Syngenta and Bayer Petition (12-215-01p) for 

Determination of Non-regulated Status of SYHT0H2 

Soybean

OECD Unique Identifier: 

SYN-ØØØH2-5

Plant Pest Risk Assessment 

April 2014

Agency Contact 

Cindy Eck

Biotechnology Regulatory Services

4700 River Road

USDA, APHIS 

Riverdale, MD 20737 

Fax: (301) 734-8669

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TABLE OF CONTENTS

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

B. Development of SYHT0H2 soybean .......................................................................... 3

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

Products, and Changes to Plant Metabolism ............................................................. 5

D. Potential Impacts on Disease and Pest Susceptibilities............................................ 10

E. Potential Impacts on Nontarget Organisms Beneficial to Agriculture ..................... 11

F. Potential for Enhanced Weediness of SYHT0H2 Soybean ...................................... 12

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

Interbreed................................................................................................................. 13

H. Potential Changes to Agriculture or Cultivation Practices....................................... 14

I. Potential Impacts from Transfer of Genetic Information to Organism with which 

SYHT0H2 Cannot Interbreed .................................................................................. 15

J. Conclusion ................................................................................................................ 16

K. References................................................................................................................. 17

i
A. Introduction

Syngenta Seeds, Inc., (Syngenta) and Bayer CropScience AG (Bayer) have petitioned the

United States Department of Agriculture (USDA), Animal and Plant Health Inspection 

Service (APHIS) for a determination that Event SYHT0H2 double herbicide-tolerant1

soybean (hereafter referred to as SYHT0H2 soybeans) 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. This petition was assigned the number 12-125-01p, and is 

hereafter referenced as Syngenta and Bayer 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 

SYHT0H2 soy 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 APHIS Administrator 

determines is a plant pest or has reason to believe is a plant pest3

. 

The Event SYHT0H2 soybean (Glycine max cultivar Jack) expresses proteins which 

impart herbicide tolerance, AvHPPD-03 from oat (Avena sativa) and phosphinothricin 

acetyltransferase (PAT) from Streptomyces viridochromogenes. The AvHPPD-03 and 

PAT proteins expressed in the soybean protect the plant from the application of the 

HPPD-inhibiting and glufosinate-amonium herbicides, respectively. SYHT0H2 soybean

1 Syngenta and Bayer have described the phenotype of SYHT0H2 soybeans 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 SYHT0H2 soybeans 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

 
was produced by the transformation of immature soybean seed using disarmed 

Agrobacterium tumefaciens. Because five of the regulatory sequences used to facilitate 

expression of the herbicide tolerance genes in SYHT0H2 soybean (figwort mosaic virus 

(FMV), cauliflower mosaic virus, Cestrum yellow leaf curling virus, tobacco mosaic 

virus (Syngenta and Bayer, 2012, p. 18), were derived from plant pests and 

Agrobacterium tumefaciens used for transformation is a plant pest, SYHT0H2 soybean

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

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

risk associated with SYHT0H2 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 SYHT0H2 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 SYHT0H2 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, 1986; 57 FR 22984, 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 biotechnology-derived 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 nontarget 

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

language used on the pesticide label in accordance with 40 CFR part 158. Other 

applicable EPA regulations include 40 CFR part 152 - Pesticide Registration and 

Classification Procedures, part 174 - Procedures and Requirements for Plant Incorporated 

Protectants (PIPs) and part 172 - Experimental Use Permits. 

2
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 

voluntary early food safety evaluation for new non-pesticidal proteins produced by new 

plant varieties intended to be used as food (FDA 2006) and a more comprehensive 

voluntary consultation process prior to commercial distribution of food or feed (57 FR 

22984).

Syngenta and Bayer have made a request to the U.S. Environmental Protection Agency to 

amend the use of mesotrione on SYHT0H2 soybeans. Currently, EPA allows a maximum 

season rate application of 1,333 g a.i./ha of mesotrione in corn (Syngenta and Bayer, 

2012, p. 133). These companies are also pursuing the consultation process with the Food 

and Drug Administration (FDA) concerning the regulation of products derived from new 

plant varieties, including those of biotechnology, as well as with the regulatory offices of 

12 countries, the Russian Federation and the European Union (Syngenta and Bayer, 2012, 

p. 19).

B. Development of SYHT0H2 soybean

There are no genetically engineered events for the insertion of the hppd gene into 

soybean or any other crop species to date, or soybean tolerant to glufosinate, although 

two petitions (09-349-01p, 11-234-01p) that confer tolerance to those herbicides are 

currently in the review process by APHIS Biotechnology Regulatory Services (BRS). 

The insertion of the hppd gene derived from oats (Avena sativa), confers to SYHT0H2 

soybeans tolerance to the 4-hydroxyphenyl-pyruvate (HPPD) inhibitor herbicide 

mesotrione (Mitchell, 2001). The inhibition of the 4-HPPD enzyme disrupts the 

metabolism of the amino acid tyrosine (Wu, 2002). The insertion of the pat gene from 

the bacterium Streptomyces viridochromogenes produces the enzyme phosphinothricin 

acetyltransferase (PAT) that inactivates the herbicide gufosinate-ammonium, allowing 

SYHT0H2 soybeans to tolerate contact with both herbicides. Syngenta and Bayer have 

developed SYHT0H2 soybean to be tolerant to both herbicides. 

HPPD-inhibitor herbicide controls a broad spectrum of grass and broadleaf weeds and is 

effective on difficult to control weeds (Mitchell, 2001; Johnson, 2002; Bollman, 2008).

The combined effects of desorption (release of the compound from the soil) and 

degradation resupply the soil solution with a bioactive product. Because of its adsorption 

characteristics, the application rate of isoxaflutole is adjusted for soil texture and organic 

matter. Depending on the concentration of organic matter, the half-life of HPPD in soil 

can be up to 30 days (Inoue, 2009). Due to the potential for leaching, especially on 

permeable soils, isoxaflutole is a restricted-use pesticide. The label prohibits its use on 

sandy soils with less than 2% organic matter where the water table is less than 25 feet 

from the surface. Isoxaflutole has a bleaching effect as chlorophyll is broken down in 

sunlight but is not replaced. The symptoms first appear on leaf edges and tips as this is 

the site of new carotenoid synthesis (Johnson, 2002). Once in the plant, isoxaflutole is 

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rapidly converted into diketonitrile (DKN) which works by inhibiting the production of 

4-hydroxyphenyl-pyruvate dioxygenase (HPPD). Inhibition of HPPD stops the 

biosynthesis of plastoquinone, a carotenoid pigment that is needed for electron transport 

process of photosynthesis (http://www.uniprot.org/keywords/618). 

Glufosinate ammonium’s salt, the herbicidal product, irreversibly inhibits glutamine 

synthetase in plants, blocking the synthesis of the amino acid glutamine from glutamate 

and ammonia. This results in the rapid accumulation of potentially toxic levels of 

ammonia in the cell, a by-product of photosynthesis (Shaner, 2003). It also results in a 

deficiency in the production of several amino acids, an inhibition of photosynthesis and 

finally the death of the plant cell (Müller, 2001). Glufosinate, an essential amino acid in 

animals and plants, is initially transformed to the corresponding oxo acid, 2-oxo-4-

(hydroxymethylphosphinyl) butanoic acid (PPO), possibly by a transamination reaction. 

