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[PMID]:28011103
[Au] Autor:Castellane TC; Campanharo JC; Colnago LA; Coutinho ID; Lopes ÉM; Lemos MV; de Macedo Lemos EG
[Ad] Endereço:São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal. Electronic address: teluque@yahoo.com.br.
[Ti] Título:Characterization of new exopolysaccharide production by Rhizobium tropici during growth on hydrocarbon substrate.
[So] Source:Int J Biol Macromol;96:361-369, 2017 Mar.
[Is] ISSN:1879-0003
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Exopolysaccharide (EPS) are produced by a diverse of rhizobia species and has been demonstrated to be a bioemulsifier with potential applications in the degradation of hydrocarbons. In the present study, attempts were made to obtain the new exopolysaccharide production by Rhizobium tropici (SEMIA 4080 and MUTZC3) strains during growth on hydrocarbon substrate. Under the different cultivation conditions, the high molecular weight exopolysaccharides from Rhizobium tropici strains cultivated for 96h mainly consisted of carbohydrates (79-85%) and a low percentage of protein. The EPSC3-D differed from the others, with only 60% of carbohydrate. However, all strains produced polymers with distinct rheology properties, such as viscosity of each EPS sample, suitable for different applications. In addition, RP-HPLC, FTIR and NMR studies revealed EPS produced by rhizobia strains were similar indicating minimal difference between EPS compositions.
[Mh] Termos MeSH primário: Hidrocarbonetos/metabolismo
Polissacarídeos Bacterianos/biossíntese
Polissacarídeos Bacterianos/química
Rhizobium tropici/crescimento & desenvolvimento
Rhizobium tropici/metabolismo
[Mh] Termos MeSH secundário: Fenômenos Químicos
Peso Molecular
Reologia
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Hydrocarbons); 0 (Polysaccharides, Bacterial)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170411
[Lr] Data última revisão:
170411
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161225
[St] Status:MEDLINE


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[PMID]:27845247
[Au] Autor:Imada EL; Rolla Dos Santos AA; Oliveira AL; Hungria M; Rodrigues EP
[Ad] Endereço:Laboratório de Genética de Microrganismos, Departamento de Biologia Geral, Universidade Estadual de Londrina, PR-445, Km 380, Campus Universitário, PO Box 6001, CP 86.051-970, Londrina, PR, Brazil. Electronic address: eddie.imada@gmail.com.
[Ti] Título:Indole-3-acetic acid production via the indole-3-pyruvate pathway by plant growth promoter Rhizobium tropici CIAT 899 is strongly inhibited by ammonium.
[So] Source:Res Microbiol;168(3):283-292, 2017 Apr.
[Is] ISSN:1769-7123
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:Like many rhizobia, Rhizobium tropici produces indole-3-acetic acid (IAA), an important signal molecule required for root hair infection in rhizobia-legume symbioses. However, the IAA biosynthesis pathway and its regulation by R. tropici are still poorly understood. In this study, IAA synthesis and the effects of mineral N in IAA production by R. tropici CIAT 899 were verified by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). Furthermore, expression of genes related to IAA biosynthesis and metabolism were evaluated by RT-qPCR. Results indicated that IAA production by CIAT 899 was 12 times lower in the presence of [Formula: see text] . Moreover, it was found that indole-3-pyruvate (IPyA) is the major IAA biosynthesis intermediate. Genes y4wE, lao and iorA were identified by analysis of R. tropici genome in silico and were upregulated by tryptophan, indicating a possible role of these genes in IAA biosynthesis by CIAT 899. In conclusion, we show that IPyA is the major pathway for IAA biosynthesis in CIAT 899 and that its production is strongly inhibited by [Formula: see text] . Although present results arose from in vitro experiments, they provide new insight into the role of nitrogen in early events related to legume nodulation.
