The Structure and Evolution of Beta-Rhizobial Symbiotic Genes Deduced from Their Complete Genomes
The Structure and Evolution of Beta-Rhizobial Symbiotic Genes Deduced from Their Complete Genomes
复制标题
从完整基因组推断β-根瘤菌共生基因的结构和进化
DOI：
10.4172/1745-7580.1000131
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
刘晓云
中科院分区：
文献类型：
--
作者：
郑家珍;王瑞;刘瑞瑞;陈俊杰;危期;吴星月;庞学微;James EK;刘晓云
固氮根瘤菌在100多年前被发现。它们被分为两个分支，α-根瘤菌和β -根瘤菌。它们的共生功能显著，但其起源和进化从系统发育的角度来看一直令人困惑。在这项研究中，我们利用从美国国家生物技术信息中心（NCBI）下载的33个公开可用的完整基因组序列，这些序列包括细菌和古菌，并聚焦于10个菌株，根据它们的基因组和先前的基因注释为它们构建共生结构图。对共生必需基因nodA和nifH的系统发育进行了研究。尽管本研究发现与先前一些研究的某些假设存在很大差异，但我们支持β -根瘤菌是豆科植物原始共生体这一普遍概念，不过它们的共生基因起源于α -根瘤菌的一个共同祖先。我们还证实，共生基因的传播和维持主要通过垂直传递发生，横向转移虽然起到重要的辅助作用。
Nitrogen-fixing Rhizobia were discovered more than 100 years ago. They are classified into two clades, Alphaand.Beta-rhizobia. Their symbiotic function is remarkable, but its origin and evolution has been confusing from.a phylogenetic perspective. In this study, we make use of 33 publicly available complete genome sequences.downloaded from NCBI, which consist of bacteria and archaea, and focus on 10 strains, constructing symbiotic.structural maps for them based on their genomes and previous gene annotations. Phylogenies of the symbiosisessential.genes nodA and nifH were examined. Although large incongruities with some hypotheses from previous.studies were detected by the present study, we support the general concept that Beta-rhizobia were the original.symbionts of legumes, but that their symbotic genes originated from a common ancestor to the Alpha-rhizobia. We.also confirm that the spread and maintenance of symbiotic genes occurred mainly through vertical transmission, with.lateral transfer playing a significant, albeit supporting, role.