Antonets K S, Onishchuk O P, Kurchak O N, Volkov K V, Lykholay A N, Andreeva E A, Andronov E E, Pinaev A G, Provorov N A, Nizhnikov A A
All-Russia Research Institute of Agricultural Microbiology, St. Petersburg, Pushkin, 196608 Russia.
St. Petersburg State University, St. Petersburg, 199034 Russia.
Mol Biol (Mosk). 2018 Sep-Oct;52(5):898-904. doi: 10.1134/S0026898418050038.
The importance of root nodule bacteria in biotechnology is determined by their distinctive feature: symbiotic nitrogen fixation resulting in the production of organic nitrogen-containing compounds. While interacting with host legume plants, the cells of these bacteria undergo global changes at all levels of expression of genetic information leading to the formation in root nodules of so-called bacteroids functioning as nitrogen fixation factories. The molecular mechanisms underlying plant-microbial symbiosis are actively investigated, and one of the most interesting and poorly studied aspects of this problem is the species-specificity of interaction between root nodule bacteria and host plants. In this work we have performed the proteomic analysis of the Sinorhizobium meliloti bacteroids isolated from two legume species: alfalfa (Medicago sativa L.) and yellow sweet clover (Melilotus officinalis L.). It has been shown that the S. meliloti bacteroids produce a lot of proteins (many of them associated with symbiosis) in a host-specific manner, i.e., only in certain host plant species. It has been demonstrated for the first time that the levels of expression in bacteroids of the genes encoding the ExoZ and MscL proteins responsible for the synthesis of surface lipopolysaccha-rides and formation of a large conductance mechanosensitive channel, respectively, depend on a host plant species that confirms the results of proteomic analysis. Overall, our data show that the regulation of bacteroid development by the host plant has species-specific features.
共生固氮作用可产生含氮有机化合物。在与宿主豆科植物相互作用时，这些细菌的细胞在遗传信息表达的各个层面都会发生全局性变化，从而导致根瘤中形成所谓的类菌体，其作为固氮工厂发挥作用。植物 - 微生物共生的分子机制正在被积极研究，而这个问题中最有趣且研究较少的方面之一是根瘤菌与宿主植物相互作用的物种特异性。在这项工作中，我们对从两种豆科植物：紫花苜蓿（Medicago sativa L.）和黄花草木樨（Melilotus officinalis L.）中分离出的苜蓿中华根瘤菌的类菌体进行了蛋白质组学分析。结果表明，苜蓿中华根瘤菌类菌体以宿主特异性方式产生大量蛋白质（其中许多与共生相关），即仅在特定宿主植物物种中产生。首次证明，分别负责表面脂多糖合成和形成大电导机械敏感通道的ExoZ和MscL蛋白编码基因在类菌体中的表达水平取决于宿主植物物种，这证实了蛋白质组学分析的结果。总体而言，我们的数据表明宿主植物对类菌体发育的调控具有物种特异性特征。