[Mh] Termos MeSH primário: Compostos de Amônio/farmacologia
Ácidos Indolacéticos/metabolismo
Reguladores de Crescimento de Planta/metabolismo
Rhizobium tropici/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Vias Biossintéticas/genética
Fabaceae/crescimento & desenvolvimento
Fabaceae/fisiologia
Regulação Bacteriana da Expressão Gênica
Indóis/metabolismo
Fixação de Nitrogênio/genética
Regiões Promotoras Genéticas
Reação em Cadeia da Polimerase em Tempo Real
Rhizobium tropici/efeitos dos fármacos
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ammonium Compounds); 0 (Bacterial Proteins); 0 (Indoleacetic Acids); 0 (Indoles); 0 (Plant Growth Regulators); 4QM0LT13A8 (indol-3-yl pyruvic acid); 6U1S09C61L (indoleacetic acid)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170413
[Lr] Data última revisão:
170413
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161116
[St] Status:MEDLINE


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[PMID]:27096734
[Au] Autor:Del Cerro P; Rolla-Santos AA; Valderrama-Fernández R; Gil-Serrano A; Bellogín RA; Gomes DF; Pérez-Montaño F; Megías M; Hungría M; Ollero FJ
[Ad] Endereço:Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain.
[Ti] Título:NrcR, a New Transcriptional Regulator of Rhizobium tropici CIAT 899 Involved in the Legume Root-Nodule Symbiosis.
[So] Source:PLoS One;11(4):e0154029, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The establishment of nitrogen-fixing rhizobium-legume symbioses requires a highly complex cascade of events. In this molecular dialogue the bacterial NodD transcriptional regulators in conjunction with plant inducers, mostly flavonoids, are responsible for the biosynthesis and secretion of Nod factors which are key molecules for successful nodulation. Other transcriptional regulators related to the symbiotic process have been identified in rhizobial genomes, including negative regulators such as NolR. Rhizobium tropici CIAT 899 is an important symbiont of common bean (Phaseolus vulgaris L.), and its genome encompasses intriguing features such as five copies of nodD genes, as well as other possible transcriptional regulators including the NolR protein. Here we describe and characterize a new regulatory gene located in the non-symbiotic plasmid pRtrCIAT899c, that shows homology (46% identity) with the nolR gene located in the chromosome of CIAT 899. The mutation of this gene, named nrcR (nolR-like plasmid c Regulator), enhanced motility and exopolysaccharide production in comparison to the wild-type strain. Interestingly, the number and decoration of Nod Factors produced by this mutant were higher than those detected in the wild-type strain, especially under salinity stress. The nrcR mutant showed delayed nodulation and reduced competitiveness with P. vulgaris, and reduction in nodule number and shoot dry weight in both P. vulgaris and Leucaena leucocephala. Moreover, the mutant exhibited reduced capacity to induce the nodC gene in comparison to the wild-type CIAT 899. The finding of a new nod-gene regulator located in a non-symbiotic plasmid may reveal the existence of even more complex mechanisms of regulation of nodulation genes in R. tropici CIAT 899 that may be applicable to other rhizobial species.
[Mh] Termos MeSH primário: Phaseolus/microbiologia
Raízes de Plantas/microbiologia
Rhizobium tropici/genética
Rhizobium tropici/fisiologia
Simbiose
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Biofilmes/crescimento & desenvolvimento
Genes Bacterianos
Mutação
Fixação de Nitrogênio
Phaseolus/fisiologia
Raízes de Plantas/fisiologia
Plasmídeos/genética
Ativação Transcricional
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160421
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0154029


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[PMID]:26951045
[Au] Autor:Pérez-Montaño F; Del Cerro P; Jiménez-Guerrero I; López-Baena FJ; Cubo MT; Hungria M; Megías M; Ollero FJ
[Ad] Endereço:Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes n° 6, 41012, Sevilla, Spain. fperezm@us.es.
[Ti] Título:RNA-seq analysis of the Rhizobium tropici CIAT 899 transcriptome shows similarities in the activation patterns of symbiotic genes in the presence of apigenin and salt.
