Heterologous Expression Screens of In planta-Expressed Blast Secreted Proteins Identify a Candidate Effector that Associates with Aquaporin-1 in Rice
W. LIU (1), X. Xie (2), G. Wang (3) (1) State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, China; (2) State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, China; (3) Department of Plant Pathology, Ohio State University, U.S.A.

Elucidating of the molecular mechanism of effector-mediated suppression of plant immunity is an emerging topic and challenging task in plant-pathogen interaction. Rice blast disease, caused by the fungus Magnaporthe oryzae, is one of the most damaging factors in rice production worldwide, affecting global food security. To cause rice blast disease, the biotrophic invasive hyphae of M. oryzae will secrete cytoplasmic effectors, which preferentially accumulate in biotrophic interfacial complexes (BICs), and eventually are translocated into the rice cytoplasm to facilitate disease development by suppressing plant defence responses. Although the M. oryzae genome consists of a large number of secreted proteins, few of them have been functionally characterized. Previously, we identified total of 851 in planta-expressed predicted effector genes in M. oryzae. Bioinformatic analysis revealed that 34 of them are predicted to contain conserved plant nucleus localization signal (NLS). Heterologous expression screens confirmed four proteins (MoNLE1-4) were localized in the nucleus of tobacco plant Nicotiana benthamiana and rice protoplast. Moreover, the MoNLE1 gene knock-out mutants were compromise of pathogenecity on rice and MoNLE1 was found to suppress Bax-induced cell death in Nicotiana benthamiana, indicating MoNLE1 is an important virulence factor that may play crucial roles in facilitating fungus colonization and fungal growth during infection. MoNLE1 associates with plasma membrane intrinsic aquaporin protein OsPIP1:1 from rice. Further in-depth functionally studies of MoNLE1 effector gene will provide insight into the function of blast effector targets in regulation of plant immunity.

Abstract Number: P9-280
Session Type: Poster