Decision Document DD2014-102
Determination of the Safety of Genective SA's Corn (Zea mays L.) Event VCO-Ø1981-5

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This Decision Document has been prepared to explain the regulatory decisions reached under Directive 94-08 (Dir94-08) - Assessment Criteria for Determining Environmental Safety of Plants with Novel Traits, its companion biology document BIO1994-11 - The Biology of Zea mays (L.) (Maize) and Section 2.6 - Guidelines for the Assessment of Novel Feeds: Plant Sources of Chapter 2 of the RG-1 Regulatory Guidance: Feed Registration Procedures and Labelling Standards.

The Canadian Food Inspection Agency (CFIA) - specifically the Plant Biosafety Office of the Plant Health and Biosecurity Directorate, the Plant and Biotechnology Risk Assessment Unit of the Plant Health Science Directorate and the Animal Feed Division of the Animal Health Directorate - has evaluated information submitted by Genective SA. This information is in regard to the herbicide tolerant corn event VCO-Ø1981-5. The CFIA has determined that this plant with a novel trait (PNT) does not present altered environmental risk nor, as a novel feed, does it present livestock feed safety concerns when compared to corn varieties currently grown and permitted to be used as livestock feed in Canada.

Taking into account these evaluations, unconfined release into the environment and use as livestock feed of corn event VCO-Ø1981-5 is therefore authorized by the Plant Biosafety Office of the Plant Health and Biosecurity Directorate and the Animal Feed Division of the Animal Health Directorate, respectively, as of February 14, 2014. Any corn lines derived from corn event VCO-Ø1981-5 may also be released into the environment and used as livestock feed, provided that

  1. no inter-specific crosses are performed;
  2. the intended uses are similar;
  3. it is known based on characterization that these plants do not display any additional novel traits and are substantially equivalent to corn varieties that are currently grown and permitted to be used as livestock feed in Canada, in terms of their potential environmental impact and livestock feed safety; and
  4. the novel gene is expressed at levels similar to those in the authorized line.

Corn event VCO-Ø1981-5 is subject to the same phytosanitary import requirements as unmodified corn varieties. Corn event VCO-Ø1981-5 is required to meet the requirements of other Canadian legislation, including but not limited to the requirements set out in the Food & Drugs Act and the Pest Control Products Act.

Please note that the livestock feed and environmental assessments of novel feeds and PNTs are critical steps in the potential commercialization of these plant types. Other requirements, such as the evaluation of novel foods by Health Canada, have been addressed separately from this review.

February 14, 2014

This bulletin was created by the Canadian Food Inspection Agency. For further information, please contact the Plant Biosafety Office or the Animal Feed Division by visiting the contact page.

Table of Contents

  1. Brief Identification of the Modified Plant
  2. Background Information
  3. Description of the Novel Trait
    1. Development Method
    2. Tolerance to Glyphosate Herbicide
    3. Stable Integration into the Plant Genome
  4. Criteria for the Environmental Assessment
    1. Potential of Corn Event VCO-Ø1981-5 to Become a Weed of Agriculture or be Invasive of Natural Habitats
    2. Potential for Gene Flow from Corn Event VCO-Ø1981-5 to Sexually Compatible Plants Whose Hybrid Offspring May Become More Weedy or More Invasive
    3. Potential for Corn Event VCO-Ø1981-5 to Become a Plant Pest
    4. Potential Impact of Corn Event VCO-Ø1981-5 or Its Gene Products on Non-Target Organisms, including Humans
    5. Potential Impact of Corn Event VCO-Ø1981-5 on Biodiversity
  5. Criteria for the Livestock Feed Assessment
    1. Potential Impact of Corn Event VCO-Ø1981-5 on Livestock Nutrition
    2. Potential Impact of Corn Event VCO-Ø1981-5 on Animal Health and Human Safety as it Relates to the Potential Transfer of Residues into Foods of Animal Origin and Worker/Bystander Exposure to the Feed
  6. New Information Requirements
  7. Regulatory Decision

I. Brief Identification of the Modified Plant

Designation of the Modified Plant: Corn event VCO-Ø1981-5 OECD Unique Identifier VCO-Ø1981-5
Applicant: Genective SA
Plant Species: Corn (Zea mays L.)
Novel Traits: Tolerance to glyphosate herbicide
Trait Introduction Method: Agrobacterium-mediated transformation
Intended Use of the Modified Plant: Corn event VCO-Ø1981-5 is intended to be grown for traditional corn human food and livestock feed uses. Corn event VCO-Ø1981-5 is not intended to be grown outside the normal production area for corn in Canada.