[So] Source:BMC Genomics;17:198, 2016 Mar 08.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Rhizobium tropici strain CIAT 899 establishes effective symbioses with several legume species, including Phaseolus vulgaris and Leucaena leucocephala. This bacterium synthesizes a large variety of nodulation factors in response to nod-gene inducing flavonoids and, surprisingly, also under salt stress conditions. The aim of this study was to identify differentially expressed genes in the presence of both inducer molecules, and analyze the promoter regions located upstream of these genes. RESULTS: Results obtained by RNA-seq analyses of CIAT 899 induced with apigenin, a nod gene-inducing flavonoid for this strain, or salt allowed the identification of 19 and 790 differentially expressed genes, respectively. Fifteen of these genes were up-regulated in both conditions and were involved in the synthesis of both Nod factors and indole-3-acetic acid. Transcription of these genes was presumably activated through binding of at least one of the five NodD proteins present in this strain to specific nod box promoter sequences when the bacterium was induced by both apigenin and salt. Finally, under saline conditions, many other transcriptional responses were detected, including an increase in the transcription of genes involved in trehalose catabolism, chemotaxis and protein secretion, as well as ribosomal genes, and a decrease in the transcription of genes involved in transmembrane transport. CONCLUSIONS: To our knowledge this is the first time that a transcriptomic study shows that salt stress induces the expression of nodulation genes in the absence of flavonoids. Thus, in the presence of both nodulation inducer molecules, apigenin and salt, R. tropici CIAT 899 up-regulated the same set of symbiotic genes. It could be possible that the increases in the transcription levels of several genes related to nodulation under saline conditions could represent a strategy to establish symbiosis under abiotic stressing conditions.
[Mh] Termos MeSH primário: Apigenina/química
Rhizobium tropici/genética
Cloreto de Sódio/química
Simbiose/genética
Transcriptoma
[Mh] Termos MeSH secundário: Sequência de Bases
Regulação Bacteriana da Expressão Gênica
Ácidos Indolacéticos/metabolismo
Óperon
Nodulação/genética
Regiões Promotoras Genéticas
RNA Bacteriano/genética
Rhizobium tropici/fisiologia
Análise de Sequência de RNA
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Indoleacetic Acids); 0 (RNA, Bacterial); 451W47IQ8X (Sodium Chloride); 6U1S09C61L (indoleacetic acid); 7V515PI7F6 (Apigenin)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160309
[St] Status:MEDLINE
[do] DOI:10.1186/s12864-016-2543-3


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[PMID]:26832644
[Au] Autor:Rouhrazi K; Khodakaramian G; Velázquez E
[Ad] Endereço:Department of Plant Protection, Faculty of Agriculture, Buali Sina University, Hamedan, 65178-38695, Iran.
[Ti] Título:Phylogenetic diversity of rhizobial species and symbiovars nodulating Phaseolus vulgaris in Iran.
[So] Source:FEMS Microbiol Lett;363(5):fnw024, 2016 Mar.
[Is] ISSN:1574-6968
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The phylogenetic diversity of 29 rhizobial strains nodulating Phaseolus vulgaris in Iran was analysed on the basis of their core and symbiotic genes. These strains displayed five 16S rRNA-RFLP patterns and belong to eight ERIC-PCR clusters. The phylogenetic analyses of 16S rRNA, recA and atpD core genes allowed the identification of several strains as Rhizobium sophoriradicis, R. leguminosarum, R. tropici and Pararhizobium giardinii, whereas other strains represented a new phylogenetic lineage related to R. vallis. These strains and those identified as R. sophoriradicis and R. leguminosarum belong to the symbiovar phaseoli carrying the γ nodC allele distributed in P. vulgaris endosymbionts in America, Europe, Africa and Asia. The strain identified as R. tropici belongs to the symbiovar tropici carried by strains of R. tropici, R. leucaenae, R. lusitanum and R. freirei nodulating P. vulgaris in America, Africa and Asia. The strain identified as P. giardinii belongs to the symbiovar giardinii together with the type strain of this species nodulating P. vulgaris in France. It is remarkable that the recently described species R. sophoriradicis is worldwide distributed in P. vulgaris nodules carrying the γ nodC allele of symbiovar phaseoli harboured by rhizobia isolated in the American distribution centers of this legume.
