Novel food information: Glyphosate tolerant cotton MON 88913

On this page

• Background
• Introduction
• Development of the modified plant
• Characterization of the modified plant
• Product information
• Dietary exposure
• Nutrition
• Chemistry/toxicology
• Conclusion

Background

Health Canada has notified Monsanto Canada Inc. that it has no objection to the food use of cottonseed oil from glyphosate tolerant cotton MON 88913. The Department conducted a comprehensive assessment of this sugar 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 with novel traits.

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

Introduction

Monsanto has developed glyphosate tolerant cotton (Gossypium hirsutum L.) based upon event MON 88913. Cotton varieties containing event MON 88913 express a CP4 5-enolpyruvylshikimate-3-phosphate (cp4-epsps) gene which confers tolerance to glyphosate herbicides (trade name, Roundup^®). Health Canada has previously indicated no objection to the sale of glyphosate tolerant corn (NK603, MON 802, MON 832), cotton (MON 1445), canola (GT 200, GT 73) soybean (GTS 40-3-2) and sugarbeet (H7-1) lines for human food applications in Canada. Like cotton containing event MON 88913, these events express the CP4 EPSPS enzyme.

The safety assessment performed by Food Directorate evaluators was conducted according to Health Canada's Guidelines for the Safety Assessment of Novel Foods. The assessment considered: how cotton containing event MON 88913 was developed; how the composition and nutritional quality of cottonseed derived from cotton varieties containing this event compares to the cottonseed of non-modified cotton varieties; and what the potential for cottonseed from varieties containing this event to be toxic or cause allergic reactions in humans.

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 cotton containing event MON 88913 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

1. the plant, animal or microorganism exhibits characteristics that were not previously observed in that plant, animal or microorganism"

Development of the modified plant

Commercial cotton variety Coker312 was genetically modified using Agrobacterium tumefaciens transformation. The transforming plasmid PV-GHGT35 carried a transfer DNA (T-DNA) sequence comprised of two cp4-epsps gene cassettes. The first cp4-epsps gene cassette contained a chimeric promoter consisting of the promoter of the tsf1 gene from Arabidopsis thaliana combined with the enhancer sequences from the Figwort Mosaic virus S35 promoter (P-FMV/TSF1), the untranslated leader (exon1) sequence from the A. thaliana tsf1 gene (L-TSF1), the intron from tsf1 gene (I-TSF1), the chloroplast transit peptide sequence from A. thaliana (TS-ctp2), the coding region of cp4 epsps from Agrobacterium sp. strain (CR-cp4 epsps) and the untranslated region of the Pisum sativum rbc E9 gene (T-E9). The second gene cassette contains a similar construct consisting of a chimeric promoter containing the promoter of the act8 gene of A. thaliana with the enhancer sequences from the Cauliflower Mosaic virus 35S promoter (P-35S/ACT8), the untranslated leader (exon 1) sequence from the A. thaliana act8 gene (L-ACT8), the intron and flanking exon of the A. thaliana act8 gene (I-ACT8), the chloroplast transit peptide sequence from A. thaliana (TS-ctp2), the coding region of cp4 epsps from Agrobacterium sp. strain CP4 (CR-cp4 epsps) and the untranslated region of the Pisum sativum rbc E9 gene (T-E9).

Characterization of the modified plant

Southern blot analysis of cotton containing event MON 88913 demonstrated the insertion of a single copy of both cp4-epsps cassettes into the cotton genome at a single locus. Southern blot analysis also demonstrated the integrity of the cp4-epsps genes and their regulatory elements, as well as the absence of any plasmid derived sequences outside the T-DNA region, such as the spectinomycin resistance gene found in the plasmid backbone. The elements contained in the cp4epsps cassettes have been shown to be stable with no rearrangements through Southern blot and sequence analysis. Sequence analysis has also shown that both cassettes were entirely integrated into the genome and that all the elements are intact.

The stability of the inserted cp4-epsps cassettes was evaluated in multiple generations of cotton grown at different locations. The results of southern blot analysis and segregation data demonstrated the stability of cotton containing event MON 88913 at the genomic level in different environments.

