油菜miR1885和miR6030调控菌核病抗性的分子机制研究

菌核病是我国油菜生产上危害最大的病害，然而目前油菜与核盘菌互作机制尚不明确。miRNA广泛参与植物与病原物互作，但其与菌核病抗性相关研究稀缺。我们前期发现油菜miR1885和miR6030响应核盘菌侵染，且下游靶标抗病（R）基因，上游可能受负调控菌核病抗性的转录因子CAMTA3（Calmodulin-binding transcription activator 3）调控。本研究拟围绕这两个miRNA，利用遗传学、分子生物学等手段，构建转基因油菜植株，明确miRNA及其下游R基因对菌核病抗性的调控功能和机制；同时利用ChIP等技术解析上游CAMTA3对miRNA基因的转录调控作用，最终揭示CAMTA3→miRNA→R基因这一途径在调控菌核病抗性中的作用。本研究对于揭示油菜与核盘菌互作机制以及开展油菜抗菌核病分子育种具有重要的理论和实践意义。

The Sclerotinia disease caused by Sclerotinia sclerotiorum is the major reason for reducing the production of Brassica napus. However, the mechanisms underlying B. napus against this pathogen are still poorly understood. Although it has been widely reported that miRNAs play an important role in the interaction between plant and pathogen, their roles in plant defense against S. sclerotiorum remain unknown. In our previous work, we identified two B. napus miRNAs, miR1885 and miR6030, which were downregulated after the infection of S. sclerotiorum. Interestingly, these two miRNAs both targeted resistance (R) genes, and their expression might be regulated by Calmodulin-binding transcription activator 3 (CAMTA3), which play a negative role in plant defense against S. sclerotiorum. In this study, we proposed to focus on these two miRNAs. Firstly, we will study the regulatory function and mechanisms of miRNAs and R genes in the resistance to S. sclerotiorum by transgenic plants. Secondly, ChIP and other technologies will be used to analyze the transcriptional regulation of miRNA genes by CAMTA3. Taken together, the final aim of our project is to reveal the function of CAMTA3-miRNA-R genes signaling pathway in the resistance to S. sclerotiorum. This study has important theoretical and practical significance in revealing the interaction mechanism between B.napus and S. sclerotiorum, as well as for carrying out resistance breeding of B. napus.