Methylation of <i>MYBA1</i> is Associated with the Coloration in “Manicure Finger” Grape Skin

Abstract

The "Manicure Finger" grape is notable for its fingerlike berries with a bright red top and yellow base; however, the mechanism underlying this color difference remains unknown. This study showed that the anthocyanin concentration and the expression levels of anthocyanin-related genes in the top skin were notably higher than those in the basal skin. The expression levels of <i>DFR</i>, <i>UFGT</i>, and <i>GST</i> were significantly correlated with the anthocyanin content. The promoters of the two <i>VvUFGT</i> alleles can be activated by VvMYBA1, which was verified by the yeast one-hybrid assay, the dual-luciferase reporter gene assay, and the electrophoretic mobility shift assay. Moreover, the methylation level of the <i>VvMYBA1</i> promoter (-1488 to -1083 bp) in the top skin was significantly lower than that in the basal skin and was positively correlated with the anthocyanin content. Our data suggest that methylation levels of the <i>VvMYBA1</i> promoter play a crucial role in regulating grape skin coloration.