Gene flow potential of MON 87708 soybean was evaluated thoroughly. The introduced 

dmo gene in MON 87708 soybean is not expected to change the ability of the plant to 

interbreed with other plant species. Furthermore, the APHIS evaluation of data provided 

by Monsanto (2012) of agronomic and phenotypic properties of MON 87708 soybean, 

including those characteristics associated with reproductive biology such as days to 50% 

flowering, plant growth stage, pollen morphology and viability, seed dormancy and 

germination and pod shattering, indicated no unintended changes likely to affect the 

potential for gene flow from MON 87708 soybean to sexually compatible species. The 

potential for gene flow to occur specifically between herbicide-resistant crop varieties 

and their sexually compatible relatives has been previously addressed (Mallory-Smith 

and Olguin 2011). Gene flow does not differ whether the herbicide resistance trait is 

introduced via genetic engineering or via conventional breeding techniques, and gene 

30
flow has been occurring between non-GE soybean and GE soybean varieties, albeit at 

very low levels in accordance with soybean’s highly self-pollinating nature. Therefore, 

the potential for gene flow and introgression of the dicamba-resistant trait from MON 

87708 soybean to other soybean varieties and its consequences are anticipated to be 

similar to those as for existing commercial soybean varieties. 

Many conditions have been identified that are required for gene flow and introgression to 

occur between a crop and its wild relatives (Carpenter et al. 2002; Jenczewski et al. 2003; 

Lu 2005; Stewart et al. 2003), including flowering synchrony, abundance and method of 

pollen spread, distance of pollen movement, genetic compatibility, and environmental 

conditions pertinent to cross-pollination, but the foremost condition is the presence of 

wild relatives within pollen or seed dispersal range from the crop. In the U. S., the lack 

of sexually compatible wild relatives of Glycine max precludes any opportunity for gene 

flow to occur between cultivated soybean and its wild relatives. The genus Glycine is 

divided into two distinct subgenera, the annual subgenus Soja which contains three 

species including G. max, and the perennial subgenus Glycine which contains multiple 

species distantly related and not known to be found in the American continents or to 

produce fertile hybrids with G. max. Within the annual subgenus Soja, all three species 

(G. max, G. soja, and G. gracilis) can hybridize to some extent, but the latter two are not 

found in America (Hymowitz 2004; Lu 2005; Section IX.D.3, p. 256, (Monsanto, 2012); 

OECD 2000). Even if free-living wild relatives of cultivated soybean were to somehow 

be introduced into the soybean growing regions in the United States, the same 

reproductive characteristics previously discussed which limit cross-pollination among 

cultivated soybean varieties would limit gene flow to wild relatives.

Potential for enhanced weediness of recipients after hybridization and/or introgression

As described earlier, there is no indication that MON 87708 soybean possesses a 

selective advantage that would result in increased weediness either in cultivated or 

unmanaged fallow fields. In the extremely unlikely event successful hybrids of 

cultivated soybean and wild relatives were to occur in the U.S., the herbicide resistance 

trait would only provide selective advantage in situations in which the hybrid was in 

contact with the herbicide (i.e., in an agricultural or fallowed field or field edge). Any 

herbicide-resistant hybrid-derived populations are likely to be controlled using other 

available chemical or mechanical means. Many broadleaf and/or broad spectrum 

herbicides that are effective for control of dicamba-resistant soybean as volunteers (see 

above section of this PPRA on the Potential for Enhanced Weediness of MON 87708 

Soybean; and Table VIII-28, p. 240, (Monsanto, 2012)) would likely be effective for 

control of hybrids formed with other conventional soybeans or related species. 

APHIS concludes, based on the information presented in the petition and in relevant 

literature, that MON 87708 soybean is not expected to increase the weed risk potential of 

other soybeans, nor of other species with which it can interbreed in the U.S. or its 

territories as other sexually compatible species do not occur there. The genetic 

modification in MON 87708 soybean is not expected to increase the potential for gene 

flow, hybridization and/or introgression to occur to sexually compatible taxa compared to 

the nontransgenic recipient or other varieties of the crop commonly grown. It is highly 

31
unlikely that soybean plants will be found outside of an agricultural setting. It is also 

highly unlikely that gene flow and introgression will occur between MON 87708 soybean 

plants and sexually compatible relatives in a natural environment, since sexually 

compatible relatives do not occur in the U.S. Herbicides and other methods are available 

to control volunteer dicamba-resistant soybeans and other soybeans and Glycine species 

with which it might cross. 