The intermediate PPO is decarboxylated to the main metabolite 3 (hydroxymethylphosphinyl) propionic acid which is considered stable in plants (Müller, 2001; Shaner, 

2003). 

In the U.S. soybeans are grown on over 78.9 million acres (Figure 1) with a value of 

$31.7 billion in 2009 (USDA-ERS, 2011). Growers select soybean lines adapted to the 

different environmental and climatic features, weed and disease pressures, cost of seed 

and other inputs, technology fees, human safety, ease and flexibility of the production 

system and marketing reasons (Reddy, 2001; Gianessi, 2006).

Figure 1. Soybean production areas in the U.S. (USDA-NASS, 2011).

For the past approximately 28 years soybean yields in the U.S. have increased 65% at an 

annual rate of about 2.3% (Figure 2, next page). In order to meet the domestic and 

export demands, soybean productivity in the U.S. has been accomplished by both 

increasing the area under cultivation and by these constant yield increases per unit area. 

4
For example, from 1924 to 2010, soybean acreage increased almost 50-fold, but in the 

last decade the increase in planted area had been only 6% (USDA-NASS, 2011). The 

annual improvement in U.S. soybean yield can be attributed to genetic and agronomic 

innovations and better control of weeds, pests and diseases that provide producers better 

tools to meet production demands (Specht, 1999), depending also on continuing infusions 

of genetic resources for yield stability and growth (USDA-ERS, 2011).

One of the agronomic innovations in soybeans has been the development of varieties that 

are tolerant to herbicides. From the early adoption of glyphosate-resistant soybean in 

1996, a great adoption increment has followed, from approximately 5% adoption in 1997 

to over 25% in 2006 (Dill, 2007). Because major crops such as soybeans, cotton and 

corn have been genetically engineered to tolerate glyphosate herbicide, dozens of weed 

species around the world have shown resistance to this herbicide (Powles, 2008). To 

maintain the high productivity of soybeans it is necessary to have adequate tools for the 

control of weeds. SYHT0H2 soybeans tolerate the contact with two herbicides that are 

different in their mode-of-action to glyphosate. SYHT0H2 soybeans have been tested in 

the U.S. since 2008 in 24 states under 20 different APHIS-BRS notifications (Syngenta 

and Bayer, 2012, appendix A, p. 137).

Figure 2. Soybean yield trend in the U.S. (USDA ERS 2011).

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 SYHT0H2 soybeans; and the integrity, stability and mode of inheritance of 

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35

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45

50

Bushels per Acre

Soybean Yields in the US

5
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.

 

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 SYHT0H2 soybeans relative to the nontransgenic counterparts. The 

assessment encompasses a consideration of the expressed proteins and any observed or 

anticipated effects on plant metabolism including, any relevant changes in levels of 

metabolites, antinutrients, or nutrients in harvested seed and fiber derived from 

SYHT0H2 soybeans event compared to those in the conventional counterpart or to other 

comparators. 

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 

SYHT0H2 soybeans; 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

The number of T-DNA integration sites, number of copies of the functional elements of 

the transformation plasmid pSYN15954, and the presence / absence of plasmid backbone 

sequence in the SYHT0H2 soybean genome was determined by Southern blot analyses 

(Syngenta and Bayer, 2012, figures V-1 and V-2, table V-1, p. 35-38). Herbicide tolerant 

Event SYHT0H2 soybean contains, at a single locus within the soybean genome that is 

stably inherited, a single copy of avhppd-03, four copies of pat, a single copy of the 

avhppd-03 enhancer complex sequence, two copies of the CaMV 35S promoter, two 

copies of the CMP promoter, two copies of the TMV enhancer, and five copies of the 

NOS terminator. It does not contain any extraneous DNA fragments of these functional 

elements elsewhere in the SYHT0H2 soybean genome, and it does not contain the FMV 

enhancer or plasmid backbone sequence from pSYN15954 (Syngenta and Bayer, 2012, p. 

38-43).

The transformation plasmid pSYN15954 was used to produce SYHT0H2 soybeans by 

Agrobacterium tumefaciens–mediated transformation of immature “Jack” soybean seed. 

The DNA region between the left and right borders of the transformation plasmid 

included gene-expression cassettes for avhppd-03, pat-03-01, and pat-03-02. The 

avhppd-03 expression cassette consisted of the avhppd-03 coding region regulated by a 

synthetic minimal plant (SMP) promoter, figwort mosaic virus (FMV) enhancer, CaMV 

35S enhancer (35S enhancer), tobacco mosaic virus (TMV) enhancer, and nopaline 

synthase (NOS) polyadenylation terminator sequence. The pat-03-01 expression cassette 

consisted of the pat-03-01 coding region regulated by a CaMV 35S promoter (35S 

promoter) and NOS terminator sequence. The pat-03-02 expression cassette consisted of 

the pat-03-02 coding region regulated by a Cestrum yellow leaf curling virus promoter 

(CMP), TMV enhancer, and NOS terminator sequence. 

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Genetic 

element Description

avhppd-03 cassette

FMV enhancer Figwort mosaic virus transcriptional enhancer region 

(similar to Accession No. X06166.1 (NCBI-Protein, 

2012)), which increases gene expression (Maiti, 1997).

35S enhancer Cauliflower mosaic virus 35S transcriptional enhancer 

region (Ow, 1987).

SMP promoter Synthetic minimal plant promoter including the TATA box, 

an adenine-rich sequence involved in transcription 

initiation, from the Cestrum yellow leaf curling virus 

promoter (Stavolone, 2003b) linked to a sequence taken 

from the region that is 3′ to the TATA box of the 35S 

promoter (Ow, 1987).

TMV enhancer The 5′ non-coding leader sequence (called omega) from 

tobacco mosaic virus (Gallie, 1987), which functions as a 

translational enhancer in plants (Gallie, 2002).

avhppd-03 The gene avhppd-03, derived from oat and codon 

optimized for enhanced expression, which encodes the 

enzyme AvHPPD-03. This enzyme catalyzes the formation 

of homogentisic acid, the aromatic precursor of 

plastoquinone and vitamin E biosynthesis (Matringe, 2005). 

In comparison with the native soybean HPPD, AvHPPD-03 

has lower binding affinity for mesotrione, an herbicide that 

inhibits HPPD. Expression of avhppd-03 in plant cells 

confers a tolerance to HPPD-inhibitor herbicides such as 

mesotrione.

NOS terminator Terminator sequence from the nopaline synthase gene of A. 

tumefaciens (Accession No. V00087.1 (NCBI-Protein, 

2012)). Provides a polyadenylation site (Depicker, 1982).

