Modified Bt Maize Research Articles

Assessment of genetically modified maize Bt11 × MIR162 × MIR604 × MON 89034 × 5307 × GA21 and 30 subcombinations, for food and feed uses, underRegulation (EC) No 1829/2003 (application EFSA-GMO-DE-2018-149).

Genetically modified maize Bt11 × MIR162 × MIR604 × MON 89034 × 5307 × GA21 was developed by crossing to combine six single events: Bt11, MIR162, MIR604, MON 89034, 5307 and GA21, the GMO Panel previously assessed the 6 single maize events and 27 out of the 56 possible subcombinations and did not identify safety concerns. No new data on the single maize events or the assessed subcombinations were identified that could lead to modification of the original conclusions on their safety. The molecular characterisation, comparative analysis (agronomic, phenotypic and compositional characteristics) and the outcome of the toxicological, allergenicity and nutritional assessment indicate that the combination of the single maize events and of the newly expressed proteins in the six-event stack maize does not give rise to food and feed safety and nutritional concerns. The GMO Panel concludes that six-event stack maize, as described in this application, is as safe as the conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable six-event stack maize grains into the environment, this would not raise environmental safety concerns. The GMO Panel assessed the likelihood of interactions among the single events in 29 of the maize subcombinations not previously assessed and covered by the scope of this application and concludes that these are expected to be as safe as the single events, the previously assessed subcombinations and the six-event stack maize. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize Bt11 × MIR162 × MIR604 × MON 89034 × 5307 × GA21. The GMO Panel concludes that six-event stack maize and the 30 subcombinations covered by the scope of the application are as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

Effect of GM maize on metabolism and performance of chicken

Effect of GM maize on metabolism and performance of chicken

Assessment of genetically modified maize Bt11 for renewal authorisation under Regulation (EC) No1829/2003 (applicationEFSA-GMO-RX-016).

Following the submission of application EFSA‐GMO‐RX‐016 under Regulation (EC) No 1829/2003 from Syngenta the Panel on Genetically Modified Organisms of the European Food Safety Authority was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the insect‐resistant and herbicide‐tolerant genetically modified maize Bt11, for food and feed uses, excluding cultivation within the European Union. The data received in the context of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses, and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequences of the event in maize Bt11 considered for renewal is identical to the sequence of the originally assessed events, the GMO Panel concludes that there is no evidence in renewal application EFSA‐GMO‐RX‐016 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize Bt11.

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/49)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/49)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/RX/Bt11)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/RX/Bt11)

Food/Feed and Environmental Risk Assessment of Application (Reference EFSA/GMO/UK/2008/56) for Authorization of Insect Resistant and Herbicide Tolerant Genetically Modified Maize Bt11 x MIR604 x GA21 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 from Syngenta Seeds

Food/Feed and Environmental Risk Assessment of Application (Reference EFSA/GMO/UK/2008/56) for Authorization of Insect Resistant and Herbicide Tolerant Genetically Modified Maize Bt11 x MIR604 x GA21 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 from Syngenta Seeds

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize Bt11 x MIR604 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/50)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize Bt11 x MIR604 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/50)

Introgression of a cry1Ab transgene into open pollinated maize and its effect on Cry protein concentration and target pest survival.

In Africa, the target pests of genetically modified Bt maize are lepidopteran stem borers, notably Busseola fusca (Lepidoptera: Noctuidae). Gene flow between Bt maize hybrids and open pollinated varieties (OPVs) that do not contain the Bt trait is highly likely in areas where both types of maize are cultivated. Consequently, introgression of the cry1Ab transgene into local OPVs will result in unknown patterns of Cry1Ab protein expression in plants during follow-up seasons when recycled seed of OPVs is planted. Too low concentrations of Cry protein in such plants may result in selection for resistant alleles and accelerate resistance evolution. The aim of this study was to determine the effects of introgression of the cry1Ab transgene into an OPV, on Cry protein concentration levels and pest survival. Bt transgene introgression was done by crossing a transgenic donor hybrid containing the cry1Ab gene with a non-Bt OPV as well as with a non-Bt near-isogenic hybrid. F1 and F2 crosses as well as back crosses were done yielding 11 genotypes (treatments). Cry1Ab protein concentrations in leaf tissue of these crosses were determined by means of ELISAs. All crosses that contained the transgene had similar or higher Cry1Ab concentrations when compared to the Bt parental hybrid, except for the Bt x OPV F1-cross that had a significantly lower Cry1Ab concentration. Survival B. fusca larvae were evaluated in assays in which larvae were reared for 14 days on whorl leaf tissue of the different treatments. Larval survival did not differ between any of the maize plant treatments which contained the Bt gene. Results suggest that Bt transgene introgression into OPVs may produce plant progenies that express Cry1Ab protein at sufficient concentrations, at last up to the F2 seed, to control B. fusca larvae. Resistance evolution is however not only influenced by the frequency of pest individuals that survive exposure to the Cry proteins but also by factors such as genetics of the pest and recipient OPV, pest biology and migration behaviour.