H. Potential Changes to Agriculture or Cultivation Practices

APHIS assessed whether there are likely to be significant changes to agricultural or 

cultivation practices associated with adoption of MON 87708 soybean, and if so, are they 

likely to impact plant diseases or pests or their management, including any APHIS 

control programs. This includes consideration of any changes in pesticide applications, 

tillage, irrigation, harvesting, etc. as they relate to plant pests and diseases.

The only agricultural or cultivation practices that are currently employed for soybean 

production that are expected to change if MON 87708 is determined to be no longer 

subject to the regulatory requirements of 7 CFR part 340 are those related to weed 

management: in particular, choice of herbicide(s) or herbicide combinations, times of 

application, and potential crop choices or buffer zones for adjacent lands to avoid spray 

drift or volatilization to sensitive plants. Although dicamba spray drift and volatilization 

can potentially injury susceptible crops in proximity to MON 88708 soybean, such 

impacts are not considered plant pest risks, and such impacts are assessed by the U.S. 

EPA.

The current and proposed uses of dicamba in soybean are described in the petition 

(Section VIII.H, pp. 208- 224, (Monsanto, 2012). Dicamba is currently labeled only for 

preplant and late postemergence (preharvest) applications in soybean. Due to insufficient 

crop tolerance of soybean to applications of dicamba, preplant restrictions regarding 

preplant treatment are required to avoid soybean injury: i.e. a maximum application rate 

of 0.5 lbs a.e. per acre, a minimum of one inch of rainfall, and a 28-day interval between 

preplant application and planting of soybean. Due to insufficient crop tolerance, dicamba 

currently also cannot be used for in-crop postemergence applications. If EPA approves 

Monsanto's submitted application to amend Registration Number 524-582 for a DGA salt 

formulation of dicamba to remove all pre-emergence planting restrictions and to allow incrop postemergence dicamba applications to MON 87708 soybean through the 

reproductive R1/R2 (beginning and full bloom) growth stage of soybean, growers would 

be authorized to apply dicamba alone or in mixtures with glyphosate (when MON 87708

soybean is stacked with MON 89788 Roundup Ready 2 Yield soybean) or other 

herbicides for preplant or in-crop postemergence applications on MON 87708 soybean. 

Non-aerial applications of dicamba would be authorized preemergence up to crop 

emergence as a single application or split applications up to a total of 1.0 lb a.e. per acre, 

and up to two postemergence applications up to 0.5 lb a.e. per acre, each through the 

R1/R2 growth stage of soybean, with a total maximum annual application rate of 2.0 lb 

dicamba a.e. per acre. 

32
As with soybean, the timing of application of dicamba differs for labeled crops depending 

on their tolerance level (Section VIII.G.1, pp. 200 - 201, (Monsanto, 2012). Since the 

requested change in the use of dicamba in MON 87708 soybean would allow in-crop 

postemergence applications at times not previously allowed or practiced, and later than 

many other postemergence applications applied to other crops grown in the regions where 

soybeans are grown, there is an increased opportunity for exposure to sensitive plants 

(both in terms of timing and total amount) from offsite drift or volatilization. Analysis in 

the petition shows that application of dicamba at or following the V4 vegetative growth 

stage is expected to be later in the growing season than the current latest in-crop 

application timings to corn, sorghum, and wheat; and dicamba is not currently applied incrop to cotton (Section VIII.H.1, pp. 217- 218, (Monsanto, 2012), although a separate 

petition for nonregulated status for dicamba and glufosinate herbicide-resistant cotton is 

also pending with APHIS (petition 12-085-01pp) (Monsanto, 2012). When Monsanto 

submitted the petition for deregulation of MON 87708 soybean, corn had the largest incrop application use of dicamba (Table VIII-14, p. 201, (Monsanto, 2012). Based on the 

planting times and growth stages of corn and soybean and environmental conditions, the 

most likely application timing for dicamba to MON 87708 soybean was projected to be 

approximately 20 days later than the current latest application timing for corn in central 

