Novel food information: Glufosinate ammonium tolerant canola (HCN92)

On this page:

• Background
• Introduction
• Development and production of the modified plant
• Product information
• Dietary exposure
• Nutrition
• Toxicology
• Conclusion

Background

Health Canada has notified AgrEvo Canada Inc. that it has no objection to the food use of refined oil from canola lines derived from the genetically modified canola line HCN92, which is tolerant to glufosinate ammonium. The Department conducted a comprehensive assessment of canola line HCN92 according to it's Guidelines for the Safety Assessment of Novel Foods (September 1994). These guidelines are based upon internationally accepted principles for establishing the safety of foods derived from genetically modified organisms.

The following provides a summary regarding the AgrEvo Canada Inc. notification to Health Canada and contains no confidential business information.

Introduction

Canola (Brassica napus L.) line HCN92 was developed through genetic modification to be tolerant to glufosinate ammonium, which is the active ingredient of the herbicide Liberty®. The modification permits farmers to use the broad-spectrum herbicide for weed control in the cultivation of canola without damaging the crop.

Development and production of the modified plant

The line HCN92 was produced by Agrobacterium-mediated transformation to introduce DNA into a line of B. napus. The introduced DNA is based on the pat gene, which was originally isolated from a common soil bacterium, Streptomyces viridochromogenes, and encodes the enzyme, phosphinothricin acetyltransferase (PAT). Also included with the introduced DNA is the nptII gene which encodes resistance to the antibiotic kanamycin. This biological marker allows researchers to identify the modified plants.

Molecular analysis indicated that two copies of the transferred DNA have been incorporated at a single locus in the plant genome. Analysis of segregation data confirms the stable integration of the DNA into the Brassica genome.

Product information

The gene products, phosphinothricin acetyl transferase (PAT) and neomycin phosphotransferase (NPTII), the selectable marker, are present in canola tissues at very low levels (< 5 ppm). The PAT protein mediates the rapid metabolism of glufosinate ammonium. Analysis demonstrated that the PAT and NPTII protein or their enzymatic activity could not be detected in the refined oil, the only canola product used for human consumption.

Dietary exposure

Human consumption of canola products is limited to the refined oil. The processing of refined canola oil destroys the enzymatic activity of the PAT and NPTII protein. As indicated above (Section 3), PAT and NPTII is not detected in the refined oil. As such, no human exposure to the introduced PAT and NPTII protein is expected as a result of the consumption of refined oil from line HCN92.

Nutrition

Compositional analysis of processed canola oil indicated that no statistically significant differences were noted between HCN92 and current commercial canola cultivars for fatty acids, glucosinolates, chlorophyll and phytosterol content. These comparisons indicated no statistically significant differences for the components analysed. The use of refined oil from line HCN92 would therefore have no significant impact on the nutritional quality of the Canadian food supply.

Toxicology

The PAT and NPTII proteins did not show any meaningful amino acid sequence homology when compared to known allergens or protein toxins. Both enzymes have been demonstrated to be highly substrate specific. In addition, they are ubiquitous in nature and do not possess proteolytic or heat stability. No adverse effects have been reported to be associated with either enzyme.

Conclusion

Health Canada's review of the information presented in support of the food use of refined oil from glufosinate ammonium tolerant canola line HCN92 concluded that such refined oil does not raise concerns related to safety. Health Canada is of the opinion that refined oil from canola line HCN92 is as safe and nutritious as refined oil from current commercial varieties.

Health Canada's opinion deals only with the food use of refined oil from the genetically modified canola line HCN92. Issues related to growing canola line HCN92 in Canada and its use as animal feed are addressed separately through existing regulatory processes in the Canadian Food Inspection Agency.

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 (September 1994).

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