摘要
通过功能互补法从Frankia菌株At4的基因文库中筛选到可互补豌豆根瘤菌nodD基因功能的pAt2GX和pAt3GX,把pAt2GX和pAt3GX重新导入tmdD突变体中,接种豌豆苗,可观察到nodD突变体恢复了结瘤功能。扫描电镜观察、根瘤内生菌抗性标记检测及内生菌重组质粒的酶切分析均表明nadD突变体恢复结瘤功能是山于带有外源质粒pAt2GX和pAt3GX所致,这就证明了pAt2GX和pAt3GX带有类nodD基因功能的DNA片段。酶切分析及DNA-DNA杂交实验结果说明pAt2GX和pAt3GX不属于同—克隆,但这两个质粒的DNA之间有同源区。
By triparental matings, two common plasmids pAt2GX and pAt3GX which can complement a nodD mutant of Rhizobium leguminosarum bv. vicae were isolated from a Frankia At4 gene bank. When the two plasmids were transferred separately into the nodD mutant, complementation was observed. Analysis show that pAt2GX and pAt3GX contain a Frankia gene that is functionally equivalent to nodD of R.leguminosarum bv..vicae.DNA-DNA hybridization was found between the two plasmids though they were not the same clone.
基金
中国科学院"八五"国家基础性研究重大关键项目--攀登计划
由国家科委资助
关键词
弗兰克氏菌
结瘤
nidD基因
Frankia
nodulation
nodD gene
complementation
homolougy
