Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| role of nodd gene product and flavonoid interactions in induction of nodulation genes in mesorhizobium ciceri. | mesorhizobium ciceri is a host specific bacterium which nodulates the genus, cicer. host specificity is regulated at first step by induction of nodulation (nod) genes in the presence of nodd protein and inducers (flavonoids) of plant origin. the inducer specificity of m. ciceri nodd gene was studied in nodd-mutant strain hn-9 carrying heterologous nodd genes and nodalacz fusion. the induction profile of nod promoter in m. ciceri revealed that nodd gene product of m. ciceri is specifically activa ... | 2010 | 23572956 |
| quantitative analysis of the naringenin-inducible proteome in rhizobium leguminosarum by isobaric tagging and mass spectrometry. | the rhizobium-legume interaction is a critical cornerstone of crop productivity and environmental sustainability. its potential improvement relies on elucidation of the complex molecular dialogue between its two partners. in the present study, the proteomic patterns of gnotobiotic cultures of rhizobium leguminosarum bv. viciae 3841 grown for 6 h in presence or absence of the nod gene-inducing plant flavonoid naringenin (10 μm) were analyzed using the itraq approach. a total of 1334 proteins were ... | 2013 | 23580418 |
| the calcium-stimulated lipid a 3-o deacylase from rhizobium etli is not essential for plant nodulation. | the lipid a component of lipopolysaccharide from the nitrogen-fixing plant endosymbiont, rhizobium etli, is structurally very different from that found in most enteric bacteria. the lipid a from free-living r. etli is structurally heterogeneous and exists as a mixture of species which are either pentaacylated or tetraacylated. in contrast, the lipid a from r. etli bacteroids is reported to consist exclusively of tetraacylated lipid a species. the tetraacylated lipid a species in both cases lack ... | 2013 | 23583844 |
| physiological changes in rhizobia after growth in peat extract may be related to improved desiccation tolerance. | improved survival of peat-cultured rhizobia compared to survival of liquid-cultured cells has been attributed to cellular adaptations during solid-state fermentation in moist peat. we have observed improved desiccation tolerance of rhizobium leguminosarum bv. trifolii ta1 and bradyrhizobium japonicum cb1809 after aerobic growth in water extracts of peat. survival of ta1 grown in crude peat extract was 18-fold greater than that of cells grown in a defined liquid medium but was diminished when cel ... | 2013 | 23603686 |
| oscpn60α1, encoding the plastid chaperonin 60α subunit, is essential for folding of rbcl. | chaperonins are involved in protein-folding. the rice genome encodes six plastid chaperonin subunits (cpn60) - three α and three β. our study showed that they were differentially expressed during normal plant development. moreover, five were induced by heat stress (42°c) but not by cold (10°c). the oscpn60α1 mutant had a pale-green phenotype at the seedling stage and development ceased after the fourth leaf appeared. transiently expressed oscpn60α1:gfp fusion protein was localized to the chlorop ... | 2013 | 23620301 |
| genome-wide transcriptional responses of two metal-tolerant symbiotic mesorhizobium isolates to zinc and cadmium exposure. | mesorhizobium metallidurans stm 2683t and mesorhizobium sp. strain stm 4661 were isolated from nodules of the metallicolous legume anthyllis vulneraria from distant mining spoils. they tolerate unusually high zinc and cadmium concentrations as compared to other mesorhizobia. this work aims to study the gene expression profiles associated with zinc or cadmium exposure and to identify genes involved in metal tolerance in these two metallicolous mesorhizobium strains of interest for mine phytostabi ... | 2013 | 23631387 |
| cyanuric acid hydrolase: evolutionary innovation by structural concatenation. | the cyanuric acid hydrolase, atzd, is the founding member of a newly identified family of ring-opening amidases. we report the first x-ray structure for this family, which is a novel fold (termed the 'toblerone' fold) that likely evolved via the concatenation of monomers of the trimeric yjgf superfamily and the acquisition of a metal binding site. structures of atzd with bound substrate (cyanuric acid) and inhibitors (phosphate, barbituric acid and melamine), along with mutagenesis studies, allo ... | 2013 | 23651355 |
| fast induction of biosynthetic polysaccharide genes lpxa, lpxe, and rkpi of rhizobium sp. strain prf 81 by common bean seed exudates is indicative of a key role in symbiosis. | rhizobial surface polysaccharides (sps) are, together with nodulation (nod) factors, recognized as key molecules for establishment of rhizobia-legume symbiosis. in rhizobium tropici, an important nitrogen-fixing symbiont of common bean (phaseolus vulgaris l.), molecular structures and symbiotic roles of the sps are poorly understood. in this study, rhizobium sp. strain prf 81 genes, belonging to the r. tropici group, were investigated: lpxa and lpxe, involved in biosynthesis and modification of ... | 2013 | 23652766 |
| malonate catabolism does not drive n2 fixation in legume nodules. | malonyl-coenzyme a (coa) decarboxylase, malonyl-coa synthetase, and malonate transporter mutants of rhizobium leguminosarum bv. viciae and trifolii fixed n2 at wild-type rates on pea and clover, respectively. thus, malonate does not drive n2 fixation in legume nodules. | 2013 | 23666330 |
| influence of elevated atmospheric carbon dioxide on transcriptional responses of bradyrhizobium japonicum in the soybean rhizoplane. | elevated atmospheric co2 can influence the structure and function of rhizoplane and rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizoplane and rhizosphere via root exudation. in these studies we investigated the transcriptional responses of bradyrhizobium japonicum cells growing in the rhizoplane of soybean plants exposed to elevated atmospheric co2. the results of microarray analyses indicated that elevated atmospheric co2 conce ... | 2013 | 23666536 |
| commonalities and differences among symbiosis islands of three mesorhizobium loti strains. | to shed light on the breadth of the host range of mesorhizobium loti strain nzp2037, we determined the sequence of the nzp2037 symbiosis island and compared it with those of strain maff303099 and r7a islands. the determined 533 kb sequence of nzp2037 symbiosis island, on which 504 genes were predicted, implied its integration into a phenylalanine-trna gene and subsequent genome rearrangement. comparative analysis revealed that the core regions of the three symbiosis islands consisted of 165 gene ... | 2013 | 23666538 |
| analysis of two polyhydroxyalkanoate synthases in bradyrhizobium japonicum usda 110. | bradyrhizobium japonicum usda 110 has five polyhydroxyalkanoate (pha) synthases (phac) annotated in its genome: bll4360 (phac1), bll6073 (phac2), blr3732 (phac3), blr2885 (phac4), and bll4548 (phac5). all these proteins possess the catalytic triad and conserved amino acid residues of polyester synthases and are distributed into four different phac classes. we obtained mutants in each of these paralogs and analyzed phac gene expression and pha production in liquid cultures. despite the genetic re ... | 2013 | 23667236 |
