| modulation of rosr expression and exopolysaccharide production in rhizobium leguminosarum bv. trifolii by phosphate and clover root exudates. | the acidic exopolysaccharide (eps) secreted in large amounts by the symbiotic nitrogen-fixing bacterium rhizobium leguminosarum bv. trifolii is required for the establishment of an effective symbiosis with the host plant trifolium spp. eps biosynthesis in rhizobia is a very complex process regulated at both transcriptional and post-transcriptional levels and influenced by various nutritional and environmental conditions. the r. leguminosarum bv. trifolii rosr gene encodes a transcriptional regul ... | 2011 | 21747729 |
| synthesis and evaluation of an n-acetylglucosamine biosynthesis inhibitor. | the structural rationale, synthesis and evaluation of an inhibitor designed to block glucosamine synthesis by competitively inhibiting the action of glutamine: fructose-6-phosphate amidotransferase and subsequently reducing the transformation of any glucosamine-6-phosphate formed to udp-n-acetylglucosamine are described. the inhibitor 2-acetamido-2,6-dideoxy-6-sulfo-d-glucose (d-glucosamine-6-sulfonate) is an analog of glucosamine-6-phosphate in which the phosphate group in the latter is replace ... | 2011 | 21843880 |
| diversity analysis of diazotrophic bacteria associated with the roots of tea (camellia sinensis (l.) o. kuntze). | the diversity elucidation by amplified ribosomal dna restriction analysis and 16s rdna sequencing of 96 associative diazotrophs, isolated from the feeder roots of tea on enriched nitrogen-free semisolid media, revealed the predominance of gram-positive over gram-negative bacteria within the kangra valley in himachal pradesh, india. the gram-positive bacteria observed belong to two taxonomic groupings; firmicutes, including the genera bacillus and paenibacillus; and actinobacteria, represented by ... | 2011 | 21715960 |
| legume-nodulating betaproteobacteria: diversity, host range and future prospects. | rhizobia form specialized nodules on the roots of legumes (fabaceae) and fix nitrogen in exchange for carbon from the host plant. although the majority of legumes form symbioses with rhizobium and its relatives in the alphaproteobacteria, some legumes, such as those in the large genus mimosa, are nodulated predominantly by betaproteobacteria in the genera burkholderia and cupriavidus. the principal centers of diversity of these bacteria are in central brazil and south africa. molecular phylogene ... | 2011 | 21830951 |
| reclassification of rhizobium tropici type a strains as rhizobium leucaenae sp. nov. | rhizobium tropici is a well-studied legume symbiont characterized by high genetic stability of the symbiotic plasmid and tolerance to tropical environmental stresses such as high temperature and low soil ph. however, high phenetic and genetic variabilities among r. tropici strains have been largely reported, with two subgroups, designated type a and b, already defined within the species. a polyphasic study comprising multilocus sequence analysis, phenotypic and genotypic characterizations, inclu ... | 2011 | 21742822 |
| evidence of an american origin for symbiosis-related genes in rhizobium lusitanum. | randomly amplified polymorphic dna (rapd) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the arcos de valdevez region of northwestern portugal. the isolates were divided into 6 groups based on the fingerprint patterns that were obtained. representatives for each group were selected for sequence analysis of 4 chromosomal dna regions. five of the groups were placed within rhizobium lusitanum, and the other group was placed within r. tropici ty ... | 2011 | 21705533 |
| the conjugative plasmid of a bean-nodulating sinorhizobium fredii strain is assembled from sequences of two rhizobium plasmids and the chromosome of a sinorhizobium strain. | abstract: | 2011 | 21702991 |
| [comparison of the adaptive potential for rhizobium leguminosarum bv. viceae nodule bacterial populations isolated in natural ecosystems and agrocenoses]. | polymorphism analysis was performed in rhizobium leguminosarum bv. viceae populations isolated from geographically distant regions of ukraine and middle asia. examination of cultural, biochemical, and symbiotic traits revealed interpopulation differences, which were attributed to the difference in conditions between natural ecosystems and agrocenoses. vetch has high species diversity and is not cultivated in middle asia, and the corresponding rhizobial population displayed higher genetic diversi ... | 2011 | 21675237 |
| medicago truncatula ipd3 is a member of the common symbiotic signaling pathway required for rhizobial and mycorrhizal symbioses. | legumes form endosymbiotic associations with nitrogen fixing bacteria and arbuscular mycorrhizal (am) fungi which facilitate nutrient uptake. both symbiotic interactions require a molecular signal exchange between the plant and the symbiont and this involves a conserved symbiosis (sym) signaling pathway. in order to identify plant genes required for intracellular accommodation of nitrogen-fixing bacteria and am fungi, we characterized medicago truncatula symbiotic mutants defective for rhizobial ... | 2011 | 21692638 |
| the yopj superfamily in plant-associated bacteria. | bacterial pathogens employ the type iii secretion system to secrete and translocate effector proteins into their hosts. the primary function of these effector proteins is believed to be the suppression of host defence responses or innate immunity. however, some effector proteins may be recognized by the host and consequently trigger a targeted immune response. the yopj/hopz/avrrxv family of bacterial effector proteins is a widely distributed and evolutionarily diverse family, found in both anima ... | 2011 | 21726386 |
| synthesis of microbial signaling molecules and their stereochemistry-activity relationships. | microbial signaling molecules such as autoinducers and microbial hormones play important roles in intercellular communication in microorganisms. information transfer between the individual cells of a microorganism is one of the most important biological events among them. researchers often suffer from extremely low levels of microbial signaling molecule contents, which prevent them from understanding chemistry and biology of intercellular communication in microorganisms. chemical synthesis is a ... | 2011 | 21821958 |
| high-level recombinant protein expression in transgenic plants by using a double-inducible viral vector. | we describe here a unique ethanol-inducible process for expression of recombinant proteins in transgenic plants. the process is based on inducible release of viral rna replicons from stably integrated dna proreplicons. a simple treatment with ethanol releases the replicon leading to rna amplification and high-level protein production. to achieve tight control of replicon activation and spread in the uninduced state, the viral vector has been deconstructed, and its two components, the replicon an ... | 2011 | 21825158 |
| plant growth-promotion (pgp) activities and molecular characterization of rhizobacterial strains isolated from soybean (glycine max l. merril) plants against charcoal rot pathogen, macrophomina phaseolina. | charcoal rot disease, caused by the fungus macrophomina phaseolina, leads to significant yield losses of soybean crops. one strategy to control charcoal rot is the use of antagonistic, root-colonizing bacteria. rhizobacteria a(5)f and fpt(7)21 and pseudomonas sp. strain grp(3) were characterized for their plant growth-promotion activities against the pathogen. rhizobacterium fpt(7)21 exhibited higher antagonistic activity against the pathogen on dual plate assay compared to strain a(5)f and grp( ... | 2011 | 21833548 |
