Duan Xingpeng, Zhang Zhidong, Wang Jin, Zuo Kaijing
Plant Biotechnology Research Center, School of Agriculture and Life Sciences, Shanghai Jiao Tong University, Shanghai, China.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
PLoS One. 2016 Apr 18;11(4):e0153988. doi: 10.1371/journal.pone.0153988. eCollection 2016.
Verticillium wilt is a disastrous vascular disease in plants caused by Verticillium dahliae. Verticillium pathogens secrete various disease-causing effectors in cotton. This study identified a subtilase gene GbSBT1 from Gossypium babardense and investigated the roles against V. dahliae infection. GbSBT1 gene expression is responsive to V. dahliae defense signals, jasmonic acid, and ethylene treatments. Moreover, the GbSBT1 protein is mainly localized in the cell membrane and moves into the cytoplasm following jasmonic acid and ethylene treatments. Silencing GbSBT1 gene expression through virus-induced GbSBT1 gene silencing reduced the tolerance of Pima-90 (resistant genotype), but not facilitated the infection process of V. dahliae in Coker-312 (sensitive genotype). Moreover, the ectopically expressed GbSBT1 gene enhanced the resistance of Arabidopsis to Fusarium oxysporum and V. dahliae infection and activated the expression levels of defense-related genes. Furthermore, pull-down, yeast two-hybrid assay, and BiFC analysis revealed that GbSBT1 interacts with a prohibitin (PHB)-like protein expressed in V. dahliae pathogens during infection. In summary, GbSBT1 recognizes the effector PHB protein secreted from V. dahliae and is involved in Verticillium-induced resistance in cotton.
黄萎病是由大丽轮枝菌引起的一种植物灾难性维管束病害。大丽轮枝菌病原体在棉花中分泌多种致病效应因子。本研究从海岛棉中鉴定出一个枯草杆菌蛋白酶基因GbSBT1，并研究了其在抵抗大丽轮枝菌感染中的作用。GbSBT1基因表达对大丽轮枝菌防御信号、茉莉酸和乙烯处理有响应。此外，GbSBT1蛋白主要定位于细胞膜，在茉莉酸和乙烯处理后进入细胞质。通过病毒诱导的GbSBT1基因沉默来沉默GbSBT1基因表达，降低了皮马-90（抗性基因型）的耐受性，但并未促进大丽轮枝菌在科克-312（敏感基因型）中的感染过程。此外，异位表达的GbSBT1基因增强了拟南芥对尖孢镰刀菌和大丽轮枝菌感染的抗性，并激活了防御相关基因的表达水平。此外，下拉实验、酵母双杂交分析和双分子荧光互补分析表明，GbSBT1在感染过程中与大丽轮枝菌病原体中表达的一种类限膜蛋白（PHB）相互作用。总之，GbSBT1识别大丽轮枝菌分泌的效应因子PHB蛋白，并参与棉花中由黄萎病菌诱导的抗性反应。