II. Background Information

Genective SA has developed a corn event that is tolerant to glyphosate herbicide.

Corn event VCO-Ø1981-5 was developed by Genective SA using recombinant deoxyribonucleic acid (DNA) technology, resulting in the introduction of the epsps grg23ace5 gene, which encodes a modified, glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from the common soil bacterium Arthrobacter globiformis.

Genective SA has provided information on the identity of corn event VCO-Ø1981-5; a detailed description of the transformation method; and information on the gene insertion site, gene copy number and levels of gene expression in the plant and the roles of the inserted gene and regulatory sequences. The novel protein was identified and characterized. Information was provided for the evaluation of the potential toxicity of the novel protein to livestock and non-target organisms and potential allergenicity of the novel protein to humans and to livestock. Information was also provided for the evaluation of herbicide residues in the feed commodities derived from the crop, following the intended herbicide application.

Hybrids of corn event VCO-Ø1981-5 were field tested at 17 sites in the United States (US) in 2009 and at two sites in Canada in 2011. The locations of the US field trials share similar environmental and agronomic conditions to corn production areas in Canada and were considered representative of major Canadian corn growing regions.

Agronomic characteristics of hybrids of corn event VCO-Ø1981-5, such as early stand count, plant vigour, plant height, ear height, final stand count, stalk lodging, root lodging, grain moisture, grain weight, days to 50% pollen shed, days to 50% silking, days to 50% tasseling, dropped ears, barrenness and yield, were compared to hybrids of an unmodified control corn variety, which was derived from the same initial transformation event as corn event VCO-Ø1981-5 but had lost the inserted genetic material during subsequent breeding. This variety shares the same genetic background as corn event VCO-Ø1981-5.

Nutritional components of hybrids of corn event VCO-Ø1981-5 grain and forage, such as crude fat, ash, protein, moisture, crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF), amino acids, fatty acids, vitamins, minerals, secondary metabolites, and anti-nutrients, were compared with those of hybrids of the unmodified control corn variety and to three conventional control corn hybrids.

The Plant and Biotechnology Risk Assessment (PBRA) Unit of the Plant Health Science Directorate, CFIA, has reviewed the above information, in light of the assessment criteria for determining environmental safety of PNTs, as described in Directive 94-08 (Dir94-08) - Assessment Criteria for Determining Environmental Safety of Plants with Novel Traits. The PBRA Unit has considered:

  • the potential of corn event VCO-Ø1981-5 to become a weed of agriculture or to be invasive of natural habitats;
  • the potential for gene flow from corn event VCO-Ø1981-5 to sexually compatible plants whose hybrid offspring may become more weedy or more invasive;
  • the potential for corn event VCO-Ø1981-5 to become a plant pest;
  • the potential impact of corn event VCO-Ø1981-5 and its gene products on non-target organisms, including humans; and
  • the potential impact of corn event VCO-Ø1981-5 on biodiversity.

The Animal Feed Division (AFD) of the CFIA has also reviewed the above information with respect to the assessment criteria for determining the safety and efficacy of livestock feed, as described in Section 2.6 - Guidelines for the Assessment of Novel Feeds: Plant Sources, of Chapter 2 of the RG-1 Regulatory Guidance: Feed Registration Procedures and Labelling Standards.

The AFD has considered both intended and unintended effects and similarities and differences between corn event VCO-Ø1981-5 and unmodified corn varieties relative to the safety and efficacy of feed ingredients derived from corn event VCO-Ø1981-5 for their intended purpose, including:

  • the potential impact of corn event VCO-Ø1981-5 on livestock nutrition; and
  • the potential impact of corn event VCO-Ø1981-5 on animal health and human safety, as it relates to the potential transfer of residues into foods of animal origin and worker/bystander exposure to the feed.

The AFD has also considered whether feeds derived from corn event VCO-Ø1981-5 meet the definitions and requirements of feeds as listed in Schedule IV of the Feeds Regulations.

Genective SA has provided the CFIA with a method for the detection and identification of corn event VCO-Ø1981-5.

