Cloning and Sequencing of a 3.7kb Enhancing Fragment from Rhizobium fredii B52  

作　　者：张学贤 

机构地区：[1]Department of Microbiology,Huazhong Agricultural University,Wuhan,430070,P.R.China

出　　处：《High Technology Letters》1996年第2期95-98,共4页高技术通讯（英文版）

基　　金：the High Technology Research and Development Programme of china.

摘　　要：The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,and then a 3.7kb enhancing fragment was isolated through plant experiment,which could im- prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained high effective strain was called HN32.It has been widely used as soybean inoculant in He- longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparing with 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert. Its nucleotide sequence was analyzed.Computer analysis indicated that there were two open reading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homology with known genes except the first 19 amino acids which had high homology with lactose transferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo- bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti. Names enfA and enfB are proposed to ORF1 and ORF2 respectively.

关 键 词：SOYBEAN RHIZOBIUM SYMBIOSIS Gene 

分 类 号：Q78[生物学—分子生物学]