<p style="text-align: justify;">The soybean line GTS 40-3-2 was developed to allow for the use of glyphosate, the active ingredient in the herbicide Roundup&reg;, as a weed control option for soybean. This genetically engineered soybean variety contains a glyphosate tolerant form of the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) isolated from the common soil bacterium, <i>Agrobacterium tumefaciens</i> strain CP4 (CP4 EPSPS).</p>

<p style="text-align: justify;">The EPSPS enzyme is part of the shikimate pathway that is involved in the production of aromatic amino acids and other aromatic compounds in plants (Steinrucken &amp; Amrhein, 1980). When conventional plants are treated with glyphosate, the plants cannot produce the aromatic amino acids needed to survive. This enzyme is present in all plants, bacteria, fungi, but not in animals, which do not synthesize their own aromatic amino acids. Because the aromatic amino acid biosynthetic pathway is not present in mammalian, avian or aquatic life forms, glyphosate has little if any toxicity for these organisms (U.S. EPA, 1993; WHO, 1994; Williams <i>et al</i>. 2000). The EPSPS enzyme is normally present in food derived from plant and microbial sources.</p>

<p style="text-align: justify;">GTS 40-3-2 was developed by introducing the CP4 EPSPS coding sequence into the soybean variety A5403, a commercial soybean variety of Asgrow Seed Company, using particle-acceleration (biolistic) transformation. A5403 is a maturity group V cultivar that combines consistently high yield potential with resistance to races 3 and 4 of the soybean cyst nematode (SCN). It also possesses good standability, excellent emergence and tolerance to many leaf and stem diseases. The glyphosate tolerance trait has since been transferred into more than one thousand commercial soybean varieties by traditional breeding techniques. Globally, glyphosate-tolerant soybeans were planted on more than 50 million hectares in 2007. One of the reasons growers have rapidly adopted the glyphosate-tolerant soybean is the simplicity it offers in weed control. Since glyphosate containing herbicides are highly effective against the vast majority of annual and perennial grasses and broadleaf weeds, growers planting glyphosate tolerant soybeans are able to reduce the number of herbicides used to control the economically destructive weeds that grow in their fields and thereby realize a savings in weed control costs. This reduction in herbicides used has benefited the environment by reducing the number of herbicide applications and also allows growers to implement integrated weed management practices in their fields - practices that are generally not possible when pre-plant or pre-emergent herbicides are used.</p>
