田菁根瘤菌YIC4027可溶性趋化受体Tlp1的功能鉴定

Characterization of the soluble chemoreceptor Tlp1 in Sinorhizobium alkalisoli YIC4027

摘要:

【目的】初步探究田菁根瘤菌Sinorhizobium alkalisoli YIC4027中唯一含有PAS结构域可溶性趋化受体Tlp1的功能机理。【方法】本研究基于Red重组系统以及三亲接合技术进行缺失突变株的构建。对野生型和突变株的生长情况、趋化能力、趋氧性、细胞凝结、生物膜的形成、胞外多糖产量、在宿主根表的定殖及竞争性结瘤等表型进行了测定。【结果】与野生型相比，突变株的生长不受影响，趋化和趋氧能力降低，在宿主根表的定殖及竞争性结瘤能力降低，而细胞凝结能力、生物膜形成以及胞外多糖产生能力等均有所提高。【结论】本研究首次证实了S. alkalisoli YIC4027中可溶性趋化受体Tlp1影响细胞的趋化运动。

关键词:Sinorhizobium alkalisoli YIC4027;可溶性趋化受体;PAS结构域;趋化

Abstract:

[Objective] To decipher the functional mechanism of Tlp1 which is the only soluble chemoreceptor containing PAS domain in Sinorhizobium alkalisoli YIC4027. [Methods] We constructed the gene-deleted mutant strain based on the Red homologous recombination system and triparental conjugation. The growth rate, chemotaxis, aerotaxis, cell flocculation, biofilm formation, exopolysaccharide (EPS) production, colonization, and competitive nodulation of the wild type and the mutant strain were studied. [Results] Compared with the wild type, the mutant strain showed unaffected growth, weakened chemotaxis, aerotaxis, colonization, and competitive nodulation, and increased cell coagulation, biofilm formation, and EPS production. [Conclusion] This study confirmed that the soluble chemoreceptor Tlp1 in YIC4027 affected the chemotactic movement of the cells for the first time.

Key words:Sinorhizobium alkalisoli YIC4027;soluble chemoreceptor;PAS domain;chemotaxis