III. Description of the Novel Trait

1. Development Method

Corn event VCO-Ø1981-5 was developed through Agrobacterium-mediated transformation of corn cells and contains the epsps grg23ace5 gene. This gene was derived from the native A. globiformis epsps gene, which encodes a naturally glyphosate-tolerant EPSPS enzyme, and modified by Genective SA using directed evolution protein engineering to encode the EPSPS ACE5 enzyme, which contains 10 amino acid changes to the native enzyme, resulting in an activity temperature range that is similar to that of the native corn EPSPS enzyme. Transformed cells were selected on the basis of tolerance to glyphosate and regenerated to produce plants. Corn event VCO-Ø1981-5 was identified as a successful transformant based on molecular analyses, herbicide efficacy and agronomic evaluations, and was thus chosen for further development.

2. Tolerance to Glyphosate Herbicide

EPSPS is an enzyme involved in the plant shikimic acid metabolic pathway which is essential for the production of aromatic amino acids. The herbicide glyphosate disrupts the shikimic acid pathway by binding to the EPSPS enzyme, leading to interference in aromatic amino acids production and growth suppression or death of the plant. The native corn EPSPS enzyme is sensitive to glyphosate but the EPSPS ACE5 expressed in corn event VCO-Ø1981-5 is glyphosate-tolerant, conferring commercial-level glyphosate tolerance to corn event VCO-Ø1981-5 by enabling it to continue to catalyze the production of aromatic amino acids in the presence of glyphosate.

The expression of the EPSPS ACE5 in corn event VCO-Ø1981-5 is driven by a constitutive promoter. Samples of corn event VCO-Ø1981-5 tissues were collected from three field trial sites in the US. Average EPSPS ACE5 expression levels, as evaluated by ELISA, were as follows: 6.2 to 18.6 micrograms protein per gram dry weight tissue (μg/g dwt) in leaf at the V4 to R6 stages, below detection to 6.8 μg/g dwt in root at the V4 to R6 stages and below detection to 12.7 μg/g dwt in whole plants at the V8 to R6 stages. Levels in pollen at the R1 stage and grain at the R6 stage were below detection.

The potential allergenicity and toxicity of the EPSPS ACE5 protein to livestock and non-target organisms were evaluated. The weight of evidence indicates that the EPSPS ACE5 protein is unlikely to be allergenic. The source of the epsps grg23ace5 gene, A. globiformis, is not commonly associated with allergenicity, the EPSPS ACE5 protein amino acid sequence lacks relevant similarities to known allergens, microbial EPSPS ACE5 protein was shown experimentally to be rapidly degraded in simulated gastric fluid and not to be heat stable, and corn event VCO-Ø1981-5 EPSPS ACE5 protein was shown experimentally to be unglycosylated. It was also concluded that the EPSPS ACE5 protein is unlikely to be toxic to livestock and non-target organisms because it lacks a mode of action to suggest that it is intrinsically toxic to livestock or non-target organisms. The EPSPS ACE5 protein amino acid sequence lacks relevant similarities to known toxins and no adverse effects were observed when microbial EPSPS ACE5 protein was ingested by mice at doses of approximately 2000 milligrams protein per kilogram body weight (mg/kg bwt). For a more detailed discussion of the potential allergenicity and toxicity of the EPSPS ACE5 protein, see Section V, part 2: Potential Impact of Corn event VCO-Ø1981-5 on Animal Health and Human Safety as it Relates to the Potential Transfer of Residues into Foods of Animal Origin and Worker/Bystander Exposure to the Feed.

3. Stable Integration into the Plant Genome

Molecular characterization by Southern blot analysis and DNA sequencing demonstrated that corn event VCO-Ø1981-5 contains one intact copy of the gene cassette containing the epsps grg23ace5 gene and its regulatory elements inserted at a single site in the corn genome. No additional elements, including intact or partial DNA fragments of the gene cassette or backbone sequences from the plasmid vector, linked or unlinked to the intact insert, were detected in corn event VCO-Ø1981-5.

The stability of the insert within corn event VCO-Ø1981-5 was verified by Southern blot analysis and by tolerance to glyphosate herbicide over four generations. The inheritance pattern of the insert and the herbicide tolerance trait across four segregating generations of corn event VCO-Ø1981-5 showed that the insert segregates according to Mendelian rules of inheritance for a single genetic locus.

