Novel Food Information: Lepidopteran Protected Corn – MON 95379

On this page

• Background
1. Introduction
2. Development of the Modified Plant
3. Characterization of the Modified Plant
4. Product Information
5. Dietary Exposure
6. Nutrition
7. Toxicology/Allergenicity
• Conclusion

Background:

Health Canada has notified Bayer CropScience Inc. that it has no objection to the food use of Lepidopteran protected corn – MON 95379. The Department conducted a comprehensive assessment of this maize variety according to its Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits.

The following provides a summary of the notification from Bayer CropScience Inc. and the evaluation by Heath Canada and contains no confidential business information.

1. Introduction

Bayer CropScience Inc. has developed a genetically modified Zea mays (maize) variety to produce two insecticidal crystalline (Cry) proteins, Cry1B.868 and Cry1Da_7, to protect against feeding damage caused by targeted lepidopteran pests. The two introduced Cry genes encode for prototoxins that are cleaved by digestive enzymes upon exposure to the midgut of the target organisms to yield the insecticidal toxin.

The safety assessment performed by Food Directorate evaluators was conducted according to Health Canada's Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based on harmonization efforts with other regulatory authorities and reflect international guidance documents in this area (e.g., Codex Alimentarius). The assessment considered: how this maize variety was developed; how the composition and nutritional quality of this variety compared to non-modified maize varieties; and the potential for this maize variety to be toxic or cause allergic reactions. Bayer CropScience Inc. has provided data that demonstrate that MON 95379 is as safe and of the same nutritional quality as traditional maize varieties used as food in Canada.

The Food Directorate has a legislated responsibility for pre-market assessment of novel foods and novel food ingredients as detailed in the Food and Drug Regulations (Division B.28). MON 95379 is considered a novel food under the following part of the definition of novel foods:

• (c) a food that is derived from a plant, animal or microorganism that has been genetically modified such that:
• (i) the plant, animal or microorganism exhibits characteristics that were not
  previously observed in that plant, animal or microorganism.

2. Development of the Modified Plant

The petitioner has provided information describing the methods used to develop MON 95379 and the molecular biology data that characterize the genetic change, which results in lepidopteran pest protection.

MON 95379 was developed through Agrobacterium-mediated transformation of maize (Zea mays L.) variety LH344 with a transformation vector (PV-ZMIR522223) containing a single transfer (T-DNA) of the two Cry genes.

The coding sequences for the Cry1B.868 and Cry1Da_7 proteins were isolated from the bacterium Bacillus thuringiensis (Bt). Both genes encode for crystalline protein prototoxins that upon exposure to the midgut of target organisms are cleaved by digestive enzymes to yield the insecticidal toxin.

The petitioner provided information to support the safety and historical use of the donor organism (B. thuringiensis) and the recipient organism (Z. mays L.). None of these organisms pose a safety concern. Furthermore, Cry proteins have been previously assessed by Health Canada in corn, soybean, tomato, cotton, and potato.

3. Characterization of the Modified Plant

The number of integration sites of the T-DNA insert in MON 95379 was characterized using a combination of whole genome sequencing (WGS) and directed sequencing (locus-specific PCR, DNA sequencing and analyses). These analyses confirmed that MON 95379 contains a single copy of the T-DNA inserted into a single locus.

The genetic stability of the T-DNA insert in the MON 95379 genome was demonstrated by assessing individual MON 95379 plants from five generations (F4, F5, F4F1, F5F1, and F6F1) by means of WGS analyses. The results indicate that the T-DNA insert is intact and stable over all five generations. Chi-square (χ2) analysis of the segregation data for three backcrossed generations was performed to test the hypothesis that the two Cry genes are inherited in a manner expected for a single insertion. The results are consistent with Mendelian principles of inheritance and support the conclusion that the MON 95379 genome contains a single T-DNA insert integrated into a single chromosomal locus within the maize genome.

4. Product Information

MON 95379 differs from its traditional counterparts by the addition of two genes: Cry1B.868 and Cry1Da_7 genes that encode for insecticidal crystalline proteins, which upon exposure to the midgut of target lepidopteran pests, are cleaved by digestive enzymes to yield the insecticidal toxin.

Expression levels of the Cry proteins in MON 95379 were analyzed using validated enzyme linked immunosorbent assays (ELISAs). Expression values were reported on a μg/g dry weight (DW) basis in maize tissues (i.e., silk, pollen, forage, grain, over season leaf ([OSL] 1 and OSL 4, and over season root [OSR] 1 and forage root) collected from MON 95379 produced in United States field trials during 2018.

The mean Cry1B.868 protein level across all sites was the highest in OSL1 at 630 µg/g dw and lowest in forage root at 22 µg/g dw. The mean Cry1B.868 protein level was 26 µg/g dw in grain. The mean Cry1Da_7 protein level across all sites was the highest in OSL1 at 92 µg/g dw and lowest in pollen (below the limit of quantitation). The mean Cry1Da_7 protein level was 0.25 µg/g dw in grain.

