Disclaimer

Monsanto Inc. has generously consented to the use of the information provided in various of their regulatory submissions for event GTS 40-3-2 as a training tool. It must be noted, however, that in order to enhance the utility of the case study as a training tool, liberties were taken with the information provided in the original applications. Certain information has been reduced to summaries and the data as presented in the case study are only a subset of that actually submitted. The case study in no way constitutes a complete application nor is it to be considered a complete safety assessment. To that end, the use of this information in the form of a training tool does not constitute an endorsement of the information or product nor should it be considered a reflection of any of the original submissions.

Preface

In order to provide some insight into the type of data usually presented in support of a novel food evaluation, a case study of genetically engineered soybean (Glycine max) event GTS 40-3-2 and its progeny has been developed. The content of the study includes excerpts from applications for food safety assessment submitted to regulatory authorities in Canada, the United Kingdom (UK), and the United States (U.S.).

Soybean is grown as a commercial crop in over 80 countries, with a combined harvest of 162 million metric tonnes. The major producers of soybeans in 2000 were the United States, Brazil, China, Argentina, India, Canada and Paraguay. Soybean is grown primarily for its seed, which has many uses in the food and industrial sectors, representing one of the major sources of edible vegetable oil and of proteins for livestock feed use.

A major food use of soybean in North America and Europe is as purified oil, used in margarines, shortenings, and cooking and salad oils. It is also a major ingredient in food products such as tofu, tempeh, soya sauce, simulated milk and meat products, and is a minor ingredient in many processed foods. Soybean meal is used as a supplement in feed rations for livestock.

Weeds are a major production problem in soybean cultivation. Typically, weeds are managed using a combination of cultural (e.g. seed bed preparation, using clean seed, variety selection, and planting date) and chemical controls. Depending on the production area and the prevalent weed species, herbicides may be applied before planting (e.g. pendimethalin, trifluralin, metribuzin), after planting but before emergence (e.g. pendimethalin, linuron, imazethapyr), and/or after emergence (e.g. bentazon, acifluorfen, fomesafen). Commonly, several different herbicides are required to adequately control weeds in soybean fields.

The soybean line GTS 40-3-2 was developed to allow for the use of glyphosate, the active ingredient in the herbicide Roundup®, as a weed control option. This genetically engineered soybean line contains a form of the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) that allows GTS 40-3-2 to survive the otherwise lethal application of glyphosate. The EPSPS gene put into GTS 40-3-2 was isolated from a strain of the common soil bacterium Agrobacterium tumefaciens called CP4; the form of EPSPS enzyme produced by this gene is tolerant to glyphosate.

The EPSPS enzyme is part of an important biochemical pathway in plants called the shikimate pathway, which is involved in the production of aromatic amino acids and other aromatic compounds. When conventional plants are treated with glyphosate, the plants cannot produce the aromatic amino acids needed to grow and survive. EPSPS is present in all plants, bacteria, and fungi. It is not present in animals, which do not synthesize their own aromatic amino acids. As the aromatic amino acid biosynthetic pathway is not present in mammals, birds or aquatic life forms, glyphosate has little if any toxicity for these organisms. The EPSPS enzyme is naturally present in foods derived from plant and microbial sources.

GTS 40-3-2 was developed by introducing the CP4 EPSPS gene into a commercial soybean variety using particle-acceleration (biolistic) transformation. The glyphosate tolerance trait expressed in GTS 40-3-2 has since been transferred into more than one thousand commercial soybean varieties by traditional breeding techniques.

GTS 40-3-2 has been tested in field trials in the United States, Central and South America, Europe, and Canada since 1991. Data collected from over 150 field trials conducted over a three-year period prior to commercialization in the United States demonstrated that GTS 40-3-2 did not differ significantly from conventional soybeans in morphology, seed production (yield), agronomic characteristics (such as time to flowering and pod set, or vigor) and tendency to weediness. GTS 40-3-2 did not negatively affect beneficial or nontarget organisms, and was not expected to impact on threatened or endangered species.

Soybean does not have any weedy relatives with which it can crossbreed in the continental United States or Canada. Cultivated soybean can naturally cross with the wild annual species G. soja, however G. soja, which occurs naturally in China, Korea, Japan, Taiwan and the former USSR, is not naturalized in North America. Additionally, soybean plants are almost completely self-pollinated and reproductive characteristics such as pollen production and viability were unchanged by the genetic modification resulting in GTS 40-3-2. It was therefore concluded that the potential for transfer of the glyphosate tolerance trait from the transgenic line to soybean relatives through gene flow (outcrossing) was negligible in managed ecosystems, and that there was no potential for transfer to wild species in Canada and the continental United States.

The food and livestock feed safety of GTS 40-3-2 soybean was established based on: the evaluation of the similarity of the structure and function of CP4 EPSPS protein to this same enzyme naturally present in foods and livestock feeds, the fact that CP4 EPSPS protein constitutes a small amount of the protein in GTS-40-3-2 soybeans so there is little dietary exposure, the lack of toxicity or allergenicity of EPSPS proteins from plants, bacteria and fungi, and by direct laboratory studies of the CP4 EPSPS protein. Comparative analyses of key nutrients, including proximates (e.g. protein, fat, fibre, ash, and carbohydrates), as well as antinutrients between GTS 40-3-2 soybeans and conventional soybeans did not reveal any significant differences. Feeding studies with rats, broiler chickens, cows, and fish further supported the safety and nutritional quality of GTS 40-3-2 as human food and livestock feed.

Event GTS 40-3-2 received its first regulatory approval in the US in 1994 (US Department of Agriculture), and has since been approved for environmental release and use in livestock feed and/or human food by a number of countries, including Argentina, Australia, Canada, Japan, and others (Table 1). In 1996, glyphosate tolerant soybeans were planted on less than 5% of the US soybean acreage. In the 2000 growing season, 54% of the soybeans - approximately 40 million acres of the 75.4 million acres of soybeans grown in the United States - were glyphosate tolerant. In Argentina, where the adoption rate is estimated at 95%, glyphosate tolerant soybeans were grown on over 20 million acres in 2000. Globally, glyphosate tolerant soybeans made up 58% of all transgenic crops grown in 2000.

A Note on Quality Standards for Documentation

The evaluation of an application for environmental release is comparable to the peer review of a manuscript for publication in a scientific journal. Accordingly, the quality of the text and data presented must be commensurate with this.

Experimental procedures should be described in sufficient detail (or referenced accordingly) so that the methodology can be repeated. Spelling and usage should be standard and laboratory jargon avoided. It is recommended that international standards for nomenclature be adopted, such as those described in the International Union of Biochemistry and Molecular Biology’s Biochemical Nomenclature and Related Documents (1992) 2nd Ed. Portland Press, Inc., Chapel Hill, NC which contains the International Union of Biochemistry rules of nomenclature for amino acids, peptides, nucleic acids, polynucleotides, vitamins, coenzymes, quinones, folic acid and related compounds, corrinoids, lipids, enzymes, proteins, cyclitols, steroids, carbohydrates, carotenoids, peptide hormones, and human immunoglobulins. Correct chemical names should be given and strains of organisms should be specified. Trade names should be identified. Système International (SI) units and symbols should be used whenever possible.

Illustrations, tables and figures must be clear and legible. Original drawings, high-quality photographs or laser prints are acceptable; poor-quality reproductions that often result from photocopying prints are not. In particular, reproductions of gels or blots must be of sufficient quality to clearly show the described results.