Illinois (representative of Midwest soybean regions) and approximately 37 days later than 

the current latest application timing for corn in western Tennessee (representative of 

southern soybean growing regions). As noted in the Introduction in this PPRA, EPA is 

currently reviewing the proposed label changes described above and a request to establish 

tolerances for residues of dicamba on soybean forage and hay. EPA’s assessment will 

analyze risks to off-target plants as well as other non-target organisms to determine if the 

label is sufficient to meet EPA’s standards for registration: “reasonable certainty of no 

harm to humans” and “no unreasonable adverse effects on the environment.” If these 

standards are not met, EPA will apply appropriate risk mitigation strategies and propose 

label modifications to address the specific concerns. After EPA has completed its

assessments and provided these to APHIS, APHIS will update this PPRA if necessary. In 

addition, issues related to herbicide drift and volatilization will be addressed in the NEPA 

document for this petition. 

Upon integration of MON 87708 soybean into the Roundup Ready soybean system, aside 

from the anticipated label changes requested, Monsanto expects that growers will have 

the ability to continue to use established soybean production practices including crop 

rotation, tillage systems, labeled herbicides, row spacing, and planting and harvesting 

machinery currently being utilized (Section VIII.H, pp. 208 - 216, (Monsanto, 2012). 

The anticipated label change would facilitate a wider window of application for dicamba 

and is expected to provide a tool for improved control of broadleaf weeds (including 

some with resistance to other herbicides such as glyphosate, ALS, and PPO chemistries) 

that can be integrated into weed management programs using no-till or reduced tillage or 

conventional tillage. Their anticipated weed management recommendations for MON 

87708 soybean combined with Roundup Ready 2 Yield soybean also include a 

preemergence (burndown at planting) application of a residual herbicide alone with 

conventional tillage, or combined with glyphosate and dicamba in conservation tillage 

33
(Table VIII-16, p. 210, (Monsanto, 2012). The impacts of this system for reducing or 

managing weeds and the evolution of herbicide-resistant weeds are being addressed in the 

NEPA document for this petition. Greater weed control could potentially reduce disease 

and pest pressure in soybean if the diseases and pests of the weeds also use soybean as a 

host.

Crop rotation practices are not expected to be impacted by the use of dicamba on fields 

planted to MON 87708 soybean. Crop rotation practices in soybean were analyzed in the 

petition (Section VIII.I, pp. 224-237, (Monsanto, 2012), and Tables VIII-24 - VIII-27 

revised by Monsanto received on October 10, 2012). Soybeans are grown in rotation for 

many reasons, including to break or mitigate disease, insect, nematode and weed cycles 

or damage (Al-Kaisi et al. 2003; Hoeft et al. 2000). In comparison to alternative 

herbicides to dicamba for use in soybean, Monsanto has indicated that dicamba has either 

an improved or neutral risk profile with respect to long rotational crop restrictions (e.g., 

through a moderate potential for residual activity) (Table VIII-19, p. 215, (Monsanto, 

2012). Dicamba can be absorbed through leaves and roots and translocated, but is 

considered only moderately persistent in soil, with a half-life of six days for dicamba acid 

under aerobic soil conditions with formation of the non-persistent degradate DCSA, and a 

half-life of 141 days under anaerobic soil conditions (US-EPA 2009). Crop rotation 

restrictions range from 30 to approximately180 days, depending on the rate applied, 

inches of rainfall and the following crop, according to the Clarity® label (BASF 2010), 

and these should be adequate for rotation to other crops the spring following harvest of 

soybeans. 

The field studies on MON 87708 soybean conducted in 2008 and 2009 in the absence or 

inclusion of dicamba treatment, respectively, described in the section Potential Plant Pest 

and Disease Impacts, demonstrate that neither the dicamba resistance trait nor the 

dicamba herbicide treatment nor the metabolites produced as a result of the breakdown of 

dicamba by MON 87708 soybean DMO appear to alter the response of MON 87708

soybean to abiotic stress, diseases, or arthropod pests under natural levels of these 

stressors, and nor were pest arthropods more abundant around MON 87708 soybean 

plots. Agronomic practices used to prepare and maintain each study site were 

characteristic of those used in each respective geographic region. All maintenance 

operations were performed uniformly over the entire trial area (p. 444, (Monsanto, 2012). 

