| a visual reporter system for virus-induced gene silencing in tomato fruit based on anthocyanin accumulation. | virus-induced gene silencing (vigs) is a powerful tool for reverse genetics in tomato (solanum lycopersicum). however, the irregular distribution of the effects of vigs hampers the identification and quantification of nonvisual phenotypes. to overcome this limitation, a visually traceable vigs system was developed for fruit, comprising two elements: (1) a transgenic tomato line (del/ros1) expressing antirrhinum majus delila and rosea1 transcription factors under the control of the fruit-specific ... | 2009 | 19429602 |
| orf4 of the bacillus cereus sigb gene cluster encodes a general stress-inducible dps-like bacterioferritin. | the function of orf4 in the sigb cluster in bacillus cereus atcc 14579 remains to be explored. amino-acid sequence analysis has revealed that orf4 is homologous with bacterioferritins and dps. in this study, we generated an orf4-null mutant and produced recombinant protein rorf4 to establish the role of orf4. in vitro, the purified rorf4 was found to exist in two distinct forms, a dimeric form and a polymer form, through size exclusion analysis. the latter form exhibited a unique filament struct ... | 2009 | 19429618 |
| hhomp--prediction and classification of outer membrane proteins. | outer membrane proteins (omps) are the transmembrane proteins found in the outer membranes of gram-negative bacteria, mitochondria and plastids. most prediction methods have focused on analogous features, such as alternating hydrophobicity patterns. here, we start from the observation that almost all beta-barrel omps are related by common ancestry. we identify proteins as omps by detecting their homologous relationships to known omps using sequence similarity. given an input sequence, hhomp buil ... | 2009 | 19429691 |
| dimerization of the quorum-sensing transcription factor trar enhances resistance to cytoplasmic proteolysis. | trar is a luxr-type quorum-sensing protein encoded by the tumour-inducing plasmid of agrobacterium tumefaciens. trar requires the pheromone n-3-oxooctanoyl-l-homoserine lactone (oohl) for biological activity, and is dimeric both in solution and when bound to dna. dimerization is mediated primarily by two alpha-helices, one in the n-terminal oohl binding domain, and the other in the c-terminal dna binding domain. each of these helices forms a parallel coiled coil with the identical helix of the o ... | 2009 | 19432796 |
| characterization of vitis vinifera npr1 homologs involved in the regulation of pathogenesis-related gene expression. | grapevine protection against diseases needs alternative strategies to the use of phytochemicals, implying a thorough knowledge of innate defense mechanisms. however, signalling pathways and regulatory elements leading to induction of defense responses have yet to be characterized in this species. in order to study defense response signalling to pathogens in vitis vinifera, we took advantage of its recently completed genome sequence to characterize two putative orthologs of npr1, a key player in ... | 2009 | 19432948 |
| snapshots of dynamics in synthesizing n(6)-isopentenyladenosine at the trna anticodon. | bacterial and eukaryotic trnas that decode codons starting with uridine have a hydrophobically hypermodified adenosine at position 37 (a(37)) adjacent to the 3'-end of the anticodon, which is essential for efficient and highly accurate protein translation by the ribosome. however, it remains unclear as to how the corresponding trnas are selected to be modified by alkylation at the correct position of the adenosine base. we have determined a series of crystal structures of bacterial trna isopente ... | 2009 | 19435325 |
| genome degradation in brucella ovis corresponds with narrowing of its host range and tissue tropism. | brucella ovis is a veterinary pathogen associated with epididymitis in sheep. despite its genetic similarity to the zoonotic pathogens b. abortus, b. melitensis and b. suis, b. ovis does not cause zoonotic disease. genomic analysis of the type strain atcc25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of b. ovis. th ... | 2009 | 19436743 |