| rhizobial nod factors are required for cortical cell division in the nodule morphogenetic programme of the aeschynomeneae legume arachis. | nod factors are among the best-studied molecules implicated in the signal exchange that leads to legume-rhizobia symbiosis. the role of these molecules in symbiosis development has been primarily studied in legumes invaded through infection threads. in these plants, nod factors generate several responses required for nodulation, including the induction of cortical cell division to form the nodule primordium. arachis hypogaea l. (peanut) exhibits a specific mode of rhizobial infection and nodule ... | 2011 | 21815984 |
| the replication origin of a repabc plasmid. | abstract: | 2011 | 21718544 |
| genome sequence of the curdlan-producing agrobacterium sp. strain atcc 31749. | agrobacterium sp. atcc 31749 is an industrial strain for the commercial production of curdlan, an important exopolysaccharide with food and medical applications. here we report the genome sequence of the curdlan-producing strain atcc 31749. genome sequencing is the first step toward the understanding of regulation of curdlan biosynthesis. | 2011 | 21685288 |
| priming by rhizobacterium protects tomato plants from biotrophic and necrotrophic pathogen infections through multiple defense mechanisms. | a selected strain of rhizobacterium, pseudomonas putida strain lsw17s (lsw17s), protects tomato plants (lycopersicon esculentum l. cv. seokwang) from bacterial speck by biotrophic pseudomonas syringae pv. tomato strain dc3000 (dc3000) and bacterial wilt by necrotrophic ralstonia solanacearum kacc 10703 (rs10703). to investigate defense mechanisms induced by lsw17s in tomato plants, transcription patterns of pathogenesis-related (pr) genes and h(2)o(2) production were analyzed in plants treated w ... | 2011 | 21710203 |
| response of root branching to abscisic acid is correlated with nodule formation both in legumes and nonlegumes. | legumes are unique among higher plants in forming a symbiosis with rhizobium. phylogenetic studies indicate this symbiosis may have evolved as many as three times within the fabaceae; alternatively, a predisposition for nodulation evolved early in the history of the legume lineage. we have identified a physiological trait-increased lateral root formation in response to abscisic acid (aba)- that marks all nodulating and non-nodulating legume species in our study set with the exception of chamaecr ... | 2005 | 21646084 |
| the biocontrol bacterium pseudomonas fluorescens pf29arp strain affects the pathogenesis-related gene expression of the take-all fungus gaeumannomyces graminis var. tritici on wheat roots. | the main effects of antagonistic rhizobacteria on plant pathogenic fungi are antibiosis, fungistasis or an indirect constraint through the induction of a plant defence response. to explore different biocontrol mechanisms, an in vitro confrontation assay was conducted with the rhizobacterium pseudomonas fluorescens pf29arp as a biocontrol agent of the fungus gaeumannomyces graminis var. tritici (ggt) on wheat roots. in parallel with the assessment of disease extension, together with the bacterial ... | 2011 | 21726382 |
| nod factors stimulate seed germination and promote growth and nodulation of pea and vetch under competitive conditions. | nod factors are lipochitooligosaccharide (lco) produced by soil bacteria commonly known as rhizobia acting as signals for the legume plants to initiate symbiosis. nod factors trigger early symbiotic responses in plant roots and initiate the development of specialized plant organs called nodules, where biological nitrogen fixation takes place. here, the effect of specific lco originating from flavonoid induced rhizobium leguminosarum bv. viciae gr09 culture was studied on germination, plant growt ... | 2011 | 21723717 |
| phylogenetic analysis reveals gene conversions in multigene families of rhizobia. | gene families are an important and intrinsic trait of rhizobial species. these gene copies can participate in non-reciprocal recombination events, also called gene conversions. gene conversion has diverse roles, but it is usually implicated in the evolution of multigene families. here, we searched for gene conversions in multigene families of six representative rhizobial genomes. we identified 11 gene families with different numbers of copies, genome location and function in cfn42 and ciat652 st ... | 2011 | 21823087 |
| t-dna as a gene tag. | the characteristics of agrobacterium-mediated plant transformation are such that the t-dna can be used as an insertional mutagen and, by extension, a gene tag. an increasing number of mutants have been obtained as a result of t-dna insertion and the versatility of this experimental system can be exploited further to tag sequences of dna which control gene expression. while the isolation of specific mutations by t-dna tagging in the past has been fortuitous, t-dna-based vectors have the potential ... | 1991 | 21736647 |
| Co-ordination of quorum-sensing regulation in Rhizobium leguminosarum by induction of an anti-repressor. | Analysis of quorum-sensing (QS) regulation in Rhizobium leguminosarum revealed an unusual type of gene regulation that relies on the population density-dependent accumulation of an anti-repressor. The cinS gene, which is co-transcribed with the N-acyl-homoserine-lactone synthase gene cinI, is required to fully induce rhiR and raiR, whose products, together with their partner AHL synthases, regulate other genes in a QS-regulated hierarchy. Purified CinS bound to the R.ÔÇâleguminosarum transcripti ... | 2011 | 21732996 |
| purl gene expression affects biofilm formation and symbiotic persistence of photorhabdus temperata in the nematode heterorhabditis bacteriophora. | extensive studies of the well-known legume and rhizobium symbiosis model system suggest that the purine metabolic pathway plays a key role in microbe-plant interactions, although the exact mechanism is unknown. here, we report the impact of a key purine metabolic gene, purl, on the symbiotic interaction between the bacterium photorhabdus temperata and its nematode partner heterorhabditis bacteriophora. real-time pcr assays showed that the purl gene was upregulated in p. temperata in the nematode ... | 2011 | 21700665 |
| matrix-assisted laser desorption ionization (maldi)-time of flight mass spectrometry- and maldi biotyper-based identification of cultured biphenyl-metabolizing bacteria from contaminated horseradish rhizosphere soil. | bacteria that are able to utilize biphenyl as a sole source of carbon were extracted and isolated from polychlorinated biphenyl (pcb)-contaminated soil vegetated by horseradish. isolates were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi-tof ms). the usage of maldi biotyper for the classification of isolates was evaluated and compared to 16s rrna gene sequence analysis. a wide spectrum of bacteria was isolated, with arthrobacter, serratia, r ... | 2011 | 21821747 |
