白术内生真菌AM478调控关键miRNA增强宿主抗根腐病的分子机制

白术临床应用广泛，被誉为健脾补气第一要药，根腐病是制约白术生产的主要障碍之一。前期研究发现内生真菌AM478 Mortierella elongata能缓解白术根腐病病情，并发现miR166i与miR397可能在白术抗病响应中发挥重要作用，但其作用机制尚不明确。本项目计划：（1）建立白术根腐病模型，从病情指数、生理生化等指标进一步明确AM478对白术根腐病的防治作用；（2）应用转录组-miRNA-降解组联合测序、生物信息学分析及qRT-PCR技术，进一步对响应AM478诱导的差异miRNA及其靶基因进行筛选；（3）通过miRNA过表达与基因敲除载体构建、拟南芥异源转化、烟草瞬时表达体系及RLM-5’-RACE等技术，对miRNA及其靶基因的功能进行验证。本项目的完成，将揭示内生真菌AM478防治白术根腐病的作用机制，为AM478作为“生物菌肥”应用于白术种植与生产提供科学依据。

Atractylodes macrocephala Koidz. (AMK) is a widely used herbal medicine in clinic and tops the herbal list on invigorating ‘Qi’ and strengthening spleen in China. Root rot disease is one of the most destructive diseases restricting AMK industrial production. Previously, we found that endophytic fungus AM478 Mortierella elongata could effectually alleviate AMK root rot disease, and miR166i and miR397 might play an important role in AMK root rot stress response. However, the related molecular mechanism of these miRNAs in the stress response is unclear. In the present study, we plan to further investigate root rot disease resistance induced by endophytic fungus AM478 in AMK by constructing root rot infected model, calculating disease index, and evaluating physiological and biochemical indicators. Multi-omics high-throughput sequencing technology, bioinformatics tools, and qRT-PCR technology will be used to find AMK key miRNA and their target genes induced by AM478. Moreover, miRNA overexpression and knock-out vectors, Arabidopsis thaliana heterogeneous transformation system, tobacco transient expression system, and RLM-5’-RACE technology will be used to verify the function of key miRNA and its target gene. Completion of the project will reveal the molecular mechanism of endophytic fungus AM478 inducing root rot disease resistance in AMK, and provide scientific basis for the application of AM478 as a biological fertilizer in AMK cultivation and industrial production.