| evidence that the linker between the methyltransferase and helicase domains of potato virus x replicase is involved in homologous rna recombination. | recombination in rna viruses, one of the main factors contributing to their genetic variability and evolution, is a widespread phenomenon. in this study, an in vivo assay to characterize rna recombination in potato virus x (pvx), under high selection pressure, was established. agrobacterium tumefaciens was used to express in nicotiana benthamiana leaf tissue both a pvx isolate labeled with green fluorescent protein (gfp) containing a coat protein deletion mutation (deltacp) and a transcript enco ... | 2009 | 19439477 |
| agrobacterium in the genomics age. | | 2009 | 19439569 |
| functional characterization of the arabidopsis beta-ketoacyl-coenzyme a reductase candidates of the fatty acid elongase. | in plants, very-long-chain fatty acids (vlcfas; >18 carbon) are precursors of sphingolipids, triacylglycerols, cuticular waxes, and suberin. vlcfas are synthesized by a multiprotein membrane-bound fatty acid elongation system that catalyzes four successive enzymatic reactions: condensation, reduction, dehydration, and a second reduction. a bioinformatics survey of the arabidopsis (arabidopsis thaliana) genome has revealed two sequences homologous to ybr159w encoding a saccharomyces cerevisiae be ... | 2009 | 19439572 |
| stilbene synthase gene transfer caused alterations in the phenylpropanoid metabolism of transgenic strawberry (fragaria x ananassa). | the gene encoding stilbene synthase is frequently used to modify plant secondary metabolism with the aim of producing the self-defence phytoalexin resveratrol. in this study, strawberry (fragaria x ananassa) was transformed with the ns-vitis3 gene encoding stilbene synthase from frost grape (vitis riparia) under the control of the cauliflower mosaic virus 35s and the floral filament-specific fil1 promoters. changes in leaf metabolites were investigated with uplc-qtof-ms (ultra performance liquid ... | 2009 | 19443619 |
| multiple activities of the plant pathogen type iii effector proteins wtse and avre require wxxxe motifs. | the broadly conserved avre-family of type iii effectors from gram-negative plant-pathogenic bacteria includes important virulence factors, yet little is known about the mechanisms by which these effectors function inside plant cells to promote disease. we have identified two conserved motifs in avre-family effectors: a wxxxe motif and a putative c-terminal endoplasmic reticulum membrane retention/retrieval signal (ermrs). the wxxxe and ermrs motifs are both required for the virulence activities ... | 2009 | 19445595 |
| the s-adenosyl-l-homocysteine hydrolase gene ahcy of agrobacterium radiobacter k84 is required for optimal growth, antibiotic production, and biocontrol of crown gall disease. | agrobacterium radiobacter k84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of a. tumefaciens. more than 2,000 transposon insertion derivatives of strain k84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocontrol. three mutants affected in biocontrol properties were identified. all three mutants displayed normal levels of attachment to tomato seed and root colonization. one of these mutants, m19-164, exhi ... | 2009 | 19445596 |
| a key enzyme of the leloir pathway is involved in pathogenicity of leptosphaeria maculans toward oilseed rape. | agrobacterium tumefaciens-mediated random insertional mutagenesis was used to investigate pathogenicity determinants in leptosphaeria maculans. one tagged nonpathogenic mutant, termed m186, is analyzed in detail here. microscopic analyses of infected plant tissues revealed that m186 is specifically blocked at the invasive growth phase after an unaffected initial penetration stage and is unable to switch to the necrotrophic lifestyle. in addition, m186 exhibits an altered cell wall and seems to b ... | 2009 | 19445597 |
| discovery and characterization of an arabidopsis thaliana n-acylphosphatidylethanolamine synthase. | n-acylethanolamines (naes) are lipids involved in several physiological processes in animal and plant cells. in brain, naes are ligands of endocannabinoid receptors, which modulate various signaling pathways. in plant, naes regulate seed germination and root development, and they are involved in plant defense against pathogen attack. this signaling activity is started by an enzyme called n-acylphosphatidylethanolamine (nape) synthase. this catalyzes the n-acylation of phosphatidylethanolamine to ... | 2009 | 19447891 |