7
Genetic 

element Description

pat-03-01 cassette

35S promoter Promoter region of cauliflower mosaic virus (Ow, 1987).

pat-03-01 Streptomyces viridochromogenes strain Tü494 gene, which 

encodes the selectable marker PAT. The native coding 

sequence (Wohllehen, 1988) was codon-optimized for 

enhanced expression. The synthetic gene pat-03-01 was 

obtained from AgrEvo, Germany. PAT confers resistance 

to herbicides containing glufosinate-ammonium 

(phosphinothricin).

NOS terminator Terminator sequence from the NOS gene of A. tumefaciens

(Accession No. V00087.1 (NCBI-Protein, 2012)), provides 

a polyadenylation site (Depicker, 1982).

pat-03-02 cassette

CMP promoter Promoter and leader sequence from the Cestrum yellow 

leaf curling virus, similar to Accession No. AF364175.3 

(NCBI-Protein, 2012) (Stavolone, 2003a).

TMV enhancer The 5′ noncoding leader sequence (called omega) from 

tobacco mosaic virus (Gallie, 1987), which functions as a 

translational enhancer in plants (Gallie, 2002).

pat-03-02 Streptomyces viridochromogenes strain Tü494 gene, which 

encodes the selectable marker PAT. The native coding 

sequence (Wohllehen, 1988) was codon-optimized for 

enhanced expression and altered to remove restriction sites. 

PAT confers resistance to herbicides containing 

glufosinate-ammonium (phosphinothricin). 

NOS terminator Terminator sequence from the nopaline synthase gene of A. 

tumefaciens (Accession No. V00087.1 (NCBI-Protein, 

2012), provides a polyadenylation site (Depicker, 1982).

8
Expression of inserted DNA, changes in gene expression, new proteins or metabolism

The AvHPPD-03 protein expressed in SYHT0H2 soybeans is nearly identical to the 

microbially-produced from recombinant Escherichia coli, except for a minor four amino 

acid truncation in the N-terminus of the AvHPPD-03 protein expressed in planta

(Syngenta and Bayer, 2012, p. 66). The PAT proteins, expressed by the genes pat-03-01

and pat-03-02, derived from Streptomyces viridochromogenes, each encoding identical 

PAT amino acid sequences, are also identical in amino acid sequence to the PAT protein 

from SYHT0H2 soybeans.

The functional activities of the HPPD and PAT proteins were confirmed in vivo from 

field-grown SYHT0H2 soybeans (tables VI-1 [p. 66] and VII-1 [p. 81]). The applicants

collected samples from leaves, roots, forage and seeds from five different growth stages 

(V4, V8, V10, R6, and R8), to quantify AvHPPD-03 and PAT proteins expression in 

SYHT0H2 soybeans. Both proteins were expressed at varying levels during all stages of 

the plant life cycle.

Detailed compositional and nutritional comparisons of SYHT0H2 soybeans and the 

conventional non-transformed soybean control Jack (Pp. 92-106), were conducted on 

samples collected from eight sites across the U.S. in 2010 (table X-5, p. 118). The 

analysis included moisture, protein, fat, ash, carbohydrates, amino acids, fatty acids, 

fibers, anti-nutrients, vitamin E isoforms, minerals and vitamins, consistent with OECD 

guidelines (OECD, 2001) (Syngenta and Bayer, 2012, table VIII-3, p. 94). SYHT0H2 

soybeans had significantly lower (2.7%) potassium (K) and iron (Fe) content (3.5%) than 

the comparator Jack variety, but not significantly different from the reference varieties 

used in this study or from the International Life Sciences Institute’ (ILSI) crop 

composition database (Syngenta and Bayer, 2012, table VIII-6, p. 99). The other 

compositional and nutritional components described above were not significantly 

different between SYHT0H2 soybeans and the conventional non-transformed soybean 

control Jack. 

Tocopherols, substances produced by plants, play an important role as antioxidants. The 

amount and composition of tocopherols are regulated in part by biotic and abiotic factors 

surrounding the plants, such as developmental stage, stresses and nutrient availability 

(Tsegaye, 2002). α-tocopherol, an isoform with the highest amount of vitamin E activity, 

is an essential dietary component for mammals (Ujiie, 2005). The level of α-tocopherol 

in SYHT0H2 was significantly lower (11.6%) than in the non-transgenic parent line Jack, 

but the percentages of vitamin E in these two soybean varieties were within the 

concentration of tocopherols in the reference varieties. No differences were detected in 

the concentration of the other tocopherols (γ and δ) between Event SYHT0H2 and Jack 

soybean varieties (Syngenta and Bayer, 2012, table VIII-8, p. 100). Significantly higher 

amounts (1.3 – 3.6%) of the amino acids aspartic acid, threonine, serine, glutamic acid, 

proline, alanine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine, were 

detected in Event SYHT0H2 than in the comparator Jack variety. No significant 

differences were found in the concentration of the glycine, valine, methionine, isoleucine, 

and tryptophan amino acids between these two varieties (Syngenta and Bayer, 2012, table 

9
VIII-9, p. 102). All the amino acid concentrations were found to be within the ranges of 

the reference varieties. As is the case of tocopherols, the levels of amino acids can be 

affected by abiotic factors (Wolf, 1982; Krishnan, 2005). Significantly higher amounts 

of palmitic, stearic, oleic, arachidic and behenic fatty acids, and significantly lower 

amounts of linoleic and linolenic fatty acids were obtained from SYHT0H2 soybean than 

from the comparator Jack variety. The concentrations of the fatty acids in Event 

SYHT0H2 and the conventional non-transformed soybean control Jack were within the 

ranges of the reference varieties and the ILSI crop composition database (Syngenta and 

Bayer, 2012, table VIII-10, p. 103). Fatty acid composition in soybeans can be 

significantly affected by abiotic factors (Tsukamoto, 1995).

Based on these results, it can be concluded that products derived from SYHT0H2 can be 

considered compositionally and nutritionally equivalent to those derived from convention 

soy.

D. Potential Impacts on Disease and Pest Susceptibilities

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 SYHT0H2 soybeans 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 SYHT0H2 soybeans 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 SYHT0H2 soybeans 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 

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

agriculture.

SYHT0H2 soybeans were field tested in eight locations in the U.S. in 2010. Minimal 

damage was noted in SYHT0H2 soybeans and its control comparator Jack by the diseases 

frogeye leaf spot (Cercospora sojina) in IL, IA and IN trials, brown spot (Septoria sp.) in 

IA, powdery mildew (Microsphaera diffusa) in PA, and cercospora leaf spot (Cercospora 

kukuchii) in IA. The incidence of insects was also minimal during these trials finding 

light damage by green clover worms (Plathypena scabra) in IL and IA, bean leaf beetles 

(Cerotoma trifurcata) in IL, IA and IN, salt marsh caterpillars (Estigmene acrea) in MO, 

soybean looper (Trichoplusia ni) in IL, Japanese beetles (Popillia japonica) in IA, 

grasshoppers in IL, MO and IN, whiteflies in IL and PA, and leafhoppers in PA (p. 120).