Transcriptome and differentially expressed genes of Busseola fusca (Lepidoptera: Noctuidae) larvae challenged with Cry1Ab toxin

Busseola fusca (Fuller) (Lepidoptera: Noctuidae), a major insect pest of maize in sub-Saharan Africa, has developed high levels of non-recessive resistance to Cry1Ab toxin expressed in genetically modified Bt maize. Multiple resistance mechanisms to various Cry toxins have been identified in Lepidoptera, but no study has yet been done to determine the mechanism of Cry1Ab resistance in B. fusca. Therefore, the larval transcriptome of B. fusca was sequenced, de novo assembled and characterized. Differential expression analysis was performed to compare gene expression profiles of Cry toxin challenged and unchallenged neonate larvae to assess the molecular basis of the defence mechanism employed by this insect. Several genes associated with Cry toxin resistance in other lepidopteran pests were detected in B. fusca. Results suggest that differential expression of metabolic and immune-related genes might explain Cry1Ab toxin defence in this pest (supplemental file). Transcript expression profiles of neonates demonstrated that 33.59% and 60.31% of the 131 differentially expressed genes were upregulated and downregulated in the toxin-challenged neonate larvae, respectively. Transcripts were grouped into two subclusters according to the similarity of their expression patterns. Transcripts in subcluster 1 were moderately upregulated in the toxin-challenged neonate larvae, and, conversely, downregulated in the unchallenged neonate larvae. The solute carrier organic anion transporter, which is involved in insecticide detoxification, was upregulated in the toxin-challenged neonate larvae. Conversely, most of the transcripts in subcluster 2 were moderately downregulated in the toxin-challenged neonate larvae, and upregulated for neonates feeding on non-challenged maize. Four unidentified transcripts were extremely down-regulated in the toxin-challenged neonate larvae, and upregulated in the unchallenged neonate larvae. Further studies are recommended to establish if there is a direct correlation between these differentially expressed genes and the observed resistance. Elucidation of such defence mechanisms is crucial for developing insect resistance management strategies to ensure sustainable use of genetically modified maize in Africa. Nevertheless, this is the first study on gene expression profiles of B. fusca strains challenged with Cry toxin. The transcriptome characterized in this study provides a significant resource base for future studies on B. fusca and contributes to understanding some of the gene regulation and signalling networks involved in the defence of B. fusca against Cry1Ab toxin.

Assessment of genetically modified maize Bt11×MIR162×MIR604×1507×5307×GA21 and subcombinations, for food and feed uses, under Regulation (EC) No1829/2003 (application EFSA-GMO-DE-2011-103).

Maize Bt11 × MIR162 × MIR604 × 1507 × 5307 × GA21 (six‐event stack maize) was produced by conventional crossing to combine six single events: Bt11, MIR162, MIR604, 1507, 5307 and GA21. The GMO Panel previously assessed the six single events and 22 of their combinations and did not identify safety concerns. No new data on the maize single events or their 22 combinations that could lead to modification of the original conclusions on their safety have been identified. The molecular characterisation, comparative analysis (agronomic, phenotypic and compositional characteristics) and the outcome of the toxicological, allergenicity and nutritional assessment indicate that the combination of the single maize events and of the newly expressed proteins in the six–event stack maize does not give rise to food and feed safety and nutritional concerns. The GMO Panel concludes that the six‐event stack maize, as described in this application, is as safe as and nutritionally equivalent to its non‐GM comparator and the non‐GM reference varieties tested. In the case of accidental release of viable grains of the six‐event stack maize into the environment, this would not raise environmental safety concerns. The GMO Panel assessed the likelihood of interactions among the single events in the 34 maize subcombinations not previously assessed and concludes that these are expected to be as safe as and nutritionally equivalent to the single events, the previously assessed subcombinations and the six‐event stack maize. The post‐market environmental monitoring plan and reporting intervals are in line with the intended uses of the six‐event stack maize. Post‐market monitoring of food/feed is not considered necessary. The GMO Panel concludes that the six‐event stack maize and its subcombinations are as safe as its non‐GM comparator and the tested non‐GM reference varieties with respect to potential effects on human and animal health and the environment.

