title: Symbiont shift towards Rhizobium nodulation in a group of phylogenetically related Phaseolus species.
abstract: Bean plants from the Phaseolus genus are widely consumed and represent a nitrogen source for human nutrition. They provide biological fertilization by establishing root nodule symbiosis with nitrogen-fixing bacteria. To establish a successful interaction, bean plants and their symbiotic bacteria need to synchronize a proper molecular crosstalk. Within the Phaseolus genus, P. vulgaris has been the prominent species to study nodulation with Rhizobium symbionts. However the Phaseolus genus comprises diverse species whose symbionts have not been analyzed. Here we identified and studied nodule bacteria from representative Phaseolus species not previously analyzed and from all the described wild species related to P. vulgaris. We found Bradyrhizobium in nodules from most species representing all Phaseolus clades except in five phylogenetically related species from the P. vulgaris clade. Therefore we propose that Bradyrhizobium nodulation is common in Phaseolus and that there was a symbiont preference shift to Rhizobium nodulation in few related species. This work sets the basis to further study the genetic basis of this symbiont substitution.
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: lservin@lcg.unam.mx.
authors: Luis E
authors: LE
authors: Servín-Garcidueñas
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: alezayas@ibt.unam.mx.
authors: Alejandra
authors: A
authors: Zayas-Del Moral
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: eormeno@ccg.unam.mx.
authors: Ernesto
authors: E
authors: Ormeño-Orrillo
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: marogel@ccg.unam.mx.
authors: Marco A
authors: MA
authors: Rogel
authors: Instituto de Biología, Universidad Nacional Autónoma de México, México D.F. 04510, Mexico. Electronic address: adelgado@ibunam2.ibiologia.unam.mx.
authors: Alfonso
authors: A
authors: Delgado-Salinas
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: federico@ibt.unam.mx.
authors: Federico
authors: F
authors: Sánchez
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. Electronic address: emartine@ccg.unam.mx.
authors: Esperanza
authors: E
authors: Martínez-Romero
mesh_terms: D020369:Bradyrhizobium / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005798:Genes, Bacterial; D008800:Mexico; D027805:Phaseolus / Q000145:classification / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D053204:Root Nodules, Plant / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S
keywords: Bradyrhizobium; Nodulation; Phaseolus; Rhizobium; Symbiosis