Abstract
Marginal variegation is a pigmentation pattern of different colors between margin and the other parts of a petal, which is caused by regulation of pigment biosynthesis and determination of the switching position. Molecular mechanisms for formation of marginal variegation were studied in Petunia petals. We analyzed composition of anthocyanins and their precursors as well as expression of anthocyanin biosynthesis related genes in different color parts. Part-specific accumulation of cinnamic acid derivatives and decrease in the transcript level of chalcone synthase gene were observed in the white part of the white marginal petal. Part-specific accumulation of flavonoids and increase in the transcript level of flavonol synthase gene were found in the white part of the colored marginal petal. These results suggest that the regulation chalcone synthase gene and flavonol synthase gene play key roles in each pattern formation, respectively.