Therefore, no changes are expected for insect and disease control practices with MON 

87708 soybean. The agronomic characteristics and cultivation practices employed when 

growing MON 87708 soybean are essentially indistinguishable from practices used to 

grow other soybean varieties, including other herbicide-resistant varieties (Section VIII, 

pp. 170-243, (Monsanto, 2012) with the exception of the changes in herbicide choices 

and timing discussed previously. 

Although pest and disease susceptibility data were not presented for MON 87708 

soybean stacked with the glyphosate-resistant trait, an evaluation of current literature 

does not suggest that the intended stacking will increase plant pest and diseases. In a 

recent review regarding claims made that glyphosate‐resistant (GR) crops sometimes 

have mineral deficiencies and increases in plant disease, an evaluation of the literature 

34
showed that: “1) although there is conflicting literature on the effects of glyphosate on 

mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in 

GR crops is not affected by either the GR trait or by application of glyphosate; 2) most of 

the available data support the view that neither the GR transgenes nor glyphosate use in 

GR crops increases crop disease; and 3) yield data on GR crops do not support the 

hypotheses that there are substantive mineral nutrition or disease problems that are 

specific to GR crops” (Duke et al. 2012). This review included an evaluation of literature 

relevant to disease development and severity of many of the major pathogens of soybean, 

comparing effects of the GR trait and glyphosate treatment. When differences in cultivar 

sensitivities to pathogens were taken into account, there was no consistent effect 

correlating the GR trait or glyphosate treatment on GR soybeans with an increase in 

Sclerotinia stem rot or white mold disease caused by Sclerotinia sclerotiorum (Lee et al. 

2000; Lee et al. 2005; Nelson et al. 2002), sudden death syndrome caused by Fusarium 

virguliforme (Njiti et al. 2003; Sanogo et al. 2000; Sanogo et al. 2001), or infections 

caused by Rhizoctonia solani (Harikrishnan and Yang 2002) or soybean cyst nematode 

(Noel and Wax 2009; Yang et al. 2002). Some efficacy of glyphosate against 

Phakopsora pachyrhizi, the cause of Asian soybean rust, was reported in both greenhouse 

(Feng et al. 2005) and field studies on GR soybeans (Feng et al. 2008).

Changes in agricultural practices related to weed control are unlikely to adversely impact 

pest and disease management practices in soybean and may provide some benefit by 

providing another tool for in-crop control of broadleaf weeds that may serve as 

alternative hosts for pests and diseases. For example, soybean cyst nematode (SCN) is 

the most important soybean ‘pathogen’ in the United States, and in addition to soybean, 

several other crops and broadleaf weeds are also hosts for SCN. Some weed hosts 

include chickweed, common mullein, henbit, hop clover, purslane, Rocky Mountain Bee

plant, and toothed medic. Proper crop rotation and control of weeds can help to reduce 

levels of SCN in the field (Nelson and Bradley 2003). Several broadleaf weeds 

(including burdock, chickweed, lambsquarters, purslane, ragweed, vetch, curly dock, 

dandelion, redroot pigweed, shepard’s-purse, velvetleaf, wild mustard and wild parsnip) 

are also hosts of white mold (Sclerotinia stem rot) (Fyksen 2012).

Most seedling diseases are controlled with fungicides included in seed treatments. For 

soybean rust, no resistant varieties are available, but several fungicides are available for 

soybean rust and recommendations for these are that the first spray should not be applied 

prior to bloom. Other major pod and stem diseases are controlled by using disease-free 

seed, rotation with non-leguminous crops, and foliar fungicides where the first 

application to soybeans are in mid-bloom to early pod-set stages (ACES 2012). Most of 

these fungicides are expected to be applied later than most of the additional application 

windows for dicamba based on Monsanto recommendations for dicamba use on MON 

87708 soybeans (stacked with glyphosate resistance) since their recommendation for 

postemergence application of dicamba (plus glyphosate) at the V4-R2 stage is only for 

more aggressive glyphosate-resistant weed species, such as Ambrosia or Amaranthus 

species (Table VIII-16, p. 210, (Monsanto, 2012).

