The grapevine transcription factor VvMYBPA1 regulates proanthocyanidin synthesis during fruit development
The grapevine transcription factor VvMYBPA1 regulates proanthocyanidin synthesis during fruit development
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DOI：
10.1104/pp.106.093203
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发表时间：
2007-03-01
期刊：
影响因子：
7.4
通讯作者：
Robinson, Simon P.
中科院分区：
文献类型：
--
作者：
Bogs, Jochen;Jaffe, Felix W.;Robinson, Simon P.
原蛋白蛋白（PAS；或凝结的单宁）可以保护植物免受草食动物的侵害，有助于许多水果的味道，并充当对人类健康有益的饮食抗氧化剂。我们先前已经表明，在葡萄葡萄（Visity Vinifera）中，PA合成涉及白细胞素蛋白还原酶（LAR）和花青素还原酶（ANR）。在这里，我们报告了葡萄感MYB转录因子VVMYBPA1的表征，该因子控制了PA途径基因的表达，包括LAR和ANR。 VVMybpa1在葡萄浆果中的表达与早期浆果发育和种子中PA的积累相关。在瞬态测定中，VVMYBPA1激活了LAR和ANR的启动子，以及几个通用类黄酮途径基因的启动子。 VVMYBPA1没有激活VVUFGT的启动子，该启动子编码了花色素特异性酶UDP-葡萄糖：类黄酮-3-O-gulcosylansylansylansylansylansferase，这表明VVMyBPA1特定于对葡萄葡萄中PA生物合成的调节。拟南芥（Arabidopsis thaliana）myb转录因子透明testa2（TT2）调节拟南芥种皮中的PA合成。通过补充拟南芥TT2突变体的PA缺陷种子表型，我们证实了VVMyBPA1作为PA合成的转录调节剂的功能。与拟南芥中TT2的异位表达相反，VVMyBPA1的本构表达导致在子叶，营养分生组织，叶毛和根中的PAS积累。据我们所知，这是控制水果中PA途径基因（包括LAR和ANR）的第一个报告，该因子都可以诱导拟南芥中的异位PA积累。
Proanthocyanidins (PAs; or condensed tannins) can protect plants against herbivores, contribute to the taste of many fruits, and act as dietary antioxidants beneficial for human health. We have previously shown that in grapevine (Vitis vinifera) PA synthesis involves both leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR). Here we report the characterization of a grapevine MYB transcription factor VvMYBPA1, which controls expression of PA pathway genes including both LAR and ANR. Expression of VvMYBPA1 in grape berries correlated with PA accumulation during early berry development and in seeds. In a transient assay, VvMYBPA1 activated the promoters of LAR and ANR, as well as the promoters of several of the general flavonoid pathway genes. VvMYBPA1 did not activate the promoter of VvUFGT, which encodes the anthocyanin-specific enzyme UDP-glucose: flavonoid-3-O-glucosyltransferase, suggesting VvMYBPA1 is specific to regulation of PA biosynthesis in grapes. The Arabidopsis (Arabidopsis thaliana) MYB transcription factor TRANSPARENT TESTA2 (TT2) regulates PA synthesis in the seed coat of Arabidopsis. By complementing the PA-deficient seed phenotype of the Arabidopsis tt2 mutant with VvMYBPA1, we confirmed the function of VvMYBPA1 as a transcriptional regulator of PA synthesis. In contrast to ectopic expression of TT2 in Arabidopsis, constitutive expression of VvMYBPA1 resulted in accumulation of PAs in cotyledons, vegetative meristems, leaf hairs, and roots in some of the transgenic seedlings. To our knowledge, this is the first report of a MYB factor that controls genes of the PA pathway in fruit, including both LAR and ANR, and this single MYB factor can induce ectopic PA accumulation in Arabidopsis.