Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)
Authors: Andreassen Åshild , Brandtzæg Per , Aasmo Finne Merethe , Lorentz Holck Askild , Jevnaker Anne-Marthe , Junttila Olavi , Sjursen Konestabo Heidi , Meadow Richard , Mikalsen Arne , M. Nielsen Kåre , Sanden Monica , Erling Sipinen Ville , Opsahl-Sorteberg Hilde-Gunn , Vikse Rose 
Published: January 2020

In preparation for a legal implementation of EU-regulation 1829/2003, the Norwegian Environment Agency (former Norwegian Directorate for Nature Management) has requested the Norwegian Food Safety Authority (NFSA) to give final opinions on all genetically modified organisms (GMOs) and products containing or consisting of GMOs that are authorized in the European Union under Directive 2001/18/EC or Regulation 1829/2003/EC within the Authority’s sectoral responsibility.  The Norwegian Food Safety Authority has therefore, by letter dated 13 February 2013 (ref. 2012/150202), requested the Norwegian Scientific Committee for Food Safety (VKM) to carry out scientific risk assessments of 39 GMOs and products containing or consisting of GMOs that are authorized in the European Union. The request covers scope(s) relevant to the Gene Technology Act. The request does not cover GMOs that VKM already has conducted its final risk assessments on. However, the Agency requests VKM to consider whether updates or other changes to earlier submitted assessments are necessary.

 The assignment includes a scientific risk assessment of oilseed rape T45 from Bayer Crop Science (Unique Identfier ACS-BNØØ8-2) for food and feed uses, import and processing. 

 Food additives produced from T45 oilseed rape were notified in the EU as existing food additives within the meaning of Article 8 (1) (b) of Regulation 1829/2003, authorized under Directive 89/10/EEC (Community Register 2005). Feed materials produced from T45 were also notified as existing feed products containing, consisting of or produced from T45 according to Articles 8 and 20 of Regulation (EC) No 1829/2003 in 2003.  

 A notification for placing on the market of T45 according to the Directive 2001/18/EC was submitted in March 2004 (C/GB/04/M5/4), covering import and processing of T45 into food and feed. The application was further transferred into Regulation (EC) No 1829/2003 in November 2005 (EFSA/GMO/UK/2005/25). An application for renewal of authorisation for continued marketing of food additives and feed materials produced from T45 oilseed rape was submitted under Regulation (EC) No 1829/2003 in 2007 (EFSA/GMO/RX/T45). The EFSA GMO Panel performed one single comprehensive risk assessment for all intended uses of genetically modified oilseed rape T45 and issued a comprehensive scientific opinion for both applications submitted under Regulation (EC) No 1829/2003. The scientific opinion was published in January 30 2008 (EFSA 2008), and food and feed products containing or produced from oilseed rape T45 was approved by Commission Decision 26 March 2009 (Commission Decision 2009/184/EC). 

 The oilseed rape T45 is however currently being phased out (EU-COM 2009). The commercialisation of T45 oilseed rape seeds in third countries was stopped after the 2005 planting season and stocks of all oilseed rape T45 lines have been recalled from distribution and destroyed. The applicant commits not to commercialize the event in the future and the import will therefore be restricted to adventitious levels in oilseed rape commodity. Thus the incidence of oilseed rape T45 in the EU is expected to be limited.

 Oilseed rape T45 has previously been risk assessed by the VKM Panel on Genetically Modified Organisms (GMO), commissioned by the NFSA related to the EFSAs public hearing in 2007 (VKM 2007a).

 The risk assessment of the oilseed rape T45 is based on information provided by the notifier in the application EFSA/GMO/UK/2005/25 and EFSA/GMO/RX/T45, and scientific comments from EFSA and other member states made available on the EFSA website GMO Extranet. The risk assessment also considered other peer-reviewed scientific literature as relevant.  

 The VKM GMO Panel has evaluated T45 with reference to its intended uses in the European Economic Area (EEA) and according to the principles described in the Norwegian Food Act, the Norwegian Gene Technology Act and regulations relating to impact assessment pursuant to the Gene Technology Act, Directive 2001/18/EC on the deliberate release into the environment of genetically modified organisms, and Regulation (EC) No 1829/2003 on genetically modified food and feed. The Norwegian Scientific Committee for Food Safety has also decided to take account of the appropriate principles described in the EFSA guidelines for the risk assessment of GM plants and derived food and feed (EFSA 2006, 2011a), the environmental risk assessment of GM plants (EFSA 2010) and the selection of comparators for the risk assessment of GM plants (EFSA 2011b). 

