Scientific Opinion on application (EFSA-GMO-UK-2008-60) for placing on the market of genetically modified herbicide tolerant maize GA21 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003 from Syngenta Seeds

This Scientific Opinion reports on an evaluation of a risk assessment for placing on the market of genetically modified maize GA21 for food and feed uses, import, processing and cultivation. Maize GA21 was developed through particle bombardment and contains a single insertion locus consisting of modified maize epsps (mepsps) gene, conferring tolerance to glyphosate-based herbicides. Bioinformatic analyses and levels of the mEPSPS protein were considered sufficient. The comparative analysis of compositional, agronomic and phenotypic characteristics indicated that maize GA21 is not different from the conventional counterpart and its composition fell within the range observed among non-GM maize varieties, except for the presence of the mEPSPS protein in maize GA21. The safety assessment of maize GA21 identified no concerns regarding potential toxicity and allergenicity. A feeding study with broiler chickens confirmed that maize GA21 is as nutritious as its conventional counterpart. The EFSA GMO Panel considers that maize GA21 is unlikely to raise additional environmental safety concerns compared to conventional maize, but that its cultivation management could result in environmental harm under certain conditions. The EFSA GMO Panel therefore recommends managing the use of glyphosate on maize GA21 within diversified cropping regimes that have similar or reduced environmental impacts compared with conventional maize cultivation. The EFSA GMO Panel recommends the deployment of case-specific monitoring to address (1) changes in botanical diversity within fields due to novel herbicide regimes, and (2) resistance evolution to glyphosate in weeds due to novel herbicide regimes. The EFSA GMO Panel agrees with the general surveillance plan of the applicant, but requests that its proposals to strengthen general surveillance are implemented. The EFSA GMO Panel concludes that the information available for maize GA21 addresses the scientific comments raised by Member States and that maize GA21, as described in this application, is as safe as its conventional counterpart and commercial maize varieties with respect to potential adverse effects on human and animal health. If subjected to appropriate management measures, the cultivation management of maize GA21 is unlikely to raise safety concerns for the environment.

© European Food Safety Authority, 2011

Following the submission of an application (Reference EFSA-GMO-UK-2008-60) under Regulation (EC) No 1829/2003 from Syngenta Seeds, the Panel on Genetically Modified Organisms of the European Food Safety Authority (EFSA GMO Panel) was asked to deliver a Scientific Opinion on the safety of the herbicide tolerant genetically modified (GM) maize GA21 (Unique Identifier MON-ØØØ21-9) for food and feed uses, import, processing and cultivation.

In delivering its Scientific Opinion, the EFSA GMO Panel considered the application EFSA-GMO-UK-2008-60, additional information supplied by the applicant, scientific comments submitted by Member States, the environmental risk assessment report of the Czech Competent Authority (CZ CA), and relevant scientific publications.

Maize GA21 expresses a modified version of 5-enolpyruvylshikimate-3-phosphate synthase (mEPSPS), which is derived from maize EPSPS, and renders maize GA21 tolerant to the herbicidal active substance glyphosate.

The EFSA GMO Panel evaluated maize GA21 with reference to its intended uses and appropriate principles described in its guidelines for the risk assessment of GM plants and derived food and feed, the environmental risk assessment of GM plants, the selection of comparators for the risk assessment of GM plants, and for the post-market environmental monitoring of GM plants. The scientific evaluation of the risk assessment included molecular characterisation of the inserted DNA and expression of target protein. An evaluation of the comparative analyses of composition, agronomic and phenotypic characteristics was undertaken, and the safety of the new protein, and the whole food/feed was evaluated with respect to potential toxicity, allergenicity and nutritional quality. An evaluation of environmental impacts and the post-market environmental monitoring plan was undertaken.

The molecular characterisation data establish that maize GA21 contains a single insertion locus consisting of six contiguous complete or truncated versions of the mepsps expression cassette used for the transformation. No other parts of the plasmid are present in the transformed plant. Bioinformatic analyses of the open reading frames spanning the junction sites within the insert or between the insert and genomic DNA did not indicate specific hazards. The stability of the inserted DNA and the herbicide tolerance trait were confirmed over several generations. Updated analyses of the levels of mEPSPS in various plant parts collected from field trials performed in Europe were considered sufficient.

Based on the results of comparative analysis, the EFSA GMO Panel concludes that maize GA21 is compositionally, phenotypically and agronomically not different from the conventional counterpart, except for the presence of the mEPSPS protein in maize GA21. Bioinformatics studies demonstrated that the newly expressed mEPSPS protein shows no homology to known toxic proteins or allergens. The in vitro digestibility studies showed that most of the protein was degraded. There were no indications of adverse effects after administration of grain from maize GA21 to rats in a repeated-dose 90-day oral toxicity study. A feeding study with broiler chickens confirmed that grain from maize GA21 is as nutritious as grain of the conventional counterpart and a reference maize variety. Based on the available information, the EFSA GMO Panel is of the opinion that maize GA21 is as safe and nutritious as the conventional counterpart and reference maize varieties, and that it is unlikely that the overall allergenicity of the whole plant is changed.

