Multilocus sequence analysis of Brazilian Rhizobium microsymbionts of common bean (Phaseolus vulgaris L.) reveals unexpected taxonomic diversity.
Res Microbiol
; 160(4): 297-306, 2009 May.
Article
em En
| MEDLINE
| ID: mdl-19403105
The diazotrophic bacteria collectively known as "rhizobia" are important for establishing symbiotic N(2)-fixing associations with many legumes. These microbes have been used for over a century as an environmentally beneficial and cost-effective means of ensuring acceptable yields of agricultural legumes. The most widely used phylogenetic marker for identification and classification of rhizobia has been the 16S rRNA gene; however, this marker fails to discriminate some closely related species. In this study, we established the first multilocus sequence analysis (MLSA) scheme for the identification and classification of rhizobial microsymbionts of common bean (Phaseolus vulgaris L.). We analyzed 12 Brazilian strains representative of a collection of over 850 isolates in addition to type and reference rhizobial strains, by sequencing recA, dnaK, gltA, glnII and rpoA genes. Gene sequence similarities among the five type/reference Rhizobium strains which are symbionts of common bean ranged from 95 to 100% for 16S rRNA, and from 83 to 99% for the other five genes. Rhizobial species described as symbionts of common bean also formed separate groups upon analysis of single and concatenated gene sequences, and clusters formed in each tree were in good mutual agreement. The five additional loci may thus be considered useful markers of the genus Rhizobium; in addition, MLSA also revealed broad genetic diversity among strains classified as Rhizobium tropici, providing evidence of new species.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rhizobium
/
Simbiose
/
Variação Genética
/
Phaseolus
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Res Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
França