Syngenta and Bayer aforementioned data indicate that SYHT0H2 soybeans are not 

biologically different from conventional soybeans (with the exception of the AvHPPD-03 

10
and PAT proteins), and the herbicide resistant phenotypes did not alter the pest and 

disease incidences on SYHT0H2 soybeans; therefore, SYHT0H2 soybeans are no more 

susceptible to pests and diseases compared to conventional soybean cultivars.

E. Potential Impacts on Nontarget Organisms Beneficial to Agriculture

Event SYHT0H2 soybean is not engineered for insect pest resistance, thus there are no

‘target’ species, and thus no non-target species either. APHIS assessed whether exposure 

or consumption of Event SYHT0H2 soybeans would have an adverse effect on beneficial 

species or wildlife associated with soybeans. As discussed earlier, Event SYHT0H2 

soybean is similar in nutritional and compositional analysis to unmodified control 

reference soybean varieties except for the intended changes in herbicide resistance

associated with the production of AvHPPD-03 and PAT proteins in the plant.

The potential allergenicity and toxicity of introduced traits AvHPPD-03 and PAT

proteins (obtained from Avena sativa and Streptomyces viridochromogenes, respectively)

was assessed, according to the recommendations of the Codex Alimentarius Commission 

(Codex, 2003). The donor organism of the avhppd-03 gene (oats) is not toxic and 

consumed by humans and animals alike (Mitchell, 2001), and the pat gene has a 

permanent exemption from food tolerances for PAT in all crops in the United States 

(EPA, 2002). 

The bioinformatic analyses performed on the similarity of amino acid sequence of 

AvHPPD-03 demonstrated that it does not share structurally or immunologically relevant 

amino acid sequence similarities with known or putatively known toxins (Pp. 70-72, table 

VI-3), or known or putatively known allergens (Pp. 73-74). Additionally, digestive fate 

experiments with the AvHPPD-03 protein found that it was rapidly digested in simulated 

gastric fluid (SGF) by pepsin, a characteristic shared among many proteins with a history 

of safe consumption. The transiently stable protein fragments in the SGF assay were 

quickly degraded during a short exposure to simulated intestinal fluid (SIF). Rapid 

digestion of the full-length protein in SGF and SIF, together with rapid degradation of the 

transiently stable fragments from the SGF assay by SIF, indicates that it is highly 

unlikely that the AvHPPD-03 protein and its fragments will reach absorptive cells of the 

intestinal mucosa (p. 75). Finally, the AvHPPD-3 protein is present at very low 

concentrations in different SYHT0H2 tissues, which range between 5.8 to 59 μg/g of 

fresh tissue weight, in roots and V4 leaves, respectively (table VI-1, p. 66).

Syngenta and Bayer have submitted SYHT0H2 soybeans for regulatory approval by US 

Food and Drug Administration (FDA) as part of a voluntary consultation process, and 

appropriate regulatory agencies in another fourteen countries and regions. Any effects on 

non-target organisms that could potentially result from proposed changes in herbicide 

labels will be evaluated by the EPA. Based on the food and feed safety data, lack of 

toxicity and allergenicity of introduced gene products, APHIS concludes that feeding of 

Event SYHT0H2 soybean plant or seed by mammals and other nontarget organisms is 

unlikely to cause any adverse impact on their survival and reproduction.

11
F. Potential for Enhanced Weediness of SYHT0H2 Soybean

APHIS assessed whether SYHT0H2 soybeans 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 SYHT0H2 soybeans compared to the nontrangsenic progenitor 

or other appropriate counterpart evaluated under field (and/or lab) conditions 

characteristic for the regions of the United States where the SYHT0H2 soybeans is 

intended to be grown 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.

Soybean is a highly domesticated legume species, and cultivated varieties of soybean in 

the US do not exhibit weedy characteristics, nor is soybean listed as a weed in any major 

weed references (Muenscher, 1952; Crockett, 1977; Holm et al., 1979). Likewise, 

soybean is not identified as a noxious weed in the Federal Noxious Weed List (7 CFR 

part 360; http://plants.usda.gov/java/noxious?rptType=Federal). Moreover, soybean does 

not possess any of the attributes commonly associated with weeds, 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 (Baker, 1965). 

Phenotypic and agronomic characteristics of Event SYHT0H2 soybean were evaluated in 

a comparative manner to assess plant pest potential (OECD, 1993). These assessments 

included 16 plant growth and development characteristics: germination, dormancy and 

emergence, vegetative growth, reproductive growth, plant survival, seed dispersal, and 

ecological interactions (table X-1, Pp. 112-113). The following results were presented 

showing that Event SYHT0H2 soybean is phenotypically and agronomically similar to 

conventional Jack control and reference varieties:

• Seed dormancy is one of the potential traits effecting volunteerism and weediness. 

No significant differences were detected between Event SYHT0H2 soybean and the 

conventional control Jack (table X-3, p. 115). In all cases 96% of the seeds 

germinated under six different temperatures regimes in the tests. Although soybean 

seeds can potentially grow as volunteer plants in a subsequent crop rotation, volunteer 

plants would most likely be killed by frost in the soybean growing regions during 

autumn or winter of the year they were produced (OECD, 2000). Even if soybean 

volunteers get established, there are effective weed management strategies to control 

such volunteers (OECD, 2000; York, 2005).

• Another measure to demonstrate that a potentially enhanced reproductive advantage 

of Event SYHT0H2 over the conventional control Jack has not occurred, was an 

assessment of pollen size and viability (Pp. 115-116). Neither the diameter of pollen 

12
nor its viability were significantly different between Event SYHT0H2 over the 

conventional control Jack (table X-4, p. 116).

• The results of the 12 plant phenotypic characteristics measured in trials conducted in 

eight different locations in the US showed that the introduced trait did not 

unexpectedly alter the phenotypic or agronomic characteristics of Event SYHT0H2

soybean compared to conventional control Jack soybean. Early plant count, plant 

density, height, test weight, seed moisture, yield, seedling vigor, days to 50% 

flowering, flower color, lodging rating, pod shattering or days to maturity were not 

significantly different between Event SYHT0H2 over the conventional control Jack 

(tables X-6 and X-7, p. 119). These are indicative of no increased weediness of Event 

SYHT0H2 compared to the conventional control Jack soybean.

Results of these evaluations indicate that there is no fundamental difference between 

Event SYHT0H2 and the conventional control Jack for traits associated with weediness. 

Collectively, these findings support the conclusion that Event SYHT0H2 soybean is no 

more likely to be a weed compared to conventional control Jack soybean. 

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

It 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, 1991; Rieseberg, 1993; Soltis, 1993; Hegde, 2006),

and even in the existing floras, the occurrence of hybridization or introgression is 

reported to be widespread (Stace, 1987; Rieseberg, 1993; Peterson, 2002). It has been a 

common practice by plant breeders to artificially introgress traits from wild relatives into 

crop plants to develop new cultivars. However, gene flow from crops to wild relatives is 

also thought of as having a potential to enhance the weediness of wild relatives, as 

observed in rice, sorghum, sunflower and few other crops (see Table 1 in Ellstrand, 

1999).

