title: Different Mesorhizobium species associated with Caragana carry similar symbiotic genes and have common host ranges.
abstract: Fourteen strains representing 11 Caragana-nodulating Mesorhizobium genomic species were identified as representing Mesorhizobium amorphae, Mesorhizobium huakuii, Mesorhizobium septentrionale and groups related to Mesorhizobium plurifarium, Mesorhizobium temperatum, Mesorhizobium tianshanense and Mesorhizobium mediterraneum by sequencing of the 16S rRNA gene, 16S-23S internal transcribed spacer, partial housekeeping recA gene, and previously performed sodium dodecyl sulfate polyacrylamide gel electrophoresis of proteins and BOX-PCR fingerprinting. Despite their different taxonomic affiliation, highly similar symbiotic genes (>93% similarity for nodC and >91.8% similarity for nifH) were found among the Caragana strains and the three type strains for M. tianshanense, M. temperatum and M. septentrionale. Cross nodulation tests revealed that each of these 14 Caragana mesorhizobia and the three type strains mentioned above could effectively infect each of their original host plants, Caragana microphylla, Glycyrrhiza (host for M. tianshanense type strain) and Astragalus adsurgens (host for M. temperatum and M. septentrionale type strains). These results provide evidence that different Mesorhizobium species can nodulate with Caragana, and they have similar symbiotic genes (probably acquired by a phenomenon of lateral gene transfer) and common host ranges.
authors.affiliation: Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture/Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, China. chenwf@cau.edu.cn
authors.forename: Wen Feng
authors.initials: WF
authors.lastname: Chen
authors.forename: Su Hua
authors.initials: SH
authors.lastname: Guan
authors.forename: Chun Tian
authors.initials: CT
authors.lastname: Zhao
authors.forename: Xue Rui
authors.initials: XR
authors.lastname: Yan
authors.forename: Chao Xin
authors.initials: CX
authors.lastname: Man
authors.forename: En Tao
authors.initials: ET
authors.lastname: Wang
authors.forename: Wen Xin
authors.initials: WX
authors.lastname: Chen
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics; D032602:Caragana / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics; D020543:Proteome / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D020543:Proteome; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; D011938:Rec A Recombinases