| rhizobium petrolearium sp. nov., isolated from oil-contaminated soil. | two gram-staining-negative, aerobic, rod-shaped bacteria, designated strains sl-1(t) and f11 which had the ability to decompose polycyclic aromatic hydrocarbons (pahs) were isolated from soil samples contaminated by oil. the cells were motile by polar or lateral flagella. according to comparison of 16s rrna gene sequences, strains sl-1(t) and f11 were identical and showed the greatest degree of similarity (96.8 %) to both r. oryzae alt505(t) and r. mesosinicum ccbau 25010(t); however, only r. or ... | 2011 | 21984664 |
| regulation of the structure and activity of pyruvate carboxylase by acetyl coa. | in this review we examine the effects of the allosteric activator, acetyl coa on both the structure and catalytic activities of pyruvate carboxylase. we describe how the binding of acetyl coa produces gross changes to the quaternary and tertiary structures of the enzyme that are visible in the electron microscope. these changes serve to stabilize the tetrameric structure of the enzyme. the main locus of activation of the enzyme by acetyl coa is the biotin carboxylation domain of the enzyme where ... | 2011 | 22120519 |
| Biological activity of (lipo)polysaccharides of the exopolysaccharide-deficient mutant Rt120 derived from Rhizobium leguminosarum bv. trifolii strain TA1. | Lipopolysaccharides (LPS) from Rhizobium leguminosarum biovar trifolii TA1 (RtTA1) and its mutant Rt120 in the pssB?pssA intergenic region as well as degraded polysaccharides (DPS) derived from the LPS were elucidated in terms of their chemical composition and biological activities. The polysaccharide portions were examined by methylation analysis, MALDI-TOF mass spectrometry, and (1)H NMR spectroscopy. A high molecular mass carbohydrate fraction obtained from Rt120 DPS by Sephadex G-50 gel chro ... | 2011 | 21999546 |
| Characterization of the galacturonosyl transferase genes rgtA, B, C, D, and E responsible for lipopolysaccharide synthesis in the nitrogen-fixing endosymbiont Rhizobium leguminosarum: Lipopolysaccharide core and lipid A galacturonosyl residues confer membrane stability. | Rhizobium lipopolysaccharide (LPS) contains four terminally linked galacturonic acid (GalA) residues: one attached to the lipid A and three attached to the core oligosaccharide moiety. Attachment of the GalA residues requires the lipid donor dodecaprenyl-phosphate GalA (Dod-P-GalA) which is synthesized by the GalA transferase (GalAT) RgtE reported here. The galacturonosyl transferases (GalATs) RgtA, B, and C utilize Dod-P-GalA to attach GalAs on the LPS core region and RgtD attaches GalA to the ... | 2011 | 22110131 |
| strigolactone biosynthesis in medicago truncatula and rice requires the symbiotic gras-type transcription factors nsp1 and nsp2. | legume gras (gai, rga, scr)-type transcription factors nodulation signaling pathway1 (nsp1) and nsp2 are essential for rhizobium nod factor-induced nodulation. both proteins are considered to be nod factor response factors regulating gene expression after symbiotic signaling. however, legume nsp1 and nsp2 can be functionally replaced by nonlegume orthologs, including rice (oryza sativa) nsp1 and nsp2, indicating that both proteins are functionally conserved in higher plants. here, we show that n ... | 2011 | 22039214 |
| effect of genomic rearrangement on heavy metal tolerance in the plant-growth-promoting rhizobacterium azospirillum brasilense sp245. | a derivative of azospirillum brasilense sp245, sp245.5, which spontaneously lost 85 and 120 mda replicons upon the formation of a new megaplasmid, has been shown to produce a novel lipopolysaccharide and to lose calcofluor-binding polysaccharides. as compared to sp245, the derivative displays notably increased heavy metal tolerance. the phenotypes of sp245 and sp245.5 are characterized by the following minimal inhibitory concentrations (mics) of heavy metals: 0.5 and 0.9 μmol l(-1) of ag(+), 0.4 ... | 2011 | 22130692 |
| Genome sequence of the diazotrophic Gram-positive rhizobacterium Paenibacillus riograndensis SBR5(T). | Paenibacillus riograndensis SBR5(T), a nitrogen-fixing Gram-positive rhizobacterium isolated from a wheat field in the south of Brazil, has a great potential for agricultural applications due to its plant growth promotion effects. Here we present the draft genome sequence of P. riograndensis SBR5(T). Its 7.37-Mb genome encodes determinants of the diazotrophic lifestyle and plant growth promotion, such as nitrogen fixation, antibiotic resistance, nitrate utilization, and iron uptake. | 2011 | 22038959 |
| change in land use alters the diversity and composition of bradyrhizobium communities and led to the introduction of rhizobium etli into the tropical rain forest of los tuxtlas (mexico). | nitrogen-fixing bacteria of the bradyrhizobium genus are major symbionts of legume plants in american tropical forests, but little is known about the effects of deforestation and change in land use on their diversity and community structure. forest clearing is followed by cropping of bean (phaseolus vulgaris) and maize as intercropped plants in los tuxtlas tropical forest of mexico. the identity of bean-nodulating rhizobia in this area is not known. using promiscuous trap plants, bradyrhizobia w ... | 2011 | 22109095 |
| Rhizobium helanshanense sp. nov., a bacterium that nodulates Sphaerophysa salsula (Pall.) DC. in China. | Studying rhizobia in the root nodules of Sphaerophysa salsula (Pall.) DC in the northwest of China, we obtained five strains classified as genus Rhizobium on the basis of their 16S rRNA gene sequences. The sequence similarity of strain CCNWQTX14(T) with the most related species was 99.0%. Further phylogenetic analysis of housekeeping genes (recA and atpD) suggested the five strains comprised a novel lineage within Rhizobium. The nifH and nodD gene sequences of CCNWQTX14(T) were phylogenetically ... | 2011 | 22065311 |
| Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs? | ABSTRACT: Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortia, refining our previous observations of aerobic degradation. ... | 2011 | 22196374 |
| isolation and functional gene analyses of aromatic-hydrocarbon-degrading bacteria from a polychlorinated-dioxin-dechlorinating process. | aerobic aromatic-hydrocarbon-degrading bacteria from a semi-anaerobic microbial microcosm that exhibited apparent complete dechlorination of polychlorinated dibenzo-p-dioxins/dibenzofurans (pcdd/fs) were isolated through enrichment and plating culture procedures with dibenzofuran as the model substrate. by 16s rrna gene sequence comparisons, these dibenzofuran-degrading isolates were identified as being members of the phyla actinobacteria, firmicutes, and proteobacteria, among which those of the ... | 2011 | 22146307 |
| novel insights into the biotin carboxylase domain reactions of pyruvate carboxylase from rhizobium etli. | the catalytic mechanism of the mgatp-dependent carboxylation of biotin in the biotin carboxylase domain of pyruvate carboxylase from r. etli (repc) is common to the biotin-dependent carboxylases. the current site-directed mutagenesis study has clarified the catalytic functions of several residues proposed to be pivotal in mgatp-binding and cleavage (glu218 and lys245), hco(3)(-) deprotonation (glu305 and arg301), and biotin enolization (arg353). the e218a mutant was inactive for any reaction inv ... | 2011 | 21957995 |