IV. Criteria for the Environmental Assessment

1. Potential of Corn Event VCO-Ø1981-5 to Become a Weed of Agriculture or be Invasive of Natural Habitats

The biology of corn, described in the CFIA biology document BIO1994-11 - The Biology of Zea mays L. (Maize), states that unmodified plants of this species are not invasive of unmanaged habitats in Canada. Corn does not possess the potential to become weedy due to the lack of seed dormancy, the non-shattering nature of corn cobs and the poor competitive ability of seedlings. According to the information provided by Genective SA, corn event VCO-Ø1981-5 was determined not to be significantly different from unmodified corn in this respect.

The CFIA evaluated data submitted by Genective SA on the reproductive biology and life history traits of corn event VCO-Ø1981-5. As previously mentioned, hybrids of corn event VCO-Ø1981-5 were field tested in the US at 17 locations in 2009 and in Canada at two locations in 2011. It was determined that the US locations share similar environmental and agronomic conditions to southern Ontario and Quebec and were considered to be representative of major Canadian corn growing regions. During the field trials, hybrids containing corn event VCO-Ø1981-5 were compared to hybrids of the unmodified control corn variety. Phenotypic and agronomic traits were evaluated, covering a broad range of characteristics that encompass the entire life cycle of the corn plant. The traits included early stand count, emergence, plant vigour, plant height, ear height, final stand count, stalk lodging, root lodging, grain moisture, grain weight, days to 50% pollen shed, days to 50% silking, days to 50% tasseling, dropped ears, barrenness and yield. Although instances of statistically significant differences were observed between hybrids of corn event VCO- Ø1981-5 and those of the unmodified control corn variety for some traits in the individual-site analyses, there were no consistent trends in the data across locations that would indicate that the differences were due to the genetic modification. Therefore, the statistical analysis of these observations showed no biologically meaningful differences between hybrids of corn event VCO-Ø1981-5 and those of the unmodified control corn variety and supports a conclusion of phenotypic and agronomic equivalence to currently grown corn varieties.

Genective SA provided information on the germination of hybrids of corn event VCO-Ø1981-5 seed under warm and cool temperature regimes. No difference was detected between hybrids of corn event VCO-Ø1981-5 and those of the unmodified control corn variety at either temperature regime. Therefore the introduction of the novel trait did not impact the germination of the corn seed and did not confer dormancy to the corn seed.

Corn event VCO-Ø1981-5 was exposed to excess moisture and nitrogen deficiency in the field during the agronomic characteristic studies. No trend in increased or decreased susceptibility to these abiotic stressors was observed between hybrids of corn event VCO-Ø1981-5 compared to those of the unmodified control corn variety.

The susceptibility of corn event VCO-Ø1981-5 to various corn pests and pathogens was evaluated in the field at the same locations as the agronomic characteristic studies (further detail provided below in Section IV, part 3: Potential for Corn Event VCO-Ø1981-5 to Become a Plant Pest). No trend in increase or decrease of susceptibility to pests and pathogens was observed in hybrids of corn event VCO-Ø1981-5 compared to those of the unmodified control corn variety.

No competitive advantage was conferred to hybrids of corn event VCO-Ø1981-5, other than that conferred by tolerance to the glyphosate herbicide, as the reproductive characteristics, growth characteristics and tolerance to abiotic and biotic stresses of hybrids of corn event VCO-Ø1981-5 were comparable to those of hybrids of the unmodified control corn variety. Tolerance to glyphosate provides a competitive advantage only when this herbicide is used and will not, in and of itself, make a glyphosate tolerant plant weedier or more invasive of natural habitats. Corn event VCO-Ø1981-5 plants growing as volunteers will not be controlled if glyphosate is used as the only weed control tool. However, control of corn event VCO-Ø1981-5 as a volunteer weed in subsequent crops or in fallow ground can be achieved by the use of other classes of herbicides or by mechanical means.

The novel trait has no intended or observed effects on weediness or invasiveness. The CFIA has therefore concluded that corn event VCO-Ø1981-5 has no altered weediness or invasiveness potential in Canada compared to currently grown corn varieties.

The CFIA considers the changes in usual agronomic practices that may arise from volunteer plants with novel herbicide tolerances. Similarly, the CFIA considers the potential that continued application of the same herbicide in subsequent rotations may lead to increased selection pressure for herbicide tolerant weed populations. In order to address these issues, an herbicide tolerance management plan, which includes integrated weed management strategies, should be implemented. These plans may include a recommendation to rotate or combine weed control products with alternate modes of action and to employ other weed control practices.

