板栗疫病菌ntl基因的功能研究  

Functional Study of ntl Gene in Chestnut Blight Fungus

作　　者：李茹[1,2] 李洋[1] 李林生[1] 廖素环[1] 白凌云[1] 陈保善[1,2] 

机构地区：[1]广西大学生命科学与技术学院,南宁530004 [2]亚热带农业生物资源保护与利用国家重点实验室,南宁530004

出　　处：《基因组学与应用生物学》2013年第4期420-427,共8页Genomics and Applied Biology

基　　金：国家自然科学基金(31260027)资助

摘　　要：板栗疫病菌(Cryphonectria parasitica)是引起板栗疫病的病原真菌。在实验室前期研究中,获得了一个不支持病毒复制且丧失致病力的板栗疫病菌紫外诱变突变株UV57。与野生型菌株EP155相比,UV57中检测不到蛋白100472的表达。为研究蛋白100472的功能,我们构建了编码100472蛋白的ntl基因的缺失突变体Δntl及其互补转化株Δntl-com。与野生型EP155相比,Δntl菌株表型不变,但对休眠板栗树枝的致病性明显降低,而互补转化株Δntl-com的致病力与野生型没有区别。ntl基因的缺失不影响低毒病毒CHV1-EP713的复制累积量,但导致参与G蛋白信号传导途径的cpga1、cpgb1、cpgc1和ste12基因以及参与MAPK途径的cpmk1转录水平明显下调。本研究结果为阐明病原真菌致病机制提供了新的知识。Cryphonectria parasitica is a causative fungus responsible for the devastating chestnut blight. In our pre- vious study, a UV-induced mutant UV57 which lacks the ability to support the replication of a hypovirus, was ob- tained. Protein 100472 encoded by ntl gene in C. parasitica was not found in UV57 as compared with the wild-type strain EP155. To investigate the function of this protein, ntl deletion mutants were constructed. The ntl null mutants were indistinguishable from the EP155 in phenotype on PDA plate, but exhibited reduced virulence on chestnut stems. Complementation strain ofntl null mutant with a wild-type copy ofntl gene restored the virulence phenotype. Deletion ofntl gene did not change the accumulation of the hypovirus dsRNA. Transcriptional analysis revealed that deletion ofntl reduced the transcript levels ofcpgal, cpgb 1, cpgc 1, ste 12, and cprnk 1 that encode Gα, Gβ, Gγ Stel2, and Cpmkl, respectively, key components of heterotrimeric G-protein pathway. These results add new knowledge toward the understanding of the mechanism of virulence regulation in a pathogenic fungus.

关 键 词：板栗疫病菌 ntl基因 低毒病毒 致病力 

分 类 号：S436.64[农业科学—农业昆虫与害虫防治]