Dall'Agnol R. F. auteur aut IRD Plotegher F. auteur aut IRD Souza R. C. auteur aut IRD Mendes I. C. auteur aut IRD dos Reis F. B. auteur aut IRD Béna Gilles auteur aut IRD Moulin Lionel auteur aut IRD Hungria M. auteur aut IRD text journalArticle eng text/pdf born digital access The bacterial genus Burkholderia comprises species occupying several habitats, including a group of symbionts of leguminous plants-also called beta-rhizobia-that has been recently ascribed to the new genus Paraburkholderia. We used common bean (Phaseolus vulgaris L.) plants to trap rhizobia from an undisturbed soil of the Brazilian Cerrado under the vegetation type 'Cerradao'. Genetic characterization started with the analyses of 181 isolates by BOX-PCR, where the majority revealed unique profiles, indicating high inter- and intra-species diversity. Restriction fragment length polymorphism-PCR of the 16S rRNA of representative strains of the BOX-PCR groups indicated two main clusters, and gene-sequencing analysis identified the minority (27%) as Rhizobium and the majority (73%) as Paraburkholderia. Phylogenetic analyses of the 16S rRNA and housekeeping (recA and gyrB) genes positioned all strains of the second cluster in the species P. nodosa, and the phylogeny of a symbiotic gene-nodC-was in agreement with the conserved genes. All isolates were stable vis-A -vis nodulating common bean, but, in general, with a low capacity for fixing N-2, although some effective strains were identified. The predominance of P. nodosa might be associated with the edaphic properties of the Cerrado biome, and might represent an important role in terms of maintenance of the ecosystem, which is characterized by acid soils with high saturation of aluminum and low N-2 content.Study of the diversity of nitrogen-fixing symbionts from a 'hot spot area', the Brazilian 'Cerradao', reveals that Paraburkholderia nodosa is the main symbiont trapped by promiscuous common bean (Phaseolus vulgaris L.).Study of the diversity of nitrogen-fixing symbionts from a 'hot spot area', the Brazilian 'Cerradao', reveals that Paraburkholderia nodosa is the main symbiont trapped by promiscuous common bean (Phaseolus vulgaris L.). specialized beta-rhizobia phylogeny of prokaryotes biological N-2 fixation Cerrado BRESIL 084 074 082 92 8 fiw108 [14 p.] 2016 0168-6496 https://www.documentation.ird.fr/hor/fdi:010068156 10.1093/femsec/fiw108 0168-6496 [F B010068156] https://www.documentation.ird.fr/hor/fdi:010068156 https://www.documentation.ird.fr/intranet/publi/2016/10/010068156.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-11-03 2017-08-23 fdi:010068156 fre