[Mh] Termos MeSH primário: Phaseolus/microbiologia
Rhizobium leguminosarum/classificação
Rhizobium leguminosarum/genética
Rhizobium tropici/genética
Nódulos Radiculares de Plantas/microbiologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Sequência de Bases
DNA Bacteriano/genética
Irã (Geográfico)
Proteínas de Membrana/genética
N-Acetilglucosaminiltransferases/genética
Filogenia
Polimorfismo de Fragmento de Restrição
RNA Ribossômico 16S/genética
Recombinases Rec A/genética
Rhizobium leguminosarum/crescimento & desenvolvimento
Rhizobium tropici/classificação
Rhizobium tropici/crescimento & desenvolvimento
Análise de Sequência de DNA
Microbiologia do Solo
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA, Bacterial); 0 (Membrane Proteins); 0 (RNA, Ribosomal, 16S); EC 2.4.1.- (N-Acetylglucosaminyltransferases); EC 2.4.1.- (NodC protein, Rhizobiales); EC 2.7.7.- (Rec A Recombinases)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160203
[St] Status:MEDLINE


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[PMID]:26502986
[Au] Autor:del Cerro P; Rolla-Santos AA; Gomes DF; Marks BB; del Rosario Espuny M; Rodríguez-Carvajal MÁ; Soria-Díaz ME; Nakatani AS; Hungria M; Ollero FJ; Megías M
[Ad] Endereço:Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes, 6 Apdo Postal 41012, Sevilla, Spain. pdelcerro@us.es.
[Ti] Título:Opening the "black box" of nodD3, nodD4 and nodD5 genes of Rhizobium tropici strain CIAT 899.
[So] Source:BMC Genomics;16:864, 2015 Oct 26.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Transcription of nodulation genes in rhizobial species is orchestrated by the regulatory nodD gene. Rhizobium tropici strain CIAT 899 is an intriguing species in possessing features such as broad host range, high tolerance of abiotic stresses and, especially, by carrying the highest known number of nodD genes--five--and the greatest diversity of Nod factors (lipochitooligosaccharides, LCOs). Here we shed light on the roles of the multiple nodD genes of CIAT 899 by reporting, for the first time, results obtained with nodD3, nodD4 and nodD5 mutants. METHODS: The three nodD mutants were built by insertion of Ω interposon. Nod factors were purified and identified by LC-MS/MS analyses. In addition, nodD1 and nodC relative gene expressions were measured by quantitative RT-PCR in the wt and derivative mutant strains. Phenotypic traits such as exopolysaccharide (EPS), lipopolysaccharide (LPS), swimming and swarming motilities, biofilm formation and indole acetid acid (IAA) production were also perfomed. All these experiments were carried out in presence of both inducers of CIAT 899, apigenin and salt. Finally, nodulation assays were evaluated in up to six different legumes, including common bean (Phaseolus vulgaris L.). RESULTS: Phenotypic and symbiotic properties, Nod factors and gene expression of nodD3, nodD4 and nodD5 mutants were compared with those of the wild-type (WT) CIAT 899, both in the presence and in the absence of the nod-gene-inducing molecule apigenin and of saline stress. No differences between the mutants and the WT were observed in exopolysaccharide (EPS) and lipopolysaccharide (LPS) profiles, motility, indole acetic acid (IAA) synthesis or biofilm production, either in the presence, or in the absence of inducers. Nodulation studies demonstrated the most complex regulatory system described so far, requiring from one (Leucaena leucocephala, Lotus burtii) to four (Lotus japonicus) nodD genes. Up to 38 different structures of Nod factors were detected, being higher under