Soybean is predominantly a self-pollinated species (OECD, 2000), yet a small amount of 

outcrossing does occur. Soybean typically exhibits a level of cross-pollination below one 

percent. Adjacent rows are measured to have between 0.03 and 3.62% outcrossing, but 

plants more than 4.5 meters apart cross at less than 0.02% (Caviness, 1966; Yoshimura, 

2006). While most sources agree that insects do not greatly increase outcrossing rate in 

domestic soybean (Erickson, 1984), there is some evidence that some insects (notably 

honeybees) can increase hybridization rates (Free, 1970; McGregor, 1976). Pollen is only 

viable for 2-4 hours (it desiccates quickly) with anthesis (pollen shed) normally occurring 

in the late morning (Caviness, 1966). Current cultivation practices to prevent out-crossing 

have been deemed sufficient to prevent unwanted gene flow. For soybean, the 

Association of Official Seed Certifying Agencies (AOSCA) mandates a zero isolation 

distance where “Fields of soybeans shall be separated from any other variety or 

uncertified seed of the same variety by a distance adequate to prevent mechanical 

mixture”. Based upon these factors, it is unlikely that Event SYHT0H2 soybean will 

13
naturally outcross or hybridize to a significant extent with other soybean varieties in 

agricultural settings.

In assessing the risk of gene introgression from Event SYHT0H2 soybean into its 

sexually compatible relatives, APHIS considers two primary issues: 1) the potential for 

gene flow and introgression and, 2) the potential impact of introgression. 

The genus Glycine is divided into two subgenera, Glycine and Soja. The subgenus Soja 

consists of three annual species: G. soja Sieb. and Zucc., the wild form of soybean; G. 

gracilis Skvortz., the weedy form of soybean; and G. max, the cultivated soybean. These 

species grow wild or semi-wild in Asia. Fertile hybrids between G. max and G. soja

(Nakayama, 2002; Mizuguti, 2010), and between G. max and G. gracilis (Karasawa, 

1952) occur. Glycine soja and G. gracilis grow naturally only in Asia, not in the United 

States (Lu, 2005). The subgenus Glycine consists of twelve wild perennial species. These 

species grow wild in Australia, South Pacific Islands and Asia (Newell, 1978), and do not 

exist naturally in the United States. Hybrids between perennial Glycine species are 

fertile. 

Glycine max is the only Glycine species located in the United States, thus there are no 

other plant species with which G. max can interbreed (OECD, 2000). Glycine max has 

never been found in the wild (Hymowitz, 1987) without human intervention. Therefore, 

it is highly unlikely that soybean plants in the United States will be found outside of an 

agricultural setting. It is also highly unlikely that gene flow and introgression will occur 

between Event SYHT0H2 soybean and soybean plants in a natural environment. USDA 

has therefore determined that any adverse consequences of gene flow from Event 

SYHT0H2 soybean to wild or weedy species in the United States are highly unlikely.

H. Potential Changes to Agriculture or Cultivation Practices

APHIS considered whether there are likely to be significant changes to agricultural 

practices associated with cultivation of SYHT0H2 soybeans, and if so, are they likely to 

significantly exacerbate plant diseases or pests, especially those for which APHIS has a 

control program. Relative to currently cultivated soybean varieties, the only agricultural 

or cultivation practices that are expected to change if Event SYHT0H2 is no longer 

subject to regulation, are those related to weed management: in particular, the use of 

herbicides. 

Some varieties of soybeans are tolerant to some of the approximately 23 herbicides 

registered for use in soybeans (Syngenta and Bayer, 2012, table XII-2, p. 131). Tolerance 

to certain kinds of herbicides, such glyphosate, has had an impact on higher adoption of 

conservation tillage in soybeans (Dill, 2008). Conservation tillage in soybeans can reduce 

the number of tillage operations, costs, and facilitate and improve weed control (USDANRCS, 2006). This tillage reduction decreases soil temperature that may be favorable for 

a higher incidence of certain pathogens. However, conservation tillage in soybeans does 

not significantly increase disease pressure in this crop (Sumner, 1981). Conservation 

tillage affects soil structure creating a habitat for an increased arthropod diversity. A 

14
higher number of arthropods in soybeans is not directly related with an increased 

arthropod pest pressure (Hammond, 1987; Stinner, 1990), therefore, planting SYHT0H2 

soybeans is not expected to necessitate different cultivation practices, nor induce higher 

disease or pest pressure in this variety, compared with conventional soybean varieties. As 

described above, field studies with Event SYHT0H2 and conventional control Jack

soybean demonstrated that neither the herbicide resistance traits nor the herbicide 

treatments appear to alter the response of these varieties to abiotic stress, diseases, or 

arthropod pests under natural levels of these stressors, nor were pest arthropods more 

abundant around Event SYHT0H2 plots.

In conclusion, as discussed throughout this document, SYHT0H2 soybeans is similar to 

conventional soybeans in its agronomic, phenotypic, environmental, and compositional 

characteristics and has levels of tolerance to insects and diseases comparable to 

conventional soybean varieties. Therefore, no significant adverse impacts on current 

agricultural or cultivation practices are expected following the introduction of Event 

SYHT0H2.

I. Potential Impacts from Transfer of Genetic Information to 

Organism with which SYHT0H2 Cannot Interbreed

The horizontal gene transfer (HGT) between unrelated organisms is one of the most

intensively studied fields since 1940, and the issue gained extra attention with the release 

of transgenic plants into the environment (Dröge et al., 1998). HGT has been implicated 

as a major contributor to the spread of antibiotic resistance amongst pathogenic bacteria 

and the emergence of increased virulence in bacteria, eukaryotes, and viruses; and has 

contributed to major transitions in evolution. Gene exchange has been documented for 

nearly all types of genes and between unrelated organisms (Gogarten, 2002). For 

example, (Yoshida, 2010) through a comparative genomics analysis, implicated HGT for 

the presence of a similar genetic sequence between the parasitic plant purple witchweed 

(Striga hermonthica), which infests cereal fields (monocots), and sorghum (Sorghum 

bicolor).

APHIS examined the potential for the new genetic material inserted into Event 

SYHT0H2 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. The Event SYHT0H2 soybean contains one coding 

sequence from oats, the modified avhppd-03 gene and two from Streptomyces 

viridochromogenes, two pat genes, and two non-coding regulatory sequences from the 

bacteria, Agrobacterium tumefaciens. Horizontal gene transfer and expression of DNA 

from a plant species to other bacterial species is unlikely to occur based on the following 

observations. 

