Genome-Wide Analysis and Functional Characterization of the UDP-Glycosyltransferase Family in Grapes

Grape (Vitis vinifera) produces a variety of secondary metabolites, which can enhance nutrients and flavor in fruit and wine. Uridine diphosphate-glycosyltransferases (UGTs) are primarily responsible for the availability of secondary metabolites by glycosylation modification. Here, a total of 228 putative UGTs were identified in V. vinifera, and VvUGTs were clustered into 15 groups (A to O) and unevenly distributed on 18 chromosomes. Diverse VvUGT members from 12 groups were transcribed, and they responded to different external stresses. More than 72% of VvUGT members were expressed at one or more stages of grape fruit development, and the expression levels of 34 VvUGT members increased gradually with fruit ripening. The VvUGT members of different groups may be involved in the synthesis and accumulation of flavonoid glycosides, glycosidically bound volatiles, and stilbenes. These results will provide guidance for further research on the functions and regulating mechanisms of UGT genes.