Co-pigmentation and flavonoid glycosyltransferases in blue Veronica persica flowers

cDNAs encoding flavone 7-O-glucuronosyltransferase and anthocyanin 3-O-glucoside-2″-O-glucosyltransferase involved in the biosynthesis of apigenin 7-O-(2-O-glucuronosyl)-glucuronide and delphinidin 3-O-(2-O-(6-O-p-coumaroyl-glucosyl)-6-O-p-coumaroyl-glucoside)-5-O-glucoside, respectively, were identified from Veronica persica. Given that the flavone showed bathochromic shift on the anthocyanin, preferential expression in the petals suggest an inevitable role of these enzymes in blue flower development.