Although there are many opportunities for plants to directly interact with fungi, bacteria, 

and parasitic plants (e.g. as commensals, symbionts, parasites, pathogens, decomposers, 

or in the guts of herbivores), so far there are no reports of significant horizontal gene 

transfer between sexually incompatible or evolutionarily distant organisms (as reviewed 

15
in Keese, 2008). Accumulated evidence show that there are universal gene-transfer 

barriers, regardless of whether transfer occurs among closely or distantly related 

organisms (Kaneko et al., 2000; Koonin et al., 2001; Wood et al., 2001; Kaneko, 2002; 

Brown, 2003; Sorek, 2007). Many genomes (or parts thereof) from bacteria that are 

closely associated with plants have been sequenced including Agrobacterium and 

Rhizobium (Kaneko et al., 2000; Wood et al., 2001; Kaneko, 2002). There is no evidence 

that these organisms contain genes derived from plants. 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 (Koonin et al., 2001; 

Brown, 2003). This is similar to the case in a recent report about of HGT between 

sorghum and purple witchweed. According to the authors (Yoshida, 2010), the 

incorporation of a specific genetic sequence occurred between sorghum and purple 

witchweed before speciation of purple witchweed (S. hermonthica) and related cowpea 

witchweed (S. gesnerioides), a parasitic plant of dicots, from their common ancestor. In 

other words, HGT is an extremely rare event, and a majority of those rare events occur 

over millions of years. 

Transgene DNA promoters and coding sequences are optimized for plant expression, not 

prokaryotic bacterial expression. Thus even if horizontal gene transfer did occur, 

proteins corresponding to the transgenes are not likely to be produced. FDA has 

evaluated horizontal gene transfer from the use of antibiotic resistance marker genes, and 

concluded that the likelihood of transfer of antibiotic resistance genes from plant 

genomes to microorganisms in the gastrointestinal tract of humans or animals, or in the 

environment, is remote (FDA, 1998). Therefore APHIS concludes that horizontal gene 

transfer is unlikely to occur from Event SYHT0H2 soybean to microorganisms and thus 

no significant plant pest risk is expected from horizontal gene transfer.

J. Conclusion

APHIS has prepared this plant pest risk assessment in order to determine if Syngenta and 

Bayer Event SYHT0H2 soybean is unlikely to pose a plant pest risk. Due to the lack of 

plant pest risk from the inserted genetic material, the lack of weediness characteristics of

Event SYHT0H2 soybean, the lack of atypical responses to disease or plant pests in the 

field, the lack of deleterious effects on non-targets or beneficial organisms in the agroecosystem, and the lack of horizontal gene transfer, APHIS concludes that Event 

SYHT0H2 soybean is unlikely to pose a plant pest risk.

APHIS has reviewed the information submitted in the petition, supporting documents, 

and other relevant information to assess the plant pest risk of SYHT0H2 soybean

compared to the unmodified variety from which it was derived. APHIS concludes that 

SYHT0H2 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 because the inserted genetic material which was derived from 

plant pests does not result in the production of infectious agents or disease symptoms 

in plants.

16
• No increase in plant pest risk was identified in SYHT0H2 soybean from the 

expression of the inserted genetic material of new proteins, because SYHT0H2 

soybean can be considered compositionally and nutritionally equivalent to those 

derived from convention soybeans.

• Disease and pest incidence and/or damage were not observed to be significantly 

increased or atypical in SYHT0H2 soybean compared to the nontransgenic 

counterpart or other comparators in field trials conducted in growing regions 

representative of where SYHT0H2 soybean is expected to be grown and greenhouse 

and laboratory studies. Observed agronomic traits also did not reveal any significant 

differences that would indirectly indicate that the SYHT0H2 soybean is more 

susceptible to pests or diseases. 

• Exposure to and/or consumption of SYHT0H2 soybean are unlikely to have any 

adverse impacts on organisms beneficial to agriculture based on the analysis of the 

potential toxicity based on lack of amino acid sequence similarities with known 

toxins and mice acute toxicity studies and the donor organisms are widely distributed 

in nature. 

• SYHT0H2 soybean is no more likely to become a weed or be weedier than 

conventional varieties of the crop based on its observed agronomic characteristics, 

weediness potential of the crop and current management practices available to control 

SYHT0H2 soybean as a weed. 

• SYHT0H2 soybean is not expected to increase the weed risk potential of other 

species with which it can interbreed in the United States or its territories.

• Significant changes to agricultural or cultivation practices (e.g. pesticide applications, 

tillage, irrigation, harvesting, etc.) from adoption of SYHT0H2 soybean were not 

identified and not likely to increase plant diseases or pests or compromise their 

management. 

• Horizontal gene transfer of the new genetic material inserted into SYHT0H2 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

Baker, H. B. (1965). "Characteristics and modes of origin of weeds." The Genetics of 

Colonizing Species. p 147-69. 

Bollman, J. D., C. M. Boerboom, R. L. Becker, and V. A. Fritz. (2008). "Efficacy and 

tolerance to HPPD-inhibiting herbicides in sweet corn." Weed Technology 22 p 666-74. 

Brown, J.R. (2003). "Ancient horizontal gene transfer." Genetics 4 p 121-32. 

Caviness, C. E. (1966). "Spacing studies with Lee soybeans." Fayetteville, Ark., 

University of Arkansas. 

Codex. (2003). "Codex principles and guidelines on food derived from biotechnology." 

Codex Alimentarius Commission. 

17
Crockett, L. (1977). "Wildly successful plants: North American weeds." University of 

Hawaii. 

Depicker, A., S. Stachel, et al. (1982). "Nopaline synthase: transcript mapping and DNA 

sequence." Journal of Molecular and Applied Genetics 1 p 561-73. 

Dill, G. M., C. A. CaJacob and S. R. Padgette. (2007). "Glyphosate-resistant crops: 

adoption, use and future considerations." Pest Management Science 64 p 326-31. 

Dill, G. M., C. A. CaJacob, and S. R. Padgette. (2008). "Glyphosate-resistant crops: 

adoption, use and future considerations." Pest Management Science 64 p 326-31. 

Dröge, M., A. Puhler, and W. Selbitschka. (1998). "Horizontal gene transfer as a 

biosafety issue: A natural phenomenon of public concern." Journal of Biotechnology 64 p 

75-90. 

Ellstrand, N. C., H. C. Prentice, et al. (1999). "Gene flow and introgression from

domesticated plants into their wild relatives." Annual Review of Ecology and 

Systematics 30 p 539-63. 

EPA, US. (2002). "Biopesticides Registration Action Document: Bacillus thuringiensis 

Cry2Ab2 protein and its genetic material necessary for its production in cotton." 

Erickson, E. H. (1984). "Soybean genetics newsletter: Soybean floral ecology and insect 

pollination." USDA-ARS 11 p 152-62. 

FDA. (1998). "Use of Antibiotic Resistance Marker Genes in Transgenic Plants." 

http://www.fda.gov/food/guidancecomplianceregulatoryinformation/guidancedocuments/

biotechnology/ucm096135.htm >.

Free, J.B. (1970). "Carthamus tinctorius L." Insect Pollination of Crops. London: 

Academic Press. p 331-32. 

Gallie, D. R. . (2002). "The 5'-leader of tobacco mosaic virus promotes translation 

through enhanced recruitment of elF4F." Nucleid Acids Research 15 p 3401-11. 

