【摘要】 克隆了中慢生华癸根瘤菌(Mesorhizobium huakuii)的mrh I和mrh R群体感应基因的启动子区域,至Lac Z翻译融合表达质粒载体p RA302中,经β-半乳糖苷酶活性检测发现,mrh I和mrh R的表达均受mrh I基因产物(自体诱导物)的正向调控。两种PTS糖类:葡萄糖和果糖的外源添加可以显著增加细菌的生长量,但却都同时抑制了mrh I和mrh R基因的表达,暗示在中慢生华癸根瘤菌中群体感应基因的表达可能受细菌中普遍存在的碳源代谢物阻遏现象的调节。更多还原

【Abstract】 The promoter regions of two quorum sensing genes,mrhI and mrhR,were cloned into a translational fusion plasmid vetor pRA302.Detections of β-galactosidase activity indicated that,expression of both mrhI and mrhR genes were dependent on autoinducer activity which was produced by mrh I itself.It also was shown that indition of PTS sugar source,e.g glucose and fructose,could significantly increase bacteria growth biomass,but inhibit both two genes expression on the other hand.These results implied that Quorum Sensing system in Mesorhizobium huakuii might be regulated by carbon catabolite repression which generally exist in bacteria.更多还原