Genective SA has submitted an herbicide tolerance management plan to the CFIA, which was determined to be satisfactory when evaluated by the PBRA Unit.

Genective SA will make this herbicide tolerance management plan readily available to growers and agriculture extension personnel, in both private and public sectors, to promote careful management practices for corn event VCO-Ø1981-5. Genective SA will provide an efficient mechanism for growers to report agronomic problems to the company, which will facilitate the ongoing monitoring of corn event VCO-Ø1981-5. Genective SA will monitor grower compliance to determine the effectiveness of the herbicide tolerance management plan and make any changes to the plan as appropriate.

2. Potential for Gene Flow from Corn Event VCO-Ø1981-5 to Sexually Compatible Plants Whose Hybrid Offspring May Become More Weedy or More Invasive

The biology of corn, as described in the CFIA biology document BIO1994-11 - The Biology of Zea mays (L.) (Maize), indicates that there are no sexually compatible plants in Canada that can hybridize with corn. The glyphosate tolerance trait is unrelated to sexual compatibility and the information submitted by Genective SA on corn event VCO-Ø1981-5 indicates that it behaves similarly to currently grown corn varieties in terms of reproduction.

This information, together with the fact that the novel trait has no intended effects on corn reproductive biology, led the CFIA to conclude that gene flow from corn event VCO-Ø1981-5 to wild relatives is not possible in Canada.

3. Potential for Corn Event VCO-Ø1981-5 to Become a Plant Pest

Corn is not considered a plant pest in Canada and the glyphosate herbicide tolerance trait introduced into corn event VCO-Ø1981-5 is unrelated to the plant pest potential (i.e., the potential for the plant to harbour new or increased populations of pathogens or pests).

The susceptibility of hybrids of corn event VCO-Ø1981-5 to various corn pests and pathogens was evaluated in the field at the same locations as the agronomic characteristic studies. The stressors observed included fall armyworm, Japanese beetles, European corn borer, aphids, grasshoppers, northern corn rootworm, common stalk borer, western corn rootworm, gray leaf spot, common rust, northern leaf blight, northern corn leaf spot, anthracnose and common smut. The evaluations of hybrids of corn event VCO-Ø1981-5 did not show any increase or decrease in susceptibility to corn pests or pathogens compared to those of the unmodified control corn variety.

The CFIA therefore concludes that corn event VCO-Ø1981-5 does not display any altered plant pest potential compared to currently grown corn varieties.

4. Potential Impact of Corn Event VCO-Ø1981-5 or Its Gene Products on Non-Target Organisms, including Humans

The glyphosate herbicide tolerance trait introduced into corn event VCO-Ø1981-5 is unrelated to a potential impact on non-target organisms.

Detailed characterization of the EPSPS ACE5 protein expressed in corn event VCO-Ø1981-5 led to the conclusion that this protein does not display any characteristic of a potential toxin or allergen (see Section III, part 2: Tolerance to Glyphosate Herbicide). Therefore, no negative impacts resulting from exposure of organisms to the EPSPS ACE5 protein expressed in corn event VCO-Ø1981-5 are expected.

Composition analyses showed that the levels of key nutrients and anti-nutrients in grain and forage from hybrids of corn event VCO-Ø1981-5 are comparable to those in hybrids of conventional corn varieties (see Section V, part 1:Potential Impact of Corn Event VCO-Ø1981-5 on Livestock Nutrition). Therefore, it is very unlikely that the introduction of the novel trait may have caused unintended changes to the composition of corn event VCO-Ø1981-5 tissues that would negatively impact organisms interacting with corn event VCO-Ø1981-5.

Field evaluations of hybrids of corn event VCO-Ø1981-5 did not show any increased resistance to insect pests or pathogens compared to the unmodified control corn variety (see Section IV, part 3: Potential for Corn Event VCO-Ø1981-5 to Become a Plant Pest).

Collectively, these information elements indicate that the interactions between corn event VCO-Ø1981-5 and the populations of animals and microorganisms interacting with corn crops will be similar compared to currently grown corn varieties.

The CFIA has therefore determined that the unconfined release of corn event VCO-Ø1981-5 in Canada will not result in altered impacts on non-target organisms, including humans, compared to currently grown corn varieties.

