大豆细胞核雄性不育基因Gmms1的功能解析

Soybean is an important economic crop, however the low yield per unit has seriously hindered the development of soybean production in China. Heterosis utilization was proved to be one of the most effective ways to increase crop yields. Modern hybrid seed production based on the cytoplasmic male sterility has been widely used in heterosis. In recent years, soybean nuclear male sterile lines have been extensively used in the soybean recurrent selection and breeding, but the genetic mechanism of controlling sterility and the genetic mechanism of male sterility is still poorly understood. Soybean nuclear male sterile candidate gene Gmms1 has been cloned through fine mapping. The role of Gmms1 is involved in the cell wall modification and tissue organ development, but how Gmms1 regulates the growth and development of soybean male organs and whether it is related to other genes or its molecular and metabolic mechanism of metabolites interacting with soybean sterility are still unclear. In this project, the biological function of Gmms1 gene will be elucidated by gene cloning, genetic transformation, expression analysis, transcriptome, metabolome sequencing and both the joint analysis as well as targeting modification. The explore the molecular mechanism of soybean sterile lines can not only provide a theoretical basis for the gene in the soybean heterosis utilization, but also can improve the level of soybean production.

杂种优势利用是提高作物产量的重要途径。近年来，大豆细胞核雄性不育系已在轮回选择群体和杂种优势方面逐渐推广利用，但控制育性相关基因及雄性不育分子机理还不清楚。项目申请人精细定位并克隆了大豆细胞核雄性不育候选基因Gmms1，生物信息学和遗传学分析证实该基因与大豆雄性不育有关，但Gmms1基因在大豆雄配子发育过程中的生物学功能及其分子调控机理尚不明确。本项目拟通过遗传转化（基因过表达/RNAi，靶向修饰CRISPR/Cas9）、启动子功能研究、互作蛋白因子发掘、转录组和代谢组联合分析等途径阐明Gmms1基因的生物学功能，解析Gmms1基因调控大豆细胞核雄性不育的生理生化基础和分子调控网络，为Gmms1基因在大豆育种中的利用提供理论依据。

利用转录组、代谢组、三代测序等技术，率先克隆了国际上寻觅50年之久的大豆ms1细胞核雄性不育基因，揭示了染色体结构变异（~38.7kb）导致大豆细胞核雄性不育的遗传基础，开发出基于结构变异的大豆ms1细胞核雄性不育分子检测方法，初步阐明了大豆细胞核雄性不育的转录代谢调控机制。研究发现细胞核雄性不育系的13号染色体上存在大片段缺失（~38.7kb），导致不育系材料中丢失了4个蛋白编码基因，利用生物信息学和基因编辑证明了编码微管驱动蛋白的NACK2基因是ms1的候选基因，并据此开发了可以特异检测该结构变异的共显性分子标记。通过对测序数据的深入分析发现二者在代谢和转录水平存在显著差异，主要表现在：不育系花粉中积累了更多的香豆素和硫代葡萄糖苷，激素代谢也发生了明显变化，不育系中产生了更多的玉米素核苷和茉莉酸异亮氨酸。在26个差异代谢通路中，苯丙烷生物合成代谢通路在不育系与可育系花粉中差异最为明显。转录组分析结果进一步证实苯丙烷生物合成相关基因的表达量在不育系中发生了显著变化，暗示ms1编码基因GmNACK2可能在稳定花粉的苯丙素的合成与代谢中发挥了重要作用。总之，研究揭示了染色体结构变异是导致大豆ms1细胞核雄性不育的遗传学机理，发现花青素、黄酮类化合物和抗氧化酶活性代谢紊乱是导致大豆细胞核雄性不育的生理机制，发现苯丙素生物合成在大豆细胞核雄性不育中发挥了重要作用，创新了大豆细胞核雄性不育性创制方法。研究成果发表在中科院一区Top期刊JIPB（2021，63: 1054–1064），申请了2项国家发明专利，育成大豆新品种1个，并实现技术和方法的成果转化，为推动杂交大豆产业化奠定了材料和方法基础。