Methylation of MYBA1 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 DFR, UFGT, and GST were significantly correlated with the anthocyanin content. The promoters of the two VvUFGT 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 VvMYBA1 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 VvMYBA1 promoter play a crucial role in regulating grape skin coloration.

Genetic and epigenetic control of the plant metabolome

“…VvMYBA1. Cytosine methylation in the promoter region of VvMYBA1 in the red top was lower, consistent with its higher expression [143].…”

“…On the promoters of UFGT were direct binding sites of a transcription factor VvMYBA1 . Cytosine methylation in the promoter region of VvMYBA1 in the red top was lower, consistent with its higher expression [143]. In an apple variety ‘Honeycrisp’, cytosine demethylation in the promoter region of MdMYB10 was associated to red stripes.…”

“…The ‘Manicure Finger’ grape has a characteristic colouring in the ripe fruit with its base being yellow and top being red. Anthocyanin concentration and expression of anthocyanin biosynthesis related genes, especially dihydroflavonol reductase ( DFR ), UDP‐glucose flavonoid‐3‐O‐glucosyltransferase ( UFGT ) and glutathione S‐transferase ( GST ) was higher in the red top [143]. UFGT is known to be the major control point for anthocyanin biosynthesis in grape berry skin with its expression much higher in red grapes compared to white varieties [144].…”

Methylation of AcGST1 Is Associated with Anthocyanin Accumulation in the Kiwifruit Outer Pericarp

“…Multiple pieces of evidence proved that the methylation level was negatively correlated with the gene transcriptional level, thereby affecting fruit coloration. For example, a low methylation level in the VvMYBA1 promoter region (−1488 to −1083 bp) was responsible for a higher gene expression at the top of the fruit, resulting in the difference in coloration at the top and base of “Manicure Finger” grapes . Methylation of the LDOX promoter causes the floral color variegation in peaches .…”

“…AcGST1 promoter truncations and coding region of AcMYB10 were cloned into pGreenII-0800-LUC and pGreenII-62-SK, respectively, and then transformed into Agrobacterium tumefaciens strain GV3101. Tobacco transient expression and dual luciferase assays referred to the method and were performed using a Dual-Luciferase reporter gene assay kit (Yeasen, Shanghai, China).…”