Analysis of the BnXTH16 gene responsible for male sterility in rapeseed (Brassica napus) breeding lines.

雄性不育是植物育种中一项重要的经济性状。它防止异交作物自花授粉，并通过遗传多样性亲本植物的异花授粉保证杂种优势的维持和提高。携带ms基因突变型（ms为野生型）的甘蓝型油菜（Brassica napus） MSL系是雄性不育的，但可以通过花发育期间的长时间热处理或在恢复基因r的存在下恢复育性。BnXTH16编码一种参与细胞壁代谢的木葡聚糖内转糖基化酶。花粉在花药中发育，花药具有四个花粉囊。花粉的发育取决于被称为绒毡层的内花粉囊层的正常功能和细胞壁物质在花粉外壳上的适当沉积。携带突变的BnXTH16基因的甘蓝型油菜MSL系雄性不育表型的细胞学、生理学和分子事件至今尚未分析。我们也不知道热诱导的男性生育能力恢复的变化。该项目将阐明BnXTH16活性如何决定可育花粉的发育。为此，将使用广泛的细胞学、生化和分子遗传学方法。特别是遗传分析，该项目将受益于甘蓝型油菜亲缘拟南芥的适应性。我们期望我们的分析将有助于在未来建立新的育种系。

Male sterility is an economically important trait in plant breeding. It prevents self-pollination of outcrossing crops and ensures the sustainment and improvement of heterosis by cross-pollination of genetically diverse parent plants. MSL lines of Brassica napus (rapeseed) that carry a mutant form of the ms gene (ms for wildtype) are male sterile but can be reverted to fertility by prolonged heat treatment during flower development or in the presence of the restorer gene R. Recently the ms locus was mapped and the gene was identified as BnXTH16. BnXTH16 codes for a xyloglucan endotransglycosylase that is involved in cell wall metabolism. Pollen develop within anthers which possess four pollen sacs. Pollen development depends on proper function of the inner pollen sac layer termed the tapetum and on proper deposition of cell wall material to the pollen coat. The cytological, pysiological and molecular events that accompany the male-sterile phenotype of MSL lines of B. napus that carry the mutated BnXTH16 gene have not been analyzed to date. Nor do we know about the changes that allow for the heat-induced restoration of male fertility. This project will elucidate how BnXTH16 activity determines development of fertile pollen. To that end a wide spectrum of cytological, biochemical, and molecular-genetic appproaches will be used. In particular for genetic analyses the project will profit from the amenability of the close B. napus relative Arabidopsis thaliana. We expect that our analyses will help establish new breeding lines in the future.