Poster: Metabolic Engineering

Abs # 995: Production and characterization of flower color-modified gentian by genetic engineering of anthocyanin biosynthesis-related genes

Presenter:	Nishihara, Masahiro , mnishiha@ibrc.or.jp
Authors	Nishihara, Masahiro  (A)   Nakatsuka, Takashi  (A)   Mishiba, Keiichiro  (A)   Yokoi, Takahide  (B)   Hosokawa, Keizo  (C)   Kikuchi, Akiko  (A)   Yamamura, Saburo  (A)
Affiliations:	(A): Iwate Biotechnology Research Center (B): Hitachi, LTD., Life Science Group (C): Department of Nutritional Management, Faculty of Health Science, Hyogo University
Web Site:	http://www.ibrc.or.jp/

Gentian plants are one of the most important ornamental flowers in Japan. Since flower color of gentian is naturally blue, the novel cultivars with color variations are needed for opening up new markets. To this end, we have been studying on modification of flower color in gentian by genetic engineering. Here we report production and characterization of white-flowered gentian by genetic transformation of antisense chalcone synthase(chs) gene. A binary vector pSMABcCHS harboring antisense cDNA of chs isolated from gentian (Gentiana triflora cv. Maciry) under the control of the CaMV35S promoter was used for transformation of gentian cv. ' Albireo' (hybrid species of G. scabra x G. triflora). The vector also contained a bar gene as a selectable marker. Seventeen transgenic plants were produced by leaf disc infection and cultured until flowering in culture vessels. Among them, three plants changed to completely white flowers. Northern analysis showed suppression of chs in the petals of the transgenic plants. The petals had 1/4 to 1/10 amount of anthocyanin. Because the transformants had a bar gene, they were expected to show herbicide-resistance. After acclimatization and overwintering, they were subjected to herbicide treatment. Application with commercial herbicide including bialaphos showed that transformants were strongly resistant to the herbicide, while untransformed control plants died within one month. Furthermore, their pollen fertility, plant height and flowering time were investigated. Both pollen fertility and plant height were not significantly different from those of untransformed plants. Flowering time was a little earlier in transgenic gentians. These results indicate that genetic modification of flower color in gentian can be successfully achieved.