35
In conclusion, MON 87708 soybean is similar to conventional soybean in its agronomic, 

phenotypic, environmental response, and compositional characteristics and has levels of 

pests and diseases or their damage levels comparable to conventional soybean. The only 

changes in agricultural or cultivation practices that are anticipated with adoption of MON 

87708 soybean (including the anticipated stack with MON 89788 Roundup Ready 2 

Yield soybean) are related to weed management practices. Anticipated changes in 

herbicide use patterns in MON 87708 soybean alone or stacked with MON 89788 

Roundup Ready 2 Yield soybean are unlikely to increase pests or diseases or adversely 

impact their management, nor will they impact APHIS pest control programs. 

I. Potential Impacts from Transfer of Genetic Information to 

Organisms with which MON 87708 Soybean Cannot Interbreed

APHIS examined the potential for the new genetic material inserted into MON 87708 

soybean to be horizontally transferred to other organisms without sexual reproduction 

and whether such an event could lead directly or indirectly to disease, damage, injury or 

harm to plants, including the creation of new or more virulent pests, pathogens, or 

parasitic plants. 

The horizontal gene transfer between unrelated organisms is one of the most intensively 

studied fields in the biosciences since 1940, and the issue gained extra attention with the 

release of transgenic plants into the environment (Dröge et al. 1998). Potential risks from 

stable horizontal gene transfer (HGT) from genetically engineered organisms to another 

organism without reproduction or human intervention were recently reviewed (Keese 

2008). Mechanisms of HGT include conjugation, transformation and transduction, and 

other diverse mechanisms of DNA and RNA uptake and recombination and 

rearrangement, most notably through viruses and mobile genetic elements. HGT has 

been a major contributor to the spread of antibiotic resistance amongst pathogenic 

bacteria; emergence of increased virulence in bacteria, eukaryotes and viruses; and, in the 

long run, to major transitions in evolution (Brown, 2003; Keeling and Palmer, 2008; 

Keese, 2008). 

MON 87708 soybean contains a protein coding region derived from the dmo gene from 

the bacterium Stenotrophomonas maltophilia and a transit peptide protein coding region 

from pea (Pisum sativum) for chloroplast targeting of the DMO protein in MON 87708 

soybean. It also contains non-protein-coding regions from Agrobacterium, plant viruses, 

and pea. One example of HGT involves a class of enzymes similar to DMO. 

Chakraborty et al. (2012) propose that HGT contributed to the distribution of ringhydroxylating oxygenase (rho) genes among prokaryotic phyla (proteobacteria, 

actinobacteria, cyanobacteria, and archaea), and note that homologues of rho genes are 

found in plants (in strains of Arabidopsis, Zea mays, Oryza sativa, Physcomitrella patens 

and Amaranthus tricolor). Ring-hydroxylating oxygenases (RHO) catalyze the addition 

of hydroxyl groups to aromatic ring compounds, initiating one of the major pathways for 

oxidative degradation of both natural and synthetic aromatic compounds in the 

environment (Peng et al. 2010). Dicamba mono-oxygenase is a unique type of RHO that 

36
initiates the degradation of dicamba by oxygenating the exocyclic methyl group, rather 

than the more conventional oxygenation of the aromatic ring of the substrate seen in most 

other RHOs (Dumitru et al. 2009). Chakraborty et al. (2012) suggest that distribution and 

diversification of rho genes can be explained by the mechanisms of gene duplication, 

transposition events and DNA rearrangements in most cases, but that HGT is assumed to 

be the primary mechanism in cases where occurrence of the genes was found to be 

limited to just one or two organisms within phyla (such as rho genes in some 

cyanobacteria, firmicutes and crenarchaeota), since the possibility of being remnants of a 

partially deleted rho operon is ruled out due to the absence of similar genes in any other 

member of these genera. Although it is widely accepted that HGT has generated novel 

degradation capabilities and increased metabolic diversity among bacterial communities 

exposed to an ever-evolving array of polycyclic aromatic compounds, such degradative 

capabilities are mostly indicative of divergent evolution from a common ancestor, not 

HGT (Peng et al. 2010). 

Potential for horizontal gene transfer to bacteria, fungi, or invertebrates

Horizontal gene transfer and expression of DNA from a plant species to bacterial, fungal

or invertebrate species is unlikely to occur based on the following observations. 

