ARCHIVED - Sethoxydim Tolerant Corn (DK412SR and DK404SR)

April, 1997

Novel Food Information - Food Biotechnology

Health Canada has notified BASF Canada Inc. that it has no objection to the food use of the corn lines DK412SR and DK404SR which are tolerant to sethoxydim. The Department conducted a comprehensive assessment of DK412SR and DK404SR according to its 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 BASF Canada Inc. notification to Health Canada and contains no confidential business information.

1. Introduction

DK412SR and DK404SR corn lines were developed through genetic modification to be tolerant to sethoxydim herbicide, Poast®. The modification permits farmers to use the herbicide for control of annual and perennial grasses in the cultivation of corn without damaging the crop.

2. Development of the Modified Plant

The sethoxydim tolerance trait was introduced into the registered corn hybrids DK412 and DK381via tissue culture due to a phenomenon known as somaclonal variation. Somatic corn embryos were grown on sethoxydim enriched media and surviving embryos were then selected. The mechanism of sethoxydim tolerance is identified as an alteration in the enzyme acetyl CoA carboxylase (ACCase). ACCase is critical in the synthesis of fatty acids within the plant, but is inhibited by herbicides in the cyclohexanediones (e.g. sethoxydim). The altered ACCase in DK412SR and DK404SR corn lines exhibits decreased herbicide inhibition, providing the tolerance to the herbicide. This tolerance was demonstrated to be stable in the subject corn lines.

This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Protection 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.

For further information, please contact:

Office of Food Biotechnology
Food Directorate
Health Protection Branch
Health Canada
Tunney's Pasture
Ottawa, Ontario K1A 0L2
Telephone: (613) 952-5137
Facsimile: (613) 952-6400

3. Product Information

The novel trait introduced into DK412SR and DK404SR corn lines is accomplished through variation of the corn genome. No new genetic material was introduced to these corn lines as a result of the modification. Performance factors to measure the growth and development of DK412SR and DK404SR corn lines were comparable to the performance factors for unmodified corn lines and were within the normal ranges for the characteristics tested.

4. Dietary Exposure

DK412SR and DK404SR corn lines are of the yellow dent variety of corn which is primarily intended for animal feeding. However, such field corn may be dry- or wet-milled into various processed corn products, such as fructose maize syrups, starch, oil, grits and flour, for human food use. The human food uses of grain from DK412SR and DK404SR corn lines is not expected to be different from the uses of unmodified field corn varieties. As such, the dietary exposure of Canadians to grain from DK412SR and DK404SR corn lines will not be different from that for other commercially available field corn varieties.

5. Nutrition

Nutritional composition for the modified and unmodified corn lines was compared. The selection of DK412SR and DK404SR corn lines through somaclonal variation has had no meaningful effect on the corn plant nutrient levels. The use of corn products derived from DK412SR and DK404SR corn lines would therefore have no significant impact on the nutritional quality of the Canadian food supply.


Health Canada's review of the information presented in support of the food use of DK412SR and DK404SR corn lines concluded that the subject corn lines do not raise concerns related to safety. Health Canada is of the opinion that food products derived from DK412SR and DK404SR corn lines are as safe and nutritious as corn products from current commercial corn varieties.

Health Canada's opinion deals only with the food use of corn products from the genetically modified DK412SR and DK404SR corn lines. Issues related to growing DK412SR and DK404SR corn lines in Canada and their use as animal feed have been addressed separately through existing regulatory processes in Agriculture & Agri- Food Canada.

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