Since the scope of the current application covers cultivation, the environmental risk assessment considered the environmental impact of full-scale commercialisation of maize GA21.

The CZ CA (including its Biosafety Commission) provided to EFSA its report on the environmental risk assessment of maize GA21 (dated 20 October 2010) on 25 October 2010 in line with Articles 6.3(c) and 18.3(c) of Regulation (EC) No 1829/2003. The report on the environmental risk assessment of the CZ CA is provided in Annex H of the EFSA Overall Opinion, and has been considered throughout this EFSA GMO Panel Scientific Opinion.

The EFSA GMO Panel considers that maize GA21 has no altered agronomic and phenotypic characteristics, except for the herbicide tolerance. The likelihood of unintended environmental effects due to the establishment, survival and spread of maize GA21 is considered to be extremely low, and will be no different from that of conventional maize varieties.

It is highly unlikely that the recombinant DNA will transfer and establish in the genome of bacteria in the environment or human and animal digestive tracts. In the rare but theoretically possible case of transfer of the mepsps gene from maize GA21 to soil bacteria, no novel property would be introduced into the soil bacterial community and thus no positive selective advantage that would not have been conferred by natural gene transfer between bacteria would be provided.

Based on the evidence provided by the applicant and relevant scientific literature on maize GA21, the EFSA GMO Panel concludes that there are no indications of adverse effects on non-target organisms due to unintended changes in maize GA21, and therefore considers trait-specific information appropriate to assess whether maize GA21 poses a risk to non-target organisms.

The studies, supplied or reviewed by the applicant, showed no adverse effects on different types of non-target organisms due to the expression of the mEPSPS protein in glyphosate tolerant crops.

The EFSA GMO Panel does not expect potential adverse effects on biogeochemical processes and the abiotic environment due to the expression of the mEPSPS protein in maize GA21.

The EFSA GMO Panel is of the opinion that potential adverse environmental effects of the cultivation of maize GA21 are associated with the use of the complementary glyphosate-based herbicide regimes. These potential adverse environmental effects comprise (1) a reduction in farmland biodiversity, (2) changes in botanical diversity due to weed shifts, with the selection of weed communities mostly composed of tolerant species, and (3) the selection of glyphosate resistant weeds. The potential harmful effects could occur at the level of arable weeds, farmland biodiversity, food webs and the ecological functions they provide. The magnitude of these potential adverse environmental effects will depend upon a series of factors, including the specific herbicide and cultivation management applied at the farm level, the crop rotation and the characteristics of receiving environments.

The EFSA GMO Panel considers that the use of glyphosate-based herbicides at recommended field application rates of glyphosate on maize GA21 is unlikely to cause adverse effects to soil microbial communities or beneficial functions mediated by them.

The conclusions of the EFSA GMO Panel on the environmental safety of maize GA21 are consistent with those of the CZ CA. The CZ CA concluded that “based on the existing information and data provided by the Syngenta Company within the evaluation process, the Czech CA considers that maize GA21 has no altered survival, multiplication or dissemination characteristics and interacts with other organisms as any conventional maize. However, the data presented on the issue of “Impacts of the specific cultivation, management and harvesting techniques” do not allow a comprehensive assessment of potential long-term effects on the environment associated to the use of the herbicide” (section 9 of the environmental risk assessment report of the CZ CA). Hence, the CZ CA identified “no potential effects on the environment either immediate, delayed, direct or indirect with the exception of those related to the change in the herbicide management” (section 8.1 of the environmental risk assessment report of the CZ CA).

The EFSA GMO Panel anticipates that the repeated use of glyphosate at recommended application rates on continuous maize GA21 and/or other glyphosate tolerant crops grown in rotation may result in reductions in botanical diversity and/or weed density in maize fields to a level that might adversely affect food chains and webs, but not necessarily biological control functions, at the field and landscape level. Such a reduction in biodiversity may be considered problematic by risk managers depending upon protection goals pertaining to their region, especially in receiving environments that sustain little farmland biodiversity or in environmentally sensitive areas. Under such situations, the EFSA GMO Panel recommends that risk mitigation measures are put in place to manage potential herbicide effects, in order to ensure that glyphosate on maize GA21 is used within diversified cropping regimes that have similar or reduced adverse effects on farmland biodiversity compared with conventional maize cultivation. Possible risk mitigation measures include protecting adjacent habitats from herbicide drift, (re)introduction and better management of field margins or other ‘out of crop’ measures, less intense in-crop weed management, and especially rotating crops.

