The barley powdery mildew effectors CSEP0139 and CSEP0182 suppress cell death and promote B. graminis fungal virulence in plants

Abstract The powdery mildew fungi secrete numerous Candidate Secreted Effector Proteins (CSEPs) to manipulate host immunity during infection of plants. However, the function most these CSEPs in cell death suppression has not yet been established. Here, we identified several from Blumeria graminis f. sp. hordei ( Bgh ) that have potential suppress BAX- and Nt MEK2 DD -triggered Nicotiana benthamiana . We further characterized two effector candidates, CSEP0139 CSEP0182, family six thirty-two, respectively. CSEP0182 contain a functional signal peptide are likely secreted effectors. Expression either or suppressed triggered by BAX but AVR a13 /MLA13 pair N. Transient overexpression also inhibited BAX-induced collapse cytoplasm barley cells. Furthermore, significantly increased haustorial formation barley, whereas host-induced gene silencing (HIGS) CSEP genes reduced formation, suggesting both promote virulence barley. In addition, expression size lesions caused necrotrophic Botrytis cinerea benthamiana. Our findings suggest may target components plants fungal virulence, which extends current understanding functions provides an opportunity for investigation relation pathways