| novel toxin-antitoxin system composed of serine protease and aaa-atpase homologues determines the high level of stability and incompatibility of the tumor-inducing plasmid ptic58. | stability of plant tumor-inducing (ti) plasmids differs among strains. a high level of stability prevents basic and applied studies including the development of useful strains. the nopaline type ti plasmid ptic58 significantly reduces the transconjugant efficiency for incoming incompatible plasmids relative to the other type, such as octopine-type plasmids. in this study we identified a region that increases the incompatibility and stability of the plasmid. this region was located on a 4.3-kbp s ... | 2009 | 19447904 |
| analysis of dna binding by a eubacterial zinc finger transcription factor. | the serratia marcescens nucc protein is structurally and functionally homologous to the p2 ogr family of eubacterial zinc finger transcription factors required for late gene expression in p2- and p4-related bacteriophages. these activators exhibit site-specific binding to a conserved dna sequence, tgt-n(3)-r-n(4)-y-n(3)-aca, that is located upstream of nucc-dependent s. marcescens promoters and the late promoters of p2-related phages. in this report we describe the interactions of nucc with the ... | 2009 | 19447913 |
| recognition of avrbs3-like proteins is mediated by specific binding to promoters of matching pepper bs3 alleles. | the pepper (capsicum annuum) bacterial spot (bs) resistance gene bs3 and its allelic variant bs3-e mediate recognition of the xanthomonas campestris pv vesicatoria type iii effector protein avrbs3 and its deletion derivative avrbs3deltarep16. recognition specificity resides in the bs3 and bs3-e promoters and is determined by a defined promoter region, the upa (for up-regulated by avrbs3) box. using site-directed mutagenesis, we defined the exact boundaries of the upa(avrbs3) box of the bs3 promo ... | 2009 | 19448036 |
| bacterial diversity analysis of larvae and adult midgut microflora using culture-dependent and culture-independent methods in lab-reared and field-collected anopheles stephensi-an asian malarial vector. | mosquitoes are intermediate hosts for numerous disease causing organisms. vector control is one of the most investigated strategy for the suppression of mosquito-borne diseases. anopheles stephensi is one of the vectors of malaria parasite plasmodium vivax. the parasite undergoes major developmental and maturation steps within the mosquito midgut and little is known about anopheles-associated midgut microbiota. identification and characterization of the mosquito midgut flora is likely to contrib ... | 2009 | 19450290 |
| chromophore structure of cyanobacterial phytochrome cph1 in the pr state: reconciling structural and spectroscopic data by qm/mm calculations. | a quantum mechanics (qm)/molecular mechanics (mm) hybrid method was applied to the pr state of the cyanobacterial phytochrome cph1 to calculate the raman spectra of the bound pcb cofactor. two qm/mm models were derived from the atomic coordinates of the crystal structure. the models differed in the protonation site of his(260) in the chromophore-binding pocket such that either the delta-nitrogen (m-hsd) or the epsilon-nitrogen (m-hse) carried a hydrogen. the optimized structures of the two model ... | 2009 | 19450486 |
| a launch vector for the production of vaccine antigens in plants. | historically, most vaccines have been based on killed or live-attenuated infectious agents. although very successful at immunizing populations against disease, both approaches raise safety concerns and often have limited production capacity. this has resulted in increased emphasis on the development of subunit vaccines. several recombinant systems have been considered for subunit vaccine manufacture, including plants, which offer advantages both in cost and in scale of production. we have develo ... | 2007 | 19453476 |
| a plant-produced influenza subunit vaccine protects ferrets against virus challenge. | influenza a viruses are of major concern for public health, causing worldwide epidemics associated with high morbidity and mortality. vaccines are critical for protection against influenza, but given the recent emergence of new strains with pandemic potential, and some limitations of the current production systems, there is a need for new approaches for vaccine development. | 2008 | 19453491 |
