<i>Heterodera avenae</i> Effector HaGLAND5 Promotes Nematode Parasitism by Suppressing Wheat Immunity through Enhancing Acetylation of Susceptibility Gene <i>TaEMB3003</i>

Wheat, a cornerstone of global food security, is critically threatened by pests such as the cyst nematode<i>Heterodera avenae</i>, which secretes effector HaGLAND5 to manipulate wheat susceptibility. Here, we demonstrate that HaGLAND5 directly interacts with the pyruvate dehydrogenase subunit TaEMB3003 in wheat. TaEMB3003 functions as a susceptibility factor, where its overexpression increases nematode infection by 147.06%, whereas silencing reduces infestation by 53.96%. Mechanistically, TaEMB3003 suppresses PTI (inhibiting <i>NbPti5</i>, <i>NbAcre31</i>, and <i>NbGras2</i> expression), attenuates a flg22-induced ROS burst, and disrupts SA/JA signaling (downregulating <i>TaFAD</i>, <i>TaLOX</i>, <i>TaPAL</i>, and <i>TaPR1</i>). Critically, HaGLAND5 enhances TaEMB3003 acetylation at lysine 39 (K39) and K39A mutation abolishes TaEMB3003-mediated susceptibility. Our findings reveal a novel strategy whereby a nematode effector hijacks a host metabolic enzyme via post-translational modification to suppress immunity and promote parasitism.