S.fredii WGF03 SiR基因的功能鉴定  

Function of SiR Gene in Sinorhizobium fredii WGF03

作　　者：郭美树[1,2] 粟月萍[1,2] 马婷婷[1,2] 申佩弘[1,2] 蒋承建[1,2] 武波[2,3] 

机构地区：[1]广西大学生命科学与技术学院,南宁530005 [2]微生物及植物遗传工程教育部重点实验室,南宁530005 [3]广西民族大学化学与生态工程学院,南宁530007

出　　处：《基因组学与应用生物学》2013年第4期432-439,共8页Genomics and Applied Biology

基　　金：国家重点基础研究发展计划(973)项目(2010CB126502)资助

摘　　要：亚硫酸盐还原酶催化亚硫酸盐还原为硫化物，参与了生物硫循环。为了明确亚硫酸盐还原酶在S船捌WGF03中是否与亚硫酸盐同化途径有关，通过分子克隆技术，采用同源双交换的方法，利用质粒pKl8mobsaeB构建SiR基因缺失突变体SiRI。用不同硫源的液体MM培养基培养检测，发现互补菌株CSiRI与野生型菌株能够利用亚硫酸盐作为唯一硫源，而突变体SiRI却不能，结果证实了亚硫酸还原酶确实与亚硫酸盐同化途径有关。植株试验表明突变株SiRI比野生菌株WGF03推迟结瘤2～3d，固氮酶活比野生菌株低12％左右，但在瘤数，瘤重，植株干重的平均值却差异不大。Sulfite reductase, can reduce sulfite to be sulfide, involved in sulfur biological cycle. To determine whether Sulfite reductase is associated with sulfite assimilation pathway in Sinorhizobium fredii WGF03, mutant strain was constructed using pK18mobsacB to delete the SiR gene by homologous double exchange method. By in- cubating the strains using MM liquid medium with different sulfur sources, we found that the complementary strain CSiRI and wild-type strain could grow normally, but the mutant strains SiRI couldn＇t grow with sulfite as the sole sulfur source. This indicated that Sulfite reductase is indeed related to sulfate assimilation pathway. The plant tests showed that, compared with the wild strain WGF03, the mutant strain SiRi delayed 2 to 3 days to nodulate with soy- bean, the nitrogenase activity and competitive nodulation efficiency were slightly lower, but there was no significant difference in the number and average weight of nodules and the dry weight of plant.

关 键 词：费氏中华根瘤菌 硫循环 亚硫酸盐还原酶 突变 植株试验 

分 类 号：S154.3[农业科学—土壤学]