<p style="text-align: justify;"><b>Dietary Exposure</b></p>

<p style="text-align: justify;">The modification to the AHAS enzyme in PWC16 will not result in any change in the consumption pattern of rice and rice-based products. The availability of many rice varieties for cultivation, the diversity of rice varieties in phenotypic traits, and the normal variation in rice composition due to differences in growing conditions, all result in a wide variation in the composition of conventional rice grain. Thus, the cultivation of PWC16 would not be expected to change the dietary exposure in the United States and Canada, any more than commercially available rice cultivars. Furthermore, PWC16 is expected to be used in similar applications as other rice cultivars by the food industry.</p>

<p style="text-align: justify;"><b>Nutritional and Compositional Data</b></p>

<p style="text-align: justify;">Nutritional components of line PWC16 were measured analytically and compared to those of its parental line, Cypress. These components included crude fat, crude fibre, crude protein, moisture, amino acids, fatty acids, B vitamins, vitamin E, phosphorous, magnesium, iron and zinc. There were no differences between PWC16 and Cypress in the levels of these nutrients, and the nutritional profile was comparable to other commercial rice varieties.</p>

<p style="text-align: justify;">The levels of the anti-nutritional factors phytic acid and trypsin inhibitor were determined in rice grain samples from PWC16 and Cypress. Phytic acid is indigestible by humans and non-ruminant livestock and inhibits the absorption of iron and other minerals. Trypsin inhibitor interferes with normal protein digestion. No differences were found between the modified and unmodified lines for either anti-nutritional factor.</p>

<p style="text-align: justify;"><b>Toxicity and Allergenicity</b></p>

<p style="text-align: justify;">The potential for toxicity and allergenicity of PWC16 was investigated by examining the amino acid sequence homology and the characteristics of the altered AHAS protein. The unmodified form of AHAS is heat sensitive and susceptible to trypsin degradation. Data from studies on the heat sensitivity and trypsin degradability of the AHAS in PWC16 were submitted and showed similar sensitivity to heat and degradability compared to unmodified AHAS. The unmodified form of AHAS showed no amino acid similarity to known allergens. The amino acid sequence of the mutated AHAS differs by only one amino acid compared to unmodified rice. Data were also submitted to show that levels of endogenous rice allergens in PWC16, such as trypsin inhibitor, were similar to those of conventional cultivated rice. Evidence was also provided to show that the protein components of PWC16 were not altered compared to the unmodified parent &lsquo;Cypress.&rsquo; Results of SDS-PAGE electrophoresis and HPLC showed that no new major proteins or increased protein expression occurred as a result of the mutation to the AHAS enzyme. From these results it was concluded that PWC16 did not demonstrate any potential for toxicity and allergenicity compared to conventional rice varieties.</p>
