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MoPpe1 partners with MoSap1 to mediate TOR and cell wall integrity signalling in growth and pathogenicity of the rice blast fungus Magnaporthe oryzae
Author(s) -
Qian Bin,
Liu Xinyu,
Jia Jia,
Cai Yongchao,
Chen Chen,
Zhang Haifeng,
Zheng Xiaobo,
Wang Ping,
Zhang Zhengguang
Publication year - 2018
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.14421
Subject(s) - biology , conidiation , appressorium , protein phosphatase 2 , microbiology and biotechnology , tor signaling , magnaporthe , kinase , signal transducing adaptor protein , protein kinase a , magnaporthe grisea , fungal protein , mapk/erk pathway , signal transduction , effector , phosphatase , saccharomyces cerevisiae , virulence , genetics , phosphorylation , gene , oryza sativa
Summary In the rice blast fungus Magnaporthe oryzae , the cell wall integrity (CWI) signalling pathway governs cell wall changes in response to external cues and normal CWI signalling is critical for appressorium function and pathogenicity. We previously characterized the mitogen‐activated protein kinase (MAPK) kinase MoMkk1 as an integral component of the CWI pathway. Using the affinity purification approach, we have identified MoMkk1‐interacting MoPpe1 as a homologue of Saccharomyces cerevisiae serine/threonine protein phosphatase Sit4/Ppe1. We found that MoPpe1 is required for vegetative growth, conidiation and full virulence. In addition, we found that MoPpe1 interacts with MoSap1, a protein with functions similar to MoPpe1. Intriguingly, we found that MoPpe1–MoSap1 interaction is related to CWI and target of rapamycin (TOR) pathways. We presented evidence suggesting that MoPpe1 and MoSap1 function as an adaptor complex linking CWI and TOR signalling and that the activation of the TOR pathway leads to suppression of CWI signalling, resulting in defects in appressorium function and pathogenicity. Taken together, our studies not only reveal important functions of MoMkk1–MoPpe1–MoSap1 interactions in growth and pathogenicity of the blast fungus, but also highlight the complexity of regulatory networks involving conserved yet novel regulatory mechanisms of CWI and TOR signalling.