Results of a 16-week Safety Assurance Study with Rats Fed Genetically Modified Bt Maize: Effect on Growth and Health Parameters.

IntroductionThe influence of feeding genetically modified MON 810 hybrid maize on the growth and haematological and biochemical indices of rats was tested.Material and MethodsTwo conventional (non-GM) and two test (MON 810) lines of maize were used in semi-purified diets at the level of 40% w/w. The non-GM I, MON 810 I, non-GM II, and MON 810 II maize lines were near-isogenic. A total of 40 male 6-week-old Wistar-derived rats were assigned to four equal feeding groups corresponding to the four maize lines for 16 weeks. Overall, health, body weight gain, clinical pathology parameters, gross changes, and appearance of tissues were compared between groups.ResultsThere were no statistically significant differences in the weight gain or relative organ weights of rats, but there were some non diet-related histopathological changes in the liver, kidneys, and spleen. Except for creatinine level, no diet-related effects were observed in haematology or most of the biochemical indices. Transgenic DNA of MON 810 maize was not detected in the tissues or faeces nor in the DNA of E. coli isolated from the rectum digesta of rats given transgenic feeds. In our experiment, various metabolic indices of rats fed non-GM diets or genetically modified (MON 810) maize for 16 weeks were similar. No adverse nutrition-related health effects were detected.ConclusionMON 810 maize seems to be as safe as the conventional maize lines.

Impact of Antibiotics on Efficacy of Cry Toxins Produced in Two Different Genetically Modified Bt Maize Varieties in Two Lepidopteran Herbivore Species, Ostrinia nubilalis and Spodoptera littoralis.

The insecticidal crystal proteins from Bacillus thuringiensis (Bt) are widely-used biopesticides that are used both as Bt spore-crystal preparations in sprayable formulations and as activated toxins in genetically modified (GM) plants. Models for their modes of action have been proposed but many issues remain unresolved. Among those is the role of commensal gut bacteria in target insect death: previous studies showed that antibiotics attenuate the toxicity of Bt sprays. We tested whether antibiotics interfere with the effects of GM plant-produced Bt toxins in larvae of two Lepidopteran species, the European corn borer Ostrinia nubilalis and the cotton leafworm Spodoptera littoralis. The larvae were reared on artificial diet with or without antibiotics and, thereafter, fed two varieties of Bt GM maize in comparison to conventional non-Bt maize leaves sprayed with antibiotic solution and/or with a Bt formulation. Antibiotics significantly reduced or delayed the toxicity of Cry toxins, although to a lesser extent than previously reported for Bt-sprays. This supports the hypothesis that Cry toxins induce mortality by themselves in the absence of Bt bacteria and spores, and of commensal gut bacteria. However, larvae that were not treated with antibiotics died faster and at a higher rate which was further compounded by plant variety and species sensitivity. These findings support a hypothesis that toxicemia alone can inflict significant mortality. However, in the absence of antibiotics, the gut bacteria likely enhance the Cry toxin effect by inflicting, additionally, bacterial septicemia. This has important implications in field situations where antibiotic substances are present—e.g., from manure of animals from conventional production systems—and for ecotoxicological testing schemes of Bt toxins and nontarget organisms that are often using artificial diets enriched with high concentrations of antibiotics.

Assessment of genetically modified maize Bt11xMIR162x1507xGA21 and three subcombinations independently of their origin, for food and feed uses under Regulation (EC) No1829/2003 (application EFSA-GMO-DE-2010-86).

In this opinion, the GMO Panel assessed the four‐event stack maize Bt11 × MIR162 × 1507 × GA21 and three of its subcombinations, independently of their origin. The GMO Panel previously assessed the four single events and seven of their combinations and did not identify safety concerns. No new data on the single events or the seven subcombinations leading to modification of the original conclusions were identified. Based on the molecular, agronomic, phenotypic and compositional characteristics, the combination of the single events in the four‐event stack maize did not give rise to food/feed safety issues. Based on the nutritional assessment of the compositional characteristics of maize Bt11 × MIR162 × 1507 × GA21, foods and feeds derived from the genetically modified (GM) maize are expected to have the same nutritional impact as those derived from non‐GM maize varieties. In the case of accidental release of viable grains of maize Bt11 × MIR162 × 1507 × GA21 into the environment, this would not raise environmental safety concerns. The GMO Panel concludes that maize Bt11 × MIR162 × 1507 × GA21 is nutritionally equivalent to and as safe as its non‐GM comparator in the context of the scope of this application. For the three subcombinations included in the scope, for which no experimental data were provided, the GMO Panel assessed the likelihood of interactions among the single events and concluded that their combinations would not raise safety concerns. These maize subcombinations are therefore expected to be as safe as the single events, the previously assessed subcombinations and the four‐event stack maize. The post‐market environmental monitoring plan and reporting intervals are in line with the intended uses of maize Bt11 × MIR162 × 1507 × GA21 and its subcombinations. A minority opinion expressed by a GMO Panel member is appended to this opinion.