| the figs (focused identification of germplasm strategy) approach identifies traits related to drought adaptation in vicia faba genetic resources. | efficient methods to explore plant agro-biodiversity for climate change adaptive traits are urgently required. the focused identification of germplasm strategy (figs) is one such approach. figs works on the premise that germplasm is likely to reflect the selection pressures of the environment in which it developed. environmental parameters describing plant germplasm collection sites are used as selection criteria to improve the probability of uncovering useful variation. this study was designed ... | 2013 | 23667581 |
| evolution of and horizontal gene transfer in the endornavirus genus. | the transfer of genetic information between unrelated species is referred to as horizontal gene transfer. previous studies have demonstrated that both retroviral and non-retroviral sequences have been integrated into eukaryotic genomes. recently, we identified many non-retroviral sequences in plant genomes. in this study, we investigated the evolutionary origin and gene transfer of domains present in endornaviruses which are double-stranded rna viruses. using the available sequences for endornav ... | 2013 | 23667703 |
| malonate inhibits virulence gene expression in vibrio cholerae. | we previously found that inhibition of the tca cycle, either through mutations or chemical inhibition, increased toxt transcription in vibrio cholerae. in this study, we found that the addition of malonate, an inhibitor of succinate dehydrogenase (sdh), decreased toxt transcription in v. cholerae, an observation inconsistent with the previous pattern observed. unlike another sdh inhibitor, 2-thenoyltrifluoroacetone (ttfa), which increased toxt transcription and slightly inhibited v. cholerae gro ... | 2013 | 23675480 |
| temporal expression program of quorum sensing-based transcription regulation in sinorhizobium meliloti. | the sin quorum sensing (qs) system of s. meliloti activates exopolysaccharide and represses flagellum production. the system consists of an n-acyl-homoserine lactone (ahl) synthase, sini, and at least two luxr-type regulators, sinr and expr. sinr appears to be independent of ahls for its control of sini expression, while expr is almost completely dependent upon ahls. in this study, we confirmed 7 previously detected expr-dna binding sites and used the consensus sequence to identify another 26 si ... | 2013 | 23687265 |
| carbohydrate kinase (rhak)-dependent abc transport of rhamnose in rhizobium leguminosarum demonstrates genetic separation of kinase and transport activities. | in rhizobium leguminosarum the abc transporter responsible for rhamnose transport is dependent on rhak, a sugar kinase that is necessary for the catabolism of rhamnose. this has led to a working hypothesis that rhak has two biochemical functions: phosphorylation of its substrate and affecting the activity of the rhamnose abc transporter. to address this hypothesis, a linker-scanning random mutagenesis of rhak was carried out. thirty-nine linker-scanning mutations were generated and mapped. allel ... | 2013 | 23708135 |
| expression of the rhizobium leguminosarum bv. trifolii pssa gene, involved in exopolysaccharide synthesis, is regulated by rosr, phosphate, and the carbon source. | rhizobium leguminosarum bv. trifolii pssa encodes a glucosyl-isoprenylphosphate (ip)-transferase involved in the first step of exopolysaccharide (eps) synthesis. it was found that the pssa gene is an important target for regulation of this biosynthetic pathway. the data of this study indicate that pssa transcription is a very complex and mainly positively regulated process. a detailed analysis of a 767-bp-long pssa upstream region revealed the presence of several sequence motifs recognized by re ... | 2013 | 23708137 |
| engineering the acyltransferase substrate specificity of assembly line polyketide synthases. | polyketide natural products act as a broad range of therapeutics, including antibiotics, immunosuppressants and anti-cancer agents. this therapeutic diversity stems from the structural diversity of these small molecules, many of which are produced in an assembly line manner by modular polyketide synthases. the acyltransferase (at) domains of these megasynthases are responsible for selection and incorporation of simple monomeric building blocks, and are thus responsible for a large amount of the ... | 2013 | 23720536 |
| abc transport is inactivated by the pts(ntr) under potassium limitation in rhizobium leguminosarum 3841. | pts(ntr) is a regulatory phosphotransferase system in many bacteria. mutation of the pts(ntr) enzymes causes pleiotropic growth phenotypes, dry colony morphology and a posttranslational inactivation of abc transporters in rhizobium leguminosarum 3841. the pts(ntr) proteins ei(ntr) and 2 copies of eiia(ntr) have been described previously. here we identify the intermediate phosphocarrier protein npr and show its phosphorylation by ei(ntr) in vitro. furthermore we demonstrate that phosphorylation o ... | 2013 | 23724079 |
| the main aeromonas pathogenic factors. | the members of the aeromonas genus are ubiquitous, water-borne bacteria. they have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestin ... | 2012 | 23724321 |
| transformation of pwwo in rhizobium leguminosarum dpt to engineer toluene degrading ability for rhizoremediation. | rhizoremediation of organic xenobiotics is based on interactions between plants and their associated micro-organisms. the present work was designed to engineer a bacterial system having toluene degradation ability along with plant growth promoting characteristics for effective rhizoremediation. pwwo harboring the genes responsible for toluene breakdown was isolated from pseudomonas putida mtcc 979 and successfully transformed in rhizobium dpt. this resulted in a bacterial strain (dpt(t)) which h ... | 2011 | 23729882 |
| transformation of pwwo in rhizobium leguminosarum dpt to engineer toluene degrading ability for rhizoremediation. | rhizoremediation of organic xenobiotics is based on interactions between plants and their associated micro-organisms. the present work was designed to engineer a bacterial system having toluene degradation ability along with plant growth promoting characteristics for effective rhizoremediation. pwwo harboring the genes responsible for toluene breakdown was isolated from pseudomonas putida mtcc 979 and successfully transformed in rhizobium dpt. this resulted in a bacterial strain (dpt(t)) which h ... | 2011 | 23729882 |
| identification of a functional type vi secretion system in campylobacter jejuni conferring capsule polysaccharide sensitive cytotoxicity. | the pathogen campylobacter jejuni is the principal cause of bacterial food-borne infections. the mechanism(s) that contribute to bacterial survival and disease are still poorly understood. in other bacterial species, type vi secretion systems (t6ss) are increasingly recognized to contribute to bacterial pathogenesis by toxic effects on host cells or competing bacterial species. here we report the presence of a functional type vi secretion system in c. jejuni. proteome and genetic analyses reveal ... | 2013 | 23737749 |
| the sinorhizobium meliloti essential porin ropa1 is a target for numerous bacteriophages. | the symbiotic nitrogen-fixing bacterium sinorhizobium meliloti harbors a gene, smc02396, which encodes a predicted outer membrane porin that is conserved in many symbiotic and pathogenic bacteria in the order rhizobiales. here, this gene (renamed ropa1) is shown to be required for infection by two commonly utilized transducing bacteriophages (φm12 and n3). mapping of s. meliloti mutations conferring resistance to φm12, n3, or both phages simultaneously revealed diverse mutations mapping within t ... | 2013 | 23749981 |
