Abstract
In plants, most of genes involved in metabolism belong to multigene families. It was reported that there are 272 cytochrome P450 genes and 107 family glycosyltransferase genes in Arabidopsis. Their huge diversity makes it difficult to determine their physiological functions precisely.
To identify flavonoid UDP-dependent glycosyltransferase (UGT) comprehensively, we utilized transcriptome coexpression analysis using known flavonoid related genes as queries. A UGT gene, UGT3, was found to be highly correlated with anthocyanin biosynthetic genes. UGT3 belongs to the flavonoid-UGT subfamily which can glycosylate a hydroxyl group of sugar moiety linked to the flavonoid aglycone. The anthocyanin profiles of ugt3 Ds-transposon inserted mutants are different from that of wild type when grown in high sucrose condition. UGT3 recombinant protein could catalyze the xylosylation of cyanidin 3-O-glucoside. UGT3 recognized UDP-xylose but not other UDP-sugars. These data show that UGT3 encodes a novel anthocyanin O-xylosyltransferase.