Risk Assessment of Insect-resistant and Herbicide Tolerant Genetically Modified Maize Bt11 for Cultivation, Import, Processing, Food and Feed Uses under Directive 2001/18/EC and Regulation (EC) Opinion

Risk Assessment of Insect-resistant and Herbicide Tolerant Genetically Modified Maize Bt11 for Cultivation, Import, Processing, Food and Feed Uses under Directive 2001/18/EC and Regulation (EC) Opinion

Risk assessment of information on the subcombination Bt11×1507×GA21, related to the application of Syngenta (EFSA-GMO-DE-2011-99) for authorisation of food and feed containing, consisting and produced from genetically modified maize Bt11×59122×MIR604×1507×GA21.

The GMO Panel has previously assessed the single events Bt11, 59122, MIR604, 1507 and GA21 as well as different stacked events corresponding to combinations of these events and no safety concerns were identified. In its assessment of the five‐event maize stack Bt11 × 59122 × MIR604 × 1507 × GA21 (application EFSA‐GMO‐DE‐2011‐99), the GMO Panel also assessed all the subcombinations of these events not previously assessed, including some for which little or no experimental data were provided, including the three‐event stack Bt11 × 1507 × GA21. In line with Article 5 of the decision for authorisation of application EFSA‐GMO‐DE‐2011‐99, the European Commission received from Syngenta information on the levels of the newly expressed proteins in subcombination Bt11 × 1507 × GA21 and tasked EFSA to analyse these data and to indicate whether they have an impact on the previously issued opinion on the five‐event stack Bt11 × 59122 × MIR604 × 1507 × GA21 and its subcombinations. Analyses of the levels of the newly expressed proteins Cry1Ab, PAT, Cry1F and mEPSPS showed that there is no indication of an interaction between the events combined in maize Bt11 × 1507 × GA21 that would affect the levels of the newly expressed proteins. Thus, the GMO Panel is of the opinion that the new information for maize Bt11 × 1507 × GA21 does not alter the conclusions of the scientific opinion on application EFSA‐GMO‐DE‐2011‐99.

Ecological guild and enzyme activities of rhizosphere soil microbial communities associated with Bt-maize cultivation under field conditions in North West Province of South Africa.

Insecticidal proteins expressed by genetically modified Bt maize may alter the enzymatic and microbial communities associated with rhizosphere soil. This study investigated the structure and enzymatic activity of rhizosphere soil microbial communities associated with field grown Bt and non-Bt maize. Rhizosphere soil samples were collected from Bt and non-Bt fields under dryland and irrigated conditions. Samples were subjected to chemical tests, enzyme analyses, and next generation sequencing. Results showed that nitrate and phosphorus concentrations were significantly higher in non-Bt maize dryland soils, while organic carbon was significantly higher in non-Bt maize irrigated field soil. Acid phosphatase and β-glucosidase activities were significantly reduced in soils under Bt maize cultivation. The species diversity differed between fields and Bt and non-Bt maize soils. Results revealed that Actinobacteria, Proteobacteria, and Acidobacteria were the dominant phyla present in these soils. Redundancy analyses indicated that some chemical properties and enzyme activities could explain differences in bacterial community structures. Variances existed in microbial community structures between Bt and non-Bt maize fields. There were also differences between the chemical and biochemical properties of rhizosphere soils under Bt and non-Bt maize cultivation. These differences could be related to agricultural practices and cultivar type.

Risk assessment of information on the subcombination Bt11×MIR162, related to the application of Syngenta (EFSA-GMO-DE-2009-66) for authorisation of food and feed containing, consisting and produced from genetically modified maize Bt11×MIR162×MIR604×GA21.