The cultivation of maize GA21 in monoculture or in rotation with other glyphosate tolerant crops, in conjunction with the repeated and/or exclusive application of glyphosate-based herbicides will cause changes in weed flora, and will favour the evolution and spread of glyphosate resistant weeds due to the selection pressure exerted by glyphosate. This, in turn, may affect food webs, and the functional value of weed vegetation for organisms of higher trophic levels (reduced functional biodiversity). Under such situations, the EFSA GMO Panel recommends that risk mitigation measures are put in place to delay resistance evolution. The selection pressure on weeds can be reduced by crop rotations (i.e., rotating glyphosate tolerant crops with non-glyphosate tolerant crops), using variable application rates and timing, applying a variety of herbicidal active substances with different modes of action, and by using non-herbicide weed control tools such as post-emergence cultivation and cover crops. To be most effective, these methods should be used in combination. A clear advantage of increasing cropping system diversification is that it would increase or conserve farmland biodiversity, as well as reducing the risk of weed shifts and the evolution of glyphosate resistant weed biotypes.

In its evaluation, the CZ CA was of the opinion that “measures should be put in place under Directive 91/414/EEC and consecutively under Regulation (EC) No 1107/2009 to ensure compliance with regulatory requirements for the pesticide regimes used in Member States. These should include measures for the appropriate management of glyphosate on GMHT maize and for the development of weed resistance management strategies in each Member State permitting the use of glyphosate on maize GA21. It is necessary to exploit properly the appropriate antiresistance strategy to avoid undue herbicide usage” (section 7.6.2 of the environmental risk assessment report of the CZ CA). The CZ CA recommended the applicant “to design appropriately a relevant Technical User Guide for farmers that should involve Good Agricultural Practices of glyphosate applications guaranteeing sustainable and safe use of the entire GA21 technology” (section 9 of the environmental risk assessment report of the CZ CA).

The EFSA GMO Panel gave its opinion and made recommendations on the scientific quality of the post-market environmental monitoring plan proposed by the applicant. In order to assess the efficacy of risk mitigation measures put in place to reduce levels of risk and in order to reduce the remaining scientific uncertainty identified in the environmental risk assessment, the EFSA GMO Panel recommends case-specific monitoring to address (1) changes in botanical diversity within fields due to novel herbicide regimes, and (2) resistance evolution to glyphosate in weeds due to novel herbicide regimes. The EFSA GMO Panel considers that risk managers should adapt monitoring methodologies to their local receiving environments, management systems and the interplay between the legislation for GMOs and plant protection products.

The EFSA GMO Panel agrees with the general surveillance plan for the cultivation of maize GA21 of the applicant (1) to establish farmer questionnaires as a reporting format of any on-farm observations of effects associated with the cultivation of maize GA21, (2) to use existing monitoring networks which observe changes in biota and production practices from farm up to regional level to obtain data on environmental impacts in the landscape where maize GA21 is cultivated, (3) to review all new scientific, technical and other information pertaining to maize GA21, and (4) to develop stewardship programs for the introduction, marketing, management and stewardship of maize GA21, but requests that its proposals and those made by the CZ CA to strengthen general surveillance are implemented. The EFSA GMO Panel agrees with the reporting intervals and modalities proposed by the applicant. The general surveillance plan for the import and processing of maize GA21 was previously evaluated by the EFSA GMO Panel.

The CZ CA considered that “case-specific monitoring is the most appropriate way to monitor identified potential environmental effects that could result from changes in the technology. Therefore it is proposed that the applicant performs a case-specific monitoring of long-term effects with focus on non-target organisms, weed shifts, the development of herbicide resistance to glyphosate and microbial biodiversity” (section 8.1 of the environmental risk assessment report of the CZ CA).

The CZ CA considered that “the general surveillance plan should be updated” and made specific proposals to strengthen general surveillance (section 8.2 of the environmental risk assessment report of the CZ CA).

In conclusion, the EFSA GMO Panel considers that the information available for maize GA21 addresses the scientific comments raised by Member States and that maize GA21, as described in this application, is as safe as its conventional counterpart and commercial maize varieties with respect to potential adverse effects on human and animal health, in the context of its intended uses. The EFSA GMO Panel also concludes that maize GA21 is unlikely to raise additional environmental safety concerns compared to conventional maize, but that its cultivation management could result in environmental harm under certain conditions. The EFSA GMO Panel therefore recommends managing the use of glyphosate on maize GA21 within diversified cropping regimes that have similar or reduced environmental impacts compared with conventional maize cultivation. The EFSA GMO Panel recommends the deployment of case-specific monitoring to address (1) changes in botanical diversity within fields due to novel herbicide regimes, and (2) resistance evolution to glyphosate in weeds due to novel herbicide regimes. If subjected to appropriate management measures, the cultivation management of maize GA21 is unlikely to raise safety concerns for the environment.

GMO, maize (Zea mays), GA21, herbicide tolerance, mepsps, risk assessment, food and feed safety, environment, environmental safety, food and feed uses, import and processing, cultivation, Regulation (EC) No 1829/2003