The scientific risk assessment of oilseed rape T45 include molecular characterisation of the inserted DNA and expression of novel proteins, comparative assessment of agronomic and phenotypic characteristics, comparative compositional analysis, food/feed safety assessments and environmental assessment.

 It is emphasized that the VKM mandate does not include assessments of contribution to sustainable development, societal utility and ethical considerations, according to the Norwegian Gene Technology Act and Regulations relating to impact assessment pursuant to the Gene Technology Act. These considerations are therefore not part of the risk assessment provided by the VKM Panel on Genetically Modified Organisms. 

 The glufosinate ammonium-tolerant oilseed rape transformation event T45 was developed by Agrobacterium-mediated transformation of protoplast from the conventional oilseed rape cultivar “AC Excel”. T45 contains a synthetic version of the native pat gene isolated from the bacteria Streptomyces viridochromogenes, strain Tü 494. The inserted gene encodes the enzyme phosphinothricin acetyltransferase (PAT), which confers tolerance to the herbical active substance glufosinate ammonium. The PAT enzyme detoxifies glufosinate-ammonium by acetylation of the L-isomer into N-acetyl-L-glufosinate ammonium (NAG) which does not inhibit glutamine synthetase and, therefore, confers tolerance to the herbicide.

 Glufosinate ammonium-tolerant oilseed rape transformation event T45 has been conventionally bred into an array of spring-type oilseed rape varieties.

 Molecular characterization:

 The molecular characterisation data established that only one copy of the gene cassette is integrated in the oilseed rape genomic DNA. Appropriate analysis of the integration site including sequence determination of the inserted DNA and flanking regions, and bioinformatics analysis have been performed. Bioinformatics analyses of junction regions demonstrated the absence of any potential new ORFs coding for known toxins or allergens. The genetic stability of transformation event T45 was demonstrated at the genomic level over multiple generations by Southern analysis. Segregation analysis shows that event T45 is inherited as dominant, single locus trait. Phenotypic stability has been confirmed by stable tolerance to the herbicide for T45 lines and varieties derived from the event grown in Canada since 1993. 

 Oilseed rape transformation event T45 and the physical, chemical and functional characteristics of the proteins have previously been evaluated by The VKM Panel on Genetically Modified Organisms, and considered satisfactory (VKM 2007a).

 Comparative assessment:

 For compositional analysis seeds were harvested from three field trials performed in Canada (1995, 2000 and 2004). These field trials were conducted using agronomic practices and field conditions typical of commercial oilseed rape cultivation and provided environmental situations representative of the geographical regions oilseed rape will be grown. The analytical data were statistically evaluated by analysis of difference between T45 oilseed rape and its non-transgenic parent variety AC Excel or to other comparators, derived from AC Excel. 

 Several of the components listed in OECDs consensus document (OECD 2011) concerning oilseed rape have not been analyzed in seed, oil or meal such as vitamin K and the antinutrient sinapine. Compositional analysis was carried out with respect to proximates, fibers, amino acids, vitamin E (alfa-, beta, gamma- and delta tocopherol, total tocopherol, minerals (phosphorus, iron, calcium, sodium, copper, magnesium, manganese, potassium and zinc), fatty acids, phytic acid and glucosinolates (alken glucosin, MSGL glucosin and indole glucosinolates). The PAT protein was detected by ELISA only in trace amounts in toasted meal from T45 oilseed rape and not detected in blended, degummed, refined, bleached and deodorized oil. The compositional analysis showed statistical differences for some of the analyzed components. However, this is not considered biological relevant because it is within the reference range from the literature.

Based on results from comparative analyses of data from field trials located at representative sites and environments in Canada in 1995-1997, it is concluded that oilseed rape T45 is agronomically and phenotypically equivalent to the conventional counterpart and commercial available reference varieties, with the exception of maturity and the herbicide tolerance conferred by the PAT protein.  The field evaluations support a conclusion of no phenotypic changes indicative of increased plant weed/pest potential of event T45 compared to conventional oilseed rape. Furthermore, the results demonstrate that in-crop applications of glufosinate herbicide do not alter the phenotypic and agronomic characteristics of event T45 compared to conventional oilseed rape.

