三叶草素基因(tfx)在快生型大豆根瘤菌(Sinorhizobium fredii)H12-2中的表达与稳定性测定  

THE EXPRESSION AND STABILITY OF TFX GENES IN SINORHIZOBIUM FREDII H12-2

作　　者：陈大松[1] 周俊初[1] 

机构地区：[1]农业部农业微生物重点开放性实验室华中农业大学,武汉430070

出　　处：《微生物学杂志》1998年第2期7-12,共6页Journal of Microbiology

基　　金：国家科委863高技术研究发展计划经费资助

摘　　要：将含有三叶草条基因的重组质粒pT2TFXK和pT2TX3K以接合转移的方式导入快生型大豆根瘤菌H12－2。转移接合子H12－2（pXK）能产三叶草素并具有抑菌活性；H12－2（P3K）表现出对三叶草素的抗性。抑菌谱试验结果表明：82％的供试快生型大豆根瘤菌菌株对三叶草素敏感；所有供试慢生型大豆根瘤菌则表现抗性。稳定性检测结果表明：在共生与人工培养条件下，导入的pXK和p3K质粒均可在宿主菌中稳定存在和表达。wo plasmids, pT2TFXK (or pXK) and PT2TX3K (p3K) containing tfx genes weretransfered into S. fredii H12 - 2 by transconjugant.One transconjugant, H12 - 2 (pXK), could produce trifolitoxin and form a growth in-hibition zone against trifolitoxin - sensitive strains. The other transconjugant, H12 - 2(p3K), showed resistance to trifolitoxin, but faired to produce it.82% of 100 tested strains of S. fredii were sensitive to trifolitoxin produced by Hl2 -2 (pXK), while all 19 tested strains of Bradyrhizobium japonicum were resistant.The results of stability experiments showed that: either pXK or p3K could stablely in-herited in S. fredii H12 - 2 in the free - living and symbiotic conditions.

关 键 词：快生型 大豆根瘤菌 细菌素 三叶草素 

分 类 号：S144.3[农业科学—肥料学] Q78[农业科学—农业基础科学]