| A plant arabinogalactan-like glycoprotein promotes a novel type of polar surface attachment by Rhizobium leguminosarum. | Rhizobium leguminosarum biovar viciae can attach to the roots of legume and non-legume plants. We wanted to determine if root exudates could affect in vitro surface attachment in a confocal microscopy assay. Root exudate from peas, other legumes, wheat and Arabidopsis, induced R.l. viciae to attach end-on (in a polar manner) to glass in hexagonal close packed arrays, rather than attaching along their long axis. This did not involve a reorientation, but was probably due to altered growth. The pol ... | 2011 | 21995765 |
| Toxicological assessment of selective pesticides towards plant growth promoting activities of phosphate solubilizing Pseudomonas aeruginosa. | The study was designed to assess the effect of selected pesticides (metribuzin, glyphosate, imidacloprid, thiamethoxam, hexaconazole, metalaxyl and kitazin) at the recommended and higher rates on plant growth promoting activities of Pseudomonas aeruginosa strain PS1 isolated from mustard (Brassica compestris) rhizosphere. The strain PS1 was specifically chosen owing to its substantial tolerance against pesticides, phosphate solubilization and considerable production of indole acetic acid, sidero ... | 2011 | 21983319 |
| studies on the biodegradation of fosfomycin: synthesis of 13c-labeled intermediates, feeding experiments with rhizobium huakuii pmy1, and isolation of labeled amino acids from cell mass by hplc. | racemic (1r*,2r*)-1,2-dihydroxy-[1-(13)c(1)]propylphosphonic acid and 1-hydroxy-[1-(13)c(1)]acetone were synthesized and fed to r. huakuii pmy1. alanine and a mixture of valine and methionine were isolated as their n-acetyl derivatives from the cell hydrolysate by reversed-phase hplc and analyzed by nmr spectroscopy. it was found that the carbon atoms of the respective carboxyl groups were highly (13)c-labeled (up to 65 %). hydroxyacetone is therefore considered an obligatory intermediate of the ... | 2011 | 22012897 |
| genetic diversity of mimosa pudica rhizobial symbionts in soils of french guiana: investigating the origin and diversity of burkholderia phymatum and other beta-rhizobia. | the genetic diversity of 221 mimosa pudica bacterial symbionts trapped from eight soils from diverse environments in french guiana was assessed by 16s rrna pcr-rflp, rep-pcr fingerprints, as well as by phylogenies of their 16s rrna and reca housekeeping genes, and by their nifh, noda and nodc symbiotic genes. interestingly, we found a large diversity of beta-rhizobia, with burkholderia phymatum and burkholderia tuberum being the most frequent and diverse symbiotic species. other species were als ... | 2011 | 22093060 |
| strigolactones promote nodulation in pea. | strigolactones are recently defined plant hormones with roles in mycorrhizal symbiosis and shoot and root architecture. their potential role in controlling nodulation, the related symbiosis between legumes and rhizobium bacteria, was explored using the strigolactone-deficient rms1 mutant in pea (pisum sativum l.). this work indicates that endogenous strigolactones are positive regulators of nodulation in pea, required for optimal nodule number but not for nodule formation per se. rms1 mutant roo ... | 2011 | 21927948 |
| A New Family of Biuret Hydrolases Involved in S-Triazine Ring Metabolism. | Biuret is an intermediate in the bacterial metabolism of s-triazine ring compounds and is occasionally used as a ruminant feed supplement. We used bioinformatics to identify a biuret hydrolase, an enzyme that has previously resisted efforts to stabilize, purify and characterize. This newly discovered enzyme is a member of the cysteine hydrolase superfamily, a family of enzymes previously not found to be involved in s-triazine metabolism. The gene from Rhizobium leguminosarum bv. viciae strain 38 ... | 2011 | 21897878 |
| catenulispora graminis sp. nov., rhizobacterium from bamboo (phyllostachys nigro var. henonis) rhizosphere soil. | a novel actinobacteria, designated strain br-34(t), was isolated from rhizosphere soil of bamboo (phyllostachys nigro var. henonis) was sampled in damyang, korea. the strain was found to have morphological and chemotaxonomic characteristics typical of the genus catenulispora. the strain contained iso-c(16:0) as major fatty acids and mk-9 (h(4)), mk-9 (h(6)) and mk-9 (h(8)) as the major isoprenoid quinone. phylogenetic analysis of the 16s rrna gene sequence of strain br-34(t) was compared with th ... | 2011 | 22199217 |
| [Features of the expression of a meristem-specific WOX5 gene during nodule organogenesis in legumes]. | In recent years, the role of WOX genes encoding homeodomain transcription factors in the development of the apical meristem of shoots and roots has been actively investigated. However, the role of WOX genes in the control of the cell proliferation in other meristem types is poorly studied. In our work, we have studied the role of the WOX5 gene in the development of the meristem in nitrogen-fixing nodules developing on the roots of legumes in a symbiosis with rhizobia. We have shown that the WOX5 ... | 2011 | 21950052 |
| Functional characterization of the quorum sensing regulator RsaL in the plant-beneficial strain Pseudomonas putida WCS358. | In many bacteria quorum sensing systems rely on a signal receptor and a synthase producing N-acyl-homoserine lactone(s) as signal molecule(s). In some species, the rsaL gene, located between the signal receptor and synthase genes, encodes for a repressor limiting signal synthase expression and hence signal molecule production.Here we investigate the molecular mechanism of action of the RsaL protein (RsaL(WCS)) in the plant growth-promoting rhizobacterium Pseudomonas putida WCS358.In P. putida WC ... | 2011 | 22113916 |
| nitrogen fixation and nitrogen fertilization of soybeans. | abstract in pot experiments with (15)n labelled soil and mineral (15)n, the influence of bradyrhizobium (rhizobium japonicum) inoculation and n fertilization on the symbiotic n(2) fixation and yield of soybeans [glycine max (l.) merill., cv. 'fiskeby v'] was investigated. symbiotic n(2) fixation only occured after inoculation with bradyrhizobium. considerable differences in efficiency of the bacterial preparations were observed. shortly after flowering, the symbiotic nitrogen fixation was fini ... | 1996 | 22088108 |
| Agrobacterium-mediated virus-induced gene silencing assay in cotton. | Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties. The large-scale gene functional analysis in cotton has been lagged behind most of the modern plant species, likely due to its large size of genome, gene duplication and polyploidy, long growth cycle and recalcitrance to genetic transformation(1). To facilitate high throughput functional genetic/genomic study in cotton, we attempt to develop rapid a ... | 2011 | 21876527 |
| microbial sucrose isomerases: producing organisms, genes and enzymes. | sucrose isomerase (si) activity is used industrially for the conversion of sucrose into isomers, particularly isomaltulose or trehalulose, which have properties advantageous over sucrose for some food uses. all of the known microbial sis are tim barrel proteins that convert sucrose without need for any cofactors, with varying kinetics and product specificities. the current analysis was undertaken to bridge key gaps between the information in patents and scientific publications about the microbes ... | 2012 | 22133441 |
