Accumulating evidence indicates that plant cell wall-associated receptor-like kinases (WAKs) involve in defense against pathogen attack, but their related signaling processes and regulatory mechanism remain largely unknown. We identified a WAK-like kinase (GhWAKL) from upland cotton (Gossypium hirsutum) and characterized its functional mechanism. Expression of GhWAKL in cotton plants was induced by Verticillium dahliae infection and responded to the application of salicylic acid (SA). Knockdown of GhWAKL expression results in the reduction of SA content and suppresses the SA-mediated defense response, enhancing cotton plants susceptibility to V. dahliae. And, ecotopic overexpression of GhWAKL in Arabidopsis thaliana conferred plant resistance to the pathogen. Further analysis demonstrated that GhWAKL interacted with a cotton DnaJ protein (GhDNAJ1) on the cell membrane. Silencing GhDNAJ1 also enhanced cotton susceptibility to V. dahliae. Moreover, the mutation of GhWAKL at site Ser628 with the phosphorylation decreased the interaction with GhDNAJ1 and compromised the plant resistance to V. dahliae. We propose that GhWAKL is a potential molecular target for improving resistance to Verticillium wilt in cotton.

越来越多的证据表明，植物细胞壁相关受体样激酶（WAKs）参与了对病原体侵袭的防御，但是其相关的信号传导过程和调控机制仍然未知。我们从陆地棉（陆地棉）中鉴定了一个WAK样激酶（GhWAKL），并描述了其功能机制。黄萎病菌的感染诱导了棉花植物中GhWAKL的表达，并响应了水杨酸（SA）的应用。抑制GhWAKL表达可导致SA含量降低并抑制SA介导的防御反应，从而增强了棉花植物对V. dahliae的敏感性。而且，异位的表达GhWAKL在拟南芥对病原体赋予的植物抗性。进一步的分析表明，GhWAKL与细胞膜上的棉花DnaJ蛋白（GhDNAJ1）相互作用。沉默GhDNAJ1也增强了棉花对大丽花的易感性。此外，在GerWAKL位点Ser628处的磷酸化突变降低了与GhDNAJ1的相互作用，并损害了植物对大丽花的抗性。我们认为，GhWAKL是提高棉花对黄萎病抗性的潜在分子靶标。