Gallie, D. R., D. E.Sleat, J. W.Watts, P. C.Tumer, and T. M. A. Wilson. (1987). "The 5'-

leader sequence of tobacco mosaic virus RNA enhances the expression of foreign gene 

transcripts in vitro and in vivo." Nucleid Acids Research 15 p 3257-73. 

Gianessi, L., and N. Reigner. (2006). "Pesticide use in U.S. crop production: 2002 with 

comparison to 1992 & 1997." Crop Protection Research Institute. 

Gogarten, J. P., W. F. Doolittle, et al. (2002). "Prokaryotic evolution in light of gene 

transfer." Molecular Biology and Evolution 19 p 2226-38. 

Grant, V. (1991). Plant Speciation. New York: Columbia University Press. 

18
Hammond, R. B., and B. R. Stinner. (1987). "Soybean foliage insects in conservation 

tillage systems: effects of tillage, previous cropping history, and soil insecticide 

application." Environmental Entomology 16 p 524-31. 

Hegde, S. G., J. D. Nason, et al. (2006). "The evolution of California's wild radish has 

resulted in the extinction of its progenitors." Evolution 60 p 1187-97. 

Holm, L., J.V. Pancho, J.P. Herbarger, and D.L. Plucknett. (1979). A geographical atlas 

of world weeds. NY: John Wiley and Sons. 

Hymowitz, T., and R. J. Singh. (1987). "Taxonomy and speciation." Soybeans: 

Improvement, Production and Uses. Madison, WI: American Society of Agronomy. p 23-

48. 

Inoue, M. H., R. S. J. Oliveira, et al. (2009). "Bioavailability of diuron, imazapic and 

isoxaflutote in soils of contrasting textures." Journal of Environmental Science and 

Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes. 44 p 757-63. 

Johnson, B. C., B. G. Young, and J. L. Matthews. (2002). "Effect of Postemergence 

Application Rate and Timing of Mesotrione on Corn (Zea mays) Response and Weed 

Control." Weed Technology 16 p 414-20. 

Kaneko, T., Y. Nakamura, et al. (2002). "Complete genome structure of the nitrogenfixing symbiotic bacterium Bradyrhizobium japonicum USDA 110." DNA Research 9 p 

189-97. 

Kaneko, Takakazu, Yasukazu Nakamura, Shusei Sato, Erika Asamizu, Tomohiko Kato, 

Shigemi Sasamoto, Akiko Watanabe, Kumi Idesawa, Atsuko Ishikawa, Kumiko 

Kawashima, Takaharu Kimura, Yoshie Kishida, Chiaki Kiyokawa, Mitsuyo Kohara, 

Midori Matsumoto, Ai Matsuno, Yoko Mochizuki, Shinobu Nakayama, Naomi Nakazaki, 

Sayaka Shimpo, Masako Sugimoto, Chie Takeuchi, Manabu Yamada, and Satoshi 

Tabata. (2000). "Complete genome structure of the nitrogen-fixing symbiotic bacterium 

Mesorhizobium loti." DNA Research 7 (6): p 331-38. 

Karasawa, K. (1952). "Crossing experiments with Glycine soja and G. gracilis." Genetica 

26 p 357-58. 

Keese, P. (2008). "Review Article: Risks from GMOs due to horizontal gene transfer." 

Environmental Biosafety Research 7 (123-149). 

Koonin, E.V., K.S. Makarova, and L. Aravind. (2001). "Horizontal gene transfer in 

prokaryotes: Quantification and classification." Annual Review of Microbiology 55 p 

709-42. 

Krishnan, H. B., J. O. Bennett, W.-S. Kim, A. H. Krishnan, and T. P. Mawhinney. 

(2005). "Nitrogen lowers the sulfur amino acid content of soybean (Glycine max [L.] 

Merr.) by regulating the accumulation of Bowman-Birk protease inhibitor." Journal of 

Agricultural and Food Chemistry 53 p 6347-54. 

19
Lu, B.-R. (2005). "Multidirectional gene flow among wild, weedy, and cultivated 

soybeans." Crop Ferailty and Volunteerism. Boca Raton, FL: CRC Press. 

Maiti, I. B., S. Gowda, J. Kiernan, S. K. Ghosh, and R. J. Shepherd. (1997). 

"Promoter/leader deletion analysis and plant expression vectors with the figwort mosaic 

virus (FMV) full length transcript (FLt) promoter containing single or double enhancer 

domains." Transgenic Research 6 p 143-56. 

Matringe, M., A. Sailland, B. Pelissier, A. Rolland, and O. Zink. (2005). "pHydroxyphenylpyruvate dioxygenase inhibitor-resistant plants." Pest Management 

Science 61 p 269-76. 

McGregor, S.E. (1976). "Insect pollination of cultivated crop plants." Agricultural 

Handbook No 496. Washington, DC: USDA-ARS. 

Mitchell, G., D. W. Bartlett, E. M. Torquil, T. R. Hawkes, D. C. Holt, J. K. Townson, and 

R. A. Wichert. (2001). "Mesotrione: a new selective herbicide for use in maize." Pest 

Management Science 57 p 120-28. 

Mizuguti, A., K. Ohigashi, et al. (2010). "Hybridization between GM soybean (Glycine 

max (L.) Merr.) and wild soybean (Glycine soja Sieb. et Zucc.) under field conditions in 

Japan." Environmental Biosafety Research 9 p 13-23. 

Muenscher, W.C. (1952). Weeds, 2nd Edition. United Kingdom: MacMillion Press Ltd. 

Müller, B. P., A. Zumdick, I. Schuphan, and B. Schmidt. (2001). "Metabolism of the 

herbicide glufosinateammonium in plant cell cultures of transgenic (rhizomania-resistant) 

and non-transgenic sugarbeet (Beta vulgaris), carrot (Daucus carota), purple foxglove 

(Digitalis purpurea) and thorn apple (Datura stramonium)." Pest Management Science 57 

p 46-56. 

Nakayama, Y. and H. Yamaguchi. (2002). "Natural hybridization in wild soybean 

(Glycine max ssp. soja) by pollen flow from cultivated soybean (Glycine max ssp. max) 

in a designed population." Weed Biology and Management 2 p 25-30. 

NCBI-Protein. (2012). "National Center for Biotechnology Information." 

http://www.ncbi.nlm.nih.gov/protein >.

Newell, C. A. and T. Hymowitz. (1978). "A reappraisal of the subgenus Glycine." 

American Journal of Botany 65 p 168-79. 

OECD. (1993). "Safety considerations for biotechnology: Scale-up of crop plants." 

OECD. 

OECD. (2000). "Consensus document on the biology of Glycine max (L.) Merr. 

(Soybean)." OECD. 

20
OECD. (2001). "Consensus document on compositional considerations for new varieties 

of soybean: key food and feed nutrients and anti-nutrients." 

Ow, D. W., J. D. Jacobs, and S. H. Howell. (1987). "Functional regions of the cauliflower 

mosaic virus 35S RNA promoter determined by use of the firefly luciferase gene as a 

reporter of promoter activity." Proceedings of the National Academies of Science 84 p 

4870-74. 

