WAK This Way: The Roles of Wall-Associated Kinases in Plant Disease Resistance

Plant wall-associated kinases (WAKs) and WAK-like kinases (WAKLs) are closely related subfamilies of receptor-like kinases (RLKs) that bridge the plant cell wall and cytoplasm and mediate essential signaling functions. Beyond their developmental roles, accumulating evidence highlights their important contributions to plant immunity. Initially identified in Arabidopsis thaliana, these proteins have emerged as important regulators of plant responses to biotic stresses. This review focuses on the disease-resistance functions of this protein family and their associated signaling pathways across diverse plant species. Notably, recent genetic evidence has challenged the long-held view that Arabidopsis WAKs serve as bona fide receptors for oligogalacturonides (OGs), highlighting unresolved questions about how WAKs and WAKLs perceive pathogen invasion. Based on current knowledge, we propose a working model for pathogen recognition by WAKs and WAKLs and outline potential shared immune signaling pathways mediated by this receptor family.