5. Potential Impact of Corn Event VCO-Ø1981-5 on Biodiversity

Corn event VCO-Ø1981-5 expresses no novel phenotypic characteristics that would extend its range beyond the current geographic range of corn production in Canada. Since corn has no wild relatives with which it can outcross in Canada, there will be no transfer of the novel trait to other species in unmanaged environments. Corn event VCO-Ø1981-5 is unlikely to cause adverse effects on non-target organisms and does not display increased weediness, invasiveness or plant pest potential. It is therefore unlikely that corn event VCO-Ø1981-5 will have any direct effects on biodiversity, in comparison to the effects that would be expected from the cultivation of corn varieties that are currently grown in Canada.

Corn event VCO-Ø1981-5 has tolerance to the glyphosate herbicide. The use of this herbicide in cropping systems has the intended effect of reducing local weed populations within agro-ecosystems. This may result in a reduction in local weed species biodiversity and may have effects on other trophic levels which utilize these weed species. It must be noted however that the goal of reduction in weed biodiversity in agricultural fields is not unique to the use of PNTs, corn event VCO-Ø1981-5 or the cultivation of corn. It is therefore unlikely that corn event VCO-Ø1981-5 will have any indirect effects on biodiversity, in comparison to the effects that would be expected from cultivation of currently grown corn varieties.

The CFIA has concluded that the novel gene and its corresponding trait do not confer to corn event VCO-Ø1981-5 any characteristic that would result in unintended environmental effects following unconfined release. The CFIA has therefore concluded that the potential impact on biodiversity of corn event VCO-Ø1981-5 is unlikely to be different from that of the corn varieties that are currently grown in Canada.

V. Criteria for the Livestock Feed Assessment

The AFD considered nutrient and anti-nutrient profiles; the safety of feed ingredients derived from corn event VCO-Ø1981-5, including the presence of gene products, residues and metabolites in terms of animal health and human safety as it relates to the potential transfer of residues into foods of animal origin and worker/bystander exposure to the feed; and whether feeds derived from corn event VCO-Ø1981-5 meet the definitions and requirements of feeds as listed in Schedule IV of the Feeds Regulations.

1. Potential Impact of Corn Event VCO-Ø1981-5 on Livestock Nutrition

Nutrient and anti-nutrient composition:

The nutritional equivalence of hybrids of corn event VCO-Ø1981-5 to those of the unmodified control corn variety and three conventional control corn hybrids was determined from five replicated field trials in the US in 2009. At each site, seeds were planted in a randomized complete block design with three replications (plots) each of hybrids containing corn event VCO-Ø1981-5; hybrids of the unmodified control corn variety and the three conventional corn hybrids. Compositional analysis was performed on forage and grain samples collected from each plot. Forage and grain samples were analysed for crude fat, ash, protein, moisture, crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF), calcium and phosphorus. Grain samples were further analysed for total dietary fibre, starch, amino acids, fatty acids, vitamins, minerals, secondary metabolites (ferulic acid, inositol and p-coumaric acid) and anti-nutrients (phytic acid, trypsin inhibitor and raffinose) as recommended by the OECD consensus document for new varieties of corn (OECD, 2002 PDF (208.5 kb)). Composition data was analyzed statistically using analysis of variance, and statistical differences observed between corn event VCO-Ø1981-5 and the unmodified control corn variety were identified (P < 0.05). The biological relevance of any significant difference between corn event VCO-Ø1981-5 and the unmodified control corn variety was assessed to determine if it was within the range of values obtained from the conventional control corn varieties and published in the scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)).

