Database Product Description
- Host Organism
- Glycine max (Soybean)
- Modified seed fatty acid content, specifically high oleic acid expression.
- Trait Introduction
- Microparticle bombardment of plant cells or tissue
- Proposed Use
Production for human consumption.
- Product Developer
- DuPont Canada Agricultural Products
Summary of Regulatory Approvals
Summary of Introduced Genetic Elements Expand
Characteristics of Glycine max (Soybean) Expand
Modification Method Expand
Characteristics of the Modification Expand
Environmental Safety Considerations Expand
Food and/or Feed Safety Considerations Expand
Soybean (Glycine max) is grown primarily for its seed, which has many uses in the food and industrial sectors, and represents one of the major sources of edible vegetable oil and of proteins for livestock feed use. The major producers of soybeans were the United States, Brazil, Argentina, China, India, Paraguay and Canada.
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.
Soybean oil is rich in polyunsaturated fatty acids and is considered a “healthy” oil due to its effects on decreasing blood cholesterol levels. However, polyunsaturated fatty acids will oxidize and are unstable at high temperatures, which makes them unsuitable for high temperature cooking. For many food applications, soybean oil requires additional processing, such as hydrogenation, before it can be used in margarines, shortening, and deep fat frying products. The hydrogenation process changes the fatty acid profile of soybean oil by converting the polyunsaturates into monounsaturated fatty acids or saturated fats depending on the use of the final product. Chemical hydrogenation also generates trans-isomers of oleic acid and other trans-fatty acids reported to have negative health effects by raising blood cholesterol levels.
Soybean lines G94-1, G94-19 and G168 were developed through a specific genetic modification to produce a soybean oil that contains high levels of oleic acid, a monounsaturated fatty acid. These high oleic soybeans contain a second copy of fatty acid desaturase gene (fad2), which is naturally present in soybeans. The fad2 gene codes for the enzyme, delta-12 desaturase, which is involved in fatty acid synthesis. Unlike conventional soybeans, the presence of a second copy of the fad2 gene in the high oleic soybeans G94-1, G94-19 and G168 causes a phenomenon known as "gene silencing" which results in both copies of the fatty acid desaturase gene being "switched off". This blocks the fatty acid biosynthetic pathway and results in the accumulation of oleic acid. As a consequence, polyunsaturated fatty acids (linoleic acid and linolenic acid) are only produced in very small amounts.
The transgenic fad2 gene in G94-1, G94-19 and G168 was isolated from G. max and introduced into a commercial soybean variety using particle acceleration (biolistic) transformation. The genetic modification affects only the seed, allowing fatty acid biosynthesis to function normally in other plant parts such as the leaves.
High oleic soybean oil contains levels of oleic acid exceeding 80%, higher than the levels found in olive oil and rapeseed oil. This oil is lower in saturated fat, contains no trans-fatty acids, and remains in a user-friendly liquid form. The high levels of oleic acid make the oil more heat-stable for cooking and edible spray applications.
G94-1, G94-19 and G168 were tested in field trials in the United States and Canada. Data collected from these trials demonstrated that G94-1, G94-19 and G168 did not differ from conventional soybeans in agronomic characteristics including seed production and susceptibility to diseases and insects. These tests also demonstrated that the transformed lines did not exhibit weedy characteristics, or negatively affect beneficial or nontarget organisms, and were not expected to impact threatened or endangered species.
Soybean does not have any weedy relatives with which it can crossbreed in the continental United States and 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 and growth characteristics were unchanged by the genetic modification resulting in G94-1, G94-19 and G168. It was therefore concluded that the potential for transfer of the trait for high oleic acid 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 high oleic soybean lines G94-1, G94-19 and G168 was established based largely on the fact that there were no new proteins present in these soybean lines. It was determined that the allergenic potential of the high oleic soybeans was the same as for conventional soybeans. The nutritional equivalence of soybeans compared to conventional (non-GM) soybeans was demonstrated by the analyses of key nutrients, including proximates (e.g., protein, fat, fibre, ash, and carbohydrates), amino acid and fatty acid composition, as well as anti-nutrients. High oleic soybean oil contains approximately 10% saturated fats, greater than 80% oleic acid, and low levels of polyunsaturated fatty acids (approximately 2% linoleic acid and 3.5% linolenic acid). Trace amounts (0.5%) of a linoleic acid 9,15 isomer were also detected, which while absent from non-hydrogenated soybean oil, is present at similar levels in butterfat, and is often found at considerably higher levels (typically 1-3%) in partially hydrogenated vegetable oils. The equivalence of high oleic soybeans to conventional soybeans was confirmed in feeding studies with pigs and broiler chickens. Soybean meal from high oleic soybeans was nutritionally equivalent to processed soybean meal derived from the conventional soybeans.
High oleic soybeans are a value-added commodity. These premium soybeans are grown under contract to preserve the identity of high oleic soybeans from the point of planting through to delivery of seed to the processing plant. Other than this, management and production practices for growing high oleic soybeans are much the same as growing any regular variety of soybean.
Links to Further Information Expand
This record was last modified on Tuesday, September 15, 2015