 Food and feed safety assessment:

 The total amino acid sequence of the PAT protein was compared to that of known toxins and allergens listed in public databases. Based on these results, no evidence for any similarity to known toxic or allergenic proteins was found. An animal feeding study was performed in broiler chickens. This study showed no indications that neither the event T45 treated with glufosinate ammonium nor untreated, has adverse effects on feeding, growth or general health. To test the case of an acute exposure of the PAT protein to the circulatory system, an acute intravenous study was conducted in mice with highly purified (>95%) PAT protein, encoded by the pat gene (produced in E. coli). PAT protein, aprotinin (negative control) or melittin (positive control) were administered at dose levels of 1 and 10 mg/kg body weight. After 15 days the animals treated with the PAT protein and aprotinin at 10 mg/kg had no visible signs of systemic toxicity, in contrast to melittin which induced 100% mortality within 5 minutes at the same dose. Macroscopic examination of internal organs showed no signs of acute toxicity following treatment with PAT protein.

 Environmental risk:

 According to the applicant, the event T45 has been phased out, and stocks of all oilseed rape T45 lines have been recalled from distribution and destroyed since 2005. However, since future cultivation and import of oilseed rape T45 into the EU/EEA area cannot be entirely ruled out, the environmental risk assessment consider exposure of viable seeds of T45 through accidental spillage into the environment during transportation, storage, handling, processing and use of derived products.

 Oilseed rape is mainly a self-pollinating species, but has entomophilous flowers capable of both self- and cross-pollinating. Normally the level of outcrossing is about 30%, but outcrossing frequencies up to 55% are reported. 

 Several plant species related to oilseed rape that are either cultivated, occurs as weeds of cultivated and disturbed lands, or grow outside cultivation areas to which gene introgression from oilseed rape could be of concern. These are found both in the Brassica species complex and in related genera. A series of controlled crosses between oilseed rape and related taxa have been reported in the scientific literature. Because of a mismatch in the chromosome numbers most hybrids have a severely reduced fertility. Exceptions are hybrids obtained from crosses between oilseed rape and wild turnip (B. rapa ssp. campestris) and to a lesser extent, mustard greens (B. juncea), where spontaneously hybridising and transgene introgression under field conditions have been confirmed. Wild turnip is native to Norway and a common weed in arable lowlands.

 There is no evidence that the herbicide tolerant trait results in enhanced fitness, persistence or invasiveness of oilseed rape T45, or hybridizing wild relatives, compared to conventional oilseed rape varieties, unless the plants are exposed to herbicides with the active substance glufosinate ammonium. Glufosinate ammonium-containing herbicides have been withdrawn from the Norwegian market since 2008, and the substance will be phased out in the EU in 2017 for reasons of reproductive toxicity.

 Accidental spillage and loss of viable seeds of T45 during transport, storage, handling in the environment and processing into derived products is, however, likely to take place over time and the establishment of small populations of oilseed rape T45 cannot be excluded. Feral oilseed rape T45 arising from spilled seed could theoretically pollinate conventional crop plants if the escaped populations are immediately adjacent to field crops and shed seeds from cross-pollinated crop plants could emerge as GM volunteers in subsequent crops. 

 However, both the occurrence of feral oilseed rape resulting from seed import spills and the introgression of genetic material from feral oilseed rape populations to wild populations are likely to be low in an import scenario. Apart from the glufosinate tolerance trait, the resulting progeny will not possess a higher fitness and will not be different from progeny arising from cross-fertilisation with conventional oilseed rape varieties. The VKM GMO Panel The occurrence of feral oilseed rape resulting from seed import spills and the introgression of genetic material from feral oilseed rape populations to wild populations are likely to be low in an import scenario in Norway. 

 Overall conclusion:

 The VKM GMO Panel concludes that T45 oilseed rape, based on current knowledge, is comparable to conventional oilseed rape varieties concerning health risks with the intended usage. The GMO Panel likewise concludes that T45 is unlikely to have any adverse effect on the environment and agriculture in Norway in the context of its intended usage.