Comparative analysis of floral pigmentation between wild-type and white-flowered varieties of

Akita, Yusuke; Ishizaka, Hiroshi*; Nakayama, Masayoshi*; Shimada, Akihiko; Kitamura, Satoshi; Hase, Yoshihiro; Narumi, Issei; Tanaka, Atsushi

The flower colour of gra6 (wild-type) is pink-purple in the flower. On the other hand, flowers of gra50 (white-flowered variant) exhibit a white colour in its flower. In this study, the relationship between floral pigmentation and expression of several anthocyanin biosynthesis genes was investigated in gra6 and gra50. The pigments in the flower consist mainly of malvidin 3,5-diglucoside in gra6. White-flowered gra50 possessed lower amounts of anthocyanins, but higher amounts of flavonols compared to gra6. Gene expression analysis demonstrated that expression of the dihydroflavonol 4-reductase gene 2 () was lower in gra50 compared with gra6, whereas the expression of other key genes did not differ greatly. These results suggest that the white-flowered variant of gra50 may result from a defect in expression of the gene.