scholarly journals Sulfation of Nod Factors via nodHPQ Is nodD Independent in Rhizobium tropici CIAT899

1998 ◽  
Vol 11 (10) ◽  
pp. 979-987 ◽  
Author(s):  
Jorge Luis Folch-Mallol ◽  
Hamid Manyani ◽  
Silvia Marroquí ◽  
Carolina Sousa ◽  
Carmen Vargas ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Leucaena Leucocephala ◽  
Regulatory Region ◽  
Constitutive Expression ◽  
Nod Factors ◽  
Rhizobium Tropici ◽  
Independent Manner ◽  
Macroptilium Atropurpureum ◽  
Tlc Analysis ◽  
Layer Chromatography

A cosmid from the Rhizobium tropici CIAT899 symbiotic plasmid, containing most of the nodulation genes described in this strain, has been isolated. Although this cosmid does not carry a nodD gene, it confers ability to heterologous Rhizobium spp. to nodulate R. tropici hosts (Phaseolus vulgaris, Macroptilium atropurpureum, and Leucaena leucocephala). The observed phenotype is due to constitutive expression of the nodABCSUIJ operon, which has lost its regulatory region and is expressed from a promoter present in the cloning vector. Thin-layer chromatography (TLC) analysis of the Nod factors produced by this construction shows that it is still capable of synthesizing sulfated compounds, suggesting that the nodHPQ genes are organized as an operon that is transcribed in a nodD-independent manner and is not regulated by flavonoids. Se ha aislado un cósmido del plásmido simbiótico de Rhizobium tropici CIAT899 que contiene la mayoría de los genes de nodulación descrito para esta estirpe, menos el gen regulador nodD. La introducción de este cósmido en una estirpe curada del plásmido simbiótico de R. tropici CIAT899 permite la nodulación en las plantas ensayadas (Phaseolus vulgaris, Macroptilium atropurpureum, y Leucaena leucocephala). El fenotipo observado se debe a la expresión constitutiva del operón nodABCSUIJ bajo el promotor del gen de resistencia a la kanamicina, que lleva el vector donde se ha clonado el fragmento de ADN. Análisis por cromatografia de capa fina demuestran que esta construcción es capaz de sulfatar el extremo reductor del factor Nod. Estas evidencias sugieren que los genes nodHPQ constituyen un operón, y que su expresión es independiente del gen regulador nodD.

scholarly journals The Rhizobium tropici CIAT 899 NodD2 protein regulates the production of Nod factors under salt stress in a flavonoid-independent manner

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Pablo del Cerro ◽  
Francisco Pérez-Montaño ◽  
Antonio Gil-Serrano ◽  
Francisco Javier López-Baena ◽  
Manuel Megías ◽  
...  
Keyword(s):  
Salt Stress ◽  
Nod Factors ◽  
Rhizobium Tropici ◽  
Independent Manner

Regulation of Nod factor sulphation genes in Rhizobium tropici CIAT899

2001 ◽  
Vol 47 (6) ◽  
pp. 574-579 ◽  
Author(s):  
Hamid Manyani ◽  
Carolina Sousa ◽  
María-Eugenia Soria Díaz ◽  
Antonio Gil-Serrano ◽  
Manuel Megías
Keyword(s):  
Wide Spectrum ◽  
Constitutive Expression ◽  
Upstream Region ◽  
Broad Host Range ◽  
Nod Factors ◽  
Rhizobium Tropici ◽  
Free Living ◽  
Nod Factor ◽  
Symbiotic Plasmid ◽  
Transcriptional Fusions