| characterization and genus identification of rhizobial symbionts from caragana arborescens in western canada. | naturally occurring nitrogen-fixing symbionts from root nodules of caragana (caragana arborescens) growing in central saskatchewan were isolated following surface sterilization of caragana root nodules and squashing and spreading of the contents on yeast extract - mannitol medium. the symbiotic nature of the strains was confirmed following inoculation onto surface-sterilized c. arborescens seed in a gnotobiotic leonard jar system. the rhizobium isolates from c. arborescens root nodules were inte ... | 2013 | 23750954 |
| members of the sinorhizobium meliloti chvi regulon identified by a dna binding screen. | the sinorhizobium meliloti exos/chvi two component regulatory system is required for n2-fixing symbiosis and exopolysaccharide synthesis. orthologous systems are present in other alphaproteobacteria, and in many instances have been shown to be necessary for normal interactions with corresponding eukaryotic hosts. only a few transcriptional regulation targets have been determined, and as a result there is limited understanding of the mechanisms that are controlled by the system. | 2013 | 23758731 |
| the mycobacterium tuberculosis secreted protein rv0203 transfers heme to membrane proteins mmpl3 and mmpl11. | mycobacterium tuberculosis is the causative agent of tuberculosis, which is becoming an increasingly global public health problem due to the rise of drug-resistant strains. while residing in the human host, m. tuberculosis needs to acquire iron for its survival. m. tuberculosis has two iron uptake mechanisms, one that utilizes non-heme iron and another that taps into the vast host heme-iron pool. to date, proteins known to be involved in mycobacterial heme uptake are rv0203, mmpl3, and mmpl11. w ... | 2013 | 23760277 |
| light regulation of swarming motility in pseudomonas syringae integrates signaling pathways mediated by a bacteriophytochrome and a lov protein. | the biological and regulatory roles of photosensory proteins are poorly understood for nonphotosynthetic bacteria. the foliar bacterial pathogen pseudomonas syringae has three photosensory protein-encoding genes that are predicted to encode the blue-light-sensing lov (light, oxygen, or voltage) histidine kinase (lov-hk) and two red/far-red-light-sensing bacteriophytochromes, bphp1 and bphp2. we provide evidence that lov-hk and bphp1 form an integrated network that regulates swarming motility in ... | 2013 | 23760465 |
| novel rhizobium lineages isolated from root nodules of the common bean (phaseolus vulgaris l.) in andean and mesoamerican areas. | the taxonomic affiliations of nineteen root-nodule bacteria isolated from the common bean (phaseolus vulgaris l.) in mexico, ecuador and brazil were investigated by analyses of 16s rrna and of four protein-coding housekeeping genes. one strain from mexico could be assigned to rhizobium etli and two from brazil to rhizobium leucaenae, whereas another from mexico corresponded to a recently described bean-nodulating species-level lineage related to r. etli and rhizobium phaseoli. ten strains isolat ... | 2013 | 23764913 |
| isolation and characterization of mutant sinorhizobium meliloti nodd1 proteins with altered responses to luteolin. | nodd1, a member of the nodd family of lysr-type transcriptional regulators (lttrs), mediates nodulation (nod) gene expression in the soil bacterium sinorhizobium meliloti in response to the plant-secreted flavonoid luteolin. we used genetic screens and targeted approaches to identify nodd1 residues that show altered responses to luteolin during the activation of nod gene transcription. here we report four types of nodd1 mutants. type i (nodd1 l69f, s104l, d134n, and m193i mutants) displays reduc ... | 2013 | 23772067 |
| the thuefgkab operon of rhizobia and agrobacterium tumefaciens codes for transport of trehalose, maltitol, and isomers of sucrose and their assimilation through the formation of their 3-keto derivatives. | the thu operon (thuefgkab) in sinorhizobium meliloti codes for transport and utilization functions of the disaccharide trehalose. sequenced genomes of members of the rhizobiaceae reveal that some rhizobia and agrobacterium possess the entire thu operon in similar organizations and that mesorhizobium loti maff303099 lacks the transport (thuefgk) genes. in this study, we show that this operon is dedicated to the transport and assimilation of maltitol and isomers of sucrose (leucrose, palatinose, a ... | 2013 | 23772075 |
| comparative genomic analysis of six bacteria belonging to the genus novosphingobium: insights into marine adaptation, cell-cell signaling and bioremediation. | bacteria belonging to the genus novosphingobium are known to be metabolically versatile and occupy different ecological niches. in the absence of genomic data and/or analysis, knowledge of the bacteria that belong to this genus is currently limited to biochemical characteristics. in this study, we analyzed the whole genome sequencing data of six bacteria in the novosphingobium genus and provide evidence to show the presence of genes that are associated with salt tolerance, cell-cell signaling an ... | 2013 | 23809012 |
| characterization of pyruvate uptake in escherichia coli k-12. | the monocarboxylate pyruvate is an important metabolite and can serve as sole carbon source for escherichia coli. although specific pyruvate transporters have been identified in two bacterial species, pyruvate transport is not well understood in e. coli. in the present study, pyruvate transport was investigated under different growth conditions. the transport of pyruvate shows specific activities depending on the growth substrate used as sole carbon source, suggesting the existence of at least t ... | 2013 | 23818977 |
| quorum sensing: a nobel target for antibacterial agents. | 2012 | 23826557 | |
| salmonella utilizes d-glucosaminate via a mannose family phosphotransferase system permease and associated enzymes. | salmonella enterica is a globally significant bacterial food-borne pathogen that utilizes a variety of carbon sources. we report here that salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium) uses d-glucosaminate (2-amino-2-deoxy-d-gluconic acid) as a carbon and nitrogen source via a previously uncharacterized mannose family phosphotransferase system (pts) permease, and we designate the genes encoding the permease dgaabcd (d-glucosaminate pts permease components eiia, eiib, e ... | 2013 | 23836865 |
| are common symbiosis genes required for endophytic rice-rhizobial interactions? | legume plants are able to establish root nodule symbioses with nitrogen-fixing bacteria, called rhizobia. recent studies revealed that the root nodule symbiosis has co-opted the signaling pathway that mediates the ancestral mycorrhizal symbiosis that occurs in most land plants. despite being unable to induce nodulation, rhizobia have been shown to be able to infect and colonize the roots of non-legumes such as rice. one fascinating question is whether establishment of such associations requires ... | 2013 | 23838959 |
| luxr- and luxi-type quorum-sensing circuits are prevalent in members of the populus deltoides microbiome. | we are interested in the root microbiome of the fast-growing eastern cottonwood tree, populus deltoides. there is a large bank of bacterial isolates from p. deltoides, and there are 44 draft genomes of bacterial endophyte and rhizosphere isolates. as a first step in efforts to understand the roles of bacterial communication and plant-bacterial signaling in p. deltoides, we focused on the prevalence of acyl-homoserine lactone (ahl) quorum-sensing-signal production and reception in members of the ... | 2013 | 23851092 |
| putting bugs to the blush: metabolic engineering for phenylpropanoid-derived products in microorganisms. | phenylpropanoids and phenylpropanoid-derived phenolic compounds such as flavonoids, anthocyanins, or stilbenes are secondary plant metabolites which serve as pigments and scent compounds or provide protection against environmental stress. due to their antioxidant properties they also have been widely recognized for their benefit on human health. traditionally, such compounds are extracted from their natural plant sources, but this approach is limited by low abundance and environmental, seasonal ... | 2013 | 23851446 |
| homoserine catabolism by rhizobium leguminosarum bv. viciae 3841 requires a plasmid-borne gene cluster that also affects competitiveness for nodulation. | homoserine represents a substantial component of pea root exudate that may be important for plant-microbe interactions in the rhizosphere. we identified a gene cluster on plasmid prl8ji that is required for homoserine utilization by rhizobium leguminosarum bv. viciae. the genes are arranged as two divergently expressed predicted operons that were induced by l-homoserine, pea root exudate, and were expressed on pea roots. a mutation in gene prl80083 that prevented utilization of homoserine as a s ... | 2014 | 23859230 |
| plant growth promotion potential is equally represented in diverse grapevine root-associated bacterial communities from different biopedoclimatic environments. | plant-associated bacteria provide important services to host plants. environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. however, whether these environmental factors may influence the plant growth promoting (pgp) potential of the root-associated bacteria is not widely understood. to address this issue, the diversity and pgp potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three medit ... | 2013 | 23878810 |
| proteogenomic analysis of bradyrhizobium japonicum usda110 using genosuite, an automated multi-algorithmic pipeline. | we present genosuite, an integrated proteogenomic pipeline to validate, refine and discover protein coding genes using high-throughput mass spectrometry (ms) data from prokaryotes. to demonstrate the effectiveness of genosuite, we analyzed proteomics data of bradyrhizobium japonicum (usda110), a model organism to study agriculturally important rhizobium-legume symbiosis. our analysis confirmed 31% of known genes, refined 49 gene models for their translation initiation site (tis) and discovered 5 ... | 2013 | 23882027 |
| [influence of rhizobial (rhizobium leguminosarum) inoculation and calcium ions on the nadph oxidase activity in roots of etiolated pea (pisum sativum l.) seedlings]. | changes in the functional activity of the nadph oxidase in the microsomal fraction of roots of etiolated pea seedlings, caused by rhizobial inoculation and calcium ions (ca2+), are shown. the enzyme activity in a medium with an exogenous source of ca2+ (cacl2, 100 microm) fluctuated, increasing 5 to 20 min and decreasing 10 and 30 min after addition. a calcium chelator (ethylene glycol tetraacetic acid (edta), 100 microm) potentiated the decrease in the enzyme activity in the presence of exogeno ... | 2015 | 23882941 |
| culture-independent investigation of the microbiome associated with the nematode acrobeloides maximus. | symbioses between metazoans and microbes are widespread and vital to many ecosystems. recent work with several nematode species has suggested that strong associations with microbial symbionts may also be common among members of this phylu. in this work we explore possible symbiosis between bacteria and the free living soil bacteriovorous nematode acrobeloides maximus. | 2013 | 23894287 |
| disclosure of the differences of mesorhizobium loti under the free-living and symbiotic conditions by comparative proteome analysis without bacteroid isolation. | rhizobia are symbiotic nitrogen-fixing soil bacteria that show a symbiotic relationship with their host legume. rhizobia have 2 different physiological conditions: a free-living condition in soil, and a symbiotic nitrogen-fixing condition in the nodule. the lifestyle of rhizobia remains largely unknown, although genome and transcriptome analyses have been carried out. to clarify the lifestyle of bacteria, proteome analysis is necessary because the protein profile directly reflects in vivo reacti ... | 2013 | 23898917 |
| the role of bacterial biofilms and surface components in plant-bacterial associations. | the role of bacterial surface components in combination with bacterial functional signals in the process of biofilm formation has been increasingly studied in recent years. plants support a diverse array of bacteria on or in their roots, transport vessels, stems, and leaves. these plant-associated bacteria have important effects on plant health and productivity. biofilm formation on plants is associated with symbiotic and pathogenic responses, but how plants regulate such associations is unclear ... | 2013 | 23903045 |
| the role of gsts in the tolerance of rhizobium leguminosarum to cadmium. | a high intraspecific difference in cadmium (cd) tolerance exits among rhizobium leguminosarum strains. the higher tolerance to cd appeared to be related to the efficiency of the glutathione (gsh)-cd chelation mechanism, but it is not known how efficiency is influenced. thus, in this work it was intended to investigate the traits behind the efficiency of intracellular cd chelation by gsh. glutathione-s-transferases (gst; ec 2.5.1.18) are a family of multi-functional dimeric proteins, found in bot ... | 2013 | 23907727 |
| synergistic interaction of rhizobium leguminosarum bv. viciae and arbuscular mycorrhizal fungi as a plant growth promoting biofertilizers for faba bean (vicia faba l.) in alkaline soil. | egyptian soils are generally characterized by slightly alkaline to alkaline ph values (7.5-8.7) which are mainly due to its dry environment. in arid and semi-arid regions, salts are less concentrated and sodium dominates in carbonate and bicarbonate forms, which enhance the formation of alkaline soils. alkaline soils have fertility problems due to poor physical properties which adversely affect the growth and the yield of crops. therefore, this study was devoted to investigating the synergistic ... | 2014 | 23920230 |
| effects of nano-tio₂ on the agronomically-relevant rhizobium-legume symbiosis. | the impact of nano-tio₂ on rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner rhizobium leguminosarum bv. viciae 3841. exposure to nano-tio₂ did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. however, nano-tio₂ exposure did impact plant development by decreasing the number of secondary lateral roots. cultured r. leguminosarum bv. viciae 3841 was also impacted by exposure to nano-tio₂, resulting in morph ... | 2014 | 23933452 |
| functional and expression analysis of the metal-inducible dmerf system from rhizobium leguminosarum bv. viciae. | a gene encoding a homolog to the cation diffusion facilitator protein dmef from cupriavidus metallidurans has been identified in the genome of rhizobium leguminosarum upm791. the r. leguminosarum dmef gene is located downstream of an open reading frame (designated dmer) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator rcnr from escherichia coli. analysis of gene expression showed that the r. leguminosarum dmerf genes are organized as a transcriptional ... | 2013 | 23934501 |
| identification and characterization of ribn, a novel family of riboflavin transporters from rhizobium leguminosarum and other proteobacteria. | rhizobia are symbiotic bacteria able to invade and colonize the roots of legume plants, inducing the formation of nodules, where bacteria reduce atmospheric nitrogen (n2) to ammonia (nh3). riboflavin availability influences the capacity of rhizobia to survive in the rhizosphere and to colonize roots. in this study, we identified the rl1692 gene of rhizobium leguminosarum downstream of a flavin mononucleotide (fmn) riboswitch. rl1692 encodes a putative transmembrane permease with two eama domains ... | 2013 | 23935051 |
| construction of a new gfp vector and its use for fusaruim oxysporum transformation. | in this study, the gfp fragment as a reporter gene had integrated into the form plasmid vector pbc-hygro which contains an expressive promoter of the fungus to facilitate the transformation of fusarium oxysporum. the resultant plasmid pbc-hygro-gfp was identified by digestion with enzymes. binary plasmids pbc-hygro-gfp were transformed into f. oxysporum by using the peg-cacl2 mediated transformation technique. results show that the recombinant plasmid pbc-hygro-gfp was constructed correctly. the ... | 2012 | 23961215 |
| construction of a new gfp vector and its use for fusaruim oxysporum transformation. | in this study, the gfp fragment as a reporter gene had integrated into the form plasmid vector pbc-hygro which contains an expressive promoter of the fungus to facilitate the transformation of fusarium oxysporum. the resultant plasmid pbc-hygro-gfp was identified by digestion with enzymes. binary plasmids pbc-hygro-gfp were transformed into f. oxysporum by using the peg-cacl2 mediated transformation technique. results show that the recombinant plasmid pbc-hygro-gfp was constructed correctly. the ... | 2012 | 23961215 |
| microbial diversity of vermicompost bacteria that exhibit useful agricultural traits and waste management potential. | vermicomposting is a non-thermophilic, boioxidative process that involves earthworms and associated microbes. this biological organic waste decomposition process yields the biofertilizer namely the vermicompost. vermicompost is a finely divided, peat like material with high porosity, good aeration, drainage, water holding capacity, microbial activity, excellent nutrient status and buffering capacity thereby resulting the required physiochemical characters congenial for soil fertility and plant g ... | 2012 | 23961356 |
| anion translocation through an slc26 transporter mediates lumen expansion during tubulogenesis. | lumen formation is a critical event in biological tube formation, yet its molecular mechanisms remain poorly understood. specifically, how lumen expansion is coordinated with other processes of tubulogenesis is not well known, and the role of membrane transporters in tubulogenesis during development has not been adequately addressed. here we identify a solute carrier 26 (slc26) family protein as an essential regulator of tubulogenesis using the notochord of the invertebrate chordate ciona intest ... | 2013 | 23980138 |
| two pfam protein families characterized by a crystal structure of protein lpg2210 from legionella pneumophila. | every genome contains a large number of uncharacterized proteins that may encode entirely novel biological systems. many of these uncharacterized proteins fall into related sequence families. by applying sequence and structural analysis we hope to provide insight into novel biology. | 2013 | 24004689 |
| host-specific nod-factors associated with medicago truncatula nodule infection differentially induce calcium influx and calcium spiking in root hairs. | rhizobial nodulation (nod) factors activate both nodule morphogenesis and infection thread development during legume nodulation. nod factors induce two different calcium responses: intra-nuclear calcium oscillations and a calcium influx at the root hair tip. calcium oscillations activate nodule development; we wanted to test if the calcium influx is associated with infection. sinorhizobium meliloti nodl and nodf mutations additively reduce infection of medicago truncatula. nod-factors made by th ... | 2013 | 24015832 |
| genome of the r-body producing marine alphaproteobacterium labrenzia alexandrii type strain (dfl-11(t)). | labrenzia alexandrii biebl et al. 2007 is a marine member of the family rhodobacteraceae in the order rhodobacterales, which has thus far only partially been characterized at the genome level. the bacterium is of interest because it lives in close association with the toxic dinoflagellate alexandrium lusitanicum. ultrastructural analysis reveals r-bodies within the bacterial cells, which are primarily known from obligate endosymbionts that trigger "killing traits" in ciliates (paramecium spp.). ... | 2013 | 24019989 |
| genetic diversity of indigenous common bean (phaseolus vulgaris l.) rhizobia from the state of minas gerais, brazil. | we characterized indigenous common bean rhizobia from five districts of the state of minas gerais, brazil. the isolates were trapped by two common bean varieties, the mineiro precoce (andean origin) and ouro negro (mesoamerican origin). analysis by box-pcr of selected isolates detected a high level of genetic diversity. | 2009 | 24031433 |
| comparative study of wild and transformed salt tolerant bacterial strains on triticum aestivum growth under salt stress. | eleven salt tolerant bacteria isolated from different sources (soil, plants) and their transformed strains were used to study their influence on triticum aestivum var. inqlab-91 growth under salt (100 mm nacl) stress. salt stress caused reduction in germination (19.4%), seedling growth (46%) and fresh weight (39%) in non-inoculated plants. in general, both wild and transformed strains stimulated germination, seedling growth and fresh weight in salt free and salt stressed conditions. at 100 mm na ... | 2010 | 24031574 |
| structural interaction between gfp-labeled diazotrophic endophytic bacterium herbaspirillum seropedicae ram10 and pineapple plantlets 'vitória'. | the events involved in the structural interaction between the diazotrophic endophytic bacterium herbaspirillum seropedicae, strain ram10, labeled with green fluorescent protein, and pineapple plantlets 'vitória' were evaluated by means of bright-field and fluorescence microscopy, combined with scanning electron microscopy for 28 days after inoculation. after 6 hours of inoculation, h. seropedicae was already adhered to the roots, colonizing mainly root hair surface and bases, followed by epiderm ... | 2011 | 24031612 |
| identification and characterization of the endophytic plant growth prompter bacillus cereus strain mq23 isolated from sophora alopecuroides root nodules. | endophytes mq23 and mq23r isolated from sophora alopecuroides root nodules were characterized by observing their ability to promote plant growth and employing molecular analysis techniques. results showed that mq23 and mq23r are potential n2-fixing endophytes and belong to the same species as bacillus cereus. mq23 was shown to be able to produce siderophores, iaa, and demonstrate certain antifungal activity to plant pathogenic fungi. co-inoculation with mq23+mq23ii showed a more significant effe ... | 2011 | 24031669 |
| characterization of free nitrogen fixing bacteria of the genus azotobacter in organic vegetable-grown colombian soils. | with the purpose of isolating and characterizing free nitrogen fixing bacteria (fnfb) of the genus azotobacter, soil samples were collected randomly from different vegetable organic cultures with neutral ph in different zones of boyacá-colombia. isolations were done in selective free nitrogen ashby-sucrose agar obtaining a recovery of 40%. twenty four isolates were evaluated for colony and cellular morphology, pigment production and metabolic activities. molecular characterization was carried ou ... | 2011 | 24031700 |
| genetic diversity of rhizobia isolates from amazon soils using cowpea (vigna unguiculata) as trap plant. | the aim of this work was to characterize rhizobia isolated from the root nodules of cowpea (vigna unguiculata) plants cultivated in amazon soils samples by means of ardra (amplified rdna restriction analysis) and sequencing analysis, to know their phylogenetic relationships. the 16s rrna gene of rhizobia was amplified by pcr (polymerase chain reaction) using universal primers y1 and y3. the amplification products were analyzed by the restriction enzymes hinfi, mspi and ddei and also sequenced wi ... | 2012 | 24031880 |
| expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of glomus intraradices. | to explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus glomus, we transcriptionally analysed spores of glomus intraradices be3 during early hyphal growth. among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacter ... | 2012 | 24031884 |
| rhizobium leguminosarum is the symbiont of lentils in the middle east and europe but not in bangladesh. | lentil is the oldest of the crops that have been domesticated in the fertile crescent and spread to other regions during the bronze age, making it an ideal model to study the evolution of rhizobia associated with crop legumes. housekeeping and nodulation genes of lentil-nodulating rhizobia from the region where lentil originated (turkey and syria) and regions to which lentil was introduced later (germany and bangladesh) were analyzed to determine their genetic diversity, population structure, an ... | 2014 | 24033582 |
| unusual spectral properties of bacteriophytochrome agp2 result from a deprotonation of the chromophore in the red-absorbing form pr. | phytochromes are widely distributed photoreceptors with a bilin chromophore that undergo a typical reversible photoconversion between the two spectrally different forms, pr and pfr. the phytochrome agp2 from agrobacterium tumefaciens belongs to the group of bathy phytochromes that have a pfr ground state as a result of the pr to pfr dark conversion. agp2 has untypical spectral properties in the pr form reminiscent of a deprotonated chromophore as confirmed by resonance raman spectroscopy. uv/vis ... | 2013 | 24036118 |
| celr, an ortholog of the diguanylate cyclase pled of caulobacter, regulates cellulose synthesis in agrobacterium tumefaciens. | cellulose fibrils play a role in attachment of agrobacterium tumefaciens to its plant host. while the genes for cellulose biosynthesis in the bacterium have been identified, little is known concerning the regulation of the process. the signal molecule cyclic di-gmp (c-di-gmp) has been linked to the regulation of exopolysaccharide biosynthesis in many bacterial species, including a. tumefaciens. in this study, we identified two putative diguanylate cyclase genes, celr (atu1297) and atu1060, that ... | 2013 | 24038703 |
| expanding the cyanuric acid hydrolase protein family to the fungal kingdom. | the known enzymes that open the s-triazine ring, the cyanuric acid hydrolases, have been confined almost exclusively to the kingdom bacteria and are all homologous members of the rare cyanuric acid hydrolase/barbiturase protein family. in the present study, a filamentous fungus, sarocladium sp. strain ca, was isolated from soil by enrichment culturing using cyanuric acid as the sole source of nitrogen. a reverse-genetic approach identified a fungal cyanuric acid hydrolase gene composed of two ex ... | 2013 | 24039269 |
| biochemical determination of enzyme-bound metabolites: preferential accumulation of a programmed octaketide on the enediyne polyketide synthase cale8. | despite considerable interest in the enediyne family of antitumor antibiotics, assembly of their polyketide core structures in nature remains poorly understood. discriminating methods to access enzyme-bound intermediates are critical for elucidating unresolved polyketide and nonribosomal peptide biosynthetic pathways. here, we describe the development of broadly applicable techniques for the mild chemical release and analysis of intermediates bound to carrier proteins (cps), providing access to ... | 2013 | 24041368 |
| calcium-dependent regulation of genes for plant nodulation in rhizobium leguminosarum detected by itraq quantitative proteomic analysis. | rhizobia, the nitrogen-fixing bacterial symbionts of legumes, represent an agricultural application of primary relevance and a model of plant-microbe molecular dialogues. we recently described rhizobium proteome alterations induced by plant flavonoids using itraq. herein, we further extend that experimentation, proving that the transient elevation in cytosolic calcium is a key signaling event necessary for the expression of the nodulation (nod) genes. ca(2+) involvement in nodulation is a novel ... | 2013 | 24041410 |
| near-full length sequencing of 16s rdna and rflp indicates that rhizobium etli is the dominant species nodulating egyptian winter berseem clover (trifolium alexandrinum l.). | egyptian winter berseem clover (ewbc) is one of the main important forage legume crops in egypt that is used for animal feeding in winter and it occupies about 2.5 million feddans (feddan=4200m(2)) in winter agricultural rotation systems. forty-eight rhizobial isolates that nodulated this legume host from different geographical regions within egypt were isolated. rflp analyses of 16s rdna (1.5kb) and whole ribosomal dna (5kb), the sequencing of 16s rdna, and the sequencing of nodc, nifh and hous ... | 2014 | 24054695 |
| characterization and molecular mechanism of arop as an aromatic amino acid and histidine transporter in corynebacterium glutamicum. | corynebacterium glutamicum is equipped with abundant membrane transporters to adapt to a changing environment. many amino acid transporters have been identified in c. glutamicum, but histidine uptake has not been investigated in detail. here, we identified the aromatic amino acid transporter encoded by arop as a histidine transporter in c. glutamicum by a combination of the growth and histidine uptake features. characterization of histidine uptake showed that arop has a moderate affinity for his ... | 2013 | 24056108 |
| microbial expression profiles in the rhizosphere of willows depend on soil contamination. | the goal of phytoremediation is to use plants to immobilize, extract or degrade organic and inorganic pollutants. in the case of organic contaminants, plants essentially act indirectly through the stimulation of rhizosphere microorganisms. a detailed understanding of the effect plants have on the activities of rhizosphere microorganisms could help optimize phytoremediation systems and enhance their use. in this study, willows were planted in contaminated and non-contaminated soils in a greenhous ... | 2013 | 24067257 |
| microbial expression profiles in the rhizosphere of willows depend on soil contamination. | the goal of phytoremediation is to use plants to immobilize, extract or degrade organic and inorganic pollutants. in the case of organic contaminants, plants essentially act indirectly through the stimulation of rhizosphere microorganisms. a detailed understanding of the effect plants have on the activities of rhizosphere microorganisms could help optimize phytoremediation systems and enhance their use. in this study, willows were planted in contaminated and non-contaminated soils in a greenhous ... | 2013 | 24067257 |
| rhizobium laguerreae sp. nov. nodulates vicia faba on several continents. | several fast-growing strains nodulating vicia faba in peru, spain and tunisia formed a cluster related to rhizobium leguminosarum. the 16s rrna gene sequences were identical to that of r. leguminosarum usda 2370(t), whereas rpob, reca and atpd gene sequences were phylogenetically distant, with sequence similarities of less than 96 %, 97 % and 94 %, respectively. dna-dna hybridization analysis showed a mean relatedness value of 43 % between strain fb206(t) and r. leguminosarum usda 2370(t). pheno ... | 2014 | 24067731 |
| exopolysaccharides from sinorhizobium meliloti can protect against h2o2-dependent damage. | sinorhizobium meliloti requires exopolysaccharides in order to form a successful nitrogen-fixing symbiosis with medicago species. additionally, during early stages of symbiosis, s. meliloti is presented with an oxidative burst that must be overcome. levels of production of the exopolysaccharides succinoglycan (eps-i) and galactoglucan (eps-ii) were found to correlate positively with survival in hydrogen peroxide (h2o2). h2o2 damage is dependent on the presence of iron and is mitigated when eps-i ... | 2013 | 24078609 |
| optimization of dairy sludge for growth of rhizobium cells. | in this study dairy sludge was evaluated as an alternative cultivation medium for rhizobium. growth of bacterial strains at different concentrations of dairy sludge was monitored. maximum growth of all strains was observed at 60% dairy sludge concentration. at 60% optical density (od) values are 0.804 for rhizobium trifolii (mtcc905), 0.825 for rhizobium trifolii (mtcc906), and 0.793 for rhizobium meliloti (mtcc100). growth pattern of strains was observed at 60% dairy sludge along with different ... | 2013 | 24089690 |
| transcriptional regulation by ferric uptake regulator (fur) in pathogenic bacteria. | in the ancient anaerobic environment, ferrous iron (fe(2+)) was one of the first metal cofactors. oxygenation of the ancient world challenged bacteria to acquire the insoluble ferric iron (fe(3+)) and later to defend against reactive oxygen species (ros) generated by the fenton chemistry. to acquire fe(3+), bacteria produce low-molecular weight compounds, known as siderophores, which have extremely high affinity for fe(3+). however, during infection the host restricts iron from pathogens by prod ... | 2013 | 24106689 |
| roles of a solo luxr in the biological control agent lysobacter enzymogenes strain oh11. | lysobacter enzymogenes is a ubiquitous plant-associated and environmentally friendly bacterium emerging as a novel biological control agent of plant disease. this bacterium produces diverse antifungal factors, such as lytic enzymes and a secondary metabolite (heat-stable antifungal factor [hsaf]) having antifungal activity with a novel structure and mode of action. the regulatory mechanisms for biosynthesis of antifungal factors is largely unknown in l. enzymogenes. the solo luxr proteins have b ... | 2014 | 24111575 |
| genomic and functional analyses of the 2-aminophenol catabolic pathway and partial conversion of its substrate into picolinic acid in burkholderia xenovorans lb400. | 2-aminophenol (2-ap) is a toxic nitrogen-containing aromatic pollutant. burkholderia xenovorans lb400 possess an amn gene cluster that encodes the 2-ap catabolic pathway. in this report, the functionality of the 2-aminophenol pathway of b. xenovorans strain lb400 was analyzed. the amnrjbacdfehg cluster located at chromosome 1 encodes the enzymes for the degradation of 2-aminophenol. the absence of haba and habb genes in lb400 genome correlates with its no growth on nitrobenzene. rt-pcr analyses ... | 2013 | 24124510 |
| maize root lectins mediate the interaction with herbaspirillum seropedicae via n-acetyl glucosamine residues of lipopolysaccharides. | herbaspirillum seropedicae is a plant growth-promoting diazotrophic betaproteobacterium which associates with important crops, such as maize, wheat, rice and sugar-cane. we have previously reported that intact lipopolysaccharide (lps) is required for h. seropedicae attachment and endophytic colonization of maize roots. in this study, we present evidence that the lps biosynthesis gene waal (codes for the o-antigen ligase) is induced during rhizosphere colonization by h. seropedicae. furthermore a ... | 2013 | 24130823 |
| thiol-based redox signaling in the nitrogen-fixing symbiosis. | in nitrogen poor soils legumes establish a symbiotic interaction with rhizobia that results in the formation of root nodules. these are unique plant organs where bacteria differentiate into bacteroids, which express the nitrogenase enzyme complex that reduces atmospheric n 2 to ammonia. nodule metabolism requires a tight control of the concentrations of reactive oxygen and nitrogen species (rons) so that they can perform useful signaling roles while avoiding nitro-oxidative damage. in nodules a ... | 2013 | 24133498 |
| the lysr-type transcription factor hbrl is a global regulator of iron homeostasis and porphyrin synthesis in rhodobacter capsulatus. | the purple bacterium rhodobacter capsulatus is unique among rhodobacteriacae as it contains a putative iron response regulator (irr) but does not possess a copy of the ferric uptake regulator (fur). interestingly, an in-frame deletion mutant of irr shows no major role in iron homeostasis. instead, we showed that the previously identified activator of haem gene expression hbrl is a crucial regulator of iron homeostasis. we demonstrated that an hbrl deletion strain is unable to grow in iron-limite ... | 2013 | 24134691 |
| nitrate and periplasmic nitrate reductases. | the nitrate anion is a simple, abundant and relatively stable species, yet plays a significant role in global cycling of nitrogen, global climate change, and human health. although it has been known for quite some time that nitrate is an important species environmentally, recent studies have identified potential medical applications. in this respect the nitrate anion remains an enigmatic species that promises to offer exciting science in years to come. many bacteria readily reduce nitrate to nit ... | 2014 | 24141308 |
| functional conservation of the capacity for ent-kaurene biosynthesis and an associated operon in certain rhizobia. | bacterial interactions with plants are accompanied by complex signal exchange processes. previously, the nitrogen-fixing symbiotic (rhizo)bacterium bradyrhizobium japonicum was found to carry adjacent genes encoding two sequentially acting diterpene cyclases that together transform geranylgeranyl diphosphate to ent-kaurene, the olefin precursor to the gibberellin plant hormones. species from the three other major genera of rhizobia were found to have homologous terpene synthase genes. cloning an ... | 2014 | 24142247 |
| diverse role of fast growing rhizobia in growth promotion and enhancement of psoralen content in psoralea corylifolia l. | psoralea corylifolia (bakuchi), a weed, which possesses a highly potent and medicinally important compound psoralen. p. corylifolia has been widely exploited since ages for its biological potential. | 2013 | 24143046 |
| a novel carboxyl-terminal protease derived from paenibacillus lautus chn26 exhibiting high activities at multiple sites of substrates. | carboxyl-terminal protease (ctpa) plays essential functions in posttranslational protein processing in prokaryotic and eukaryotic cells. to date, only a few bacterial ctpa genes have been characterized. here we cloned and characterized a novel ctpa. the encoding gene, ctpap (ctpa of paenibacillus lautus), was derived from p. lautus chn26, a gram-positive bacterium isolated by functional screening. recombinant protein was obtained from protein over-expression in escherichia coli and the biochemic ... | 2013 | 24161150 |
| comparative metabolic systems analysis of pathogenic burkholderia. | burkholderia cenocepacia and burkholderia multivorans are opportunistic drug-resistant pathogens that account for the majority of burkholderia cepacia complex infections in cystic fibrosis patients and also infect other immunocompromised individuals. while they share similar genetic compositions, b. cenocepacia and b. multivorans exhibit important differences in pathogenesis. we have developed reconciled genome-scale metabolic network reconstructions of b. cenocepacia j2315 and b. multivorans at ... | 2014 | 24163337 |
| narrow-host-range bacteriophages that infect rhizobium etli associate with distinct genomic types. | in this work, we isolated and characterized 14 bacteriophages that infect rhizobium etli. they were obtained from rhizosphere soil of bean plants from agricultural lands in mexico using an enrichment method. the host range of these phages was narrow but variable within a collection of 48 r. etli strains. we obtained the complete genome sequence of nine phages. four phages were resistant to several restriction enzymes and in vivo cloning, probably due to nucleotide modifications. the genome size ... | 2014 | 24185856 |
| crystallization and preliminary x-ray study of alanine dehydrogenase from bacillus pseudofirmus of4. | alanine dehydrogenase (of4ald) from the alkaliphilic bacillus pseudofirmus of4 was expressed and purified with a his6 tag in a form suitable for x-ray crystallographic analysis. crystals were grown by the hanging-drop vapour-diffusion method at 289 k using a solution consisting of 0.1 m tris-hcl ph 8.0, 0.2 m liso4, 22%(w/v) peg 3350. x-ray diffraction data were collected to 2.8 å resolution. the crystal belonged to the triclinic space group p1, with unit-cell parameters a = 88.04, b = 105.59, c ... | 2013 | 24192355 |
| transposon tn5 as an identifiable marker in rhizobia: survival and genetic stability of tn5 mutant bean rhizobia under temperature stressed conditions in desert soils. | five transposon tn5 insertion mutants of a beanrhizobium strain (rhizobium leguminosarum b. v.phaseoli) were used in an ecological study to evaluate the extent to which transposon tn5 was stable to serve as an identifiable marker in rhizobia under a high temperature stress condition in two sonoran desert soils. all the mutants possessed single chromosomal insertions of the transposon. in both soils, under the temperature stress conditions that were employed (40°c), both wild type and mutant popu ... | 1991 | 24194199 |
| differential accumulation of hydroxyproline-rich glycoproteins in bean root nodule cells infected with a wild-type strain or a c4-dicarboxylic acid mutant of rhizobium leguminosarum bv. phaseoli. | an antiserum raised against deglycosylated hydroxyproline-rich glycoproteins (hpgps) from melon (cucumis melo l.) was used to study the relationship between rhizobium infection and induction of hrgps in bean (phaseolus vulgaris l.) root nodule cells infected with either the wild-type or a c4-dicarboxylic acid mutant strain of rhizobium leguminosarum bv. phaseoli. in effective nodules, where fixation of atmospheric dinitrogen is taking place, hrgps were found to accumulate mainly in the walls of ... | 1991 | 24194237 |
| distribution of glucose/mannose-specific isolectins in pea (pisum sativum l.) seedlings. | we report on the distribution and initial characterization of glucose/mannose-specific isolectins of 4- and 7-d-old pea (pisum sativum l.) seedlings grown with or without nitrate supply. particular attention was payed to root lectin, which probably functions as a determinant of host-plant specificity during the infection of pea roots by rhizobium leguminosarum bv. viciae. a pair of seedling cotyledons yielded 545±49 μg of affinity-purified lectin, approx. 25% more lectin than did dry seeds. shoo ... | 1990 | 24196924 |
| the occurrence of unusual laminated structures rich in β-1,4-glucans in plastids of phaseolus vulgaris root-nodule cells infected by an ineffective c4-dicarboxylic-acid mutant of rhizobium leguminosarum bv. phaseoli. | root nodules induced in phaseolus vulgaris l. by the wild-type (wt) and a c4-dicarboxylic-acid mutant strain of rhizobium leguminosarum biovar. phaseoli were compared on the basis of ultrastructure and cytochemistry of cellulose subunits. the mutant bacteroids failed to colonize infected host cells in a normal manner, and presented a premature degenerative appearance. starch granules, rough endoplasmic reticulum and mitochondria were found to accumulate in the ineffective nodules. the most strik ... | 1990 | 24202009 |
| the ethylene-inhibitor aminoethoxyvinylglycine restores normal nodulation by rhizobium leguminosarum biovar. viciae on vicia sativa subsp. nigra by suppressing the 'thick and short roots' phenotype. | nodulation of vicia sativa subsp. nigra l. by rhizobium bacteria is coupled to the development of thick and short roots (tsr). this root phenotype as well as root-hair induction (hai) and root-hair deformation (had) are caused by a factor(s) produced by the bacteria in response to plant flavonoids. when very low inoculum concentrations (0.5-5 bacteria·ml(-1)) were used, v. sativa plants did not develop the tsr phenotype and became nodulated earlier than plants with tsr roots. furthermore, the no ... | 1989 | 24212336 |
| the twin arginine translocation system is essential for aerobic growth and full virulence of burkholderia thailandensis. | the twin arginine translocation (tat) system in bacteria is responsible for transporting folded proteins across the cytoplasmic membrane, and in some bacteria, tat-exported substrates have been linked to virulence. we report here that the tat machinery is present in burkholderia pseudomallei, b. mallei, and b. thailandensis, and we show that the system is essential for aerobic but not anaerobic growth. switching off of the tat system in b. thailandensis grown anaerobically resulted in filamentou ... | 2014 | 24214943 |
| isolation of monoclonal antibodies reacting with peribacteriod membranes and other components of pea root nodules containing rhizobium leguminosarum. | plant and bacterial antigens contributing to nodule development and symbiosis in pea (pisum sativum l.) roots were identified after isolation of a set of monoclonal antibody (mcab)-producing hybridoma lines. rats were immunised with the peribacteriod material released by mild osmotic shock treatment from membrane-enclosed bacteroids of rhizobium leguminosarum bv. viceae. in order to diversify the range of mcab specificities, this material was either used as immunogen directly (method 1), or afte ... | 1988 | 24226395 |
| lectin-gene expression in pea (pisum sativum l.) roots. | the expression of a lectin gene in pea (pisum sativum l.) roots has been investigated using the copy dna of a pea seed lectin as a probe. an mrna which has the same size as the seed mrna but which is about 4000 times less abundant has been detected in 21-d-old roots. the probe detected lectin expression as early as 4 d after sowing, with the highest level being reached at 10 d, i.e. just before nodulation. in later stages (16-d- and 21-d-old roots), expression was substantially decreased. the co ... | 1988 | 24226543 |
| induced genetic variability in rhizobium leguminosarum for nitrogen fixation parameters in vicia faba l. | the objective of this work was to know the behaviour and variability of rhizobium leguminosarum after irradiation. the induced variation was tested under greenhouse conditions on the variety jv 3 of broad beans (vicia faba) in six replications. induced genetic variabilty was observed for strain, parent and mutant versus parent. out of 24 irradiated strains, strain 93-32 performed better with a greater number of nodules and higher dry weight of nodules per plant and biological yield. environment ... | 1989 | 24227253 |