| the role of respiratory burst oxidase homologues in elicitor-induced stomatal closure and hypersensitive response in nicotiana benthamiana. | active oxygen species (aos) are central components of the defence reactions of plants against pathogens. plant respiratory burst oxidase homologues (rboh) of gp91(phox), a plasma membrane protein of the neutrophil nicotinamide adenine dinucleotide phosphate (nadph) oxidase, play a prominent role in aos production. the role of two rboh from nicotiana benthamiana, nbrboha and nbrbohb that encode plant nadph oxidase in the process of elicitor-induced stomatal closure and hypersensitive cell death i ... | 2009 | 19454596 |
| the fast technique: a simplified agrobacterium-based transformation method for transient gene expression analysis in seedlings of arabidopsis and other plant species. | abstract: | 2009 | 19457242 |
| iron translocation into and out of listeria innocua dps and size distribution of the protein-enclosed nanomineral are modulated by the electrostatic gradient at the 3-fold "ferritin-like" pores. | elucidating pore function at the 3-fold channels of 12-subunit, microbial dps proteins is important in understanding their role in the management of iron/hydrogen peroxide. the dps pores are called "ferritin-like" because of the structural resemblance to the 3-fold channels of 24-subunit ferritins used for iron entry and exit to and from the protein cage. in ferritins, negatively charged residues lining the pores generate a negative electrostatic gradient that guides iron ions toward the ferroxi ... | 2009 | 19457858 |
| host and pathogen factors controlling the rice-xanthomonas oryzae interaction. | | 2009 | 19458115 |
| pseudo-outbreak of rhizobium radiobacter infection resulting from laboratory contamination of saline solution. | we report a pseudo-outbreak of rhizobium radiobacter infections resulting from contamination by a saline dispenser in the microbiology laboratory. isolates from clinical specimens had identical antimicrobial susceptibilities and electrophoretic fingerprints. the episode resolved with autoclaving of the dispenser. this demonstrates the importance of timely, thorough investigation of unusual organisms, particularly when they appear as a cluster. | 2009 | 19458174 |
| suppressed expression of retrograde-regulated male sterility restores pollen fertility in cytoplasmic male sterile rice plants. | conflict/reconciliation between mitochondria and nuclei in plants is manifested by the fate of pollen (viable or nonviable) in the cytoplasmic male sterility (cms)/fertility restoration (rf) system. through positional cloning, we identified a nuclear candidate gene, retrograde-regulated male sterility (rms) for rf17, a fertility restorer gene for chinese wild rice (cw)-type cms in rice (oryza sativa l.). rna interference-mediated gene silencing of rms restored fertility to a cms plant, whereas i ... | 2009 | 19458265 |
| quorum-sensing signal production by agrobacterium vitis strains and their tumor-inducing and tartrate-catabolic plasmids. | agrobacterium vitis strains, their tumor-inducing (pti) and tartrate utilization (ptr) plasmid transconjugants and grapevine tumors were analyzed for the presence of n-acyl-homoserine lactones (ahls). all wild-type a. vitis strains produced long-chain signals. pcr analysis of the a. vitis long-chain ahl synthase gene, avsi, showed the predicted amplicon. agrobacterium tumefaciens ubapf2 harboring various a. vitis pti plasmids produced n-(3-oxo-octanoyl)-l-homoserine lactone encoded also by ptis ... | 2009 | 19459947 |
| geminiviruses: a tale of a plasmid becoming a virus. | geminiviruses (family geminiviridae) are small single-stranded (ss) dna viruses infecting plants. their virion morphology is unique in the known viral world - two incomplete t = 1 icosahedra are joined together to form twinned particles. geminiviruses utilize a rolling-circle mode to replicate their genomes. a limited sequence similarity between the three conserved motifs of the rolling-circle replication initiation proteins (rcr reps) of geminiviruses and plasmids of gram-positive bacteria allo ... | 2009 | 19460138 |
| rhizobium leguminosarum biovar viciae 3841, deficient in 27-hydroxyoctacosanoate-modified lipopolysaccharide, is impaired in desiccation tolerance, biofilm formation and motility. | the lipopolysaccharide (lps) of the gram-negative legume symbiont rhizobium leguminosarum biovar viciae 3,841 contains several unique modifications, including the addition of a 27-hydroxyoctacosanoic acid (27ohc28 : 0), also termed the very long chain fatty acid (vlcfa), attached at the 2' position of lipid a. a transposon mutant that lacks expression of two putative 3-oxo-acyl [acyl-carrier protein] synthase ii genes, fabf1 and fabf2, from the vlcfa biosynthetic cluster, was isolated and charac ... | 2009 | 19460825 |