Although there are many opportunities for plants to directly interact with fungi and 

bacteria (e.g. as commensals, symbionts, parasites, pathogens, decomposers, or in the 

guts of herbivores) and with invertebrates as plant pests, there are almost no evolutionary 

examples of HGT from eukaryotes to bacteria or from plants to fungi or invertebrates

(Keese 2008). Examples of HGT between eukaryotes and fungi primarily involve gene 

acquisition or transfer by fungi to or from other distantly related fungi or bacteria

(Keeling and Palmer 2008; Keese 2008) and HGT between plants and fungi is extremely 

rare (Richards et al 2009). Examples of HGT between plants and invertebrates are also 

extremely rare, and most examples of HGT in insects involve acquisition of genes from 

their pathogens or endosymbionts (Keese 2008; Zhu et al, 2011; Acuna et al 2012).

Horizontal transfer from and expression in bacteria of the foreign DNA inserted into the 

nuclear genome of the GE plant is unlikely to occur. First, many genomes (or parts 

thereof) have been sequenced from bacteria that are closely associated with plants 

including Agrobacterium and Rhizobium (Wood et al. 2001; Kaneko et al. 2002). There 

is no evidence that these organisms contain genes derived from plants. HGT from plants 

to bacteria is a very low frequency event, primarily because functional and selective 

barriers to HGT increase with genetic distance (Keese 2008). Second, in cases where 

review of sequence data implied that horizontal gene transfer occurred, these events are 

inferred to occur on an evolutionary time scale on the order of millions of years (Brown 

2003; EFSA 2009; Koonin et al. 2001). Third, transgene DNA promoters and coding 

sequences are optimized for plant expression, not prokaryotic bacterial expression. Thus 

even if horizontal gene transfer occurred, proteins corresponding to the transgenes are not 

likely to be produced. Fourth, both the FDA (US-FDA 1998) and the European Food 

Safety Authority (EFSA 2009) have evaluated horizontal gene transfer from the use of 

antibiotic resistance marker genes and concluded that the likelihood of transfer of 

37
antibiotic resistance genes from plant genomes to microorganisms in the gastrointestinal 

tract of humans or animals, or in the environment, is very rare or remote.

Potential for horizontal gene transfer to viruses 

APHIS also considered whether horizontal transfer of DNA from the GE plant to plant 

viruses was likely to occur and would lead to the creation or selection of plant viruses 

that are more virulent or have a broader host range. This issue has been considered before 

by other science review panels and government regulatory bodies (EPA-FIFRA-SAP 

2006; Keese 2008). HGT is not unusual among plant viruses; however this is generally 

limited to exchange between viruses present in the same host organism in mixed 

infections, and most commonly involves homologous recombination, relying on sequence 

similarity at the point of crossover (Keese 2008). HGT from virus sequences engineered 

into plants has been demonstrated with infecting or challenge viruses, including both 

DNA viruses (e.g. geminiviruses which replicate in the nucleus) (Frischmuth and Stanley 

1998) and RNA viruses (which typically replicate in the cytoplasm); however most have 

been under conditions that favor recombination to restore a defective virus (Fuchs and 

Gonsalves 2007; Keese 2008; Thompson and Tepfer 2010). Populations of recombinants 

between virus transgenes expressed in transgenic plants infected with related viruses are 

similar to recombinants found in mixed infections of the same viruses in nontransgenic 

plants, indicating that there was no novel recombination mechanism in the transgenic 

plants and no increased risk is expected over what is expected from mixed infections

(Keese 2008; Turturo et al 2008). Nonhomologous recombination in HGT among viruses 

or between virus transgenes and infecting viruses can occur, but frequently results in gene 

deletions which can result in nonviable viruses (Morroni et al 2013). Depending on the 

particular virus and sequences involved, various hot-spots for recombination have been 

found in both coding and noncoding regions, and strategies implemented in design of

transgenes to avoid recombination have been suggested. No recombinant or undesirable 

viruses with new properties have been detected for over at least 8-10 years in field tests 

or during commercial growth of deregulated virus resistant plum, squash, or papaya 

engineered with genes from viruses that have been deregulated in the U.S. (Fuchs and 

Gonsalves 2007). 

The only virus sequences inserted in MON 87708 soybean are the promoter for the 

peanut chlorotic streak virus (PCSV) and the 5' non-translated region from the tobacco 

etch virus (TEV) involved in regulating gene expression. Soybean is considered 

susceptible to PCSV, but not to TEV (Brunt et al. 1996). PCSV belongs to the 

Caulimovirus family of pararetroviruses, double-stranded DNA viruses in which 

replication occurs in the cytoplasm via reverse transcription of an RNA intermediate. 

