Novel Food Information - Imidazolinone Tolerant (Clearfield') Canola Quality Brassica juncea S006

Health Canada has notified BASF Canada Inc. that it has no objection to the sale of food derived from Imidazolinone Tolerant Canola Quality Brassica juncea S006. The Department conducted a comprehensive assessment of this canola event 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 BASF Canada Inc. and the evaluation by Heath Canada. This document contains no confidential business information.

1. Introduction

BASF Canada Inc., developed Imidazolinone Tolerant Canola Quality Brassica juncea S006 (hereafter Clearfield™ B. juncea S006) using a combination of chemical mutagenesis of seed and traditional breeding. Chemical mutagenesis caused genetic changes in the acetohydroxyacid synthase (AHAS1 and AHAS3) genes, resulting in a one amino acid change in each of the encoded proteins. This change causes the B. juncea plants to grow in the presence of imidazolinone herbicides. Health Canada has previously indicated no objection to the sale of imidazolinone tolerant canola (NS738, NS1471, NS1473), corn (XI-12), lentils (RH-44), sunflower (X81359), rice (CL121, CL141, CFX51, PWC16, CL IMINTA 1, CL IMINTA 4), bread wheat (SWP 965001, AP602CL, AP205CL, Teal11A, BW255-2 , BW238-3, DW7), and durum wheat (DW1, DW12) in the Canadian marketplace.

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 reflects international guidance documents in this area (eg., Codex Alimentarius). The assessment considered: how Clearfield™ B. juncea S006 was developed; how the composition and nutritional quality of Clearfield™ B. juncea S006 compared to non-modified canola varieties; and what the potential is for Clearfield™ B. juncea S006 to be toxic or cause allergic reactions. BASF Canada Inc. has provided data which demonstrates that Clearfield™ B. juncea S006 is as safe and of the same nutritional quality as traditional canola 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 Division 28 of Part B of the Food and Drug Regulations (Novel Foods). Foods derived from Clearfield™ B. juncea S006 are considered novel foods 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

Clearfield™ B. juncea S006 was developed in a three step process. In the first step, canola-quality B. juncea variety Arid was mutagenized using ethyl methanesulfate (EMS).  Seedlings which were tolerant to imidazolinone were selected.  It was confirmed that the imidazolinone tolerant phenotype was due to a single nucleotide change in the AHAS1 gene, causing a one amino acid change in the AHAS1 protein.  This mutation is referred to as bR and the resulting line is designated B. juncea line J04E-0044.  This process has been described by the petitioner and is similar to how previously approved Clearfield products were developed.

Independently, imidazolinone tolerance from previously approved Clearfield™ B. napus 45A71, which carries the PM2 mutation in AHAS3, was crossed into wild-type canola quality B. juncea variety Arid, then into a commercial cultivar Dahinda.  The selected line was a double haploid B. juncea line J04Z-00120 (PM2PM2).  Clearfield™ B. napus 45A71 is registered with CFIA and is derived from event NS1471, which was authorized in 1995 for food, feed and environmental release.

Finally, B. juncea line J04Z-00120 was crossed with B. juncea line J04E-0044 and the resulting line J01D-09694 was tested to confirm both the bR and PM2 mutations.  F1 seeds from this line were then used as donor to create the final line S006.

3. Characterization of the Modified Plant

The petitioner has confirmed that the imidazolinone tolerant phenotype is due to single nucleotide changes in the AHAS1 and AHAS3 genes, causing single amino acid changes in the AHAS1and AHAS3 proteins.  The petitioner has provided data indicating that the trait has been stably inherited across six generations, in the expected Mendelian manner.

4. Product Information

Clearfield™ B. juncea S006 differs from its traditional counterparts in that it is tolerant to Imidazolinone herbicides. This is due to the mutations introduced in the produced AHAS enzymes. A mutation in the AHAS enzyme in canola could affect the biosynthesis of the essential amino acids isoleucine, leucine, and valine. The amino acid composition of Clearfield™ B. juncea S006 was compared to its parent, confirming that the AHAS activity of the imidazolinone-tolerant canola was not affected by the mutation.

5. Dietary Exposure

Clearfield™ B. juncea S006 is expected to be used in similar applications as traditional B. juncea varieties by the food industry. 

6. Nutrition

The nutritional data pertaining to ClearfieldÔ B. juncea S006 were obtained from a study conducted in Canada in 2006.  The study was conducted at three locations and plots were arranged in a randomized block design with four replicates at each site.  The seed samples from the genetically modified ClearfieldÔ B. juncea S006, wild-type parent variety, and three conventional varieties (Dahinda, Davin and Estlin) were analysed.  The seed samples from three out of the four replicates were analyzed for proximates, amino acids and fatty acid profile, vitamins, minerals, and antinutrients (trypsin inhibitor, glucosinolate and phytic acid).

The results of the compositional study demonstrated that the seed from the genetically modified ClearfieldÔ B. juncea S006 variety was comparable in composition with its wild-type parent and three conventional varieties.  For the few comparisons where the differences were statistically significant, nutritionally they were considered not important as the values fall within the range developed from three conventional varieties.

7. Toxicology

The weight of evidence suggests that the mutant AHAS from ClearfieldÔ B. juncea S006 is unlikely to be a toxin or allergen under normal conditions of consumption.  This conclusion is based on the observations that the modified protein is expressed in very low amounts in the edible part of the canola plant, its activity is heat-labile and would be destroyed during normal food preparation processes, the protein is as sensitive to degradation in the human gastrointestinal tract by trypsin as the native protein and the major food use for this plant is oil, which contains negligible amounts of protein. Consequently, systemic exposure to the active AHAS protein was considered remote.

The modified AHAS protein, like the native AHAS protein,  is not homologous to any known allergens.  As well, ClearfieldÔ B. juncea S006 does not appear to express any new major proteins or altered amounts of other proteins, including endogenous canola allergens.

In conclusion, no additional health concerns would be expected to be associated with the consumption of food products derived from imidazolinone tolerant ClearfieldÔ B. juncea S006, as compared with the wild-type variety Arid.


Health Canada’s review of the information presented in support of the food use of Imidazolinone Tolerant Canola Quality Brassica juncea S006 concluded that derived food products do not raise concerns related to safety. Health Canada is of the opinion that Imidazolinone Tolerant Canola Quality Brassica juncea S006is similar to conventional canola in terms of being an acceptable food source.

Health Canada's opinion deals only with the human food use of Imidazolinone Tolerant Canola Quality Brassica juncea S006. Issues related to the environmental safety of Imidazolinone Tolerant Canola Quality Brassica juncea S006 in Canada and its use as livestock feed have been 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.

(Également disponible en français)

For further information, please contact:

Novel Foods Section
Food Directorate
Health Products and Food Branch
Health Canada, PL2204E
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9

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