芝麻95ms-5雄性败育的遗传及分子机理解析

Sesame performs strong hybrid vigor, and male sterile lines are important for heterosis utilization. Our previous work indicated that 95ms-5 was a recessive genic male sterility mutant in sesame, which performs thoroughly male sterility. Therefore, 95ms-5 is a wonderful material for studying male sterility and heterosis utilization. Based on the primary mapping of 95ms-5 sterility QTL, the Target Site Capture Sequencing would be used to genotype the F2 group in this project, and a regional high-density linkage map would be constructed to fine mapping the candidate gene SiMs1. Also, an integrated proteomics and metabolomics analysis of 95ms-5 would be conducted to characterize the metabolic pathways of the different expressed proteins and metabolites both enriched, and through bioinformatics integration analysis of the differentially expressed proteins and metabolites in the pathways, the key proteins that regulate the fertility of 95ms-5 would be verified. Integrating with the cytological features of 95ms-5 male abortion and physiological and biochemical analysis, the genetic and molecular mechanisms of 95ms-5 would be further confirmed. Completion of this project can not only provide fundamental basis for SiMs1 cloning, but also provide a new idea for exploring male sterile gene resources and utilizations in sesame, and has great significance for sesame hybrid vigor utilization and genetic improvement.

芝麻具有较强的杂种优势，雄性不育材料是杂种优势利用的重要途径。本项目前期工作中发现，芝麻95ms-5是一个受单基因控制的隐性细胞核雄性不育系，具有败育彻底、不育性稳定的特点，是研究雄性不育机理和杂种优势利用的优异资源。本项目旨在已完成95ms-5育性QTL初步定位的基础上，进一步利用定制化目标捕获测序技术对已构建的F2群体基因分型，构建目标区域局部高密度遗传图谱，精细定位到目标基因SiMs1。同时结合95ms-5的花药蛋白质组和代谢组的整合研究，分析差异表达蛋白和差异代谢物共同显著富集的代谢通路，并鉴定引起相关代谢物差异的调控蛋白，获得调控95ms-5育性的关键基因，进一步结合细胞学鉴定及生理生化分析，揭示95ms-5雄性败育的分子机理。本项目的开展，将为芝麻育性基因SiMs1的克隆奠定基础，为芝麻雄性不育基因的挖掘和利用提供新思路，对于芝麻杂种优势利用和遗传改良具有重要的意义

芝麻既是我国的传统特色油料作物，也是重要的药食同源作物，经济价值和营养价值极高。然而芝麻产量一直徘徊不前，无法满足市场需求。杂交育种是作物提高产量的重要途径，而雄性不育材料是杂种优势利用的重要资源。本项目以芝麻隐性细胞核雄性不育系95ms-5AB为研究材料，通过QTL定位结合蛋白组学，鉴定到候选育性基因Siatpb，并克隆了该基因。Siatpb编码ATP合酶β亚基。进一步比较野生型95ms-5B和突变体95ms-5A的花药发育过程发现，与野生型相比，突变体的绒毡层细胞无法向分泌型绒毡层细胞转变，小孢子内基本无胞质成分，且在花粉发育过程中，小孢子逐渐皱缩，花粉壁异常沉积，不能形成正常的花粉外壁和内壁。TUNEL实验进一步证实，突变体的绒毡层PCD延迟。胼胝质染色发现，突变体花药发育过程中，胼胝质未降解。蛋白组和代谢组整合分析表明，与野生型相比，95ms-5A突变体氨基酸合成和脂肪酸代谢异常，且一些孢粉素合成相关基因在突变体中异常表达。蛋白互作分析表明，Siatpb可能通过与参与PCD、氨基酸合成、脂肪酸代谢的蛋白互作，来影响花粉发育。此外，通过蛋白组分析和功能验证，我们挖掘了3个育性相关基因。研究结果将为芝麻雄性不育机理研究，雄性不育材料创制及杂种优势利用奠定基础。