Rhizobium tropici CIAT899 is a tropical symbiont able to nodulate various legumes such as Leucaena, Phaseolus, and Macroptilium. Broad host range of this species is related to its Nod factors wide spectrum. R. tropici contains Nod factors sulphation nod genes, nodHPQ genes, which control nodulation efficiency in Leucaena. To study nodHPQ regulation, we carried out different interposon insertions in its upstream region. One of these generated interruptions, nodI mutant produced nonsulphated Nod factors suggesting a possible dependence of these genes on nodI upstream region. Moreover, analysis results of lacZ transcriptional fusions with these genes in symbiotic plasmid showed dependence of these genes on NodD protein. In order to determine nodHPQ organization, we studied the effect of interposon insertion upstream of each lacZ transcriptional fusion, and the data obtained was used to indicate that nodHPQ belong to the nodABCSUIJ operon. However, comparison between nodP::lacZ β-galactosidase activity in the symbiotic plasmid and in the pHM500 plasmid (containing nodHPQ genes) suggested constitutive expression in free living, and flavonoid inducible expression in symbiotic conditions. Constitutive nodHPQ expression may play a role in bacterial house-keeping metabolism. On the other hand, the transference of R. tropici nodHPQ genes to other rhizobia that do not present sulphated substitutions demonstrated that NodH protein sulphotransference is specific to C6 at the reducing end.Key words: Nod factors, nodHPQ genes, Rhizobium tropici, nod-box.

scholarly journals Nitrogen-Fixing Nodules with Ensifer adhaerens Harboring Rhizobium tropici Symbiotic Plasmids

2001 ◽  
Vol 67 (7) ◽  
pp. 3264-3268 ◽  
Author(s):  
M. Antonio Rogel ◽  
Ismael Hern�ndez-Lucas ◽  
L. David Kuykendall ◽  
David L. Balkwill ◽  
Esperanza Martinez-Romero
Keyword(s):  
Phaseolus Vulgaris ◽  
Leucaena Leucocephala ◽  
Small Subunit ◽  
Rrna Gene ◽  
Nitrogen Fixing ◽  
Small Subunit Rrna ◽  
Rhizobium Tropici ◽  
Selective Media ◽  
Small Subunit Rrna Gene ◽  
Ensifer Adhaerens

ABSTRACT Ensifer adhaerens is a soil bacterium that attaches to other bacteria and may cause lysis of these other bacteria. Based on the sequence of its small-subunit rRNA gene, E. adhaerensis related to Sinorhizobium spp. E. adhaerensATCC 33499 did not nodulate Phaseolus vulgaris (bean) orLeucaena leucocephala, but with symbiotic plasmids fromRhizobium tropici CFN299 it formed nitrogen-fixing nodules on both hosts. The nodule isolates were identified as E. adhaerens isolates by growth on selective media.

scholarly journals Rhizobium lusitanum sp. nov. a bacterium that nodulates Phaseolus vulgaris

2006 ◽  
Vol 56 (11) ◽  
pp. 2631-2637 ◽  
Author(s):  
Angel Valverde ◽  
José M. Igual ◽  
Alvaro Peix ◽  
Emilio Cervantes ◽  
Encarna Velázquez
Keyword(s):  
Phaseolus Vulgaris ◽  
Type Strain ◽  
Random Amplified Polymorphic Dna ◽  
Intergenic Spacer ◽  
Rrna Gene ◽  
Rhizobium Tropici ◽  
The Family ◽  
Dna Pattern ◽  
Macroptilium Atropurpureum ◽  
Type Strains

