禾谷镰孢菌小G蛋白FgSpg1的生物学功能  

Biological function of the small GTPase FgSpg1 in fungal pathogen Fusarium graminearum

作　　者：吴一可 赵晨钟 王晓妍 张承启[1] Wu Yike;Zhao Chenzhong;Wang Xiaoyan;Zhang Chengqi(Key Laboratory of Agri-Products Quality and Biosafety,Ministry of Education,School of Plant Protection,Anhui Agricultural University,Hefei 230036,Anhui Province,China)

机构地区：[1]安徽农业大学植物保护学院,农产品质量与生物安全教育部重点实验室,合肥230036

出　　处：《植物保护学报》2024年第4期782-793,共12页Journal of Plant Protection

基　　金：国家重点研发计划(2022YFD1400100)。

摘　　要：为探究禾谷镰孢菌Fusarium graminearum中小G蛋白FgSpg1的功能,以禾谷镰孢菌野生型菌株PH-1为材料,通过基因敲除和回补FgSpg1分别获得了基因缺失突变体ΔFgSpg1与回补菌株ΔFgSpg1-C,测定野生型菌株PH-1、基因缺失突变体ΔFgSpg1和回补菌株ΔFgSpg1-C的生长发育、逆境胁迫响应、致病力、脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)产量和TRI基因的相对表达量,通过比较三者之间的差异明确FgSpg1的作用。结果显示:与野生型菌株PH-1和回补菌株ΔFgSpg1-C相比,基因缺失突变体ΔFgSpg1的菌落直径明显减小,色素变少,菌丝变细;具有4~7个隔膜数的分生孢子占比明显增多;对NaCl和KCl的敏感性下降,但对刚果红、戊唑醇和氟唑菌酰羟胺的敏感性增加;对小麦胚芽鞘和麦穗的致病力明显减弱,DON毒素产量明显减少,参与DON毒素生物合成的TRI基因的相对表达量均显著下调。表明FgSpg1在禾谷镰孢菌生长发育、隔膜形成、响应外界环境胁迫以及致病和产毒过程中发挥着重要作用。To investigate the function of the small GTPase FgSpg1 in fungal pathogen Fusarium graminearum,gene deletion and complementation of the wild-type strain PH-1 were performed to obtain the null mutantΔFgSpg1 and the complemented strainΔFgSpg1-C,respectively.The growth and development,stress response,virulence,deoxynivalenol(DON)production,and relative expression levels of TRI genes were assayed in the wild-type strain PH-1,the gene disruption mutantΔFgSpg1,and the complemented strainΔFgSpg1-C.By comparing the differences among these strains,the role of FgSpg1 was elucidated.The results showed that the colony diameter of the gene disruption mutantΔFgSpg1 was significantly reduced,with decreased pigmentation and thinner hyphae compared with the wild-type strain PH-1 and the complemented strainΔFgSpg1-C.The proportion of conidia with fourseven septa increased significantly.Sensitivity to NaCl and KCl decreased,while sensitivity to Congo red,tebuconazole,and pydiflumetofen increased.Virulence on wheat heads and coleoptiles was significantly reduced,DON production markedly decreased,and the expression levels of TRI genes involved in DON biosynthesis were significantly downregulated.These findings underscore the pivotal role of the small GTPase FgSpg1 in vegetative growth,septum formation,response to external stimuli,virulence and DON biosynthesis in F.graminearum.

关 键 词：禾谷镰孢菌 FgSpg1 生长 发育 环境胁迫 致病性 

分 类 号：S432.4[农业科学—植物病理学]