1. Development of the Modified Plant<br>The T45 transformant was produced by Agrobacterium-mediated transformation of the canola (Brassica napus L.) Cultivar AC Excel with additional genetic material (DNA). The introduced DNA is based on the pat gene which was originally isolated from a common soil bacterium, Streptomyces viridochromogenes, and encodes the enzyme, phosphinothricin acetyltransferase (PAT). The gene inroduced in transformants T45 was modified to optimize its expression in plants without altering the amino acid sequence it encodes.<br>Molecular analysis of T45 plants indicated that a single copy of the transferred DNA was incorporated into the B. napus genome. The only gene transferred into the T45 transformant was the pat gene, and the integration of the transferred DNA was demonstrated to be stable.<br>2. Product Information<br>Expression of the pat gene in T45 plants results in the production of the PAT protein in canola tissues at low levels (&lt; 0.5 ppm). The PAT protein mediates the rapid metabolism of glufosinate ammonium. Analysis demonstrated that the PAT protein or its enzymatic activity could not be detected in the refined oil, the only canola product used for human consumption.<br>The only newly expressed material in T45-derived plants is the PAT protein. The PAT protein is an enzyme which is highly specific for glufosinate ammonium, and does not possess proteolytic or heat stability. PAT has been compared with known toxins and allergens in the GENBANK database which demonstrated that the amino acid sequence of the PAT protein did not share similarity with sequences of known toxins or allergens.