The EFSA Panel on Genetically Modified Organisms (GMO) has previously assessed the single events Bt11, MIR162, MIR604 and GA21 as well as different stacked events corresponding to combinations of these events. These maize events were found to be as safe as their conventional counterparts and other appropriate comparators with respect to potential effects on human and animal health and the environment. In its assessment of the four‐event maize stack Bt11 × MIR162 × MIR604 × GA21, the GMO Panel also assessed all the subcombinations of these events not previously assessed, including some for which little or no experimental data were provided, including the two‐stack maize event Bt11 × MIR162 (application EFSA‐GMO‐DE‐2009‐66). On 8 November 2016, the European Commission received from Syngenta information on the subcombination Bt11 × MIR162. On 14 December 2016, the European Commission tasked EFSA to analyse these data and to indicate whether they have an impact on the previously issued opinion on the four‐event stack Bt11 × MIR162 × MIR604 × GA21 and its subcombinations. The GMO Panel used the appropriate principles described in its guidelines for the risk assessment of genetically modified (GM) plants to analyse the provided data. The levels of the newly expressed proteins Cry1Ab, PAT, Vip3Aa20 and PMI are similar between the two‐event stack Bt11 × MIR162 and the corresponding single events Bt11 and MIR162. Based on this analysis, there is no indication of an interaction between the events combined in maize Bt11 × MIR162 that would affect the levels of the newly expressed proteins. Thus, the GMO Panel considers that the new information for maize Bt11 × MIR162 does not alter the conclusions of the scientific opinion on application EFSA‐GMO‐DE‐2009‐66.

Movement and survival of Busseola fusca (Lepidoptera: Noctuidae) larvae within maize plantings with different ratios of non-Bt and Bt seed.

Products of plant biotechnology, for example genetically modified Bt maize, provide useful tools for pest management. The benefits provided by insect-resistant plants are, however, threatened by the evolution of resistance by target pest species. The high-dose/refuge insect resistance management strategy (IRM) as well as seed mixtures are globally used as IRM strategies. Busseola fusca (Lepidoptera: Noctuidae), the target stem borer of Bt maize in Africa, evolved resistance to Bt maize expressing Cry1Ab protein in South Africa. Owing to high larval mobility and subsequent sublethal exposure of larvae moving between non-Bt and Bt plants, more rapid resistance evolution has been proposed as a possibility with deployment of seed mixture strategies. Laboratory and field studies were conducted to study B. fusca larval mobility. In the laboratory, different scenarios of B. fusca larval movement between single-gene (Cry1Ab) and stacked-trait (Cry1A.105 and Cry2Ab2) Bt maize were studied. Data on larval survival and mass over time indicated that Cry proteins do not kill larvae above certain developmental stages. A 2 year field study with the single gene and the stacked event was conducted using seed mixtures containing 5, 10, 15 and 20% non-Bt seed as well as a control treatment (non-Bt seed only). Larval movement continued for 5 weeks and resulted in a significant incidence of Bt and non-Bt damaged plants, indicating that the movement behaviour of B. fusca is of such a nature that seed mixtures as an IRM strategy may not be effective to delay resistance evolution. © 2016 Society of Chemical Industry.

CytochromecOxidase I and CytochromebGene Sequences Indicate Low Genetic Diversity in South AfricanBusseola fusca(Lepidoptera: Noctuidae) from maize

The African maize stem borer, Busseola fusca, feeds on a limited number of host plant species (Calatayud et al. 2014), which include crops such as maize, pearl millet and sorghum. This pest occurs throughout sub-Saharan Africa where it causes economic damage to maize and sorghum crops (Kfir et al. 2002). In an attempt to combat lepidopteran stem borers, genetically modified Bt maize that express insecticidal Cry toxins were developed to kill larvae that feed on these plants (George et al. 2011). Bt maize was introduced into South Africa during 1998 and within the first decade after release, field-evolved resistance of B. fusca to Bt maize was reported (Van Rensburg 2007). Since this first report, resistant populations have been reported from several parts of the maize-production region of South Africa (Kruger et al. 2011; Van den Berg et al. 2013). Explanations provided for this rapid resistance development were confined to agronomical reasons (VanRensburg 2007; Kruger et al. 2009, 2011),non-compliance to refuge requirements (Kruger etal. 2009) and non-recessive inheritance of resistance (Campagne et al. 2013). Notmuchis however understood about the molecular genetics of B.fusca. Previously, Sezonlin et al. (2006b) noted that limited population genetic and phylogeography data are available for B. fusca.

Relevance of a new scientific publication (Trtikova et al., 2015) on previous EFSA GMO Panel conclusions on the risk assessment of maize MON 810 and other Cry1Ab‐expressing Bt‐maize events

Relevance of a new scientific publication (Trtikova et al., 2015) on previous EFSA GMO Panel conclusions on the risk assessment of maize MON 810 and other Cry1Ab‐expressing Bt‐maize events