| identification of the chloroplast adenosine-to-inosine trna editing enzyme. | plastids (chloroplasts) of higher plants exhibit two types of conversional rna editing: cytidine-to-uridine editing in mrnas and adenosine-to-inosine editing in at least one plastid genome-encoded trna, the trna-arg(acg). the enzymes catalyzing rna editing reactions in plastids are unknown. here we report the identification of the a-to-i trna editing enzyme from chloroplasts of the model plant arabidopsis thaliana. the protein (attada) has an unusual structure in that it harbors a large n-termin ... | 2009 | 19460869 |
| antityrosinase and antimicrobial activities of trans-cinnamaldehyde thiosemicarbazone. | tyrosinase (ec 1.14.18.1) is a key enzyme in pigment biosynthesis of organisms. trans-cinnamaldehyde thiosemicarbazone, a derivative of benzaldehyde thiosemicarbazone, was synthesized as an inhibitor of tyrosinase. the inhibitory effects of this compound on the activity of mushroom tyrosinase were investigated. the results showed that trans-cinnamaldehyde thiosemicarbazone could potently inhibit both monophenolase activity and diphenolase activity of tyrosinase. for monophenolase activity, trans ... | 2009 | 19462982 |
| characterization of a gene cluster involved in 4-chlorocatechol degradation by pseudomonas reinekei mt1. | pseudomonas reinekei mt1 has previously been reported to degrade 4- and 5-chlorosalicylate by a pathway with 4-chlorocatechol, 3-chloromuconate, 4-chloromuconolactone, and maleylacetate as intermediates, and a gene cluster channeling various salicylates into an intradiol cleavage route has been reported. we now report that during growth on 5-chlorosalicylate, besides a novel (chloro)catechol 1,2-dioxygenase, c12o(ccaa), a novel (chloro)muconate cycloisomerase, mci(ccab), which showed features no ... | 2009 | 19465655 |
| overexpression of citrus junos mitochondrial citrate synthase gene in nicotiana benthamiana confers aluminum tolerance. | aluminum (al) toxicity is one of the major factors that limit plant growth in acid soils. al-induced release of organic acids into rhizosphere from the root apex has been identified as a major al-tolerance mechanism in many plant species. in this study, al tolerance of yuzu (citrus junos sieb. ex tanaka) was tested on the basis of root elongation and the results demonstrated that yuzu was al tolerant compared with other plant species. exposure to al triggered the exudation of citrate from the yu ... | 2009 | 19466450 |
| rolc strawberry plant adaptability, productivity, and tolerance to soil-borne disease and mycorrhizal interactions. | the potential to improve strawberry cultivation was assessed regarding the use the rolc genes from agrobacterium rhizogenes that can confer higher levels of free cytokinins. strawberry (cv. calypso) rolc lines were produced by genetic transformation of agrobacterium tumefaciens. yield and fruit quality of the control and transgenic lines were measured under open-field conditions. the effects of the transgenic rolc lines depended on gene copy number: rolc lines with one (line a) or two gene (line ... | 2009 | 19466576 |
| overexpression of a weed (solanum americanum) proteinase inhibitor in transgenic tobacco results in increased glandular trichome density and enhanced resistance to helicoverpa armigera and spodoptera litura. | in this study we produced transgenic tobacco plants by overexpressing a serine proteinase inhibitor gene, sapin2a, from the american black nightshade solanum americanum under the control of the camv 35s promoter using agrobacterium tumefaciens-mediated transformation. sapin2a was properly transcribed and translated as indicated by northern blot and western blot analyses. functional integrity of sapin2a in transgenic plants was confirmed by proteinase inhibitory activity assay. bioassays for inse ... | 2009 | 19468345 |
| osysl18 is a rice iron(iii)-deoxymugineic acid transporter specifically expressed in reproductive organs and phloem of lamina joints. | iron uptake and translocation in plants are important processes for both plant and human nutrition, whereas relatively little is known about the molecular mechanisms of iron transport within the plant body. several reports have shown that yellow stripe 1 (ys1) and ys1-like (ysl) transporters mediate metal-phytosiderophore uptake and/or metal-nicotianamine translocation. among the 18 ysl genes in rice (osysls), osysl18 is predicted to encode a polypeptide of 679 amino acids containing 13 putative ... | 2009 | 19468840 |
