Plant fungal pathogens secrete numerous proteins into the apoplast at the plant-fungus contact sites to facilitate colonization.However,only a few secretory proteins were functionally characterized in Magnaporthe oryzae,the fungal pathogen causing rice blast disease worldwide.Asparagine-linked glycosylation 3(Alg3)is an a-l,3-mannosyltransferase functioning in the N-glycan synthesis of N-glycosylated secretory proteins.Fungal pathogenicity and cell wall integrity are impaired in Aalg3 mutants,but the secreted proteins affected in Aalg3 mutants are largely unknown.In this study,we compared the secretomes of the wild-type strain and the Aalg3 mutant and identified 51 proteins that require Alg3 for proper secretion.These proteins were predicted to be involved in metabolic processes,interspecies interactions,cell wall organization,and response to chemicals.Nine proteins were selected for further validation.We found that these proteins were localized at the apoplastic region surrounding the fungal infection hyphae.Moreover,the N-glycosylation of these proteins was significantly changed in the Aalg3 mutant,leading to the decreased protein secretion and abnormal protein localization.Furthermore,we tested the biological functions of two genes,INV1(encoding invertase 1,a secreted invertase)and AMCase(encoding acid mammalian chinitase,a secreted chitinase).The fungal virulence was significantly reduced,and the cell wall integrity was altered in the Ainv1 and Aamcase mutant strains.Moreover,the N-glycosylation was essential for the function and secretion of AMCase.Taken together,our study provides new insight into the role of N-glycosylated secretory proteins in fungal virulence and cell wall integrity.

Ning Liu;Linlu Qi;Manna Huang;Deng Chen;Changfa Yin;Yiying Zhang;Xingbin Wang;Guixin Yuan;Rui-Jin Wang;Jun Yang;You-Liang Peng;Xunli Lu

State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Pest Monitoring and Green Management,China Agricultural University,Beijing 100193,China;Graduate School of China Agricultural University,Beijing 100193,China;MOA Key Laboratory of Pest Monitoring and Green Management,College of Plant Protection,China Agricultural University,Beijing 100193,China

基因组蛋白质组与生物信息学报（英文版）

[1]Ning Liu;Linlu Qi;Manna Huang;Deng Chen;Changfa Yin;Yiying Zhang;Xingbin Wang;Guixin Yuan;Rui-Jin Wang;Jun Yang;You-Liang Peng;Xunli Lu-.Comparative Secretome Analysis of Magnaporthe oryzae Identified Proteins Involved in Virulence and Cell Wall Integrity)[J].基因组蛋白质组与生物信息学报（英文版）,2022(04):728-746

Secretome,Virulence,Alg3,mannosyltransferase,Aalg3,secretomes,INV1,AMCase,chinitase,Ainv1,Aamcase

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