项目名称: 慢生与快生大豆根瘤菌生物地理分布差异的遗传进化机制
项目编号: No.31200002
项目类型: 青年科学基金项目
立项/批准年度: 2013
项目学科: 微生物学、植物学
项目作者: 田长富
作者单位: 中国农业大学
项目金额: 25万元
中文摘要: 进化生物学中的一个基本问题是了解生物用怎样的遗传机制来适应不同的环境条件。我们的前期研究表明:中国是大豆根瘤菌种质资源最为丰富的国家,在酸性土壤条件下与大豆共生的根瘤菌主要是慢生根瘤菌(Bradyrhizobium),而在碱性土壤中大豆主要与大豆快生根瘤菌(Sinorhizobium)共生,呈现出明显的生物地理分布特征;进一步的比较基因组学分析发现已知的与Sinorhizobium耐碱相关的基因多是该属特有的,而Bradyrhizobium和Sinorhizobium各自的属特有基因中绝大多数是功能未知的。本项目将利用新一代高通量测序技术,通过比较高覆盖度随机突变体库在不同pH值条件下的突变体组成变化,来高通量筛选与大豆慢/快生根瘤菌适应不同pH相关的基因;并针对相关基因利用比较基因组学和种群遗传学方法研究基因复制、水平基因转移、遗传重组和自然选择在大豆根瘤菌适应性进化中的作用机制。
中文关键词: 根瘤菌;大豆;进化;功能基因组;
英文摘要: A fundamental topic of evolutionary biology is to understanding the genetics of how organisms adapt to different environmental conditions. Our earlier findings suggested that the germplasm of soybean rhizobia is particularly enriched in China, with Bradyrhizobium as the dominant microsymbionts of soybean in regions of acidic soil, and Sinorhizobium dominating the nodules of soybean in alkaline soil, showing clear biogeographic patterns. Futher comparative genomics uncovered that most documented genes related to alkaline adaptations of Sinorhizobium belong to the genus specific gene set, though functions of the majority of genus specific genes of Bradyrhizobium/Sinorhizobium remain unkown. In this study, the next-generation sequencing technology will be used to monitoring the compositional changes, in different pH conditions, of the high-coverage Tn5 mutant library. By doing this, Bradyrhizobium/Sinorhizobium genes involved in adaptations to different pH conditions will be uncovered in a high throughput manner. Related functional genes will be subject to comparative genomics and population genetics, and the role of gene duplication, latteral gene transfer, recombination and natural selection in the adaptive evolution of soybean rhizobia will be investigated.
英文关键词: rhizobium;soybean;evolution;funcional genomics;