| Symbiotic effectiveness of rhizobial mutualists varies in interactions with native Australian legume genera. | Interactions between plants and beneficial soil organisms (e.g. rhizobial bacteria, mycorrhizal fungi) are models for investigating the ecological impacts of such associations in plant communities, and the evolution and maintenance of variation in mutualisms (e.g. host specificity and the level of benefits provided). With relatively few exceptions, variation in symbiotic effectiveness across wild host species is largely unexplored. | 2011 | 21887270 |
| Interplay of flg22-induced defence responses and nodulation in Lotus japonicus. | In this study the interplay between the symbiotic and defence signalling pathways in Lotus japonicus was investigated by comparing the responses to Mesorhizobium loti, the symbiotic partner of L. japonicus, and the elicitor flg22, a conserved peptide motif present in flagellar protein of a wide range of bacteria. It was found that defence and symbiotic pathways overlap in the interaction between L. japonicus and M. loti since similar responses were induced by the mutualistic bacteria and flg22. ... | 2012 | 21934117 |
| Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense. | Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utili ... | 2012 | 22092983 |
| modulation of host immunity by beneficial microbes. | in nature, plants abundantly form beneficial associations with soilborne microbes that are important for plant survival and, as such, affect plant biodiversity and ecosystem functioning. classical examples of symbiotic microbes are mycorrhizal fungi that aid in the uptake of water and minerals, and rhizobium bacteria that fix atmospheric nitrogen for the plant. several other types of beneficial soilborne microbes, such as plant-growth-promoting rhizobacteria and fungi with biological control act ... | 2011 | 21995763 |
| contribution of nfp lysm domains to the recognition of nod factors during the medicago truncatula/sinorhizobium meliloti symbiosis. | the root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. the establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called nod factors (nfs), produced by the rhizobia. this recognition is highly specific, as precise nf structures are required depending on the host plant. here, we study the imp ... | 2011 | 22087221 |
| environmental microbiota represents a natural reservoir for dissemination of clinically relevant metallo-beta-lactamases. | a total of 10 metallo-β-lactamase-producing isolates of six different species, including brevundimonas diminuta (n = 3), rhizobium radiobacter (n = 2), pseudomonas monteilii (n = 1), pseudomonas aeruginosa (n = 2), ochrobactrum anthropi (n = 1), and enterobacter ludwigii (n = 1), were detected in the sewage water of a hospital. the presence of bla(vim-13) associated with a tn1721-class 1 integron structure was detected in all but one of the isolates (e. ludwigii, which produced vim-2), and in tw ... | 2011 | 21859934 |
| early signaling in actinorhizal symbioses. | nitrogen-fixing root nodulation, confined to four plant orders, encompasses more than 14,000 leguminosae species, and approximately 200 actinorhizal species forming symbioses with rhizobia (rhizobium, bradyrhizobium, etc) and frankia bacterial species, respectively. while several genetic components of the host-symbiont interaction have been identified in legumes, little is known about the genetic bases of actinorhizal symbiosis. however, we recently demonstrated the existence of common symbiotic ... | 2011 | 21847030 |
| rhizobium radiobacter bacteremia in a neonate. | rhizobium radiobacter bacteremia is an infrequent cause of human infection. we report a rare manifestation of r. radiobacter infection in which bacteremia occurred in a newborn infant without other risk factors. | 2011 | 22038113 |
| natural variation in host-specific nodulation of pea is associated with a haplotype of the sym37 lysm-type receptor-like kinase. | rhizobium leguminosarum bv. viciae, which nodulates pea and vetch, makes a mixture of secreted nodulation signals (nod factors) carrying either a c18:4 or a c18:1 n-linked acyl chain. mutation of node blocks the formation of the c18:4 acyl chain, and node mutants, which produce only c18:1-containing nod factors, are less efficient at nodulating pea. however, there is significant natural variation in the levels of nodulation of different pea cultivars by a node mutant of r. leguminosarum bv. vici ... | 2011 | 21995800 |
| Identification and Characterization of the Rhizobium sp. Strain GIN611 Glycoside Oxidoreductase Resulting in the Deglycosylation of Ginsenosides. | Using enrichment culture, Rhizobium sp. strain GIN611 was isolated as having activity for deglycosylation of a ginsenoside, compound K (CK). The purified heterodimeric protein complex from Rhizobium sp. GIN611 consisted of two subunits with molecular masses of 63.5 kDa and 17.5 kDa. In the genome, the coding sequence for the small subunit was located right after the sequence for the large subunit, with one nucleotide overlapping. The large subunit showed CK oxidation activity, and the deglycosyl ... | 2012 | 22020506 |
| evolutionary origin of rhizobium nod factor signaling. | for over two decades now, it is known that the nodule symbiosis between legume plants and nitrogen fixing rhizobium bacteria is set in motion by the bacterial signal molecule named nodulation (nod) factor. ( 1) upon nod factor perception a signaling cascade is activated that is also essential for endomycorrhizal symbiosis (fig. 1). this suggests that rhizobium co-opted the evolutionary far more ancient mycorrhizal signaling pathway in order to establish an endosymbiotic interaction with legumes ... | 2011 | 21904113 |
| how good is the turbid medium-based approach for accounting for light partitioning in contrasted grass--legume intercropping systems? | most studies dealing with light partitioning in intercropping systems have used statistical models based on the turbid medium approach, thus assuming homogeneous canopies. however, these models could not be directly validated although spatial heterogeneities could arise in such canopies. the aim of the present study was to assess the ability of the turbid medium approach to accurately estimate light partitioning within grass-legume mixed canopies. | 2011 | 21865218 |
| mutualism and adaptive divergence: co-invasion of a heterogeneous grassland by an exotic legume-rhizobium symbiosis. | species interactions play a critical role in biological invasions. for example, exotic plant and microbe mutualists can facilitate each other's spread as they co-invade novel ranges. environmental context may influence the effect of mutualisms on invasions in heterogeneous environments, however these effects are poorly understood. we examined the mutualism between the legume, medicago polymorpha, and the rhizobium, ensifer medicae, which have both invaded california grasslands. many of these inv ... | 2011 | 22174755 |
| effect of applying an arsenic-resistant and plant growth-promoting rhizobacterium to enhance soil arsenic phytoremediation by populus deltoides lh05-17. | bioremediation of highly arsenic (as)-contaminated soil is difficult because as is very toxic for plants and micro-organisms. the aim of this study was to investigate soil arsenic removal effects using poplar in combination with the inoculation of a plant growth-promoting rhizobacterium (pgpr). | 2011 | 21895895 |
