<p style="text-align: justify;">A purified, linear DNA fragment derived from plasmid pAC321 was used to transform embryogenic axis tissue derived from the apical meristem of a single soybean seed of the commercial variety Conquista using particle bombardment. No carrier DNA was used in the process.</p>

<p style="text-align: justify;">Soybean tissues were transformed with an approximately 6.2 kb linear fragment <i>Pvu</i>II fragment derived from plasmid pAC321 containing the <i>csr1-2</i> gene cassette.</p>

<p style="text-align: justify;">The pAC321 fragment contains genomic Arabidopsis DNA including the mutant Arabidopsis acetohydroxyacid synthase large subunit (<i>ahasl</i>) coding sequence (also referred to in the literature as <i>csr1-2</i>) with transcription directed by the wild type Arabidopsis AHASL 5&rsquo; and 3&rsquo; untranslated regions (UTR) containing the putative promoter and terminator region. The <i>csr1-2</i> coding sequence is 2013 bp long and includes the S653N point mutation which confers tolerance to imidazolinone herbicides. In addition to the S653N mutation, a second mutation was discovered in the Arabidopsis ahas coding sequence integrated in the CV127 soybean genome. This second mutation, in which arginine at position 272 of the AtAHAS protein is replaced by lysine, does not impact the enzymatic function of the AHAS enzyme or its herbicide tolerance properties.</p>
