Wang Dan, Jiang Changyue, Liu Wandi, Wang Yuejin
College of Horticulture, Northwest A & F University, Yangling, Shaanxi, P.R. China.
Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China.
J Exp Bot. 2020 May 30;71(10):3211-3226. doi: 10.1093/jxb/eraa097.
Resveratrol is notable not only for its functions in disease resistance in plants but also for its health benefits when it forms part of the human diet. Identification of new transcription factors helps to reveal the regulatory mechanisms of stilbene synthesis. Here, the WRKY53 transcription factor was isolated from the Chinese wild grape, Vitis quinquangularis. Vqwrky53 was expressed in a variety of tissues and responded to powdery mildew infection and to exogenous hormone application. VqWRKY53 was located in the nucleus and had transcriptional activation activity in yeast. A yeast two-hybrid assay and a bimolecular fluorescence complementation assay confirmed that VqWRKY53 interacted physically with VqMYB14 and VqMYB15, which have previously been reported to regulate stilbene synthesis. When Vqwrky53 was overexpressed in grape leaves, the expression of VqSTS32 and VqSTS41 and the content of stilbenes were increased. A yeast one-hybrid assay demonstrated that VqWRKY53 could bind directly to the promoters of STS genes. Overexpression of Vqwrky53 activated β-glucuronidase expression, driven by STS promoters, and co-expressing Vqwrky53 with VqMYB14 and VqMYB15 showed stronger regulatory functions. Heterologous overexpression of Vqwrky53 in Arabidopsis accelerated leaf senescence and disease resistance to PstDC3000.
白藜芦醇不仅因其在植物抗病中的功能而闻名，还因其成为人类饮食的一部分时对健康有益而受到关注。鉴定新的转录因子有助于揭示芪合成的调控机制。在此，从中国野生葡萄毛葡萄中分离出WRKY53转录因子。Vqwrky53在多种组织中表达，并对白粉病感染和外源激素处理有反应。VqWRKY53定位于细胞核，在酵母中具有转录激活活性。酵母双杂交试验和双分子荧光互补试验证实，VqWRKY53与之前报道的调控芪合成的VqMYB14和VqMYB15发生了物理相互作用。当Vqwrky53在葡萄叶片中过表达时，VqSTS32和VqSTS41的表达以及芪的含量增加。酵母单杂交试验表明，VqWRKY53可以直接结合到STS基因的启动子上。Vqwrky53的过表达激活了由STS启动子驱动的β-葡萄糖醛酸酶表达，并且将Vqwrky53与VqMYB14和VqMYB15共表达显示出更强的调控功能。Vqwrky53在拟南芥中的异源过表达加速了叶片衰老和对PstDC3000的抗病性。
