Wang Jie, Yao Wenkong, Wang Lei, Ma Fuli, Tong Weihuo, Wang Chen, Bao Rui, Jiang Changyue, Yang Yazhou, Zhang Jianxia, Xu Yan, Wang Xiping, Zhang Chaohong, Wang Yuejin
College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, China; State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.
College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China; Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, China; State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Plant Sci. 2017 Oct;263:142-155. doi: 10.1016/j.plantsci.2017.07.004. Epub 2017 Jul 13.
An F-box protein (VpEIFP1) induced by Erysiphe necator was isolated from Vitis pseudoreticulata, a wild Chinese grapevine species naturally resistant to powdery mildew (PM). It contains an F-box domain and two Kelch-repeat motifs. Expression profiles indicate the VpEIFP1 is strongly induced at both transcriptional and translational levels by PM infection. A subcellular localisation assay showed that VpEIFP1 is predominantly located in the nucleus and cytoplasm. Overexpression of VpEIFP1 accelerated the accumulation of hydrogen peroxide (HO) and up-regulated the expressions of ICS2, NPR1 and PR1 involved in defence responses, resulting in suppression of PM germination and growth. As an F-box protein, VpEIFP1 interacts with thioredoxin z (VpTrxz) in the yeast-two-hybrid (Y2H) assay and in the bimolecular fluorescence complementation (BiFC) assay. Decreased amounts of VpTrxz protein in transgenic grapevine leaves overexpressing VpEIFP1 were restored by proteasome inhibitor MG132, implying that VpEIFP1 mediated VpTrxz for degradation through the SCF (Skp1-Cullin-F-box) E3 ubiquitin ligase complex. The RNA interference line of VpTrxz showed increased HO accumulation following PM inoculation. We propose VpEIFP1 positively modulates the grapevine defence response to PM by inducing the degradation of VpTrxz via the ubiquitin/26S proteasome system.
从自然抗白粉病的野生中国葡萄品种——华东葡萄中分离出一种由白粉菌诱导的F-box蛋白（VpEIFP1）。它包含一个F-box结构域和两个kelch重复基序。表达谱表明，VpEIFP1在转录和翻译水平上均受到白粉病感染的强烈诱导。亚细胞定位分析表明，VpEIFP1主要位于细胞核和细胞质中。VpEIFP1的过表达加速了过氧化氢（H₂O₂）的积累，并上调了参与防御反应的ICS2、NPR1和PR1的表达，从而抑制了白粉病的萌发和生长。作为一种F-box蛋白，VpEIFP1在酵母双杂交（Y2H）试验和双分子荧光互补（BiFC）试验中与硫氧还蛋白z（VpTrxz）相互作用。蛋白酶体抑制剂MG132恢复了过表达VpEIFP1的转基因葡萄叶片中VpTrxz蛋白含量的降低，这意味着VpEIFP1通过SCF（Skp1-Cullin-F-box）E3泛素连接酶复合体介导VpTrxz的降解。VpTrxz的RNA干扰株系在接种白粉病后显示出H₂O₂积累增加。我们认为，VpEIFP1通过泛素/26S蛋白酶体系统诱导VpTrxz的降解，从而正向调节葡萄对白粉病的防御反应。
