<p style="text-align: justify;"><b>The Introduced DNA</b></p>

<p style="text-align: justify;">Since AP205CL wheat is a product of mutagenesis and conventional seed increase techniques there was no introduction or incorporation of heterologous DNA into the plant genome. The tolerance to imazamox is due to a single point mutation of a single nucleotide in one (<i>als</i>2) of the three AHAS genes. The amino acid sequence of the mutated enzyme differs by one amino acid from that of the unmodified enzyme. This single change in the amino acid sequence alters the binding site on AHAS to imazamox, such that herbicide cannot inhibit the enzyme&rsquo;s activity. The mutation of the AHAS gene was identified from information on the gene sequence.</p>

<p style="text-align: justify;"><b>Genetic Stability of the Introduced Trait</b></p>

<p style="text-align: justify;">Segregation analysis of crosses with AP205CL demonstrated the inheritance of a single semi-dominant or co-dominant gene. Progeny from these crosses segregated in a 3:1 ratio (herbicide tolerant : susceptible to herbicide).</p>

<p style="text-align: justify;"><b>Expressed material</b></p>

<p style="text-align: justify;">The modified AHAS gene, conferring tolerance to imazamox, is under control of the native AHAS promoter and is believed to be constitutively expressed. Whole plant tolerance to this herbicide was expressed in AP205CL.</p>

<p style="text-align: justify;">In the unmodified plant, the levels of valine, leucine and isoleucine are regulated by feedback inhibition of AHAS. A mutation in the AHAS enzyme could affect the regulation of the biosynthesis of these amino acids. Data were submitted to show that the modified AHAS was feedback inhibited by valine and leucine, similar to the unmodified enzyme. Levels of valine, leucine and isoleucine in AP205CL were comparable to those in the unmodified plant.</p>
