title: Multilocus sequence analysis reveals taxonomic differences among Bradyrhizobium sp. symbionts of Lupinus albescens plants growing in arenized and non-arenized areas.
abstract: Lupinus albescens is a leguminous plant that belongs to "New World" lupine species, which is native to southern Brazil. This Brazilian region is characterized by poor degraded soils with low organic matter and is designated as an arenized area. The symbiosis between Lupinus plants and nitrogen-fixing bacteria belonging to the Bradyrhizobium genus may help the plant establish itself in these areas. To characterize the bradyrhizobial population symbionts of L. albescens plants grown in arenized and non-arenized areas, a multilocus phylogenetic analysis allied to genetic diversity indices were conducted. Seventy-four bradyrhizobial isolates were analyzed, 38 coming from L. albescens plants growing in an arenized area and 36 from a non-arenized area. Isolates were different between arenized and non-arenized areas. Phylogenetic analysis of the 16S rRNA, dnaK, atpD, recA, glnII, rpoB, gyrB, nodA, nodB, and nodZ genes resulted in three supported clades, which were most likely to be three different new Bradyrhizobium species: one species from the arenized area and two from the non-arenized area. Estimates of genetic diversity, which decreased in arenized areas, were positively correlated with habitat variability. These results suggested that a few resistant and efficient Bradyrhizobium sp. strains were capable of forming nodules on L. albescens plants growing in an arenized area. An in vivo inoculation experiment with L. albescens plants showed that Bradyrhizobium ssp. isolated from this extreme environment were more efficient at promoting plant growth than those from the non-arenized area. This result suggested that the environment affected the selection of more efficient plant growth promoters in order to sustain plant growth.
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Caixa Postal 15.053, 91501-970 Porto Alegre, RS, Brazil; Centro Universitário UNIVATES, Rua Avelino Tallini 171, 95900-000 Lajeado, RS, Brazil.
authors.forename: Camille E
authors.initials: CE
authors.lastname: Granada
authors.affiliation: Fundação Estadual de Pesquisa Agropecuária (FEPAGRO), Rua Gonçalves Dias 570, 90130-060 Porto Alegre, RS, Brazil.
authors.forename: Anelise
authors.initials: A
authors.lastname: Beneduzi
authors.affiliation: Fundação Estadual de Pesquisa Agropecuária (FEPAGRO), Rua Gonçalves Dias 570, 90130-060 Porto Alegre, RS, Brazil.
authors.forename: Bruno B
authors.initials: BB
authors.lastname: Lisboa
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Caixa Postal 15.053, 91501-970 Porto Alegre, RS, Brazil.
authors.forename: Andreia C
authors.initials: AC
authors.lastname: Turchetto-Zolet
authors.affiliation: Fundação Estadual de Pesquisa Agropecuária (FEPAGRO), Rua Gonçalves Dias 570, 90130-060 Porto Alegre, RS, Brazil.
authors.forename: Luciano K
authors.initials: LK
authors.lastname: Vargas
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Caixa Postal 15.053, 91501-970 Porto Alegre, RS, Brazil. Electronic address: luciane.passaglia@ufrgs.br.
authors.forename: Luciane M P
authors.initials: LM
authors.lastname: Passaglia
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D020369:Bradyrhizobium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D001938:Brazil; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D031297:Lupinus / Q000382:microbiology*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: Arenized areas; Bradyrhizobium sp.; Lupinus sp.; Taxonomic diversity