<p style="text-align: justify;">Transgenic lines 4, 11, 15, and 16 were developed using recombinant DNA techniques to produce flowers with a unique violet/mauve colour by introducing two genes from petunia (<i>Petunia hybrida</i>) that function together in the biosynthesis of the anthocyanin pigment delphinidin. The transgenic lines were derived from the parent cultivar &lsquo;White Unesco&rsquo;, which is a white coloured carnation that was selected for a mutation in the dihydroflavonol reductase (DFR) encoding gene that did not allow for expression of a functional enzyme, and thus did not produce the anthocyanin type pigments that give rise to blue and red coloured flowers. The two genes introduced into the transgenic carnation lines included a functional dihydroflavonol reductase encoding gene and a gene encoding the enzyme flavonoid 3&rsquo;, 5&rsquo;-hydroxylase (F3&rsquo;, 5&rsquo;H), a member of the NADPH-Cytochrome P450 reductase family. Expression of the F3&rsquo;, 5&rsquo;H encoding gene allows for the production of blue coloured delphinidin anthocyanin pigments, which are not normally found in carnations.</p>

<p style="text-align: justify;">An additional gene encoding a variant form of the enzyme acetolactate synthase (ALS) was also introduced into this transgenic carnation line in order to confer the trait of tolerance to sulfonylurea type herbicides (<i>e.g.</i>, chlorsulfuron, commonly known as Glean&trade;), which are potent inhibitors of ALS. Acetolactate synthase (also known as acetohydroxy acid synthase; AHAS) is involved in the conversion of threonine to alpha-aceto-alpha-hydroxybutyrate and pyruvate to alpha-acetolactate, which are key precursors in the biosynthesis of the essential branched chain amino acids isoleucine and valine, respectively. Alpha-acetolactate is also a precursor in the synthesis of leucine. The variant form of ALS introduced into this carnation line was isolated from a chlorsulfuron tolerant tobacco (<i>Nicotiana tabacum</i>). This trait was introduced as a means of selecting for transformed plants during tissue culture regeneration as sulfonylurea herbicides are not, and will not be, used in the carnation industry.</p>
