Roest H P, Mulders I H, Spaink H P, Wijffelman C A, Lugtenberg B J
Leiden University, Institute of Molecular Plant Sciences, Clusius Laboratory, Netherlands.
Mol Plant Microbe Interact. 1997 Sep;10(7):938-41. doi: 10.1094/MPMI.1997.10.7.938.
Introduction of the Sym plasmid pRL1JI into the cured Rhizobium leguminosarum bv. trifolii strain RCR5 resulted in a strain, designated RBL5523, that was expected to nodulate plants of the pea cross-inoculation group. However, effective nodulation occurred only on Vicia sativa plants, not on V. hirsuta or Pisum sativum. After random Tn5 mutagenesis, a derivative of RBL5523 was isolated that effectively nodulated and fixed nitrogen on P. sativum and V. hirsuta. Characterization of the mutant, RBL5787, indicated the cell surface components, extracellular polysaccharides, lipopolysaccharides, and outer membrane proteins, as well as the pattern of Nod metabolites, were indistinguishable from those of the parental strain. To obtain an indication of the function of the mutated locus, the flanking regions were sequenced and used to perform searches in protein and nonredundant nucleotide data-bases. No significant similarity or homology with any known sequence was detected.
将共生质粒pRL1JI导入经除菌处理的豆科根瘤菌三叶草生物型菌株RCR5后，得到了一个命名为RBL5523的菌株，预计该菌株能够使豌豆交叉接种组的植物结瘤。然而，有效的结瘤仅发生在紫花苕子植株上，在硬毛野豌豆或豌豆上并未出现。经过随机Tn5诱变后，分离出了RBL5523的一个衍生物，它能够在豌豆和硬毛野豌豆上有效地结瘤并固氮。对突变体RBL5787的特性分析表明，其细胞表面成分、胞外多糖、脂多糖和外膜蛋白，以及结瘤代谢产物的模式与亲本菌株并无差异。为了探究突变位点的功能，对其侧翼区域进行了测序，并用于在蛋白质和非冗余核苷酸数据库中进行搜索。未检测到与任何已知序列有显著的相似性或同源性。