The species Phaseolus vulgaris is a promiscuous legume nodulated by several species of the family Rhizobiaceae. During a study of rhizobia nodulating this legume in Portugal, we isolated several strains that nodulate P. vulgaris effectively and also Macroptilium atropurpureum and Leucaena leucocephala, but they form ineffective nodules in Medicago sativa. According to phylogenetic analysis of the 16S rRNA gene sequence, the strains from this study belong to the genus Rhizobium, with Rhizobium rhizogenes and Rhizobium tropici as the closest related species, with 99.9 and 99.2 % similarity, respectively, between the type strains of these species and strain P1-7T. The nodD and nifH genes carried by strain P1-7T are phylogenetically related to those of other species nodulating Phaseolus. This strain does not carry virulence genes present in the type strain of R. rhizogenes, ATCC 11325T. Analysis of the recA and atpD genes confirms this phylogenetic arrangement, showing low similarity with respect to those of R. rhizogenes ATCC 11325T (91.9 and 94.1 % similarity, respectively) and R. tropici IIB CIAT 899T (90.6 % and 91.8 % similarity, respectively). The intergenic spacer (ITS) of the strains from this study is phylogenetically divergent from those of R. rhizogenes ATCC 11235T and R. tropici CIAT 899T, with 85.9 and 82.8 % similarity, respectively, with respect to strain P1-7T. The tRNA profile and two-primer random amplified polymorphic DNA pattern of strain P1-7T are also different from those of R. rhizogenes ATCC 11235T and R. tropici CIAT 899T. The strains isolated in this study can be also differentiated from R. rhizogenes and R. tropici by several phenotypic characteristics. The results of DNA–DNA hybridization showed means of 28 and 25 % similarity between strain P1-7T and R. rhizogenes ATCC 11235T and R. tropici CIAT 899T, respectively. All these data showed that the strains isolated in this study belong to a novel species of the genus Rhizobium, for which we propose the name Rhizobium lusitanum sp. nov.; the type strain is P1-7T (=LMG 22705T=CECT 7016T).

Promiscuous nodulation of Phaseolus vulgaris, Macroptilium atropurpureum, and Leucaena leucocephala by indigenous Rhizobium meliloti

1990 ◽  
Vol 36 (5) ◽  
pp. 369-372 ◽  
Author(s):  
E. S. P. Bromfield ◽  
L. R. Barran
Keyword(s):  
Phaseolus Vulgaris ◽  
Host Range ◽  
Leucaena Leucocephala ◽  
Rhizobium Meliloti ◽  
Symbiotic Genes ◽  
Apparent Relationship ◽  
Macroptilium Atropurpureum ◽  
Axenic Conditions ◽  
Cryptic Plasmids ◽  
Reference Strains

Thirty-three isolates of indigenous Rhizobium meliloti, either possessing cryptic plasmids that hybridize to probes for symbiotic genes or lacking a 1500-kb megaplasmid band in Eckhardt gels, were tested for infectivity on 10 legume species grown under axenic conditions. A previous study had shown that all but two isolates were symbiotically effective with Medicago sativa. All indigenous isolates and two reference strains of R. meliloti induced nodules which were symbiotically ineffective on Trigonella foenum-graecum (100% plants nodulated) and Phaseolus vulgaris (40 to 100% plants nodulated). Eighteen indigenous isolates of R. meliloti elicited ineffective nodules on Macroptilium atropurpureum (2 to 25% plants nodulated) and Leucaena leucocephala (11 to 75% plants nodulated). The identity of single colony nodule isolates from each R. meliloti inoculant and host combination was verified by phage typing and analysis of plasmid profiles; tests with subsamples of these isolates showed that all were capable of nodulating M. sativa. There was no apparent relationship between the host range of indigenous R. meliloti and either the presence of cryptic plasmids that hybridize to probes for symbiotic genes or the absence of a megaplasmid band in Eckhardt gels. The data suggest that nodulation promiscuity may be a relatively common characteristic of R. meliloti. Key words: host range, Rhizobium meliloti, Leucaena, Macroptilium, Phaseolus.

scholarly journals Phaseolus vulgaris Recognizes Azorhizobium caulinodans Nod Factors with a Variety of Chemical Substituents

1999 ◽  
Vol 12 (9) ◽  
pp. 820-824 ◽  
Author(s):  
T. Laeremans ◽  
C. Snoeck ◽  
J. Mariën ◽  
C. Verreth ◽  
E. Martínez-Romero ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Host Plant ◽  
Wide Spectrum ◽  
Nod Factors ◽  
Azorhizobium Caulinodans ◽  
Rhizobium Tropici ◽  
Nod Factor ◽  
Mutant Strains