There were no statistically significant differences between forage from the hybrids of the unmodified control corn variety and forage from hybrids of corn event VCO-Ø1981-5 for crude fat, ash, protein, CF, ADF, NDF, carbohydrates (calculated), calcium and phosphorous levels. Comparison of crude fat, ash, protein, moisture and fibre levels in grain samples from hybrids of corn event VCO-Ø1981-5 and those of the unmodified control corn variety resulted in no statistically significant differences for crude fat, crude protein, ash, carbohydrates (calculated), CF, ADF, NDF, total dietary fibre and starch. Although statistically significant differences were noted for levels of calcium, copper, potassium , β-carotene, niacin and total tocopherols between grain from hybrids of corn event VCO-Ø1981-5 and grain from hybrids of the unmodified control corn variety, the mean values were within the range of the values observed in the conventional control corn hybrids and the published scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)); and therefore the differences were not considered biologically relevant. There were no statistically significant differences in the concentrations of iron, magnesium, phosphorus, sodium, zinc, folic acid and vitamins B1, B2, B5 and B6, between grain from hybrids of corn event VCO-Ø1981-5 and grain from hybrids of the unmodified control corn variety. Except for arginine, phenylalanine, and tyrosine, no statistically significant differences were observed between hybrids of corn event VCO-Ø1981-5 and those of the unmodified control corn variety for the other amino acids measured in grain. The mean values for arginine, phenylalanine, and tyrosine were within the range of the values observed in the conventional control corn hybrids and the published scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)); and therefore the differences were not considered biologically relevant. Statistically significant differences were observed between hybrids of corn event VCO-Ø1981-5 and hybrids of the unmodified control corn variety for the levels of palmitic, linoleic and eicosenoic acids in grain; however, the mean values in hybrids of corn event VCO-Ø1981-5 were within the range of values observed in the conventional control corn hybrids and the published scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)). There were no statistically significant differences in mean concentrations of inositol and p-coumaric acid in grain between hybrids of corn event VCO-Ø1981-5 and hybrids of the unmodified control corn variety. Ferulic acid was significantly lower in hybrids of corn event VCO-Ø1981-5 than in hybrids of the unmodified control corn variety, but was within the range of values observed in the conventional control corn hybrids and in published scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)). The secondary metabolite furfural was below the lower limit of quantification in grain from hybrids of both corn event VCO-Ø1981-5 and the unmodified control corn variety. There were no statistically significant differences between the mean concentrations of phytic acid, raffinose and trypsin inhibitor in grain from hybrids of corn event VCO-Ø1981-5 and hybrids of the unmodified control corn variety. All means were within the range of values observed in the conventional control corn hybrids and in published scientific literature (ILSI, 2010, OECD, 2002 PDF (208.5 kb)).

Conclusion:

It was concluded, based on the evidence provided by Genective SA, that the nutritional composition of hybrids of corn event VCO-Ø1981-5 is similar to that of hybrids of the conventional control corn varieties and to that reported for other corn varieties in the published scientific literature.

2. Potential Impact of Corn Event VCO-Ø1981-5 on Animal Health and Human Safety as it Relates to the Potential Transfer of Residues into Foods of Animal Origin and Worker/Bystander Exposure to the Feed

Corn event VCO-Ø1981-5 is tolerant to glyphosate herbicides due to production of the EPSPS ACE5 protein. The assessment of corn event VCO-Ø1981-5 evaluated the impact of the following potential hazards relative to the safety of feed ingredients derived from this event:

  • The presence of novel protein EPSPS ACE5
  • The chemical pesticide residue profile

EPSPS ACE5 protein:

To obtain sufficient quantities of EPSPS ACE5 protein for evaluation of environmental and feed safety, it was necessary to express the epsps grg23ace5 gene in a microbial production system. The equivalency of the corn event VCO-Ø1981-5-produced EPSPS ACE5 protein to the microbially-produced EPSPS ACE5 protein was evaluated by comparing their molecular weights, immunoreactivities, glycosylation, tryptic peptide mass mapping results, and N-terminal sequences. Based on the results, the proteins were found to be equivalent. Demonstration of equivalence between the microbially-produced EPSPS ACE5 protein and the EPSPS ACE5 protein produced in corn event VCO-Ø1981-5 allows utilization of the microbially-produced EPSPS ACE5 protein in studies to confirm the safety of the EPSPS ACE5 protein produced in corn event VCO-Ø1981-5.

The potential mammalian allergenicity and toxicity of the EPSPS ACE5 protein were evaluated. With respect to its potential allergenicity, it is recognized that no single experimental method yields decisive evidence for allergenicity, thus a weight-of-evidence approach was taken, taking into account information obtained with various test methods. The source of the epsps grg23ace5 gene, A. globiformis, is not commonly associated with allergenicity and a bioinformatics evaluation of the EPSPS ACE5 protein amino acid sequence confirmed the lack of relevant similarities between the EPSPS ACE5 protein and known allergens. Unlike many allergens, studies with the microbial EPSPS ACE5 protein indicated that the protein is rapidly degraded in simulated gastric fluid and is not heat stable, and studies with corn event VCO-Ø1981-5 EPSPS ACE5 indicated that it is not glycosylated. The weight of evidence thus indicates that the EPSPS ACE5 protein is unlikely to be allergenic.

