核盘菌引起的菌核病是危害我国油菜生产的一大重要病害，而目前油菜抗病育种受制于抗病资源的缺乏。我们前期对核盘菌侵染寄主甘蓝和非寄主水稻进行转录组测序，发现与菌丝生长和侵染垫形成相关的核盘菌基因SscipC的表达在水稻中被显著抑制，沉默该基因后的核盘菌致病力显著下降。生物信息学预测和sRNA测序发现水稻能产生靶向SscipC基因的sRNA，而芸苔属作物中则没有。我们推测水稻能产生靶向核盘菌致病基因的sRNA可能是其对核盘菌免疫的一个原因。本研究拟利用CRISPR/Cas9技术敲除水稻sRNA的关键序列，并根据SscipC基因序列和水稻sRNA序列构建寄主诱导的基因沉默（HIGS）载体转化油菜，在油菜中特异表达靶向SscipC基因的sRNA。本研究试图阐明sRNA在水稻抗菌核病中的分子机制，并以此为线索利用HIGS改良油菜的菌核病抗性。该项目的执行将对油菜菌核病抗病育种具有重要的理论和实践意义。

Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most devastating diseases in rapeseed, but the resistance breeding of rapeseed is hampered due to the lack of resistant source. In our previous study, transcriptome sequencing was conducted in S. sclerotiorum before and after infecting the host Brassica oleracea and non-host species rice (Oryza sativa), we found a S. sclerotiorum gene SscipC which involved in mycelium and infection cushion development showed significantly suppressed expression in rice. RNAi-based gene silencing of SscipC in S. sclerotiorum resulted in reduced virulence on host plant. Special sRNA in rice targeting SscipC was detected by Bioinformatics analysis and sRNA sequencing, but there were no such sRNA in Brassicacea. We hypothesis that sRNA targeting the pathogenicity gene may involve in the immune mechanism of rice against S. sclerotiorum. In this project, we will knockout the special sRNA in rice via CRISPR/Cas9 system, conduct the HIGS vector and express the sRNA targeting SscipC in HIGS transgenic rapeseed. This project endeavor to elucidate the resistance mechanism of sRNA in rice against S. sclerotiorum, and the mechanism will be utilized in improving the Sclerotinia resistance of rapeseed via HIGS. This project will theoretically and practically be of great benefit for the Sclerotinia resistance breeding of rapeseed.