导入额外拷贝nifA基因对费氏中华根瘤菌共生固氮作用的影响  

INTRODUCTION OF EXTRA nifA GENE INTO Sinorhizobium fredii AND ITS EFFECT ON THE SYMBIOTIC NITROGEN FIXATION

作　　者：李友国[1] 周俊初[2] 

机构地区：[1]农业部农业微生物重点实验室,武汉430070 [2]华中农业大学武汉,武汉430070

出　　处：《微生物学杂志》2000年第2期1-4,共4页Journal of Microbiology

基　　金：国家863高技术研究发展计划课题

摘　　要：以广宿主、稳定性质粒pTR102为载体构建重组质粒pHN306，其上克隆有来自肺炎克氏杆菌（Klebsiellapneumoniae）的nifA基因和来自pDB30所含的发光酶标记基因（luxAB）。经三亲本接合转移，将pHN306导入费氏中华根瘤菌（Sinorhizobiumfredii）HN01，GR3和YC4。与出发菌相比较的盆栽试验结果表明：HN01（pHN306）和GR3（pHN306）分别在大豆渝豆一号和黑龙33上能显著提高瘤数，瘤重，植株地上部分干重和总氮量，YC4（pHN306）在大豆渝豆一号上也能显著提高瘤数，癌重和总氮量，对植株地上部分干重表现出一定的促进作用。结果表明：nifA基因对固氮效率和结瘤能力的促进作用与受体根瘤菌和大豆品种等因素有关。以luxAB为报告基因进行的菌落和根瘤发光检测结果表明：pHN306可在供试根瘤菌中稳定遗传。A reoominant plasmid pHN306 cdring nifA gene from Klebsiella pneumoniae and reporter gene lux AB from pDB30 was conducted by using pTR102 as a vector. pHN306 plasmid was then intreduced into Sinorhizobium fredii strain HN01, YC4 and GR3 by tri-parental meting. Plant for experiments were carried out for the recipient strains and their transconjugans. It was confirmed that recombinant strains HN01 (pHN306) and GR3 (pHN306) could sikmificantly increree the root nedule number, nedule fresh weight, shoot dry weight (biomass) and total nitrogen content of the plant with soybean valleties of Yudou No1 and Heilong 33 respectively. Tranconjugant YC4 (pHN306) could also significantly increase the root nedule number, nedule fresh weight and total nitrogen content of the plant with soybean variety Yudou No1. The results suggested that the effect of extra nifA gene on the syrnbiotic nitrogen fixation was relevant to many factors such as soybean vdriety, soil driility and recipient rhizobia. The results of colony and nedule flourescent-detection indicated that the recombinant plasmid pHN306 was stable in S. fredii tested under both free-living and syrnbiotic conditioas.

关 键 词：NIFA 费氏中华根瘤菌 固氮效率 结瘤能力 

分 类 号：Q933.114[生物学—微生物学] Q78