<p style="text-align: justify;">Soybean (<i>Glycine max</i>) 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.</p>

<p style="text-align: justify;">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.</p>

<p style="text-align: justify;">Weeds are a major production problem in soybean cultivation. Typically, weeds are managed using a combination of cultural (<i>e.g.</i>, seed bed preparation, use of 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 (<i>e.g.</i>, pendimethalin, trifluralin, metribuzin), after planting but before emergence (e.g. pendimethalin, linuron, imazethapyr), and/or after emergence (<i>e.g.</i>, bentazon, acifluorfen, fomesafen). Commonly, several different herbicides are required to adequately control weeds in soybean fields.</p>

<p style="text-align: justify;">The soybean line A5547-127 was developed to allow for the use of glufosinate ammonium, the active ingredient in phosphinothricin herbicides (Basta&reg;, Ignite&reg;, Rely&reg;, Liberty&reg;, Harvest&reg;, and Finale&reg;) as a weed control option. This genetically engineered soybean line contains the fungal enzyme phosphinothricin-N-acetyltransferase (PAT), which allows these plants to survive the otherwise lethal application of glufosinate. The <i>pat</i> gene inserted into A5547-127 was isolated from a common soil fungus, <i>Streptomyces viridochromogenes</i>, and introduced into the soybean genome by particle acceleration (biolistic) transformation.</p>

<p style="text-align: justify;">The PAT enzyme in soybean line A5547-127 converts L-phosphinothricin (PPT), the active ingredient in glufosinate ammonium, to an inactive form thereby conferring resistance to the herbicide. In the absence of PAT, application of glufosinate leads to reduced production of the amino acid glutamine and increased ammonia levels in the plant tissues, which are lethal to the plant. The PAT enzyme is not known to have any toxic properties.</p>

<p style="text-align: justify;">Glufosinate-tolerant soybean line A5547-127 was tested in field trials in the United States (1996-1997). It was demonstrated that the transformed line did not exhibit weedy characteristics, or negatively affect beneficial or nontarget organisms. A5547-127 was not expected to impact on threatened or endangered species.</p>

<p style="text-align: justify;">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 <i>G. soja</i>, however <i>G. soja</i>, 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 A5547-127. It was therefore concluded that the potential for transfer of the glufosinate 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.</p>

<p style="text-align: justify;">In order to establish the nutritional equivalence of A5547-127 to conventional soybean, samples of forage, seed, hulls, and toasted and non-toasted defatted soy meal from the transgenic event were subjected to proximate analyses (moisture, crude protein, crude fat, ash, acid detergent fibre, neutral detergent fibre, carbohydrate). As well, seed samples were subjected to fatty acid analysis, amino acid analysis, and analyses of minerals (calcium, phosphorous, and potassium). In all cases, there were no statistically significant differences between the values determined for A5547-127 and corresponding samples obtained from non-transgenic control plants.</p>

<p style="text-align: justify;">The toxicity potential of A5547-127 was established from samples of seed analyzed for the naturally occurring anti-nutrients stachyose, raffinose, phytic acid, trypsin inhibitor and lectins. The concentrations of phytoestrogens, such as daidzein, genistein, and glycitein, were determined for samples of seed, and toasted and non-toasted soy meal. The levels of these compounds were not statistically different between samples from A5547-127 and non-transgenic soybeans.</p>

<p style="text-align: justify;">The low potential for allergenicity of the PAT protein has previously been established through amino acid sequence comparisons with known protein allergens and digestibility studies using simulated gastric and intestinal fluids. Additionally, soybean seed extracts from line A5547-127 and from non-transgenic control plants were screened against a panel of sera from 16 soy-allergic individuals using the radioallergosorbent test (RAST). The results of this study did not reveal any qualitative or quantitative difference in endogenous soybean allergen content between transgenic and non-transgenic soybean.</p>
