Genetic and environmental impacts on the biosynthesis of anthocyanins in grapes

Because of the commercial importance of grapes (Vitis spp.), it is important to understand how grape coloration is affected by genetic and environmental factors, as this knowledge may contribute to more stable production of high-quality grapes. The color of berry skins is determined mainly by the quantity and composition of anthocyanins. This review summarizes the results of recent studies of the genetic and environmental regulation of anthocyanin biosynthesis in grape berry skin: (i) The myeloblastosis (MYB) haplotype composition at the color locus is the major genetic factor that determines the anthocyanin content. (ii) The MYB haplotype composition at the color locus and the anthocyanin O-methyltransferase locus are major genetic determinants of the ratios of tri- to di-hydroxylated anthocyanins and of methylated to non-methylated anthocyanins. (iii) The accumulation of anthocyanins depends on both low temperature and light, and the two factors have a synergistic effect on the expression of genes within the anthocyanin biosynthesis pathway. (iv) Comprehensive transcriptome analysis using a grape oligo-DNA microarray let my research group identify many candidate genes involved in low-temperature-induced abscisic acid signaling and light signaling networks related to anthocyanin accumulation in grape berry skin. These findings will allow prediction of the skin color of grapes from seedlings at a very young stage by examining the MYB haplotype composition. Furthermore, these results will contribute to a fuller understanding of how grape coloration is affected by environmental factors, thereby helping grape growers to develop cultivation techniques that contribute to the production of highly pigmented grapes.