【摘要】 根瘤菌可以和豆科植物共生固氮,在很多根瘤菌中群体感应系统参与了结瘤固氮等相关生理过程的调节。本研究从野外不同生境紫云英宿主根部瘤体中分离了26株根瘤菌,体外定量检测了各菌株产生自体诱导物(AI)信号分子的能力,以及不同菌株AI激活中慢生华癸根瘤菌Mh菌株AHLs合成酶基因mrh I表达的情况,发现紫云英根瘤菌种内不同菌株间存在群体感应交互性。通过导入外源Att M水解酶观察菌株AI活性的变化,应用薄层层析法定性分析不同菌株的AI结构,初步揭示了不同紫云英根瘤菌产生AI特性的差异和多样性。更多还原

【Abstract】 Rhizobia can symbiotically fix nitrogen from the atmosphere in which quorum sensing system is involved. The quorum sensing system in rhizobia is the typical Lux I/R-type regulatory system in the Gram-negative bacteria. Twenty-six rhizobia were isolated from the nodules of Astragalus sinicus from different areas. Examination of AIs production activity and the ability to cross-activation with lux I/R quorum sensing system of M. huakuii revealed that the quorum sensing patterns in M. huakuii species were different. Att M hydrolytic enzyme reaction and TLC analysis indicated that the AIs production of M. huakuii were divided into two groups, one was AHLs family and the other one was non-AHLs family. These data suggested that the quorum sensing autoinducer production in M. huakuii may be different from each other.更多还原