Following the submission of application EFSA-GMO-DE-2009-66 under Regulation (EC) No 1829/2003 from Syngenta, the Panel on Genetically Modified Organisms of the European Food Safety Authority (referred to hereafter as EFSA GMO Panel) was asked to deliver a scientific opinion on the safety of herbicide tolerant and insect resistant genetically modified maize Bt11 × MIR162 × MIR604 × GA21 (referred to hereafter as ‘four-event stack maize’) and on all its subcombinations (referred to as ‘subcombinations independently of their origin’ in the Commission implementing regulation (EU) No 503/2013). The scope of application EFSA-GMO-DE-2009-66 is for food and feed uses, import and processing, but excludes cultivation within the European Union (EU).
The term ‘subcombination’ refers to any combination of up to three of the events present in the four-event stack maize Bt11 × MIR162 × MIR604 × GA21. Subcombinations occur as segregating progeny in the harvested grains of Bt11 × MIR162 × MIR604 × GA21 (embryo and albumen), and their safety is evaluated within the assessment of the four-event stack maize Bt11 × MIR162 × MIR604 × GA21 in Section 4 of the present opinion.
‘Subcombination’ also refers to any combination of up to three of the events Bt11, MIR162, MIR604 or GA21 that has either been or could be produced by conventional crossing, through targeted breeding approaches (EFSA GMO Panel, 2011a).These are maize stacks that can be bred, produced and marketed independently of the four-event stack Bt11 × MIR162 × MIR604 × GA21. These stacks, including their segregating progeny, are risk assessed in the Section 5 of the present opinion.
In accordance with the EFSA GMO Panel guidance document applicable to this application (EFSA, 2007a), “where all single events have been assessed, the risk assessment of stacked events should focus mainly on issues related to a) stability, b) expression of the events and c) potential interactions between the events”. For application EFSA-GMO-DE-2009-66, previous assessments of the four single events (Bt11, MIR162, MIR604 and GA21) provided a basis to evaluate the four-event stack maize and the 10 subcombinations.
The four-event stack maize Bt11 × MIR162 × MIR604 × GA21 was produced by conventional crossing to combine four single maize events. Maize containing the single events, Bt11 (expressing Cry1Ab and PAT proteins), MIR162 (expressing Vip3Aa20 and PMI proteins), MIR604 (expressing mCry3A and PMI proteins) and GA21 (expressing mEPSPS protein), were assessed previously and no concerns were identified. No safety issue was identified by updated bioinformatic analyses, nor reported by the applicant concerning the four single maize events, since the publication of the scientific opinions. Consequently, the EFSA GMO Panel considers that its previous conclusions on the safety of the single maize events remain valid (Section 3).
For the four-event stack maize, the risk assessment included the molecular characterisation of the inserted DNA and the analysis of the proteins’ expression. An evaluation of the comparative analyses of compositional, agronomic and phenotypic characteristics was undertaken, and the safety of the newly expressed proteins and the whole food/feed was evaluated with respect to potential toxicity, allergenicity and nutritional characteristics. Evaluation of environmental impacts and the Post-Market Environmental Monitoring (PMEM) plan was also undertaken.
The molecular data establish that the transformation events stacked in maize Bt11 × MIR162 × MIR604 × GA21 have the same molecular properties and characteristics as the single transformation events. Protein expression analyses showed that the levels of the newly expressed proteins are similar in the four-event stack and the single events, with the exception of PMI. Comparison of the levels of the newly expressed proteins between the four-event stack and the respective single events did not reveal an interaction that would affect protein expression level.
The newly expressed proteins in the four-event stack maize did not raise concerns for human and animal health. The compositional data indicate that maize Bt11 × MIR162 × MIR604 × GA21 would be expected to deliver the same nutritional characteristics as its conventional counterpart. This was confirmed by the results of an animal feeding study in chickens for fattening.
The EFSA GMO Panel considers that there is no reason to expect interactions that could impact on the food and feed safety. No safety concerns are foreseen for any subcombinations of the individual events, including those not previously assessed by EFSA.
Considering the introduced traits, the outcome of the comparative analysis, the routes of exposure and the limited exposure levels, the EFSA GMO Panel concluded that this four-event stack maize would not raise safety concerns in the event of accidental release of viable GM maize grains into the environment, irrespective of possible interactions between the individual events within this four-event stack maize.
In conclusion, the EFSA GMO Panel is of the opinion that the four-event stack maize is as safe and as nutritious as its conventional counterpart and commercial maize varieties in the context of its scope.
Concerning the 10 subcombinations, EFSA GMO Panel previously assessed four of them (i.e. Bt11 × GA21, MIR604 × GA21, Bt11 × MIR604, Bt11 × GA21 × MIR604) and did not identify safety concerns. No new scientific information regarding these subcombinations was retrieved in a literature search covering the period since the publication of the respective scientific opinions. Moreover, the additional data available on protein expression, agronomic, phenotypic and compositional characteristics of maize Bt11 × MIR604 × GA21 confirmed the result of the previous assessment. Consequently, the EFSA GMO Panel considers that its previous conclusions on these four subcombinations remain valid.
For the remaining six subcombinations, with the exception of Bt11 × MIR162 × GA21, the applicant provided no experimental data. The EFSA GMO Panel used a weight-of-evidence approach to conclude on the safety of these six subcombinations, considering information from: (i) the previous assessments of the four single maize events, (ii) the assessment of the four-event stack maize, and (iii) the four subcombinations previous assessed and the newly available data. The EFSA GMO Panel is of the opinion that the six subcombinations are expected to be as safe as the four-event stack maize.
The EFSA GMO Panel considers that post-market monitoring of food/feed derived from maize Bt11 × MIR162 × MIR604 × GA21 or 10 subcombinations is not necessary, given the absence of safety concerns identified.
The EFSA GMO Panel is of the opinion that the PMEM plans provided by the applicant are in line with the scope of the four-event stack maize and the four subcombinations previously assessed. However, the PMEM plan submitted by the applicant for the four-event stack maize does not include any provision for the six subcombinations that were not previously assessed. Therefore, the EFSA GMO Panel recommends the applicant to revise the plan accordingly.
The EFSA GMO Panel did not find indication that the subcombinations, resulting from combination of any of the single events included in the four-stack, would raise safety concerns. However, for some subcombinations (Bt11 x MIR162 x MIR604, MIR162 x MIR604 x GA21, Bt11 x MIR162, MIR162 x MIR604, MIR162 x GA21) that could be produced by conventional crossing through targeted breeding approaches, little or no specific data were submitted. For these the EFSA GMO Panel has drawn conclusions on a weight-of-evidence approach, giving rise to uncertainties due to data gaps.
In order to reduce these uncertainties and to confirm assumptions made for the assessment of these subcombinations, the EFSA GMO Panel recommends that the applicant collate relevant information, if these subcombinations were to be created via targeted breeding approaches and commercialised in the future. In this case, this information should focus on expression levels of the newly expressed proteins.
In delivering its scientific opinion, the EFSA GMO Panel considered the data available on the four-event stack maize and the subcombinations, the scientific comments submitted by the Member States and the relevant scientific publications.