salt stress, except for the nodD5 mutant; in addition, a high number of structures was synthesized by the nodD4 mutant in the absence of any inducer. Probable activator (nodD3 and nodD5) or repressor roles (nodD4), possibly via nodD1 and/or nodD2, were attributed to the three nodD genes. Expression of nodC, nodD1 and each nodD studied by RT-qPCR confirmed that nodD3 is an activator of nodD1, both in the presence of apigenin and salt stress. In contrast, nodD4 might be an inducer with apigenin and a repressor under saline stress, whereas nodD5 was an inducer under both conditions. CONCLUSIONS: We report for R. tropici CIAT 899 the most complex model of regulation of nodulation genes described so far. Five nodD genes performed different roles depending on the host plant and the inducing environment. Nodulation required from one to four nodD genes, depending on the host legume. nodD3 and nodD5 were identified as activators of the nodD1 gene, whereas, for the first time, it was shown that a regulatory nodD gene-nodD4-might act as repressor or inducer, depending on the inducing environment, giving support to the hypothesis that nodD roles go beyond nodulation, in terms of responses to abiotic stresses.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Regulação Bacteriana da Expressão Gênica
Rhizobium tropici/genética
Rhizobium tropici/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins)
[Em] Mês de entrada:1607
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151028
[St] Status:MEDLINE
[do] DOI:10.1186/s12864-015-2033-z


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[PMID]:26273251
[Au] Autor:Marra LM; de Oliveira-Longatti SM; Soares CR; de Lima JM; Olivares FL; Moreira FM
[Ad] Endereço:Universidade Federal de Lavras, Programa de Pós-Graduação em Ciência do Solo, Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, MG, Brasil, Programa de Pós-Graduação em Ciência do Solo, Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, MG, Brazil.
[Ti] Título:Initial pH of medium affects organic acids production but do not affect phosphate solubilization.
[So] Source:Braz J Microbiol;46(2):367-75, 2015 Jun.
[Is] ISSN:1678-4405
[Cp] País de publicação:Brazil
[La] Idioma:eng
[Ab] Resumo:The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.
[Mh] Termos MeSH primário: Acinetobacter/metabolismo
Ácidos Carboxílicos/metabolismo
Meios de Cultura/química
Paenibacillus/metabolismo
Fosfatos/metabolismo
Rhizobium tropici/metabolismo
[Mh] Termos MeSH secundário: Acinetobacter/crescimento & desenvolvimento
Acinetobacter/isolamento & purificação
Fabaceae/microbiologia
Concentração de Íons de Hidrogênio
Paenibacillus/crescimento & desenvolvimento
Paenibacillus/isolamento & purificação
Rhizobium tropici/crescimento & desenvolvimento
Rhizobium tropici/isolamento & purificação
Nódulos Radiculares de Plantas/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carboxylic Acids); 0 (Culture Media); 0 (Phosphates)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150815
[St] Status:MEDLINE


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[PMID]:25880529
[Au] Autor:del Cerro P; Rolla-Santos AA; Gomes DF; Marks BB; Pérez-Montaño F; Rodríguez-Carvajal MÁ; Nakatani AS; Gil-Serrano A; Megías M; Ollero FJ; Hungria M
[Ad] Endereço:Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes, 6 Apdo Postal 41012, Sevilla, Spain. pdelcerro@us.es.
[Ti] Título:Regulatory nodD1 and nodD2 genes of Rhizobium tropici strain CIAT 899 and their roles in the early stages of molecular signaling and host-legume nodulation.
