FLAVONOID HYDROXYLASE GENES FROM BLUE FLOWER, BUTTERFLY PEA AND ASCOCENDA ORCHID AND ITS ENDOGENOUS EXPRESSION IN THAI ORCHID FLOWERS

    Flavonoid 3', 5'-hydroxylase (F3'5'H) is the key enzyme for the expression of blue flower color. A 3'RACE cDNA for the f3'5'h gene was cloned from petal of Clitoria ternatea and Vancostylis Pine River orchid The partially sequence of Vancostylis Pine River f3'5'h gene is 90% similarity to that of C. ternatea. Comparision of the amino acid sequences of both C. ternatea and Vancostylis Pine River with other related proteins shows 66% similarity to Petunia hybrida F3'H. Furthermore, the cDNA encoding f3h gene fragment from Vancostylis Pine River was cloned and sequenced. The deduced amino acid sequence shows 90% similarity with Bromheadia finlaysoniana F3H enzyme. The expression of f3h gene was detected by RT-PCR method and Northern blot analysis in various kind of orchids including Mokara, Dendrobium, Vanda and Ascocenda with white, red, violet, purple and red-purple orchid flowers. All of reddish and purple flowers gave positive results, except some white orchid flowers of Dendrobium Jaquelyn Thomus, Den. 5N and C. ternatea. In addition, the f3'5'h gene expression could be detected in red-purple orchid flowers and C. ternatea but not with white flowers. The information of flavonoid hydroxylase gene expression in orchid flower could be a useful for genetic engineering of a novel flower color in orchid