Caulimoviruses generally have a narrow host range (Hansen and Heslop-Harrison 2004). 

The only other caulimovirus that soybean is susceptible to is a soybean chlorotic mottle 

caulimovirus (SbCMV) (Brunt et al. 1996). Neither of these viruses are considered 

widely prevalent in the United States (University of Georgia 2012), therefore exposure of 

either of these two viruses to the PCSV sequences in MON 87708 soybean is expected to 

be low or unlikely. Moreover, recombination in Caulimoviruses occurs predominantly, if 

not exclusively, in the cytoplasm by template switching between RNA transcripts during 

38
the replication process, although a low level of recombination involving viral DNA may 

occur in the nucleus (Froissart et al. 2005). Since the Caulimovirus promoter sequences 

are not transcribed in transgenic plants, there is little or no opportunity for them to 

recombine with any related Caulimoviruses that may infect soybean. Although TEV 

occurs in the United States and is considered widely prevalent (University of Georgia 

2012), since soybean is not susceptible to this virus, it is unlikely that TEV would be 

exposed to sequences from TEV in MON 87708. Since the TEV sequence in MON 

87708 is a 5' non-translated region, even if recombination were to occur with another 

related potyvirus that infects soybean, it is unlikely to encode a peptide. Based on the 

foregoing, horizontal transfer of DNA from MON 87708 soybean to plant viruses is 

unlikely to occur or is unlikely to lead to the creation or selection of plant viruses that are 

more virulent or have a broader host range. 

Potential for horizontal gene transfer to parasitic plants

Evidence for HGT from plants to other plants is limited to two specific scenarios: (1) 

exchange of genes between a parasitic plant and its host; and (2) exchange of genes 

between cells of two plants living in close proximity, such as in a graft junction. In both 

cases, this type of HGT requires physical contacts between the two plants. Most cases of 

HGT in plants involve transfer of mitochondrial genomes, which are primarily maternally 

inherited in plants (Barr et al 2005), to other mitochondria genomes, and mostly involve 

parasitic plants and their hosts (Richardson and Palmer 2007). Recently, Yoshida et al 

(2010) through a comparative genomics analysis implicated HGT for the incorporation of 

a specific genetic sequence in the parasitic plant purple witchweed (Striga hermonthica) 

from its monocot host plant. According to this study, the incorporation of the specific 

genetic sequence (with an unknown function) occurred between sorghum and purple 

witchweed. However, this HGT occurred before speciation of purple witchweed and 

related cowpea witchweed (S. gesnerioides) from their common ancestor. More recent 

studies demonstrated that in a few parasitic species of the Rafflesiaceae family, out of 

several genetic sequences examined, about 2.1% of nuclear (Xi et al 2012) and 24 –41% 

of mitochondrial (Xi et al 2013) gene transcripts appeared to be acquired from their 

obligate host species. However, all the above-mentioned instances of HGT between 

parasitic plants and their hosts were reported to be of ancient origins, on an evolutionary 

time scale spanning thousands to millions of years ago. Furthermore in the GE crop, the 

DNA sequences were inserted into the nuclear genome, not the mitochondrial genome.

genome.

If the GE plant becomes infected by a parasitic plant or is naturally grafted to another 

plant, there is a very low probability that HGT could result in the other plant acquiring 

DNA from the GE plant. However, in both scenarios this newly introduced DNA would 

likely reside in somatic cells, and with little chance of reaching the germ cells, this 

introduced DNA could not persist in subsequent generations unless the recipient plant 

reproduced asexually from the affected cells. 

Based on the above analysis, APHIS therefore concludes that HGT of the new genetic 

material inserted into MON 87708 soybean to a variety of other organisms with which it 

cannot interbreed is highly unlikely, and is not expected to lead directly or indirectly to 

39
disease, damage, injury or harm to plants, including the creation of new or more virulent 

pests, pathogens, or parasitic plants.

