title: Genetic diversity of Mimosa pudica rhizobial symbionts in soils of French Guiana: investigating the origin and diversity of Burkholderia phymatum and other beta-rhizobia.
abstract: The genetic diversity of 221 Mimosa pudica bacterial symbionts trapped from eight soils from diverse environments in French Guiana was assessed by 16S rRNA PCR-RFLP, REP-PCR fingerprints, as well as by phylogenies of their 16S rRNA and recA housekeeping genes, and by their nifH, nodA and nodC symbiotic genes. Interestingly, we found a large diversity of beta-rhizobia, with Burkholderia phymatum and Burkholderia tuberum being the most frequent and diverse symbiotic species. Other species were also found, such as Burkholderia mimosarum, an unnamed Burkholderia species and, for the first time in South America, Cupriavidus taiwanensis. The sampling site had a strong influence on the diversity of the symbionts sampled, and the specific distributions of symbiotic populations between the soils were related to soil composition in some cases. Some alpha-rhizobial strains taxonomically close to Rhizobium endophyticum were also trapped in one soil, and these carried two copies of the nodA gene, a feature not previously reported. Phylogenies of nodA, nodC and nifH genes showed a monophyly of symbiotic genes for beta-rhizobia isolated from Mimosa spp., indicative of a long history of interaction between beta-rhizobia and Mimosa species. Based on their symbiotic gene phylogenies and legume hosts, B. tuberum was shown to contain two large biovars: one specific to the mimosoid genus Mimosa and one to South African papilionoid legumes.
authors.affiliation: IRD, UMR LSTM, Montpellier, France.
authors.forename: Ravi P N
authors.initials: RP
authors.lastname: Mishra
authors.forename: Pierre
authors.initials: P
authors.lastname: Tisseyre
authors.forename: Rémy
authors.initials: R
authors.lastname: Melkonian
authors.forename: Clémence
authors.initials: C
authors.lastname: Chaintreuil
authors.forename: Lucie
authors.initials: L
authors.lastname: Miché
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Klonowska
authors.forename: Sophie
authors.initials: S
authors.lastname: Gonzalez
authors.forename: Gilles
authors.initials: G
authors.lastname: Bena
authors.forename: Gisèle
authors.initials: G
authors.lastname: Laguerre
authors.forename: Lionel
authors.initials: L
authors.lastname: Moulin
mesh_terms: D001483:Base Sequence; D019117:Burkholderia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D049921:Cupriavidus / Q000145:classification / Q000254:growth & development; D005616:French Guiana; D014644:Genetic Variation; D031298:Mimosa / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil; D013020:South America; D013559:Symbiosis
chemical_list: D012336:RNA, Ribosomal, 16S; D012987:Soil