Some white carnation varieties are white because they lack specific enzymes in the biosynthetic pathway leading to anthocyanin type pigments.<br>These pigments are responsible for production of blue and red coloured flowers. Florigene has inserted into appropriate white carnation<br>varieties two of the anthocyanin biosynthesis genes. The two genes are from petunia and encode the enzymes flavonoid 3'5' hydroxylase and<br>dihydroflavonol reductase. The genetically modified plants produce flowers with a violet/mauve colour, as a result of biosynthesis of the<br>anthocyanin delphinidin. In nature, carnation does not produce delphinidin pigments and so the flowers produced by the genetic modification<br>have a unique colour. <br>In addition to the genes for altered flower colour, a gene for herbicide resistance has been inserted into the carnation. This gene, which confers<br>resistance to sulfonylurea type herbicides, is only to allow selection of transgenic plants in tissue culture. Such herbicides are not, and will not<br>be, used in the carnation industry.