Plant receptor-like kinases (RLKs) are important players in response to pathogen infections. Verticillium and Fusarium wilts, caused by Verticillium dahliae (Vd) and Fusarium oxysporum f. sp vasinfectum (Fov), respectively, are among the most devastating diseases in cotton (Gossypium spp). To understand the cotton response to these soil-borne fungal pathogens, we performed a genome-wide in silico characterization and functional screen of diverse RLKs for their involvement in cotton wilt diseases. We identified Gossypium hirsutum GhWAK7A, a wall-associated kinase, that positively regulates cotton response to both Vd and Fov infections. Chitin, the major constituent of the fungal cell wall, is perceived by lysin-motif-containing RLKs (LYKs/CERK1), leading to the activation of plant defense against fungal pathogens. A conserved chitin sensing and signaling system is present in cotton, including chitin-induced GhLYK5-GhCERK1 dimerization and phosphorylation, and contributes to cotton defense against Vd and Fov. Importantly, GhWAK7A directly interacts with both GhLYK5 and GhCERK1 and promotes chitin-induced GhLYK5-GhCERK1 dimerization. GhWAK7A phosphorylates GhLYK5, which itself does not have kinase activity, but requires phosphorylation for its function. Consequently, GhWAK7A plays a crucial role in chitin-induced responses. Thus, our data reveal GhWAK7A as an important component in cotton response to fungal wilt pathogens by complexing with the chitin receptors.

植物受体样激酶（RLK）是应对病原体感染的重要参与者。黄萎病和镰刀菌枯萎病，由大丽黄萎病菌( Vd ) 和尖镰孢菌f 引起。sp vasinfectum ( Fov ) 分别是棉花 ( Gossypium spp)中最具破坏性的疾病之一。为了了解棉花对这些土传真菌病原体的反应，我们对不同的 RLK 进行了全基因组计算机表征和功能筛选，以确定它们与棉花枯萎病的关系。我们发现了陆地棉GhWAK7A，一种壁相关激酶，它可以积极调节棉花对Vd和Fov感染的反应。甲壳素是真菌细胞壁的主要成分，可被含有溶素基序的 RLK (LYKs/CERK1) 感知，从而激活植物对真菌病原体的防御。棉花中存在保守的几丁质传感和信号系统，包括几丁质诱导的 GhLYK5-GhCERK1 二聚化和磷酸化，有助于棉花防御Vd和Fov。重要的是，GhWAK7A 直接与 GhLYK5 和 GhCERK1 相互作用，并促进几丁质诱导的 GhLYK5-GhCERK1 二聚化。GhWAK7A 磷酸化 GhLYK5，GhLYK5 本身不具有激酶活性，但需要磷酸化才能发挥其功能。因此，GhWAK7A 在几丁质诱导的反应中起着至关重要的作用。因此，我们的数据表明 GhWAK7A 通过与几丁质受体复合而成为棉花对枯萎病病原体反应的重要组成部分。