title: Diverse Mesorhizobium bacteria nodulate native Astragalus and Oxytropis in arctic and subarctic areas in Eurasia.
abstract: Rhizobia nodulating native Astragalus and Oxytropis spp. in Northern Europe are not well-studied. In this study, we isolated bacteria from nodules of four Astragalus spp. and two Oxytropis spp. from the arctic and subarctic regions of Sweden and Russia. The phylogenetic analyses were performed by using sequences of three housekeeping genes (16S rRNA, rpoB and recA) and two accessory genes (nodC and nifH). The results of our multilocus sequence analysis (MLSA) of the three housekeeping genes tree showed that all the 13 isolates belonged to the genus Mesorhizobium and were positioned in six clades. Our concatenated housekeeping gene tree also suggested that the isolates nodulating Astragalus inopinatus, Astragalus frigidus, Astragalus alpinus ssp. alpinus and Oxytropis revoluta might be designated as four new Mesorhizobium species. The 13 isolates were grouped in three clades in the nodC and nifH trees.15N analysis suggested that the legumes in association with these isolates were actively fixing nitrogen.
authors.affiliation: Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences (SLU), SE-90183, Umeå, Sweden. Electronic address: oseiampomah@yahoo.com.
authors.forename: Osei Yaw
authors.initials: OY
authors.lastname: Ampomah
authors.affiliation: Department of Environmental Sciences, Viikinkaari 2a, P.O. Box 65, University of Helsinki, FIN-00014, Helsinki, Finland.
authors.forename: Seyed Abdollah
authors.initials: SA
authors.lastname: Mousavi
authors.affiliation: Department of Environmental Sciences, Viikinkaari 2a, P.O. Box 65, University of Helsinki, FIN-00014, Helsinki, Finland.
authors.forename: Kristina
authors.initials: K
authors.lastname: Lindström
authors.affiliation: Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences (SLU), SE-90183, Umeå, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Huss-Danell
mesh_terms: D001110:Arctic Regions; D027883:Astragalus Plant / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D014644:Genetic Variation; D059128:Mesorhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D058885:Multilocus Sequence Typing; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics; D033021:Oxytropis / Q000382:microbiology*; D010802:Phylogeny; D055170:Plant Root Nodulation; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D053204:Root Nodules, Plant / Q000382:microbiology*; D012426:Russia; D013548:Sweden
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; D011938:Rec A Recombinases; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit
keywords: Astragalus; MLSA; Mesorhizobia; Nitrogen fixation; Oxytropis