Peterson, C. D., D. A. Pearman, et al. (2002). New Atlas of the British flora. London, 

England.: Oxford University Press. 

Powles, S. B. (2008). "Evolved glyphosate-resistant weeds around the world: lessons to 

be learnt." Pest Management Science 64 p 360-65. 

Reddy, N. K. (2001). "Glyphosate-resistant soybean as a weed management tool: 

Opportunities and challenges." Weed Biology and Management 1 p 193–202. 

Rieseberg, L. H. and J. F. Wendel. (1993). "Introgression and its consequences in plants." 

Hybrid Zones and the Evolutionary Process. Oxford, U.K.: Oxford University Press. p 

70-109. 

Shaner, D. L. (2003). "Herbicide safety relative to common targets in plants and 

mammals." Pest Management Science 60 p 17-24. 

Soltis, D. E. and P. S. Soltis. (1993). "Molecular data and the dynamic nature of 

polyploidy." Critical Reviews in Plant Sciences 12 p 243-73. 

Sorek, R., Y. Zhu, et al. (2007). "Genome-wide experimental determination of barriers to 

horizontal gene transfer." Science 318 p 1449-52. 

Specht, J. E., D. J. Hume, and S. V. Kumudini. (1999). "Soybean yield potential—A 

genetic and physiological perspective." Crop Science 39 p 1560-70. 

Stace, C. A. (1987). "Hybridization and the plant species." Differentiation Patterns in 

Higher Plants. New York, NY: Academic Press. p 115-27. 

Stavolone, L., A. Ragozzino, and T. Hohn. (2003a). "Characterization of Cestrum yellow 

leaf curling virus: a new member of the family Caulimoviridae." Journal of General 

Virology 84 p 3459–64. 

Stavolone, L., M. Kononova, S. Pauli, A. Ragozzino, P. de Haan, S. Milligan, K. Lawton, 

and Thomas Hohn. (2003b). "Cestrum yellow leaf curling virus (CmYLCV) promoter: a 

new strong constitutive promoter for heterologous gene expression in a wide variety of 

crops." Plant Molecular Biology 53 p 703-13. 

Stinner, B. R., and G. J. House. (1990). "Arthropods and other invertebrates in 

conservation-tillage agriculture." Annual Review of Entomology 35 p 299-318. 

21
Sumner, D. R., B. Doupnik, Jr., and M. G. Boosalis. (1981). "Effects of reduced tillage 

and multiple cropping on plant diseases." Annual Review of Phytopathology 19 p 167-

87. 

Syngenta and Bayer. (2012). "Petition for determination of nonregulated status for 

herbicide-tolerant Event SYHT0H2 soybean. OECD unique identifier: SYN-ØØØH2-5." 

Syngenta Seeds, Inc., and Bayer CropSciences AG. 

Tsegaye, Y., D. K. Shintani, and D. DellaPenna. (2002). "Overexpression of the enzyme 

p-hydroxyphenolpyruvate dioxygenase in Arabidopsis and its relation to tocopherol 

biosynthesis." Plant Physiology and Biochemistry 40 p 913-20. 

Tsukamoto, C., S. Shimada, K. Igita, S. Kudou, M. Kokubun, K. Okubo, and K. 

Kitamurat. (1995). "Factors affecting isoflavone content in soybean seeds: changes in 

isoflavones, saponins, and composition of fatty acids at different temperatures during 

seed development." Journal of Agricultural and Food Chemistry 43 p 1184-92. 

Ujiie, A., T. Yamada, et al. (2005). "Identification of soybean varieties with high αtocopherol content." Breeding Science 55 p 123-25. 

USDA-ERS. (2011). "US Department of Agriculture - Economic Research Service." 

http://www.ers.usda.gov/ >.

USDA-NASS. (2011). "U.S. Department of Agriculture - National Agricultural Statistics 

Service." http://www.nass.usda.gov/ >.

USDA-NRCS. (2006). "The economics of on-site conservation tillage." West National 

Technology Support Center Technical Note: Econ 101.01. Last Accessed: Nov. 2012 < 

http://www.google.com/#hl=en&safe=active&tbo=d&q=minimum+tillage+soybean+acre

age+site:gov&sa=X&ei=2jK2UJXiFPPK0AHZk4HIAw&ved=0CCoQ7xYoAA&bav=on

.2,or.r_gc.r_pw.r_qf.&fp=2285b4be99251865&bpcl=38897761&biw=772&bih=411 >.

Wohllehen, W., W. Arnold, I. Broer, D. Hillemaan, E. Strauch, and A. Ptihler. (1988). 

"Nucleotide sequence of the phosphinnthricin IV-acetyltransferase gene from 

Streptomyces viridoehromogenes Tii494 and its expression in Nicotiana tabacum." Gene 

70 p 25-37. 

Wolf, R. B., J. F. Cavins, R. Kleiman, and L. T. Black. (1982). "Effect of temperature on 

soybean seed constituents: oil, protein, moisture, fatty acids, amino acids and sugars." 

Journal of the American Oil Chemists' Society 59 p 230-32. 

Wood, D.W., J.C. Setubal, R. Kaul, D.E. Monks, J.P. Kitajima, V.K. Okura, Y. Zhou, 

L. Chen, G.E. Wood, N F. Almeida Jr., L. Woo, Y. Chen, I.T. Paulsen, J.A. Eisen, 

P.D. Karp, D. Bovee Sr., P. Chapman, J. Clendenning, G. Deatherage, W. Gillet, C. 

Grant, T. Kutyavin, R. Levy, M.-J. Li, E. McClelland, A. Palmieri, C. Raymond, G. 

Rouse, C. Saenphimmachak, Z. Wu, P. Romero, D. Gordon, S. Zhang, H. Yoo, Y. 

Tao, P. Biddle, M. Jung, W. Krespan, M. Perry, B. Gordon-Kamm, L. Liao, S. Kim, 

C. Hendrick, Z.-Y. Zhao, M. Dolan, F. Chumley, S.V. Tingey, J.-F. Tomb, M.P. 

22
Gordon, M.V. Olson, and E.W. Nester. (2001). "The genome of the natural genetic 

engineer Agrobacterium tumefaciens C58." Science 294 p 2317-23. 

Wu, C.-S., J.-L. Huang, Y.-S. Sun, and D.-Y. Yang. (2002). "Mode of action of 4-

hydroxyphenylpyruvate dioxygenase inhibition by triketone-type inhibitors." Journal of 

Medical Chemistry 45 p 2222-28. 

York, A. C., J. B. Beam, et al. (2005). "Control of volunteer glyphosate-resistant soybean 

in cotton." Journal of Cotton Science 9 p 102-09. 

Yoshida, S., S. Maruyama, et al. (2010). "Horizontal gene transfer by the parasitic plant 

Striga hermonthica." Science 328 p 1128. 

Yoshimura, Y., K. Matsuo, et al. (2006). "Gene flow from GM Glyphosate-tolerant to 

conventional soybeans under field conditions in Japan." Environmental Biosafety 

Research 5 p 169-73.

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