Data/hora: 17/06/2024 02:09:54

Biblioteca(s): | Embrapa Agrobiologia.
Data corrente: | 21/05/2021
Data da última atualização: | 21/05/2021
Autoria: | MATOS, G. F. de; ROUWS, L. F. M.; ARAUJO, J. L. S. de; BALDANI, J. I.
Afiliação: | GUSTAVO FEITOSA DE MATOS, UFRRJ; LUC FELICIANUS MARIE ROUWS, CNPAB; JEAN LUIZ SIMOES DE ARAUJO, CNPAB; JOSE IVO BALDANI, CNPAB.
Título: | Evolution and function of nitrogen fixation gene clusters in sugarcane associated Bradyrhizobium strains.
Ano de publicação: | 2021
Fonte/Imprenta: | Environmental Microbiology, Published Online 15 May 2021.
Idioma: | Inglês
Conteúdo: | Bradyrhizobium spp. are well known to mediate biological nitrogen &#57345;xation (BNF) as microsymbionts inhabiting nodules on leguminous plants. However, they may also contribute to plant growth via freeliving N2 &#57345;xation (FLNF) in association with nonlegumes. Notably, several Bradyrhizobium strains from sugarcane roots display FLNF ctivity. Among them, Bradyrhizobium sacchari is a legume symbiotic species, whereas strains AG48 and M12 are non-symbiotic. In the present study, a phylogenomic pproach was applied to study peculiarities of these and other Bradyrhizobium strains with respect to N &#57345;xation (nif) gene content in order to reveal genetic features that enable FNLF in Bradyrhizobium spp. All FLNF strains carry an ancestral ?non-symbiotic? nifgene cluster (NSC). B. sacchari also contains a second ?symbiotic? nif-gene cluster (SC), a characteristic observed in only three of 156 evaluated genomes. B. sacchari stood out and presented a high level of sequence divergence between individual nif-gene homologues and we discuss scenarios for the evolutionary origin of these clusters. The transcript level of NSC nifH gene increased during FLNF, when compared to symbiotic conditions. The data suggest that sugarcane roots harbor diverse Bradyrhizobium spp. that are genetically adapted to a dynamic environment where leguminous and non-leguminous host plants are alternately available.
Palavras-Chave: | Biological nitrogen fixation; Fabaceae family.
Categoria do assunto: | P Recursos Naturais, Ciências Ambientais e da Terra
Registro original: | Embrapa Agrobiologia (CNPAB)
Exemplares: | CNPAB - (41731-1) - UPC - AP - DD -  -  -  - DIS