Effects of leaf removal on the accumulation of anthocyanins and the expression of anthocyanin biosynthetic genes in Cabernet Sauvignon (Vitis vinifera L.) grapes.

BACKGROUND Anthocyanins, a major class of flavonoids, determine the color and quality of wine. Recent research revealed that basal leaf removal can increase the contents of these compounds. This study determined the effects of basal leaf removal on the anthocyanin profiles of Cabernet Sauvignon grapes. RESULTS The effects of basal leaf removal on anthocyanin composition in Cabernet Sauvignon grapes were investigated over two growing seasons. Leaf removal at 5% veraison (VB6) and at 100% veraison (VC6) was compared with a control. Reducing sugar and total anthocyanin contents in leaf removal group were significantly higher than those in the control group at harvest for both vintages. Leaf removal increased individual anthocyanin contents and significantly improved the Mv-3-glc, Pn-3-glc and Mv-3-acglc contents of the VB6 group. At harvest, VB6 treatment increased the transcript abundance of structural and regulator genes in the anthocyanins pathway, especially VvF3'5'H, VvLDOX and VvDFR. CONCLUSIONS Our results suggest that Leaf removal at 5% veraison may be useful for improving the anthocyanin contents in grapes. This article is protected by copyright. All rights reserved.