自噬相关蛋白CfAtg8在果生刺盘孢中的功能分析

Functional analysis of the autophagy-related protein CfAtg8 in Colletotrichum fructicola

油茶炭疽病是由刺盘孢属Colletotrichum真菌引起的重要病害,在中国各油茶产区均有发生,严重威胁茶油的产量与品质。前期发现果生刺盘孢Colletotrichum fructicola是油茶炭疽病的优势致病菌,自噬相关蛋白Atg8在果生刺盘孢中的生物学功能尚不清楚。本研究根据同源重组的原理及PEG介导的原生质体转化方法,获得了CfATG8基因敲除突变体及其互补菌株。进一步通过生物学表型分析,发现突变体生长减慢、产孢量减少、附着胞形成率降低、对细胞壁完整性胁迫耐受性降低,并且丧失对油茶的致病性。上述结果表明,CfAtg8参与调控果生刺盘孢的营养生长、无性繁殖、附着胞形成、对外界胁迫应答及致病过程。

Anthracnose on Camellia oleifera is an important disease caused by Colletotrichum species,and always occurs in producing regions of C.oleifera in China.Our previous studies revealed that Colletotrichum fructicola was the major pathogen of anthracnose on C.oleifera,but the functions of the autophagy-related protein Atg8 in C.fructicola remains unknown.Based on homologous recombination principle and the PEG-mediated protoplast transformation,the CfATG8 gene-deletion mutants and the related complemented strains were obtained.It was found that the gene-deletion mutants showed reduction of growth rate,decrease in conidial production and appressorial formation,more sensitive to cell wall integrity stress,and no pathogenicity to C.oleifera.Our results reveal that CfAtg8 is functionally important to the vegetative growth,asexual reproduction,appressorial formation,external stress response and pathogenicity of C.fructicola.