细胞质雄性不育（CMS）是芥菜杂种优势利用的主要途径之一。本课题组前期研究发现，芥菜oxa CMS无论是在细胞学水平还是在分子水平上均与已报道的十字花科作物细胞质雄性不育类型不同，为一种新的细胞质雄性不育源，但其不育基因的功能及其作用机制尚不明晰。本研究拟以芥菜oxa胞质不育系、保持系和恢复系为材料，通过线粒体基因组测序与构图，并结合转录本分析，筛选并验证不育系和保持系之间的差异基因或者ORFs，克隆获得不育候选基因。转化拟南芥和芥菜验证该不育基因的功能，并通过酵母双杂交、Pull down、BiFC等技术手段分离和验证其互作蛋白。本项目的实施，将获得新的芥菜细胞质雄性不育基因，明确芥菜oxa CMS不育相关基因的结构和功能，初步揭示该不育基因的作用机制，促进新型细胞质雄性不育源在十字花科蔬菜杂种优势的利用，具有重要的理论意义和应用前景。

Cytoplasmic male sterility (CMS) is one of the major approach of heterosis utilization in Brassica juncea. Previously, cytological and molecular methods have been performed to characterization the oxa CMS phenotype. It was found that the oxa CMS is significantly distinguished from any other CMS type that has been reported in cruciferous crops. However, the CMS gene that is responsible for the male sterility in oxa CMS line is urged to be identified. And the mechanism of oxa CMS are largely unknown in Brassica juncea. In this project, differential mitochondrial genes or ORFs between the sterile line and its maintainer through sequencing are planning to obtain by comparing the two mitochondrial genomes. The male sterility associated genes will be selected for further study. The candidate gene will introduced into Arabidopsis and B. juncea by the transgenic modification methods for functional analysis; To reveal the mechanism underlying infertility of oxa CMS, yeast two hybrid technology will be used to identify the proteins that interact with the CMS protein. Subsequently, Pull-down and BiFC methods will be further used to confirm the protein interaction. By implementation of this project, we should not only identify the sterile gene of oxa CMS in B. juncea, but also clarify its structure and function. Morever, the mechanism of oxa CMS in B. juncea should be preliminarily illustrated. This research may help to promote the use of this novel oxa CMS in heterosis and increase its application in the breeding project about cruciferous vegetables. For this reason, this project may have great theoretical value, economic worth and broad application future.