J. Conclusion

APHIS has reviewed the information submitted in the petition, supporting documents, 

public comments in response to the Federal Register notice concerning this petition and 

other relevant information to assess the plant pest risk of MON 87708 soybean compared 

to the unmodified variety from which it was derived and other commercial reference 

soybean varieites. APHIS concludes that the MON 87708 soybean is unlikely to pose a 

plant pest risk based on the following findings. 

• No plant pest risk was identified from the transformation process or the insertion of 

new genetic material in MON 87708: the Agrobacterium transformation vector was 

disarmed, transformed material was treated to kill the bacterium, and the plant pest 

sequences inserted do not cause disease or create an infectious agent. 

• No increase in plant pest risk was identified from expression of the inserted genetic 

material, the new MON 87708 DMO protein, or changes in metabolism or 

composition. The composition of MON 87708 grain and forage were determined to 

be substantially equivalent to other soybeans commercially grown and the mode of 

action and specificity of MON 87708 DMO raises no plant pest concerns.

• Disease and pest incidence and/or damage were not observed to be significantly 

increased or atypical in MON 87708 compared to the nontransgenic counterpart in 

field trials conducted in growing regions representative of where this soybean is 

expected to be grown. Neither the dicamba resistance trait nor the dicamba herbicide 

treatment (including any metabolites produced as a result) significantly alter the 

response of MON 87708 to diseases, or arthropod pests under natural levels of these 

stressors, and nor were pest arthropods more abundant around MON 87708 plots 

compared to the control line. Observed agronomic traits also did not reveal any 

significant differences that would indirectly indicate that MON 87708 is more 

susceptible to pests or diseases. Therefore no plant pest effects are expected on these 

or other agricultural products and no impacts are expected to APHIS pest control 

programs. 

• Exposure to and/or consumption of MON 87708 soybean are unlikely to have any

adverse impacts on organisms beneficial to agriculture based on APHIS analysis of 

studies on MON 87708 soybean food and feed safety, nutrient and anti-nutrient 

composition, levels of DMO in tissues, environmental interactions with beneficial 

arthropods, pollen characteristics and association with nitrogen fixing symbionts. 

• MON 87708 soybean is unlikely to become more of a weed or volunteer problem

than other conventional or commercial soybean varieties based on its observed 

agronomic characteristics, the low weediness potential of soybean and current 

management practices available to control MON 87708 as a weed. MON 87708

volunteers, although resistant to dicamba and less sensitive to some other phenoxy 

synthetic auxin herbicides, can still be controlled with other currently available weed 

control methods.

40
• MON 87708 is not expected to increase the weed risk potential of other soybeans, and

other species with which it can interbreed do not naturally occur in the U.S. or its 

territories. The genetic modification in MON 87708 soybean is not expected to 

increase its potential for gene flow, hybridization and/or introgression to sexually 

compatible taxa, nor is it likely to increase their weediness potential in the event that 

such species were to be introduced. Introgression of the dicamba resistant trait into 

other soybeans or related species will likely make them resistant to dicamba and less 

sensitive to other phenoxy synthetic auxin herbicides, but other currently available 

weed control methods could be used for their control.

• Changes in agricultural or cultivation practices anticipated with adoption of MON 

87708 soybean (including the anticipated stack with MON 89788 Roundup Ready 2 

Yield soybean) are only related to weed management practices and herbicide use 

patterns, and these are unlikely to increase pests or diseases or adversely impact their 

management, nor will they impact APHIS pest control programs. 

• Horizontal gene transfer of the new genetic material inserted into MON 87708 

soybean to other organisms is highly unlikely and is not expected to lead directly or 

indirectly to disease, damage, injury or harm to plants, including the creation of new 

or more virulent pests, pathogens, or parasitic plants.

K. References

7 CFR part 201.76 (2014 Edition) "Minimum land, isolation, field, and seed standards." 

Regulations of the United States Department of Agriculture, Agricultural 

Marketing Service. Last Accessed: Aug 2014 

http://www.gpo.gov/fdsys/pkg/CFR-2014-title7-vol3/pdf/CFR-2014-title7-vol3-

sec201-76.pdf.

7 CFR part 340 (2014 Edition) "Introduction of organisms and products altered or 

produced through genetic engineering which are plant pests or which there is 

reason to believe are plant pests." Regulations of the United States Department of 

Agriculture, Animal and Plant Health Inspection Service. Last Accessed: Aug 

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