华癸中慢生根瘤菌7653R SraG sRNA的共生固氮功能  

Symbiotic nitrogen fixation function of SraG sRNA in Mesorhizobium huakuii 7653R

作　　者：李振鹏[1] 马春草[1] 谢福莉[1] 陈大松[1] 李友国[1] 

机构地区：[1]华中农业大学农业微生物学国家重点实验室,武汉430070

出　　处：《华中农业大学学报》2016年第5期51-57,共7页Journal of Huazhong Agricultural University

基　　金：国家重点基础研究发展计划("973"计划)(2010CB126500);国家自然科学基金项目(31371549);高等学校博士点基金专项(20110146110012)

摘　　要：基于前期对华癸中慢生根瘤菌(Mesorhizobium huakuii)7653RsRNA(small non-coding RNA,sRNA)的生物信息学预测,经Northern blot验证获得SraGsRNA。本研究采用RACE与转录组高通量深度测序确定了SraG全长,并分别利用RNAfold软件和TargetRNA软件预测了SraG二级结构和靶位点,进而构建了M.huakuii 7653R的SraG插入失活突变体(M.huakuii SraGmut),并对突变体接种紫云英的共生表型进行了检测。盆栽试验结果表明,与野生型菌株M.huakuii 7653R相比,接种突变株M.huakuii SraGmut的固氮能力显著下降,突变株固氮酶活性下降约40%,植株鲜质量和根瘤数目也显著降低。结果表明,SraG的功能与M.huakuii 7653R的共生固氮过程相关,作为sRNA可能参与根瘤菌的共生固氮调控过程。Based on the bioinformatics prediction of small non-coding RNA(sRNA),SraG sRNA was predicted and confirmed by Northern blotting.The full-lengh SraG was obtained with RACE and high-throughput sequencing of transcriptome.The secondary structure and target genes of SraG were predicted with RNAfold and TargetRNA software,respectively.To confirm the function of the SraG gene in symbiotic nitrogen fixation,a disruptant strain of SraG was constructed and named M.huakuii SraGmut.The pot experiments of plant nodulation were conducted to examine the nitrogen fixation ability of the disruptant strain.The nitrogenase activity of A.sinicus L.inoculated M.huakuii SraGmut was only 40% of that of inoculated M.huakuii 7653 R,indicating that SraGas a RNA affected the symbiotic nitrogen ability of the rhizobium tested.It provides a solid foundation for studying the functional mechanism of sRNA during symbiotic nitrogen fixation of rhizobium in the future.

关 键 词：华癸中慢生根瘤菌 SRNA 突变体 共生固氮 表型 

分 类 号：Q939.114[生物学—微生物学]