Preliminary Environmental Risk Assessment of Insect Resistant Genetically Modified Maize MON 89034 for Cultivation (EFSA/GMO/BE/2011/90)
Authors: Nerland Audun Helge , Bernhoft Aksel , Brandtzæg Per , Finne Merethe Aasmo , Holck Askild Lorentz , Junttila Olavi , Konestabo Heidi Sjursen , Meadow Richard , Nielsen Kåre M. , Sipinen Ville Erling , Opsahl-Sorteberg Hilde-Gunn , Vikse Rose , Andreassen Åshild 
Published: November 2019

The environmental risk assessment of the insect resistant genetically modified maize MON 89034 (Reference EFSA/GMO/BE/2011/90) has been performed by the Panel on Genetically Modified Organisms (GMO) of the Norwegian Scientific Committee for Food Safety (VKM). VKM has been requested by the Norwegian Directorate for Nature Management and the Norwegian Food Safety Authority to issue a preliminary scientific opinion on the safety of the genetically modified maize MON 89034 (Unique identifier MON-89Ø34-3) for cultivation, and submit relevant scientific comments or questions to EFSA on the application EFSA/GMOBE/2011/90. The current submission is intended to complement application EFSA-GMO-NL-2007-37, which was approved by Commission Decision 2009/813/EC of 30 October 2009, authorising the placing on the market of products containing, consisting of, or produced from genetically modified maize MON 89034 (scope import, processing, food and feed). Maize MON89034 has previously been assessed by the VKM GMO Panel in connection with EFSA´s public hearing of the application EFSA/GMO/NL/2007/37 (VKM 2008a). Preliminary health- and environmental risk assessments of several stacked events, with MON 89034 as one of the parental lines, have also been performed by the VKM GMO Panel (VKM 2009a, b, c; VKM 2010a,b).

The environmental risk assessment of the maize MON 89034 is based on information provided by the applicant in the application EFSA/GMO/BE/2011/90, and scientific comments from EFSA and other member states made available on the EFSA website GMO Extranet. The risk assessment also considered peer-reviewed scientific literature as relevant.

The VKM GMO Panel has evaluated MON 89034 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), the selection of comparators for the risk assessment of GM plants (EFSA 2011b), and for the post-market environmental monitoring of GM plants (EFSA 2006, 2011c).

The scientific risk assessment of maize MON 89034 include molecular characterisation of the inserted DNA and expression of target proteins, comparative assessment of agronomic and phenotypic characteristics, unintended effects on plant fitness, potential for gene transfer, interactions between the GM plant and target and non-target organisms, effects on biogeochemical processes and evaluations of the post-market environmental plan.

In line with its mandate, VKM emphasised that assessments of 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, shall not be carried out by the Panel on Genetically Modified Organisms.

The genetically modified maize MON 89034 was developed to provide protection against certain lepidopteran target pest, including European corn borer (Ostrinia nubilalis) and Mediterranean corn borer (Sesamia nonagrioides). Protection is achieved through expression in the plant of two insecticidal Cry proteins, Cry1A.105 and Cry2Ab2, derived from Bacillus thuringiensis, a common soil bacterium. Cry1A.105, encoded by the cry1A.105 gene, is a chimeric protein made up of different functional domains derived from three wild-type Cry proteins from B. thuringiensis subspecies kurstaki and aizawai. The Cry2Ab2 protein is encoded by the cry2Ab2 gene derived from B. thuringiensis subspecies kurstaki.

Molecular characterization:

Appropriate analysis of the integration site, including flanking sequence and bioinformatics analysis, has been performed to characterise the transformation event MON 89034. The results of the segregation analysis are consistent with a single site of insertion for the cry1A.105 and cry2Ab2 gene expression cassettes and confirm the results of the molecular characterisation. Molecular analysis of both self-pollinated and cross-fertilised lines, representing a total of seven different generations, indicates that the inserted DNA is stably transformed and inherited from one generation to the next. No genes that encode resistance to antibiotics are present in the genome of MON 89034 maize. The molecular characterisation confirmed the absence of both the aad and nptII genes, which were used in the cloning and transformation process.

Event MON 89034 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 2008a).

Comparative assessment:

The field trials for comparative assessment of agronomic and phenotypic characteristics of maize MON 89034 in the USA (2004-2005) and Europe (2007), have been performed in accordance with the EFSAs guidelines for risk assessment of genetically modified plants and derived food and feed (EFSA 2010, 2011a). Based on results from the comparative analyses, it is concluded that maize MON 89034 is agronomically and phenotypically equivalent to the conventional counterpart and commercial available reference varieties, with the exception of the lepidopteran-protection trait. The field evaluations support a conclusion of no phenotypic changes indicative of increased plant weed/pest potential of MON 89034 compared to conventional maize. Evaluations of ecological interactions between maize MON 89034 and the biotic and abiotic environment indicate no unintended effects of the introduced trait on agronomic and phenotypic characteristics.

Environmental risk:

There are no reports of the target Lepidopteran species attaining pest status on maize in Norway. Since there are no Bt-based insecticides approved for use in Norway, and lepidopteran pests have not been registered in maize, issues related to resistance evolution in target pests are not relevant at present for Norwegian agriculture.

Published scientific studies show no or negligible adverse effects of Cry1A.105 and Cry2Ab2 proteins on non-target arthropods that live on or in the vicinity of maize plants. Cultivation of maize MON 89034 is not considered to represent a threat to the prevalence of red-listed species in Norway.

Few studies have been published examining potential effects of Cry1A.105 and Cry2Ab toxin on ecosystems in soil, mineralization, nutrient turnover and soil communities. Some field studies have indicated that root exudates and decaying plant material containing Cry proteins may affect population size and activity of rhizosphere organisms (soil protozoa and microorganisms). However, data are only available from short term experiments and predictions of potential long term effects are difficult to deduce. Most studies conclude that effects on soil microorganisms and microbial communities are transient and minor compared to effects caused by agronomic and environmental factors.

Few studies have assessed the impact of Cry proteins on non-target aquatic arthropods and the fate of these proteins in senescent and decaying maize detritus in aquatic environments. Further studies with better experimental design are needed for the assessment of the potential effects of Bt crops on aquatic organisms. However, exposure of non-target organisms to Cry proteins in aquatic ecosystems is likely to be very low, and potential exposure of Bt toxins to non-target organisms in stream ecosystems in Norway is considered to be negligible.

Maize is the only representative of the genus Zea in Europe, and there are no cross-compatible wild or weedy relatives outside cultivation with which maize can hybridise and form backcross progeny. Vertical gene transfer in maize therefore depends on cross-pollination with other conventional or organic maize varieties. In addition, unintended admixture of genetically modified material in seeds represents a possible way for gene flow between different crop cultivations. The risk of pollen flow from maize volunteers is negligible under Norwegian growing conditions.

In addition to the data presented by the applicant, the VKM GMO Panel is not aware of any scientific report of increased establishment and spread of maize MON 89034 and any change in survival (including over-wintering), persistence and invasiveness capacity. Because the general characteristics of maize MON 89034 are unchanged, insect resistance are not likely to provide a selective advantage outside cultivation in Norway.

Since MON 89034 has no altered agronomic and phenotypic characteristics, except for the specific target pest resistance, the VKM GMO Panel is of the opinion that the likelihood of unintended environmental effects due to the establishment and survival of maize MON 89034 will be no different to that of conventional maize varieties in Norway

The environmental risk assessment will be completed and finalized by the VKM Panel on Genetically Modified Organisms when requested additional information from the applicant is available.