LAUSR

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 WRKY transcription factor Vqwrky53 was isolated from the Chinese wild grape, Vitisquinquangularis. 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. The yeast two-hybrid (Y2H) assay and the bimolecular fluorescence complementation (BiFC) 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 expressions of VqSTS32 and VqSTS41 and the content of stilbenes were increased. The yeast one-hybrid assay demonstrated that Vqwrky53 could bind directly to the promoters of STS genes. Overexpression of Vqwrky53 activated GUS 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.