Phaseolus vulgaris is a promiscuous host plant that can be nodulated by many different rhizobia representing a wide spectrum of Nod factors. In this study, we introduced the Rhizobium tropici CFN299 Nod factor sulfation genes nodHPQ into Azorhizobium caulinodans. The A. caulinodans transconjugants produce Nod factors that are mostly if not all sulfated and often with an arabinosyl residue as the reducing end glycosylation. Using A. caulinodans mutant strains, affected in reducing end decorations, and their respective transconjugants in a bean nodulation assay, we demonstrated that bean nodule induction efficiency, in decreasing order, is modulated by the Nod factor reducing end decorations fucose, arabinose or sulfate, and hydrogen.

scholarly journals TLC analysis of some phenolic compounds in kombucha beverage

2004 ◽  
pp. 199-205 ◽  
Author(s):  
Radomir Malbasa ◽  
Eva Loncar ◽  
Ljiljana Kolarov
Keyword(s):  
Phenolic Compounds ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Green Tea ◽  
Black Tea ◽  
Wide Range ◽  
Tea Fungus ◽  
Natural Phenolic Compounds ◽  
Tlc Analysis ◽  
Layer Chromatography

Black and green tea contains a wide range of natural phenolic compounds Flavanoids and their glycosides, catechins and the products of their condensation, and phenolic acids are the most important. Kombucha beverage is obtained by fermentation of tea fungus on black or green tea sweetened with sucrose. The aim of this paper was to investigate the composition of some phenolic compounds, catechin, epicatechin, quercetin, myricetin, gallic and tanic acid, and monitoring of their status during tea fungus fermentation. The method used for this study was thin layer chromatography with two different systems. The main phenolic compounds in the samples with green tea were catechin and epicatechin, and in the samples with black tea it was quercetin.

Mutations Causing Constitutive Invertase Synthesis in Yeast: Genetic Interactions with snf Mutations

Genetics ◽  
1987 ◽  
Vol 115 (2) ◽  
pp. 247-253
Author(s):  
Lenore Neigeborn ◽  
Marian Carlson
Keyword(s):  
Regulatory Region ◽  
Constitutive Expression ◽  
Genetic Interactions ◽  
The Third ◽  
Recessive Mutations ◽  
Constitutive Mutation ◽  
Complementation Groups ◽  
High Level ◽  
Yeast Genetic ◽  
Very High

ABSTRACT We have selected 210 mutants able to grow on sucrose in the presence of 2-deoxyglucose. We identified recessive mutations in three major complementation groups that cause constitutive (glucose-insensitive) secreted invertase synthesis. Two groups comprise alleles of the previously identified HXK2 and REG1 genes, and the third group was designated cid1 (constitutive invertase derepression). The effect of cid1 on SUC2 expression is mediated by the SUC2 upstream regulatory region, as judged by the constitutive expression of a SUC2-LEU2-lacZ fusion in which the LEU2 promoter is under control of SUC2 upstream sequences. A cid1 mutation also causes glucose-insensitive expression of maltase. The previously isolated constitutive mutation ssn6 is epistatic to cid1, reg1 and hxk2 for very high level constitutive invertase expression. Mutations in SNF genes that prevent derepression of invertase are epistatic to cid1, reg1 and hxk2; we have previously shown that ssn6 has different epistasis relationships with snf mutations. The constitutive mutation tup1 was found to resemble ssn6 in its genetic interactions with snf mutations. These findings suggest that CID1, REG1 and HXK2 are functionally distinct from SSN6 and TUP1.

scholarly journals Rhizobium tropici Genes Involved in Free-Living Salt Tolerance are Required for the Establishment of Efficient Nitrogen-Fixing Symbiosis with Phaseolus vulgaris

