Light quality affects flavonoid biosynthesis in young berries of Cabernet Sauvignon grape
- 作者：Kazuya Koyama ; koyama@nrib.go.jp ; Hiroko Ikeda ; Puspa Raj Poudel ; Nami Goto-Yamamoto
- 关键词：Red-wine grape ; Vitis vinifera ; Vitaceae ; Ultraviolet ; Visible light ; Photoprotection ; Secondary metabolism ; MYB transcription factor superfamily ; Flavonoid ; Proanthocyanidin ; Flavonol
- 刊名：Phytochemistry
- 出版年：2012
- 期刊代码：85_00319422
- 类别：ch
- 出版时间：June, 2012
- 卷：78
- 期：Complete
- 页码：54-64
- 文件大小：681 K
摘要
Biosynthesis of phenolic compounds is known to be sensitive to light environments, which reflects the possible role of these compounds for photoprotection in plants. Herein, the effects of UV and visible light on biosynthesis of flavonoids was investigated, i.e., proanthocyanidins (PAs) and flavonols, in young berry skins of a red-wine grape, Vitis vinifera cv. Cabernet Sauvignon. Shading with light-proof boxes from the flowering stage until 49 days after treatment (DAT) partially decreased PA concentrations, and completely decreased flavonol concentrations in the berry skins. Shading decreased the transcript abundance of a flavonol-related gene more remarkably than those of PA-related genes. In addition, light exclusion influenced the composition of PAs, such as the decrease in the proportion of trihydroxylated subunits and the mean degree of polymerization (mDP) within PAs. However, solar UV exclusion did not affect the concentration and composition of PAs, whereas this exclusion remarkably decreased the flavonol concentration. Consistently, UV exclusion did not influence the transcript levels of PA-related genes, whereas it dramatically decreased that of flavonol-related genes. These findings indicated a different light regulation of the biosynthesis of these flavonoids in young berry skins of wine grape. Visible light primarily induces biosynthesis of PAs and affects their composition, whereas UV light specifically induces biosynthesis of flavonols. Distinct roles of members of a MYB transcription factor family for light regulation of flavonoid biosynthesis were proposed.