糖类碳源对中慢生华癸根瘤菌群体感应基因mrhI/R表达的影响  

Effect of Sugar Carbon Source on Quorum Sensing Genes mrhI/mrhR Expression

作　　者：朱庆成[1] 毛怡玲 茅冬梅[1] 郑会明[1] 钟增涛[1] 朱军[1] 

机构地区：[1]南京农业大学生命科学学院,南京210095

出　　处：《土壤》2014年第5期856-861,共6页Soils

基　　金：国家重大基础研究"973"项目(2010CB126500-G);国家自然科学基金面上项目(31170077)资助

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。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 mrhl and mrhR genes were dependent on autoinducer activity which was produced by mrhl 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.

关 键 词：中慢生华癸根瘤菌 群体感应 葡萄糖 果糖 碳源代谢物阻遏 

分 类 号：Q933[生物学—微生物学]