植物病原体分泌许多分子进入环境以建立微生物生态位并促进宿主感染。植物病原真菌果炭疽病,导致梨炭疽病,可以定殖不同的植物组织,如叶子和果实,被多种微生物占据。我们推测这种真菌产生抗微生物效应物,以胜过与宿主相关的竞争性微生物。在这里,我们鉴定出两种分泌的核糖核酸酶,CfRibo1和CfRibo2,来自果果梭菌分泌组。两种核糖核酸酶均具有核糖核酸酶活性,并在烟草本氏中显示细胞毒性,而不以酶活性依赖性方式触发免疫力。CfRibo1和CfRibo2重组蛋白对大肠杆菌表现出毒性,酿酒酵母,and,重要的是,从梨宿主中分离出的叶球微生物。在这些分离的微生物菌株中,海拔芽孢杆菌是一种引起梨软腐病的致病菌。引人注目的是,发现CfRibo1和CfRibo2直接拮抗B.alithdinis以促进果果梭菌感染。更重要的是,CfRibo1和CfRibo2在存在宿主相关微生物的情况下充当果果梭菌的必需毒力因子。进一步分析显示,这两种核糖核酸酶广泛分布于真菌中,并正在进行纯化选择。我们的结果提供了炭疽菌真菌中抗菌效应物的第一个证据,并扩展了真菌核糖核酸酶在植物-害虫-环境相互作用中的功能多样性。
目的:果炭疽病是一种在农业中引起各种作物炭疽病的破坏性病原真菌,了解这种真菌如何建立成功的感染对炭疽病的管理具有重要意义。已知真菌产生分泌的效应物作为促进毒力的武器。在阐明效应子如何操纵植物免疫方面已经取得了相当大的进展;然而,它们在调节环境微生物方面的重要性经常被忽视。本研究确定了两种分泌的核糖核酸酶,CfRibo1和CfRibo2,作为果果梭菌的抗微生物效应子。这两种蛋白质都对梨叶球微生物具有毒性,它们有效地拮抗竞争性微生物以促进梨宿主的感染。这项研究代表了炭疽病真菌中抗菌效应物的第一个证据,并且我们认为CfRibo1和CfRibo2将来可以用于多种作物的炭疽病管理。
Phytopathogens secrete numerous molecules into the environment to establish a microbial niche and facilitate host infection. The phytopathogenic fungus Colletotrichum fructicola, which causes pear anthracnose, can colonize different plant tissues like leaves and fruits, which are occupied by a diversity of microbes. We speculate that this fungus produces antimicrobial effectors to outcompete host-associated competitive microorganisms. Herein, we identified two secreted
ribonucleases, CfRibo1 and CfRibo2, from the C. fructicola secretome. The two
ribonucleases both possess ribonuclease activity and showed cytotoxicity in Nicotianan benthamiana without triggering immunity in an enzymatic activity-dependent manner. CfRibo1 and CfRibo2 recombinant proteins exhibited toxicity against Escherichia coli, Saccharomyces cerevisiae, and, importantly, the phyllosphere microorganisms isolated from the pear host. Among these isolated microbial strains, Bacillus altitudinis is a pathogenic bacterium causing pear soft rot. Strikingly, CfRibo1 and CfRibo2 were found to directly antagonize B. altitudinis to facilitate C. fructicola infection. More importantly, CfRibo1 and CfRibo2 functioned as essential virulence factors of C. fructicola in the presence of host-associated microorganisms. Further analysis revealed these two
ribonucleases are widely distributed in fungi and are undergoing purifying selection. Our results provide the first evidence of antimicrobial effectors in Colletotrichum fungi and extend the functional diversity of fungal
ribonucleases in plant-pest-environment interactions.
OBJECTIVE: Colletotrichum fructicola is emerging as a devastating pathogenic fungus causing anthracnose in various crops in agriculture, and understanding how this fungus establishes successful infection is of great significance for anthracnose disease management. Fungi are known to produce secreted effectors as weapons to promote virulence. Considerable progress has been made in elucidating how effectors manipulate plant immunity; however, their importance in modulating environmental microbes is frequently neglected. The present study identified two secreted
ribonucleases, CfRibo1 and CfRibo2, as antimicrobial effectors of C. fructicola. These two proteins both possess toxicity to pear phyllosphere microorganisms, and they efficiently antagonize competitive microbes to facilitate the infection of pear hosts. This study represents the first evidence of antimicrobial effectors in Colletotrichum fungi, and we consider that CfRibo1 and CfRibo2 could be targeted for anthracnose disease management in diverse crops in the future.