| [polymorphism of lectin genes in lathyrus plants]. | the carbohydrate-binding sequences of the lectin genes from spring vetchling lathyrus vernus (l.) bernh., marsh vetchling l. palustris (l.), and gmelin's vetchling l. gmelinii (fitsch) (fabaceae) were determined. computer-aided analysis revealed substantial differences between nucleotide and predicted amino acid sequences of the lectin gene regions examined in each of the three vetchling species tested. in the phylogenetic trees based on sequence similarity of carbohydrate-biding regions of legu ... | 2011 | 21938955 |
| glutamine synthetase is a molecular target of nitric oxide in root nodules of medicago truncatula and is regulated by tyrosine nitration. | nitric oxide (no) is emerging as an important regulatory player in the rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. to unravel the signal transduction cascade and ultimately no function, it is necessary to identify its molecular targets. this study provides evidence that glutamine synthetase (gs), a key enzyme for root nodule metabolism, is a molecular target of no in root nodules of medicago truncatula, being regulated by tyrosine ... | 2011 | 21914816 |
| Casuarina Root Exudates Alter the Physiology, Surface Properties, and Plant Infectivity of Frankia sp. Strain CcI3. | The actinomycete genus Frankia forms nitrogen-fixing symbioses with 8 different families of actinorhizal plants, representing more than 200 different species. Very little is known about the initial molecular interactions between Frankia and host plants in the rhizosphere. Root exudates are important in Rhizobium-legume symbiosis, especially for initiating Nod factor synthesis. We measured differences in Frankia physiology after exposure to host aqueous root exudates to assess their effects on ac ... | 2012 | 22101047 |
| rhizobium grahamii sp. nov. from dalea leporina, leucaena leucocephala, clitoria ternatea nodules, and rhizobium mesoamericanum sp. nov. from phaseolus vulgaris, siratro, cowpea and mimosa pudica nodules. | two novel related rhizobium species, rhizobium grahamii and rhizobium mesoamericanum were identified by a polyphasic approach using dna-dna hybridization, whole genome sequencing, phylogenetic and phenotypic characterization including nodulation of leucaena leucocephala and phaseolus vulgaris (bean). as similar bacteria were found in los tuxtlas rain forest and in central america we suggest the existence of a mesoamerican microbiological corridor. the type strain of rhizobium grahamii sp. nov. i ... | 2011 | 22081714 |
| characterization of rhizobia from legumes of agronomic interest grown in semi-arid areas of central spain relates genetic differences to soil properties. | a study of symbiotic bacteria from traditional agricultural legumes from central spain was performed to create a collection of rhizobia from soils differing in physicochemical, analytical and/or agroecological properties which could be well-adapted to the environmental conditions of this region, and be used for sustainable agricultural practices. thirty-six isolates were obtained from root-nodules of fifteen legume species (including cicer arietinum, lathyrus sativus, lens culinaris, lupinus spp ... | 2011 | 21953333 |
| systemically induced resistance and microbial competitive exclusion: implications on biological control. | the root-knot nematode, meloidogyne incognita, is among the most damaging agricultural pests, particularly to tomato. the mutualistic endophytes fusarium oxysporum strain fo162 (fo162) and rhizobium etli strain g12 (g12) have been shown to systemically induce resistance towards m. incognita. by using triple-split-root tomato plants, spatially-separated but simultaneous inoculation of both endophytes did not lead to additive reductions in m. incognita infection. more importantly, spatially-separa ... | 2011 | 21899390 |
| effects of glyphosate-resistant crop cultivation on soil and water quality. | transgenic glyphosate-resistant crops (grcs) have been commercialized and grown extensively in the western hemisphere and, to a lesser extent, elsewhere. grcs have generally become dominant in those countries where they have been approved for growing. potential effects of glyphosate on soil and water are minimal, compared the effects of the herbicides that are replaced when grcs are adopted. perhaps the most important indirect effect is that grcs crops promote the adoption of reduced- or no-till ... | 2010 | 21912208 |
| preference in the nodulation of phaseolus vulgaris cv. rab39. ii. effect of delayed inoculation or low cell representation in the inoculant on nodule occupancy by rhizobium tropici umr1899. | common bean (phaseolus vulgaris l.) is a traditional crop in much of latin america, where it is often planted into soils containing numerous, sometimes ineffective, indigenous rhizobia. the presence of these indigenous organisms can limit response to inoculation. because of this, we have sought bean cultivars that will nodulate preferentially with the inoculant strain, and have previously reported on the preference between the bean cultivar rab39 and strains of rhizobium tropici. we have detaile ... | 1996 | 22049998 |
| growth and cesium uptake responses of phytolacca americana linn. and amaranthus cruentus l. grown on cesium contaminated soil to elevated co2 or inoculation with a plant growth promoting rhizobacterium burkholderia sp. d54, or in combination. | growth and cesium uptake responses of plants to elevated co(2) and microbial inoculation, alone or in combination, can be explored for clean-up of contaminated soils, and this induced phytoextraction may be better than the natural process. the present study used open-top chambers to investigate combined effects of burkholderia sp. d54 inoculation and elevated co(2) (860 μl l(-1)) on growth and cs uptake by phytolacca americana and amaranthus cruentus grown on soil spiked with various levels of c ... | 2011 | 22074893 |
| the superoxide dismutase soda is targeted to the periplasm in a seca-dependent manner by a novel mechanism. | the manganese/iron-type superoxide dismutase (soda) of rhizobium leguminosarum bv. viciae 3841 is exported to the periplasm of r. l. bv. viciae and escherichia coli. however, it does not possess a hydrophobic cleaved n-terminal signal peptide typically present in soluble proteins exported by the sec-dependent (sec) pathway or the twin-arginine translocation (tat) pathway. a tatc mutant of r. l. bv. viciae exported soda to the periplasm, ruling out export of soda as a complex with a tat substrate ... | 2011 | 21854464 |
| rhizobium halophytocola sp. nov., a novel bacterium isolated from the root of a coastal dune plant. | during a study of endophytic bacteria from coastal dune plants, a bacterial strain, designated yc6881t, was isolated from the root of rosa rugosa collected from the coastal dune areas of namhae island. the bacterium was found to be gram-negative, motile, halophilic and heterotrophic with a polar single flagellum. strain yc6881t exhibited growth at temperature 4-37 °c (optimum at 28-32 °c), ph 6.0-9.0 (optimum at ph 7.0-8.0) and was able to grow at nacl concentrations in the range of 0-7.5 % (w/v ... | 2011 | 22021574 |