Confirmation of the protein's identity was generated using MALDI-ToF and supported by N-terminal sequence analysis. Protein expression levels determined through ELISA showed that CP4 EPSPS represented 0.12% of the total dry weight of MON 88913 cottonseed, which enters the human food supply in cottonseed oil. The amounts of seed protein found in cottonseed oil are negligible and no CP4 EPSPS protein is detected.

Product information

Cotton containing event MON 88913 differs from its traditional counterpart by the addition of cp4-epsps gene sequences and their associated regulatory elements into the genome, and the expression of the CP4 EPSPS protein. The protein encoded by this gene is expressed at different levels throughout the plant tissue and throughout the life of the plant.

Dietary exposure

It is expected that cottonseed from cotton containing event MON 88913 varieties will be used in applications similar to that derived from other cotton varieties. The use of cotton for human consumption is limited to refined cottonseed oil and linters, short fibres that are processed as a source of food grade cellulose and found in products such as bologna and sausage casings. The use of theses linters in human food is routine, safe and well documented.

Nutrition

The samples of cottonseed were analysed for proximates, fibre, (acid detergent fibre, neutral detergent fibre and total dietary fibre), amino acids, fatty acids, minerals, vitamin E, gossypol (free and total), alfatoxins (in one study) and cyclopropenoid fatty acids. The samples of raw cottonseed meal were analysed for proximates, fibre (acid detergent fibre, neutral detergent fibre and total dietary fibre), amino acids, fatty acids, minerals, gossypol (free and total) and cyclopropenoid fatty acids. The cottonseed oil samples were analysed for fatty acids, cyclopropenoid fatty acids, vitamin E and gossypol (free and total).

The chemical and nutritional composition of the cottonseed (acid and mechanically delinted), raw cottonseed meal and oil from cotton containing event MON 88913 and control cotton samples were comparable. For the few comparisons where the differences were statistically significant, nutritionally they were not considered important and the values fall within the range established from the literature.

Chemistry/toxicology

The available evidence suggests that the novel protein present in Roundup Ready^TM Flex Cotton MON 88913 is unlikely to be a toxin. The CP4 EPSPS protein was not acutely toxic in mice at a dose that was orders of magnitude greater that the range associated with toxic proteins. Neither is the CP4 EPSPS protein homologous to any known toxins, and therefore would not be expected to possess activity associated with these proteins. Submitted data regarding endogenous toxins present in cotton MON 88913 showed no significant increase in levels of gossypol or cyclopropenoid fatty acids compared to the control variety and these levels are within the range for commercial cotton. It was also demonstrated that cotton containing event MON 88913 does not contain higher amounts of aflatoxins than cotton plants not expressing CP4 EPSPS.

The available evidence suggests that the novel protein present in Roundup Ready^TM cotton MON 88913 is unlikely to be an allergen. The protein is not homologous to any known allergens and therefore should no be expected to possess activity associated with these proteins. Previously completed studies have also demonstrated through western blot analysis that the CP4 EPSPS is highly degraded in the gastric and intestinal system. These results under simulated gastric conditions indicate that the CP4 EPSPS protein would be readily digested in the mammalian digestive tract.

No introduced health concerns would be expected to be associated with the consumption of Roundup Ready^TM Flex cotton MON 88913 compared with its conventional cotton parent variety. Cotton containing event MON 88913 is deemed to be similar to the conventional cotton parental variety of cotton in terms of being an acceptable food source.

Conclusion

Health Canada's review of the information presented in support of the food use of glyphosate tolerant cotton MON 88913 concluded that the food use of cottonseed from cotton containing event MON 88913 does not raise concerns related to safety. Health Canada is of the opinion that cottonseed from cotton MON 88913 is as safe and nutritious as cottonseed from current commercial cotton varieties.

Health Canada's opinion deals only with the food use of glyphosate tolerant cotton MON 88913. Issues related to its use as animal 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 (September 1994).

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