5. Dietary Exposure

It is expected that MON 95379 will be used in applications similar to conventional corn varieties. The petitioner does not anticipate a significant change in the food use of corn with the introduction of MON 95379.

6. Nutrition

To evaluate if there were any unanticipated consequences of the genetic modifications to
MON 95379 maize, the nutritional and anti-nutritional components of the modified maize were analyzed and compared to a conventional control with a similar genetic background. This was done as part of a field trial conducted in 2018, using a randomized block design with four replicates at each of the five locations in the United States. The compositional analytes measured in MON 95379 maize and non-genetically modified control maize grain were: proximates and fibres, amino acids, fatty acids, minerals, vitamins, anti-nutrients and secondary metabolites as suggested by the Organisation for Economic Co-operation and Development (OECD) consensus document on compositional considerations for new varieties of corn.

Of the analytes measured, the following showed a statistically significant difference (MON 95379 vs. conventional counterpart, units): carbohydrates (85.23 vs. 85.73, % DW), total protein (9.61 vs. 9.18, % DW), alanine (0.75 vs. 0.71, % DW), glutamic acid (1.80 vs. 1.71, % DW), isoleucine (0.34 vs. 0.33, % DW), leucine (1.24 vs. 1.17, % DW), methionine (0.22 vs. 0.21, % DW), phenylalanine (0.49 vs. 0.47, % DW), serine (0.48 vs. 0.45, % DW), threonine (0.34 vs. 0.33, % DW), valine (0.45 vs. 0.43, % DW), alpha-linolenic acid (1.15 vs. 1.17, % total FA), copper (1.48 vs. 1.31, mg/kg DW), iron (17.16 vs. 16.35, mg/kg DW), manganese (5.58 vs. 4.96, mg/kg DW), phosphorus (0.32 vs. 0.31, % DW), zinc (19.40 vs. 17.93, mg/kg DW), beta-carotene (1.11 vs. 1.03, mg/kg DW). In all cases, the composition of MON 95379 corn was within the expected range for conventional corn.

Based on the information provided on the composition of MON 95379 corn and control varieties, there are no safety concerns with the use of MON 95379 as a food ingredient in Canada from a nutritional perspective.

7. Toxicology/Allergenicity

There are no known equivalent receptor sites for Cry proteins in mammalian species and the more acidic environment of the mammalian gut leads to degradation of Cry proteins; therefore, this toxic mode of action is not considered relevant to humans. To support this conclusion, the petitioner submitted acute oral toxicity studies, and conducted searches of the publicly available databases assessing the sequence similarity of these proteins to known and suspected toxins and allergens.

In the acute oral toxicity studies, mice (10/sex/group) were exposed by gavage to 0 or 5000 mg/kg bw Cry1B.868 or Cry 1Da_7 protein. The no observed adverse effect level (NOAEL) was ≥5000 mg/kg bw in both studies.

The plant pest potential was observed to be similar between the modified corn line and conventional corn varieties. Based on that information, Health Canada is of the opinion that it is unlikely that MON 95379 will be more susceptible to mycotoxin-producing fungi relative to conventional varieties of corn.

The petitioner compared the amino acid sequences of the novel proteins to those of known toxins using the GenBank protein database (last updated 2019) and refined the results using keywords related to toxicity. No significant homology between these novel proteins and known or suspected toxins was identified.

The host organism, corn, has a long history of safe food use in Canada and is not associated with allergenic concerns. In addition, the donor organism (Bt) is widespread in the environment and has not been reported as a source of known allergens.

The petitioner conducted a bioinformatics analysis to compare the amino acid sequences of the two Cry proteins to sequences of known allergens using the COMPARE database (last updated 2019). No matches were identified. These proteins do not share sequence similarity with known allergens. No significant homology between these novel proteins and known or suspected food allergens was identified.

Based on the information reviewed, there are no safety concerns regarding the food use of
MON 95379 corn compared to conventional corn varieties from toxicological and allergenic perspectives.

Conclusion:

Health Canada's review of the information presented in support of the food use of MON 95379 does not raise concerns related to food safety. Health Canada is of the opinion that food derived from this maize variety is as safe and nutritious as food derived from current commercial maize varieties.

Health Canada's opinion deals only with the food use of MON 95379. Issues related to its environmental release and use as animal feed have been addressed separately through existing regulatory processes in the Canadian Food Inspection Agency (CFIA).

This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Products and Food Branch, Health Canada. This opinion is based upon the comprehensive review of information submitted by the petitioner according to the Guidelines for the Safety Assessment of Novel Foods.

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For further information, please contact:

Novel Foods Section
Food Directorate
Health Products and Food Branch
Health Canada, PL2204A1
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9
bmh-bdm@hc-sc.gc.ca