Małek W
Department of General Microbiology, M. Curie-Skłodowska University, Lublin, Poland.
J Basic Microbiol. 1996;36(5):319-26. doi: 10.1002/jobm.3620360505.
An expression of nodC promoter of R. meliloti 1021, cloned in front of the Escherichia coli lacZ gene, was used to study the presence of R. meliloti nodC gene-inducing compound(s) in extracts and exudates of A. incana seeds and roots. The regulatory gene nodD was expressed at comparable level in bacterial culture of R. meliloti with and without the studied plant extracts and exudates, whereas the nodC-lacZ fusion expression was increased 4 times by seed exudates of grey alder and 2 times by seed extracts and root ingredients in comparison to the nodC-lacZ fusion expression in R. meliloti grown in a medium free of plant compounds. Induction of R. meliloti nodC gene expression by A. incana substances was also supported in plant test. Sterile filtrate of coculture of R. meliloti with seed exudates of A. incana induced root hair deformations and nodule-like structures on Medicago sativa.
将苜蓿中华根瘤菌1021的nodC启动子表达克隆于大肠杆菌lacZ基因前，用于研究灰毛紫穗槐种子和根的提取物及渗出物中是否存在诱导苜蓿中华根瘤菌nodC基因的化合物。在有或没有所研究植物提取物及渗出物的苜蓿中华根瘤菌细菌培养物中，调节基因nodD的表达水平相当，而与在不含植物化合物的培养基中生长的苜蓿中华根瘤菌中的nodC-lacZ融合表达相比，灰毛紫穗槐种子渗出物使nodC-lacZ融合表达增加4倍，种子提取物和根成分使其增加2倍。植物试验也证实了灰毛紫穗槐物质对苜蓿中华根瘤菌nodC基因表达的诱导作用。苜蓿中华根瘤菌与灰毛紫穗槐种子渗出物共培养的无菌滤液诱导了紫花苜蓿根毛变形和类根瘤结构。
