AN ANTISENSE CHALCONE SYNTHASE CDNA LEADS TO NOVEL COLOR PATTERNS IN LISIANTHUS (EUSTOMA-GRANDIFLORUM) FLOWERS

Three cultivars of lisianthus (Eustoma grandiflorum (Grise.)) were tra nsformed with a homologous antisense CHS cDNA via Agrobacterium-mediat ed transformation. Over 50% of the transgenics derived from the purple flowering lines exhibited an altered flower colour pattern ranging fr om small streaks of white on the wild-type purple background through t o completely white flowers. A significant portion of the transgenic li nes showed unstable phenotypes. Northern and biochemical analysis show ed that the altered flower patterns were associated with a loss of CHS gene transcript and a corresponding loss of CHS enzyme activity. In t he white flowering line the level of total flavonoids was reduced to c a. 2.0% of the wild-type level. Some of the transgenic plants also exh ibited alterations in flower form such as the formation of frilled pet al tips and reduced flower opening. Several of the new patterned lines ale being evaluated for stability and possible commercial release.