2002 ◽  
Vol 15 (3) ◽  
pp. 225-232 ◽  
Author(s):  
Joaquina Nogales ◽  
Rosario Campos ◽  
Hanaa BenAbdelkhalek ◽  
José Olivares ◽  
Carmen Lluch ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Phaseolus Vulgaris ◽  
Environmental Changes ◽  
Nitrogenase Activity ◽  
Regulation Of Gene Expression ◽  
Elongation Factor ◽  
Regulatory System ◽  
Trna Synthetase ◽  
Nitrogen Fixing ◽  
Rhizobium Tropici

Characterization of nine transposon-induced mutants of Rhizobium tropici with decreased salt tolerance (DST) allowed the identification of eight gene loci required for adaptation to high external NaCl. Most of the genes also were involved in adaptation to hyperosmotic media and were required to overcome the toxicity of LiCl. According to their possible functions, genes identified could be classified into three groups. The first group included two genes involved in regulation of gene expression, such as ntrY, the sensor element of the bacterial ntrY/ntrX two-component regulatory system involved in regulation of nitrogen metabolism, and greA, which encodes a transcription elongation factor. The second group included genes related to synthesis, assembly, or maturation of proteins, such as alaS coding for alanine-tRNA synthetase, dnaJ, which encodes a molecular chaperone, and a nifS homolog probably encoding a cysteine desulfurase involved in the maturation of Fe-S proteins. Genes related with cellular build-up and maintenance were in the third group, such as a noeJ-homolog, encoding a mannose-1-phosphate guanylyltransferase likely involved in lipopolysaccharide biosynthesis, and kup, specifying an inner-membrane protein involved in potassium uptake. Another gene was identified that had no homology to known genes but that could be conserved in other rhizobia. When inoculated on Phaseolus vulgaris growing under nonsaline conditions, all DST mutants displayed severe symbiotic defects: ntrY and noeJ mutants were impaired in nodulation, and the remaining mutants formed symbiosis with very reduced nitrogenase activity. The results suggest that bacterial ability to adapt to hyper-osmotic and salt stress is important for the bacteroid nitrogen-fixing function inside the legume nodule and provide genetic evidence supporting the suggestion that rhizobia face severe environmental changes after their release into plant cells.

scholarly journals Avaliação quantitativa e qualitativa da fitomassa de leguminosas para uso como cobertura de solo

2004 ◽  
Vol 34 (3) ◽  
pp. 947-949 ◽  
Author(s):  
João Tavares Nascimento ◽  
Ivandro de França da Silva
Keyword(s):  
Leucaena Leucocephala ◽  
Cajanus Cajan ◽  
Pueraria Phaseoloides ◽  
Crotalaria Juncea ◽  
Clitoria Ternatea ◽  
Canavalia Ensiformis ◽  
Calopogonium Mucunoides ◽  
Macroptilium Atropurpureum

Para uso como adubo verde em um experimento em Alagoinha-PB, avaliaram-se doze espécies de leguminosas: crotalária (Crotalaria juncea L), guandu (Cajanus cajan L), guandu anão (Cajanus cajan (L) Millsp), calopogônio (Calopogonium mucunoides L), feijão-de-porco (Canavalia ensiformis L), lab-lab (Dolichos lab lab L), kudzu tropical (Pueraria phaseoloides L), siratro (Macroptilium atropurpureum L), leucena (Leucaena leucocephala L), cunhã (Clitoria ternatea L), mucuna preta (Styzolobium aterrimum L), e mucuna cinza (Styzolobium cinereum Piper e Tracy), no DBC com 12 tratamentos, em parcelas de 20m2, com três repetições. Constataram-se as maiores produções de fitomassa para leucena, guandu, mucuna preta, kudzu tropical, feijão-de-porco e cunhã, enquanto que para a crotalária, a menor produção. A fitomassa do kudzu tropical mostrou-se com melhor qualidade para a incorporação.

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