[So] Source:BMC Genomics;16:251, 2015 Mar 28.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Nodulation and symbiotic nitrogen fixation are mediated by several genes, both of the host legume and of the bacterium. The rhizobial regulatory nodD gene plays a critical role, orchestrating the transcription of the other nodulation genes. Rhizobium tropici strain CIAT 899 is an effective symbiont of several legumes-with an emphasis on common bean (Phaseolus vulgaris)-and is unusual in carrying multiple copies of nodD, the roles of which remain to be elucidated. RESULTS: Phenotypes, Nod factors and gene expression of nodD1 and nodD2 mutants of CIAT 899 were compared with those of the wild type strain, both in the presence and in the absence of the nod-gene-inducing molecules apigenin and salt (NaCl). Differences between the wild type and mutants were observed in swimming motility and IAA (indole acetic acid) synthesis. In the presence of both apigenin and salt, large numbers of Nod factors were detected in CIAT 899, with fewer detected in the mutants. nodC expression was lower in both mutants; differences in nodD1 and nodD2 expression were observed between the wild type and the mutants, with variation according to the inducing molecule, and with a major role of apigenin with nodD1 and of salt with nodD2. In the nodD1 mutant, nodulation was markedly reduced in common bean and abolished in leucaena (Leucaena leucocephala) and siratro (Macroptilium atropurpureum), whereas a mutation in nodD2 reduced nodulation in common bean, but not in the other two legumes. CONCLUSION: Our proposed model considers that full nodulation of common bean by R. tropici requires both nodD1 and nodD2, whereas, in other legume species that might represent the original host, nodD1 plays the major role. In general, nodD2 is an activator of nod-gene transcription, but, in specific conditions, it can slightly repress nodD1. nodD1 and nodD2 play other roles beyond nodulation, such as swimming motility and IAA synthesis.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Fabaceae/microbiologia
Genes Bacterianos
Rhizobium tropici/genética
[Mh] Termos MeSH secundário: Apigenina/farmacologia
Proteínas de Bactérias/metabolismo
Fabaceae/crescimento & desenvolvimento
Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos
Ácidos Indolacéticos/metabolismo
Mutação
Fixação de Nitrogênio/efeitos dos fármacos
Fenótipo
Nodulação/efeitos dos fármacos
Raízes de Plantas/microbiologia
Rhizobium tropici/fisiologia
Cloreto de Sódio/farmacologia
Simbiose/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Indoleacetic Acids); 0 (NodD protein, Bacteria); 451W47IQ8X (Sodium Chloride); 6U1S09C61L (indoleacetic acid); 7V515PI7F6 (Apigenin)
[Em] Mês de entrada:1601
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150417
[St] Status:MEDLINE
[do] DOI:10.1186/s12864-015-1458-8


  9 / 51 MEDLINE  
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[PMID]:25716616
[Au] Autor:Wang RR; Wang Q; He LY; Qiu G; Sheng XF
[Ad] Endereço:Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
[Ti] Título:Isolation and the interaction between a mineral-weathering Rhizobium tropici Q34 and silicate minerals.
[So] Source:World J Microbiol Biotechnol;31(5):747-53, 2015 May.
[Is] ISSN:1573-0972
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The purposes of this study were to isolate and evaluate the interaction between mineral-weathering bacteria and silicate minerals (feldspar and biotite). A mineral-weathering bacterium was isolated from weathered rocks and identified as Rhizobium tropici Q34 based on 16S rRNA gene sequence analysis. Si and K concentrations were increased by 1.3- to 4.0-fold and 1.1- to 1.7-fold in the live bacterium-inoculated cultures compared with the controls respectively. Significant increases in the productions of tartaric and succinic acids and extracellular polysaccharides by strain Q34 were observed in cultures with minerals. Furthermore, significantly more tartaric acid and polysaccharide productions by strain Q34 were obtained in the presence of feldspar, while better growth and more citric acid production of strain Q34 were observed in the presence of biotite. Mineral dissolution experiments showed that the organic acids and polysaccharides produced by strain Q34 were also capable of promoting the release of Si and K from the minerals. The results showed that the growth and metabolite production of strain Q34 were enhanced in the presence of the minerals and different mineral exerted distinct impacts on the growth and metabolite production. The bio-weathering process is probably a synergistic action of organic acids and extracellular polysaccharides produced by the bacterium.
