Spatiotemporal metabolic regulation of anthocyanin and related compounds during the development of marginal picotee petals in Petunia hybrida (Solanaceae)

Structures and levels of anthocyanin-related compounds were analyzed during the development of marginal picotee petals in white-center and white-marginal cultivars of Petunia hybrida. In the white site of a white-center cultivar, higher concentrations of quercetin derivatives possessing 7-O-glucoside and/or 3'-O-glucoside occurred than in the colored site, suggesting that these two quercetin glycosylation steps are site-specifically regulated. The boundary areas of petal coloration were composed of cells showing various color densities, whose uniformity among adjacent cells varied between these cultivars. These results indicate diversity in spatiotemporal regulation of anthocyanin biosynthesis and flavonol glycosylations between Petunia cultivars during marginal picotee formation.