| effect of fungicides on plant growth promoting activities of phosphate solubilizing pseudomonasputida isolated from mustard (brassica compestris) rhizosphere. | this study was navigated to examine the effects of fungicide-stress on the activities of plant-growth-promoting rhizobacterium pseudomonasputida with inherent phosphate solubilizing activity. the fungicide-tolerant and phosphate solubilizing p.putida strain ps9 was isolated from the mustard rhizosphere and tentatively identified following standard morphological, physiological and biochemical tests. to further consolidate the identity of the strain ps9, the 16s rdna sequence analysis was performe ... | 2011 | 22133911 |
| escherichia coli bdca controls biofilm dispersal in pseudomonas aeruginosa and rhizobium meliloti. | abstract: | 2011 | 22029875 |
| interaction between the biotin carboxyl carrier domain and the biotin carboxylase domain in pyruvate carboxylase from rhizobium etli. | pyruvate carboxylase (pc) catalyzes the atp-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. to effect catalysis, the tethered biotin of pc must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. previous studies have demonstrated that a mutation of threonine 882 to alanine in pc from rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of biotin i ... | 2011 | 21958016 |
| galega orientalis is more diverse than galega officinalis in caucasus--whole-genome aflp analysis and phylogenetics of symbiosis-related genes. | legume plants can obtain combined nitrogen for their growth in an efficient way through symbiosis with specific bacteria. the symbiosis between rhizobium galegae and its host plant galega is an interesting case where the plant species g. orientalis and g. officinalis form effective, nitrogen-fixing, symbioses only with the appropriate rhizobial counterpart, r. galegae bv. orientalis and r. galegae bv. officinalis, respectively. the symbiotic properties of nitrogen-fixing rhizobia are well studie ... | 2011 | 21980996 |
| variations in exopolysaccharide production by rhizobium tropici. | rhizobium tropici, a legume-symbiont soil bacterium, is known for its copious production of exopolysaccharide (eps). many aspects of this organism's growth and eps production, however, remain uncharacterized, including the influence of environment and culturing conditions upon eps. here, we demonstrate that r. tropici eps chemical composition and yield differ when grown with different substrates in a defined minimal medium in batch culture. exopolysaccharide was quantified from r. tropici grown ... | 2011 | 21858649 |
| polyphasic approach for the characterization of rhizobial symbionts effective in fixing n(2) with common bean (phaseolus vulgaris l.). | common bean (phaseolus vulgaris l.) is a legume that has been reported as highly promiscuous in nodulating with a variety of rhizobial strains, often with low effectiveness in fixing nitrogen. the aim of this work was to assess the symbiotic efficiency of rhizobial strains isolated from common bean seeds, nodules of arachis hypogaea, mucuna pruriens, and soils from various brazilian agroecosystems, followed by the characterization of elite strains identified in the first screening. forty-five el ... | 2011 | 22159885 |
| Diversity of 16S rRNA genes from bacteria of sugarcane rhizosphere soil. | Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire ba ... | 2011 | 22042267 |
| locoweed dose responses to nitrogen: positive for biomass and primary physiology, but inconsistent for an alkaloid. | • premise of the study: plant communities may be influenced by toxic secondary metabolites or enhanced plant growth from plant-symbiont interactions. the c:n hypothesis predicts that carbon or nitrogen constrains plant secondary metabolite production, but it does not consider compounds produced by plant symbionts. locoweeds are legumes that can have fungal endophyte alkaloid (swainsonine [swa]) production, which causes livestock poisoning. we studied four locoweed taxa to test whether average sw ... | 2011 | 22130270 |
| Genomic lineages of Rhizobium etli revealed by the extent of nucleotide polymorphisms and low recombination. | Most of the DNA variations found in bacterial species are in the form of single nucleotide polymorphisms (SNPs), but there is some debate regarding how much of this variation comes from mutation versus recombination. The nitrogen-fixing symbiotic bacteria Rhizobium etli is highly variable in both genomic structure and gene content. However, no previous report has provided a detailed genomic analysis of this variation at nucleotide level or the role of recombination in generating diversity in thi ... | 2011 | 22004448 |
| Identification of a novel gene for biosynthesis of a bacteroid-specific electron carrier menaquinone. | Ubiquinone (UQ) has been considered as an electron mediator in electron transfer that generates ATP in Rhizobium under both free-living and symbiosis conditions. When mutated, the dmtH gene has a symbiotic phenotype of forming ineffective nodules on Astragalus sinicus. The gene was isolated from a Mesorhizobium huakuii 7653R transposon-inserted mutant library. The DNA sequence and conserved protein domain analyses revealed that dmtH encodes demethylmenaquinone (DMK) methyltransferase, which cata ... | 2011 | 22194970 |
| role for rhizobium rhizogenes k84 cell envelope polysaccharides in surface interactions. | rhizobium rhizogenes strain k84 is a commercial biocontrol agent used worldwide to control crown gall disease. the organism binds tightly to polypropylene substrate and efficiently colonizes root surfaces as complex, multilayered biofilms. a genetic screen identified two mutants in which these surface interactions were affected. one of these mutants failed to attach and form biofilms on the abiotic surface; although, interestingly, it exhibited normal biofilm formation on the biological root tip ... | 2011 | 22210213 |
| atomic force microscopy of a ctpa mutant in rhizobium leguminosarum reveals surface defects linking ctpa function to biofilm formation. | atomic force microscopy was used to investigate the surface ultrastructure, adhesive properties and biofilm formation of rhizobium leguminosarum and a ctpa mutant strain. the surface ultrastructure of wild-type r. leguminosarum consists of tightly packed surface subunits, whereas the ctpa mutant has much larger subunits with loose lateral packing. the ctpa mutant strain is not capable of developing fully mature biofilms, consistent with its altered surface ultrastructure, greater roughness and s ... | 2011 | 21852352 |
| nodulin 41, a novel late nodulin of common bean with peptidase activity. | the legume-rhizobium symbiosis requires the formation of root nodules, specialized organs where the nitrogen fixation process takes place. nodule development is accompanied by the induction of specific plant genes, referred to as nodulin genes. important roles in processes such as morphogenesis and metabolism have been assigned to nodulins during the legume-rhizobium symbiosis. | 2011 | 21985276 |
| glutathione is required by rhizobium etli for glutamine utilization and symbiotic effectiveness. | here we provide genetic and biochemical evidence indicating that the ability of rhizobium etli bacteria to efficiently catabolize glutamine depends on its ability to produce reduced glutathione (l-γ-glutamyl-l-cysteinylglycine, gsh). we find that gsh-deficient strains, namely a gshb (gsh synthetase) and a gor (gsh reductase) mutant, can use different amino acids including histidine, alanine and asparagine, but not glutamine, as sole source of carbon/energy and nitrogen. moreover, l-buthionine(s, ... | 2011 | 22007600 |
| [phenotypic and genotypic characterization of twelve rhizobial isolates from different regions of venezuela]. | rhizobial taxonomy and systematics have progressed substantially, nevertheless, few studies have been developed on venezuelan species. this study evaluated the phenotypic and genetic variation between 12 venezuelan indigenous rhizobial isolates and 10 international referential strains, by phenotypical traits and dna molecular markers. in this regard, a pcr-rflp of the 16s rdna gene, the presence of large plasmids, metabolic assays in solid media, salinity resistance, ph and temperature growth co ... | 2011 | 22017109 |
| Role of bioinoculants and organic fertilizers in fodder production and quality of leguminous tree species. | The comparative effect of dual inoculation of native N fixer (Rhizobium) and AM fungi consortia with different organic fertilizers (vermicompost and farm yard manure) on fodder production and quality of two leguminous tree species (Leucaena leucocephala (Lam) de. Wit. and Sesbania sesban (L.) Merr.) in silvopastoral system and their impact on the fodder production of un-inoculated Panicum maximum Jacq. under cut and carry system. After three years of plantation maximum tree survival was in L. le ... | 2011 | 21888233 |
| Roles of secreted peptides in intercellular communication and root development. | Intercellular signaling networks control cell identity and activity in all multicellular organisms. Secreted peptides that function as extracellular ligands play essential roles in local communication between adjacent plant cells. The extracellular domain of receptor kinases bind to secreted peptides and initiate downstream cellular responses, resulting in cell proliferation, growth, or differentiation in multicellular organisms. Root growth and development are highly organized processes involvi ... | 2012 | 22195583 |
| Biogeography of symbiotic and other endophytic bacteria isolated from medicinal Glycyrrhiza species in China. | A total of 159 endophytic bacteria were isolated from surface-sterilized root nodules of wild perennial Glycyrrhiza legumes growing on 40 sites in central and northwestern China. Amplified fragment length polymorphism (AFLP) genomic fingerprinting and sequencing of partial 16S rRNA genes revealed that the collection mainly consisted of Mesorhizobium, Rhizobium, Sinorhizobium, Agrobacterium and Paenibacillus species. Based on symbiotic properties with the legume hosts Glycyrrhiza uralensis and Gl ... | 2011 | 22066910 |
| Burkholderia phytofirmans strain PsJN primes Vitis vinifera L. and confers a better tolerance to low non-freezing temperatures. | Several endophytic bacteria reportedly induce resistance to biotic stress and abiotic stress tolerance in several plant species. Burkholderia phytofirmans strain PsJN (PsJN) is a plant growth-promoting rhizobacterium (PGPR) that is able to colonize grapevine tissues and induce resistance to gray mold. Further, PsJN induces physiological changes that increase grapevine tolerance to low non-freezing temperatures. To better understand how bacteria induced the observed phenomena, stress-related gene ... | 2011 | 21942451 |
| Mutation of the sensor kinase chvG in Rhizobium leguminosarum negatively impacts cellular metabolism, outer membrane stability, and symbiosis. | Two component signal transduction systems (TCS) are a main strategy used by bacteria to sense and adapt to changes in their environment. In the legume symbiont Rhizobium leguminosarum biovar viciae VF39, mutation of the histidine kinase, chvG, caused a number of pleiotropic phenotypes. ChvG mutants are unable to grow on proline, glutamate, histidine, or arginine as the sole carbon source. The chvG mutant secreted lower amounts of acidic and neutral surface polysaccharides, and accumulated abnorm ... | 2011 | 22155778 |
| Evaluation of the coal-degrading ability of Rhizobium and chelatococcus strains isolated from the formation water of an Indian coal bed. | The rise in global energy demand has prompted researches on developing strategies for transforming coal into a cleaner fuel. This requires isolation of microbes with the capability to degrade complex coal into simpler substrates to support methanogenesis in the coal beds. In this study, aerobic bacteria were isolated from an Indian coal bed that can solubilize and utilize coal as the sole source of carbon. The six bacterial isolates capable of growing on coal agar medium were identified on the b ... | 2011 | 22127119 |
| novel root nodule bacteria belonging to the genus caulobacter. | aim of this study is to determine the genetic variation of rhizobia associated with horse gram [macrotyloma uniflorum (lam.) verdc.] plants grown in different regions of andhra pradesh, india. | 2011 | 21919926 |
| Lotus japonicus nodulation is photomorphogenetically controlled by sensing the red/far red (R/FR) ratio through jasmonic acid (JA) signaling. | Light is critical for supplying carbon to the energetically expensive, nitrogen-fixing symbiosis between legumes and rhizobia. Here, we show that phytochrome B (phyB) is part of the monitoring system to detect suboptimal light conditions, which normally suppress Lotus japonicus nodule development after Mesorhizobium loti inoculation. We found that the number of nodules produced by L. japonicus phyB mutants is significantly reduced compared with the number produced of WT Miyakojima MG20. To explo ... | 2011 | 21930895 |
| nitric oxide in legume-rhizobium symbiosis. | nitric oxide (no) is a gaseous signaling molecule with a broad spectrum of regulatory functions in plant growth and development. no has been found to be involved in various pathogenic or symbiotic plant-microbe interactions. during the last decade, increasing evidence of the occurrence of no during legume-rhizobium symbioses has been reported, from early steps of plant-bacteria interaction, to the nitrogen-fixing step in mature nodules. this review focuses on recent advances on no production and ... | 2011 | 21893254 |
| microvirga lupini sp. nov., microvirga lotononidis sp. nov., and microvirga zambiensis sp. nov. are alphaproteobacterial root nodule bacteria that specifically nodulate and fix nitrogen with geographically and taxonomically separate legume hosts. | strains of gram-negative, rod-shaped, non-spore-forming bacteria were isolated from nitrogen-fixing nodules of the native legumes listia angolensis (from zambia) and lupinus texensis (from texas, usa). phylogenetic analysis of the 16s rrna gene showed that the novel strains belong to the genus microvirga, with 96.1 % or greater sequence similarity with type strains of this genus. the closest relative of the representative strains lut6t and wsm3557t was m. flocculans tfbt, with 97.6-98.0 % simila ... | 2011 | 22199210 |
| A phylogenetic strategy based on a legume-specific whole genome duplication yields symbiotic cytokinin type-a response regulators. | Legumes host their Rhizobium spp. symbiont in novel root organs called nodules. Nodules originate from differentiated root cortical cells that dedifferentiate and subsequently form nodule primordia, a process controlled by cytokinin. A whole-genome duplication has occurred at the root of the legume Papilionoideae subfamily. We hypothesize that gene pairs originating from this duplication event and are conserved in distinct Papilionoideae lineages have evolved symbiotic functions. A phylogenetic ... | 2011 | 22034625 |