[Mh] Termos MeSH primário: Rhizobium tropici/classificação
Rhizobium tropici/metabolismo
Silicatos/metabolismo
[Mh] Termos MeSH secundário: Ácidos Carboxílicos/metabolismo
DNA Bacteriano/química
DNA Bacteriano/genética
DNA Ribossômico/química
DNA Ribossômico/genética
Dados de Sequência Molecular
Polissacarídeos Bacterianos/metabolismo
Potássio/metabolismo
RNA Ribossômico 16S/genética
Rhizobium tropici/genética
Rhizobium tropici/isolamento & purificação
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carboxylic Acids); 0 (DNA, Bacterial); 0 (DNA, Ribosomal); 0 (Polysaccharides, Bacterial); 0 (RNA, Ribosomal, 16S); 0 (Silicates); RWP5GA015D (Potassium)
[Em] Mês de entrada:1512
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150227
[St] Status:MEDLINE
[do] DOI:10.1007/s11274-015-1827-0


  10 / 51 MEDLINE  
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[PMID]:25220497
[Au] Autor:López-Gómez M; Cobos-Porras L; Hidalgo-Castellanos J; Lluch C
[Ad] Endereço:Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain. Electronic address: mlgomez@ugr.es.
[Ti] Título:Occurrence of polyamines in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici in response to salt stress.
[So] Source:Phytochemistry;107:32-41, 2014 Nov.
[Is] ISSN:1873-3700
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Polyamines (PAs) are low molecular weight aliphatic compounds that have been shown to be an important part of plant responses to salt stress. For that reason in this work we have investigated the involvement of PAs in the response to salt stress in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici. The level and variety of PAs was higher in nodules, compared to leaves and roots, and in addition to the common PAs (putrescine, spermidine and spermine) we found homospermidine (Homspd) as the most abundant polyamine in nodules. UPLC-mass spectrometry analysis revealed the presence of 4-aminobutylcadaverine (4-ABcad), only described in nodules of Vigna angularis before. Indeed, the analysis of different nodular fractions revealed higher level of 4-ABcad, as well as Homspd, in bacteroids which indicate the production of these PAs by the bacteria in symbiosis. The genes involved in PAs biosynthesis in nodules displayed an induction under salt stress conditions which was not consistent with the decline of free PAs levels, probably due to the nitrogen limitations provoked by the nitrogenase activity depletion and/or the conversion of free PAs to theirs soluble conjugated forms, that seems to be one of the mechanisms involved in the regulation of PAs levels. On the contrary, cadaverine (Cad) and 4-ABcad concentrations augmented by the salinity, which might be due to their involvement in the response of bacteroids to hyper-osmotic conditions. In conclusion, the results shown in this work suggest the alteration of the bacteroidal metabolism towards the production of uncommon PAs such as 4-ABcad in the response to salt stress in legume root nodules.
[Mh] Termos MeSH primário: Cadaverina/análogos & derivados
Cadaverina/metabolismo
Phaseolus/metabolismo
Poliaminas/metabolismo
Rhizobium tropici/metabolismo
Nódulos Radiculares de Plantas/metabolismo
[Mh] Termos MeSH secundário: Cadaverina/análise
Fabaceae/metabolismo
Fixação de Nitrogênio
Phaseolus/genética
Folhas de Planta/metabolismo
Raízes de Plantas/metabolismo
Poliaminas/análise
Reação em Cadeia da Polimerase
Putrescina/análise
Putrescina/metabolismo
Salinidade
Tolerância a Sal/fisiologia
Homologia de Sequência do Ácido Nucleico
Cloreto de Sódio/farmacologia
Espermidina/análise
Espermidina/metabolismo
Espermina/análise
Espermina/metabolismo
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (4-aminobutylcadaverine); 0 (Polyamines); 2FZ7Y3VOQX (Spermine); 451W47IQ8X (Sodium Chloride); L90BEN6OLL (Cadaverine); U87FK77H25 (Spermidine); V10TVZ52E4 (Putrescine)
[Em] Mês de entrada:1502
[Cu] Atualização por classe:151119
[Lr] Data última revisão:
151119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140916
[St] Status:MEDLINE



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