Isolation of WDR and bHLH genes related to flavonoid synthesis in grapevine (Vitis vinifera L.)
Isolation of WDR and bHLH genes related to flavonoid synthesis in grapevine (Vitis vinifera L.)
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DOI：
10.1007/s11103-010-9597-4
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发表时间：
2010-04-01
影响因子：
5.1
通讯作者：
Arce-Johnson, P.
中科院分区：
文献类型：
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作者：
Matus, J. T.;Poupin, M. J.;Arce-Johnson, P.
花青素和单宁是葡萄藤中发现的两种最丰富的黄酮类化合物，它们的合成来自苯丙素途径。如对模式物种如拟南芥、玉米和矮牵牛所述，该途径的终点分支受到三个调控因子家族的组合相互作用的严格调控; MYB、bHLH（也称为MYC）和WDR蛋白。在这些基因中，只有MYB基因以前在葡萄中被发现。在这里，我们报告的分离的第一个成员从WDR和bHLH家族中发现的葡萄属葡萄，命名为WDR 1，WDR 2和MYCA 1。WDR 1在A. thaliana中，虽然不可能通过异位表达来确定WDR 2的功能。通过GFP融合蛋白观察到WDR 1和MYCA 1的亚细胞定位，表明细胞质和细胞核定位，与MYB因子仅在细胞核中的定位相反。在整个发育过程中，这些基因的表达模式在有色生殖器官中进行定量，并与花青素积累和类黄酮相关的MYBA 1 -2，UFGT和ANR基因的表达谱相关。在高盐浓度下生长的葡萄藤苗表现出品种依赖的花青素积累反应，这与MYBA 1 -2，MYCA 1和WDR 1基因的表达相关。这些结果表明，MYCA 1可以调节ANR和UFGT，并且当MYBA基因缺失或低丰度时，最后一种控制更容易区分。未来的研究应解决这些蛋白质的具体相互作用和它们的定量贡献类黄酮合成葡萄浆果。
Anthocyanins and tannins are two of the most abundant flavonoids found in grapevine, and their synthesis is derived from the phenylpropanoid pathway. As described for model species such as Arabidopsis thaliana, maize and petunia, the end-point branches of this pathway are tightly regulated by the combinatorial interaction of three families of regulatory factors; MYB, bHLH (also known as MYC) and WDR proteins. Among these, only MYB genes have been previously identified in grapes. Here, we report the isolation of the first members from the WDR and bHLH families found in Vitis vinifera, named WDR1, WDR2 and MYCA1. WDR1 contributed positively to the accumulation of anthocyanins when it was overexpressed in A. thaliana, although it was not possible to determine the function of WDR2 by ectopic expression. The sub-cellular localizations of WDR1 and MYCA1 were observed by means of GFP-fusion proteins, indicating both cytoplasm and nuclear localization, in contrast to the localization of a MYB factor exclusively in the nucleus. The expression patterns of these genes were quantified in coloured reproductive organs throughout development, and correlated with anthocyanin accumulation and the expression profiles of the flavonoid-related MYBA1-2, UFGT, and ANR genes. In vitro grapevine plantlets grown under high salt concentrations showed a cultivar-dependent response for anthocyanin accumulation, which correlated with the expression of MYBA1-2, MYCA1 and WDR1 genes. These results suggest that MYCA1 may regulate ANR and UFGT and that this last control is easier to distinguish whenever MYBA genes are absent or in low abundance. Future studies should address the specific interactions of these proteins and their quantitative contribution to flavonoid synthesis in grape berries.