Bioinformatic analysis and functional characterization of the cfem proteins in maize anthracnose fungus Colletotrichum graminicola  

作　　者：GONG An-dong JING Zhong-ying ZHANG Kai TAN Qing-qun WANG Guo-liang LIU Wen-de 

机构地区：[1]State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100193,P.R.China [2]College of Life Science,Xinyang Normal University,Xinyang 464000,P.R.China [3]Department of Plant Pathology,The Ohio State University,Columbus,Ohio 43210,USA

出　　处：《Journal of Integrative Agriculture》2020年第2期541-550,共10页农业科学学报（英文版）

基　　金：supported by the National Program for Support of Top-notch Young Professionals of China

摘　　要：Fungal secreted proteins that contain the Common in Fungal Extracellular Membrane(CFEM)domain are important for pathogenicity.The hemibiotrophic fungus Colletotrichum graminicola causes the serious anthracnose disease of maize.In this study,we identified 24 CgCFEM proteins in the genome of C.graminicola.Phylogenic analysis revealed that these 24 proteins(CgCFEM1–24)can be divided into 2 clades based on the presence of the trans-membrane domain.Sequence alignment analysis indicated that the amino acids of the CFEM domain are highly conserved and contain 8 spaced cysteines,with the exception that CgCFEM1 and CgCFEM24 lack 1 and 2 cysteines,respectively.Ten CgCFEM proteins with a signal peptide and without the trans-membrane domain were considered as candidate effectors and,thus were selected for structural prediction and functional analyses.The CFEM domain in the candidate effectors can form a helical-basket structure homologous to the Csa2 protein in Candida albicans,which is responsible for haem acquisition and pathogenicity.Subcellular localization analysis revealed that these effectors accumulate in the cell membrane,nucleus,and cytosolic bodies.Additionally,5 effectors,CgCFEM6,7,8,9 and 15,can suppress the BAX-induced programmed cell death in Nicotiana benthamiana with or without the signal peptide.These results demonstrate that these 10 CgCFEM candidate effectors with different structures and subcellular localizations in host cells may play important roles during the pathogenic processes on maize plants.Fungal secreted proteins that contain the Common in Fungal Extracellular Membrane(CFEM) domain are important for pathogenicity. The hemibiotrophic fungus Colletotrichum graminicola causes the serious anthracnose disease of maize. In this study, we identified 24 CgCFEM proteins in the genome of C. graminicola. Phylogenic analysis revealed that these 24 proteins(CgCFEM1–24) can be divided into 2 clades based on the presence of the trans-membrane domain. Sequence alignment analysis indicated that the amino acids of the CFEM domain are highly conserved and contain 8 spaced cysteines, with the exception that CgCFEM1 and CgCFEM24 lack 1 and 2 cysteines, respectively. Ten CgCFEM proteins with a signal peptide and without the trans-membrane domain were considered as candidate effectors and, thus were selected for structural prediction and functional analyses. The CFEM domain in the candidate effectors can form a helical-basket structure homologous to the Csa2 protein in Candida albicans, which is responsible for haem acquisition and pathogenicity. Subcellular localization analysis revealed that these effectors accumulate in the cell membrane, nucleus, and cytosolic bodies. Additionally, 5 effectors, CgCFEM6, 7, 8, 9 and 15, can suppress the BAX-induced programmed cell death in Nicotiana benthamiana with or without the signal peptide. These results demonstrate that these 10 CgCFEM candidate effectors with different structures and subcellular localizations in host cells may play important roles during the pathogenic processes on maize plants.

关 键 词：CFEM domain candidate effector anthracnose disease MAIZE Colletotrichum graminicola 

分 类 号：S435.131[农业科学—农业昆虫与害虫防治]