Diverse rhizobia that nodulate two species of Kummerowia in China.
A total of 63 bacterial strains were isolated from root nodules of Kummerowia striata and K. stipulacea grown in different geographic regions of China. These bacteria could be divided into fast-growing (FG) rhizobia and slow-growing (SG) rhizobia according to their growth rate. Genetic diversity and taxonomic relationships among these rhizobia were revealed by PCR-based 16 S rDNA RFLP and sequencing, 16 S-IGS RFLP, SDS-PAGE of whole cell soluble proteins, BOX-PCR and symbiotic gene (nifH/nodC) analyses. The symbiotic FG strains were mainly isolated from temperate regions and they were identified as four genomic species in Rhizobium and Sinorhizobium meliloti based on the consensus of grouping results. The SG strains were classified as five genomic species within Bradyrhizobium and they were mainly isolated fron the subtropic and tropical regions. The phylogenetic analyses of nifH and nodC genes showed relationships similar to that of 16 S rDNA but the symbiotic genes of Bradyrhizobium strains isolated from Kummerowia were distinct from those isolated from Arachis and soybean. These results offered evidence for rhizobial biogeography and demonstrated that the Kummerowia-nodulating ability might have evolved independently in different regions in association with distinctive genomic species of rhizobia.
Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture/College of Biological Sciences, China Agricultural University, Beijing, 100094, China.
Dong Xu
DX
Lin
Chao Xin
CX
Man
En Tao
ET
Wang
Wen Xin
WX
Chen
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002681:China; D007887:Fabaceae / Q000145:classification* / Q000382:microbiology*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D020579:Sinorhizobium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D013045:Species Specificity; D013559:Symbiosis
D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase