College of Horticulture, Northwest A & F University, Yangling, China.
Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, China.
Mol Plant Pathol. 2023 Feb;24(2):123-141. doi: 10.1111/mpp.13280. Epub 2022 Nov 20.
Resveratrol is a phytoalexin that is synthesized by stilbene synthase (STS). Resveratrol in the human diet is known to have beneficial effects on health. We previously identified six novel STS (VqNSTS) transcripts from the transcriptome data of Vitis quinquangularis accession Danfeng-2. However, the functions of and defensive mechanisms triggered by these VqNSTS transcripts remain unknown. In the present study, we demonstrate that the expression of five of these six novel members, VqNSTS2-VqNSTS6, can be induced by the powdery mildew-causing fungus Uncinula necator. Additionally, overexpression of VqNSTS4 in the V. vinifera susceptible cultivar Thompson Seedless promoted accumulation of stilbenes and enhanced resistance to U. necator by activating salicylic acid (SA) signalling. Furthermore, our results indicate that the Alfin-like (AL) transcription factor VqAL4 can directly bind to the G-rich element (CACCTC) in the VqNSTS4 promoter and activate gene expression. Moreover, overexpression of VqAL4 in Thompson Seedless enhanced resistance to U. necator by promoting stilbene accumulation and activating SA signalling. Conversely, RNA interference-mediated silencing of VqNSTS4 and VqAL4 resulted in increased susceptibility to U. necator. Collectively, our results reveal that VqNSTS4, regulated by VqAL4, enhances grapevine resistance to powdery mildew by activating SA signalling. Our findings may be useful to improve disease resistance in perennial fruit trees.
白藜芦醇是一种植物抗毒素，由芪合酶（STS）合成。人类饮食中的白藜芦醇对健康有有益的影响。我们之前从葡萄转录组数据中鉴定出六个新的 STS（VqNSTS）转录本。然而，这些 VqNSTS 转录本的功能和触发的防御机制仍不清楚。在本研究中，我们证明了这六个新成员中的五个，VqNSTS2-VqNSTS6，可以被白粉病引起的真菌 Uncinula necator 诱导。此外，在易感品种汤普森无核葡萄中过表达 VqNSTS4 可通过激活水杨酸（SA）信号来促进芪类物质的积累并增强对 U.necator 的抗性。此外，我们的结果表明，Alfin-like（AL）转录因子 VqAL4 可以直接结合 VqNSTS4 启动子中的 G-丰富元件（CACCTC）并激活基因表达。此外，在汤普森无核葡萄中过表达 VqAL4 通过促进芪类物质积累和激活 SA 信号来增强对 U.necator 的抗性。相反，VqNSTS4 和 VqAL4 的 RNA 干扰介导的沉默导致对 U.necator 的敏感性增加。总之，我们的结果表明，VqNSTS4 受 VqAL4 调控，通过激活 SA 信号增强葡萄对白粉病的抗性。我们的发现可能有助于提高多年生果树的抗病性。
