HMGR在生防菌盾壳霉分生孢子形成和重寄生过程中的功能解析

Coniothyrium minitans is an important sclerotial parasite of fungal phytopathogen, Sclerotinia sclerotiorum. Conidial production and parasitic ability are two important considerations for the commercialization of this biological control agent. AS 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGR) is the rate-limiting enzyme of isoprene synthesis, previous studies about HMGR were focused on the impact of metabolites synthesis. However, little is known about the effect of HMGR on hyphal growth, conidial production and pathogenicity of filamentous fungi. Previously, we found two genes (CmHmgr1 and CmHmgr2) encoding HMGR were existed in the genome of C. minitans and CmHmgr1 deletion mutants showed significantly reduced hyphal growth, conidial production and mycoparasitism. In order to decipher the function of HMGR in C.minitans, single/double knockout and overexpression strategies combine with LC-MS based metabolism technique and the association analysis between phenotypes and secondary metabolites will be used to clarify the function and mechanism of CmHmgr1 and CmHmgr2 in conidiogenesis, mycoparasitism and secondary metabolic process of C. minitans. The results of this research will give the theoreticl supports to improve the biocontrol potential and provide important gene resources for strain improvement of C. minitans. Furthermore, it will have important value for the conidial production of filamentous fungi.

盾壳霉是植物病原真菌核盘菌的寄主特异性重寄生真菌，产孢和重寄生能力直接影响其生防潜能。3-羟基-3-甲基戊二酸单酰辅酶A还原酶（HMGR）作为类异戊二烯途径的关键调控点是否调控丝状真菌生长、产孢和致病过程尚未见系统报道。申请者前期研究发现，盾壳霉基因组含有2个编码HMGR同源蛋白的基因CmHmgr1和CmHmgr2，敲除基因CmHmgr1导致盾壳霉生长变慢、产孢量减少、重寄生能力减弱。为系统解析HMGR在盾壳霉分生孢子形成和重寄生过程中的功能，本项目拟在上述基础上进一步采用基因单敲除、双敲除及超量表达方式，结合基于LC-MS的代谢组研究手段，明确HMGR在盾壳霉生长发育和次级代谢过程中的作用；根据生物学特性与次级代谢产物的关联，解析HMGR影响盾壳霉生长、产孢和重寄生的调控机制。研究结果不仅能为盾壳霉生防潜能提升和优质菌株改良提供重要理论依据，更有助于进一步认知丝状真菌无性繁殖的分子机制。

3-羟基-3-甲基戊二酸单酰辅酶A还原酶（HMGR）作为类异戊二烯途径的关键调控点是否调控丝状真菌生长、产孢和致病过程尚未见系统报道。本研究通过基因敲除、互补及超量表达等研究手段，明确了编码HMGR的基因CmHmgr1参与盾壳霉生长、产孢与重寄生等生长发育过程。敲除基因CmHmgr1导致盾壳霉生长变慢、产孢减少、寄生核盘菌的能力变弱；并且通过超量表达CmHmgr1获得了重寄生能力更强的盾壳霉工程菌株；进一步通过代谢组技术分析解析了CmHmgr1对盾壳霉次生代谢和生长发育的影响。本项目的研究结果为改良盾壳霉菌株、提升盾壳霉商业化生产和应用潜能提供理论依据。项目资助发表研究论文1篇，待发表3篇；申请专利2项；培养出站博士后1人。项目投入经费24万元，支出22.466万元，各项支出基本与预算相符。剩余经费1.534万元，剩余经费计划用于本项目研究后续支出。