Iron Supply Affects Anthocyanin Content and Related Gene Expression in Berries of Vitis vinifera cv. Cabernet Sauvignon.
The effect of phosphate (Pi) starvation on anthocyanin biosynthesis was examined in suspension-cultured grape cells derived from Bailey Alicante A grapes. Cyanindin-3-O-glucoside, peonidin-3-O-glucoside, cyanidin-3-O-(6-O״-p-coumaroyl)-glucoside and peonidin-3-O-(6-O״-p-coumaroyl)-glucoside were detected in cells in both the complete (+Pi)- and Pi-deficient Murashige-Skoog (-Pi) medium but accumulation was much more substantial cells in -Pi cultures. Highest incorporation of [ring-(14)C]phenylalanine into anthocyanins was found at days 3-14 in the cells in -Pi medium. Time-course expression profiles of anthocyanin biosynthetic enzyme genes and a regulatory gene were examined after cells were transferred to the +Pi and -Pi medium. The transcript levels of UFGT and VvmybA1 in -Pi cells were higher than in +Pi cells 24 h after transfer coinciding with the start of anthocyanin accumulation in -Pi cells.