The fungal pathogen Magnaporthe oryzae suppresses innate immunity by modulating a host potassium channel.

• Main Authors: Xuetao Shi, Yu Long, Feng He, Chongyang Zhang, Ruyi Wang, Ting Zhang, Wei Wu, Zeyun Hao, Yi Wang, Guo-Liang Wang, Yuese Ning
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2018-01-01
• Series: PLoS Pathogens
• Online Access: http://europepmc.org/articles/PMC5809103?pdf=render

Potassium (K+) is required by plants for growth and development, and also contributes to immunity against pathogens. However, it has not been established whether pathogens modulate host K+ signaling pathways to enhance virulence and subvert host immunity. Here, we show that the effector protein AvrPiz-t from the rice blast pathogen Magnaporthe oryzae targets a K+ channel to subvert plant immunity. AvrPiz-t interacts with the rice plasma-membrane-localized K+ channel protein OsAKT1 and specifically suppresses the OsAKT1-mediated K+ currents. Genetic and phenotypic analyses show that loss of OsAKT1 leads to decreased K+ content and reduced resistance against M. oryzae. Strikingly, AvrPiz-t interferes with the association of OsAKT1 with its upstream regulator, the cytoplasmic kinase OsCIPK23, which also plays a positive role in K+ absorption and resistance to M. oryzae. Furthermore, we show a direct correlation between blast disease resistance and external K+ status in rice plants. Together, our data present a novel mechanism by which a pathogen suppresses plant host immunity by modulating a host K+ channel.