提高大豆根瘤菌质粒稳定性的研究  

STUDY ON THE IMPROVEMENT OF PLASMID STABILITY IN SOYBEAN RHIZOBIA

作　　者：刘墨青[1] 李友国[2] 周俊初[2] 

机构地区：[1]中国科学院微生物研究所 [2]华中农业大学

出　　处：《微生物学报》2000年第3期296-300,共5页Acta Microbiologica Sinica

基　　金：国家 8 63高技术研究发展计划资助! ( 863 1 0 1 0 3 0 3 0 7)

摘　　要：以发光酶基因luxAB作为报告基因 ,将广谱稳定性质粒 pTR1 0 2的 parCBA/DE基因导入含 3 7kb增效片段的 pLARF3并去除该质粒的cos序列 ,构建成重组质粒 pHN1 1 5和pHN1 56。同时 ,构建只带有cos序列和luxAB的参比质粒 pHN1 57和 pHN1 58。将上述 4种质粒通过三亲本杂交分别导入费氏中华根瘤菌 (Sinorhizobium fredii)HN0 1 ,将 pHN1 55和pHN1 58通过两亲本杂交分别导入大豆慢生根瘤菌 (Bradyrhizobiumjaponicum)TA1 1 ,在人工继代培养条件下比较测定其质粒保持率。结果表明 ;经连续转接培养 7次后 ,pHN1 55、pHN1 56、pHN1 57和 pHN1 58在HN0 1中的质粒保持率分别为 1 0 0 %、67%、72 %和 92 %。连续转接培养 4次后 ,pHN1 55和 pHN1 58在TA1 1中的质粒保持率分别为 98%和 92 %。说明parCBA/DE基因能显著提高质粒在快、慢生型大豆根瘤菌中的遗传稳定性 ,cos序列的去除也有一定的作用。By using luxAB as the report genes,3.2kb parCBA/DE gene fragment from pTR102 was inserted into pLAFR3 which contained a 3.7kb enhancing fragment and deleted its cos site. Recombant plasmids pHN155 and pHN156 were obtained. Contrasted plasmids pHN157 and pHN158 which contained cos site were also constructed. These four plasmids were transferred into Sinorhizobium fredii HN01 by tri parental mating, and plasmid pHN155 and pHN158 were introduced into Bradyrhizobium japonicum TA11 by two parental mating. The stability of the above plamids was compared under free living conditions and the results showed that the parCBA/DE could obviously enhance plasmid stability both in S.fredii and B.japonicum , and deletion of cos site showed only less effect.

关 键 词：根瘤菌 质粒稳定性 Par基因 重组质粒 

分 类 号：Q939.113.03[生物学—微生物学]