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Nitrogen-fixing rhizobial strains isolated from common bean seeds: phylogeny, physiology, and genome analysis.
Mora, Yolanda; Díaz, Rafael; Vargas-Lagunas, Carmen; Peralta, Humberto; Guerrero, Gabriela; Aguilar, Alejandro; Encarnación, Sergio; Girard, Lourdes; Mora, Jaime.
Afiliação
  • Mora Y; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Díaz R; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Vargas-Lagunas C; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Peralta H; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Guerrero G; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Aguilar A; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Encarnación S; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Girard L; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico.
  • Mora J; Program of Functional Genomics of Prokaryotes, Center for Genomic Sciences, National University of Mexico, Chamilpa, Cuernavaca, Morelos, Mexico mora@ccg.unam.mx.
Appl Environ Microbiol ; 80(18): 5644-54, 2014 Sep.
Article em En | MEDLINE | ID: mdl-25002426
Rhizobial bacteria are commonly found in soil but also establish symbiotic relationships with legumes, inhabiting the root nodules, where they fix nitrogen. Endophytic rhizobia have also been reported in the roots and stems of legumes and other plants. We isolated several rhizobial strains from the nodules of noninoculated bean plants and looked for their provenance in the interiors of the seeds. Nine isolates were obtained, covering most known bean symbiont species, which belong to the Rhizobium and Sinorhizobium groups. The strains showed several large plasmids, except for a Sinorhizobium americanum isolate. Two strains, one Rhizobium phaseoli and one S. americanum strain, were thoroughly characterized. Optimal symbiotic performance was observed for both of these strains. The S. americanum strain showed biotin prototrophy when subcultured, as well as high pyruvate dehydrogenase (PDH) activity, both of which are key factors in maintaining optimal growth. The R. phaseoli strain was a biotin auxotroph, did not grow when subcultured, accumulated a large amount of poly-ß-hydroxybutyrate, and exhibited low PDH activity. The physiology and genomes of these strains showed features that may have resulted from their lifestyle inside the seeds: stress sensitivity, a ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) complex, a homocitrate synthase (usually present only in free-living diazotrophs), a hydrogenase uptake cluster, and the presence of prophages. We propose that colonization by rhizobia and their presence in Phaseolus seeds may be part of a persistence mechanism that helps to retain and disperse rhizobial strains.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Rhizobium / Simbiose / Sinorhizobium / Phaseolus / Fixação de Nitrogênio Idioma: En Revista: Appl Environ Microbiol Ano de publicação: 2014 Tipo de documento: Article País de afiliação: México País de publicação: Estados Unidos
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Rhizobium / Simbiose / Sinorhizobium / Phaseolus / Fixação de Nitrogênio Idioma: En Revista: Appl Environ Microbiol Ano de publicação: 2014 Tipo de documento: Article País de afiliação: México País de publicação: Estados Unidos