In terms of its potential toxicity, the EPSPS ACE5 protein lacks a mode of action to suggest that it is intrinsically toxic to livestock and a bioinformatics evaluation of the EPSPS ACE5 protein amino acid sequence confirmed the lack of relevant similarities between the EPSPS ACE5 protein and known toxins. In addition, no adverse effects were observed when the microbial EPSPS ACE5 protein was ingested by mice at doses of approximately 2000 mg/ kg bwt. This information indicates that the EPSPS ACE5 protein is unlikely to be toxic to livestock.

The livestock exposure to the EPSPS ACE5 protein is expected to be negligible as the EPSPS ACE5 protein is expressed at very low levels in corn event VCO-Ø1981-5, it is rapidly degraded under conditions which simulate the mammalian digestive tract and it is unstable under heating conditions expected to be encountered during processing of some corn products.

Chemical pesticide residue profile:

The safety of herbicide residues and metabolites in corn event VCO-Ø1981-5, following application of herbicides, was also evaluated as part of the feed safety assessment.

It was determined that potential glyphosate residues in livestock commodities: grain corn, its by-products and corn oil from corn event VCO-Ø1981-5, would not present levels of concern to livestock, nor humans, via the potential transfer into foods of animal origin when comparing the estimated exposure to established legal residue limits in Canada and the US.

Conclusion:

It was concluded, based on the evidence provided by Genective SA that the novel EPSPS ACE5 protein-based herbicide tolerance trait will not confer to corn event VCO-Ø1981-5 any characteristic that would raise concerns regarding its safety. Feed ingredients derived from corn event VCO-Ø1981-5 are considered to meet present ingredient definitions for corn.

VI. New Information Requirements

If at any time, Genective SA becomes aware of any new information regarding risk to the environment, livestock, or human health, which could result from release or livestock feed use of corn event VCO-Ø1981-5 or lines derived from it, Genective SA is required to immediately provide such information to the CFIA. On the basis of such new information, the CFIA will re-evaluate the potential impact of corn event VCO-Ø1981-5 on the environment, livestock and human health and may re-evaluate its decision with respect to the livestock feed use and environmental release authorizations of corn event VCO-Ø1981-5.

VII. Regulatory Decision

Based on the review of the data and information submitted by Genective SA and input from other relevant scientific sources, the Plant and Biotechnology Risk Assessment Unit of the Plant Health Science Directorate, CFIA, has concluded that the unconfined environmental release of corn event VCO-Ø1981-5 does not present altered environmental risk when compared to corn varieties that are currently grown in Canada.

Based on the review of the data and information submitted by Genective SA and input from other relevant scientific sources, the Animal Feed Division of the Animal Health Directorate, CFIA, has concluded that the novel EPSPS ACE5 protein-based herbicide tolerance trait will not confer to corn event VCO-Ø1981-5 any characteristic that would raise concerns regarding the safety or nutritional composition of corn event VCO-Ø1981-5. Grain corn, its by-products and corn oil are currently listed in Schedule IV of the Feeds Regulations and are therefore approved for use in livestock feeds in Canada. Corn event VCO-Ø1981-5 has been found to be as safe as, and as nutritious as currently and historically grown corn varieties. Corn event VCO-Ø1981-5 and its products are considered to meet present ingredient definitions and are approved for use as livestock feed ingredients in Canada.

Unconfined release into the environment and use as livestock feed of corn event VCO-Ø1981-5 is therefore authorized by the Plant Biosafety Office of the Plant Health and Biosecurity Directorate and the Animal Feed Division of the Animal Health Directorate as of February 14, 2014. Any corn lines derived from corn event VCO-Ø1981-5 may also be released into the environment and used as livestock feed, provided that (i) no inter-specific crosses are performed, (ii) the intended uses are similar, (iii) it is known based on characterization that these plants do not display any additional novel traits and are substantially equivalent to corn varieties that are currently grown and permitted to be used as livestock feed in Canada, in terms of their potential environmental impact and livestock feed safety, respectively and (iv) the novel gene is expressed at levels similar to those in the authorized line.

Corn event VCO-Ø1981-5 is subject to the same phytosanitary import requirements as unmodified corn varieties. Corn event VCO-Ø1981-5 is required to meet the requirements of other Canadian legislation, including but not limited to the requirements set out in the Food & Drugs Act and the Pest Control Products Act.

Please refer to Health Canada's Decisions on Novel Foods for a description of the food safety assessment of corn event VCO-Ø1981-5.

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