Diverse rhizobia associated with Sophora alopecuroides grown in different regions of Loess Plateau in China

• Published in: Systematic and applied microbiology 2010-12, Vol.33 (8), p.468-477
• Main Authors: Zhao, Longfei, Deng, Zhenshan, Yang, Wenquan, Cao, Ying, Wang, Entao, Wei, Gehong
• Format: Article
• Language: English
• Subjects: Acyltransferases - genetics; Agrobacterium tumefaciens; Agrobacterium tumefaciens - classification; Agrobacterium tumefaciens - isolation & purification; Agronomy. Soil science and plant productions; Alhagi; Animal, plant and microbial ecology; Bacteria; Bacterial Proteins - genetics; Bacteriology; Biological and medical sciences; China; DNA, Ribosomal - genetics; Ecological region; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Genetic diversity; genomics; Genotypes; Mesorhizobium; Microbial ecology; Microbiology; Microflora of plants; Miscellaneous; Molecular Sequence Data; NifH gene; Oxidoreductases - genetics; Phyllobacterium; Phylogeny; Plant Roots - microbiology; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Pyruvic acid; Rec A Recombinases - genetics; RecA protein; Rhizobia; Rhizobium; Rhizobium - classification; Rhizobium - genetics; Rhizobium - isolation & purification; RNA, Ribosomal, 16S - genetics; Roots; rRNA 16S; Sinorhizobium fredii; Sophora - growth & development; Sophora - microbiology; Sophora alopecuroides; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Symbiosis - genetics
• ISSN: 0723-2020; 1618-0984
• DOI: 10.1016/j.syapm.2010.08.004

A total of seventy-five symbiotic bacterial strains isolated from root nodules of wild Sophora alopecuroides grown in different regions of China's Loess Plateau were characterized. Based on the combined RFLP patterns, thirty-five genotypes were defined among the rhizobia and they were classified into nine genomic species, including Mesorhizobium alhagi and M. gobiense as the main groups, as well as Agrobacterium tumefaciens, M. amorphae, Phyllobacterium trifolii, Rhizobium giardinii, R. indigoferae, Sinorhizobium fredii and S. meliloti as the minor groups according to the 16S rRNA and recA gene analyses. Five and three lineages of nodA and nifH were found, respectively, in these strains, implying that the symbiotic genes of the S. alopecuroides rhizobia had different origins or had divergently evolved. Results of correspondence analysis showed that there was a correlation between rhizobial genotypes and the geographic origins. Possible lateral transfer of the recA and 16S rRNA genes between the P. trifolii and A. tumefaciens strains, and that of symbiotic genes (nodA, nifH) between different genera, was shown by discrepancies of the phylogenetic relationships of the four gene loci. These results revealed diverse rhizobia associated with wild S. alopecuroides grown in different regions of China's Loess Plateau, and demonstrated for the first time the existence of symbiotic A. tumefaciens strains in root nodules of S. alopecuroides.