| systems level analysis of two-component signal transduction systems in erwinia amylovora: role in virulence, regulation of amylovoran biosynthesis and swarming motility. | two-component signal transduction systems (tcsts), consisting of a histidine kinase (hk) and a response regulator (rr), represent a major paradigm for signal transduction in prokaryotes. tcsts play critical roles in sensing and responding to environmental conditions, and in bacterial pathogenesis. most tcsts in erwinia amylovora have either not been identified or have not yet been studied. | 2009 | 19470164 |
| remorin, a solanaceae protein resident in membrane rafts and plasmodesmata, impairs potato virus x movement. | remorins (rems) are proteins of unknown function specific to vascular plants. we have used imaging and biochemical approaches and in situ labeling to demonstrate that rem clusters at plasmodesmata and in approximately 70-nm membrane domains, similar to lipid rafts, in the cytosolic leaflet of the plasma membrane. from a manipulation of rem levels in transgenic tomato (solanum lycopersicum) plants, we show that potato virus x (pvx) movement is inversely related to rem accumulation. we show that r ... | 2009 | 19470590 |
| inactivation of thioredoxin-like gene alters oxidative stress resistance and reduces cytochrome c oxidase activity in agrobacterium tumefaciens. | thioredoxin-like protein (tlpa) is a membrane-anchored periplasmic protein that contains a thioredoxin domain at its c-terminus. an agrobacterium tumefaciens mutant lacking functional tlpa shows increased sensitivity to a superoxide generator, increased resistance to h2o2, and reduced cytochrome c oxidase activity. whereas the levels of antioxidant enzymes, including total superoxide dismutase (sod) and catalases, are unaltered, high expression of periplasmic sod partially restores the superoxid ... | 2009 | 19473258 |
| biofilm forming abilities of salmonella are correlated with persistence in fish meal- and feed factories. | feed contaminated with salmonella spp. constitutes a risk of salmonella infections in animals, and subsequently in the consumers of animal products. salmonella are occasionally isolated from the feed factory environment and some clones of salmonella persist in the factory environment for several years. one hypothesis is that biofilm formation facilitates persistence by protecting bacteria against environmental stress, e.g. disinfection. the aim of this study was to investigate the biofilm formin ... | 2009 | 19473515 |
| fine-tuning of the cytoplasmic ca2+ concentration is essential for pollen tube growth. | pollen tube growth is crucial for the delivery of sperm cells to the ovule during flowering plant reproduction. previous in vitro imaging of lilium longiflorum and nicotiana tabacum has shown that growing pollen tubes exhibit a tip-focused ca(2+) concentration ([ca(2+)]) gradient and regular oscillations of the cytosolic [ca(2+)] ([ca(2+)](cyt)) in the tip region. whether this [ca(2+)] gradient and/or [ca(2+)](cyt) oscillations are present as the tube grows through the stigma (in vivo condition) ... | 2009 | 19474213 |
| fitness of escherichia coli during urinary tract infection requires gluconeogenesis and the tca cycle. | microbial pathogenesis studies traditionally encompass dissection of virulence properties such as the bacterium's ability to elaborate toxins, adhere to and invade host cells, cause tissue damage, or otherwise disrupt normal host immune and cellular functions. in contrast, bacterial metabolism during infection has only been recently appreciated to contribute to persistence as much as their virulence properties. in this study, we used comparative proteomics to investigate the expression of uropat ... | 2009 | 19478872 |
| comparative genomic characterization of francisella tularensis strains belonging to low and high virulence subspecies. | tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. it is caused by infection by a gram-negative bacterium, francisella tularensis. in order to better understand its potency as an etiological agent as well as its potential as a biological weapon, we have completed draft assemblies and report the first complete genomic characterization of five strains belonging to the following different francisella subspecies (subsp.): the f. tularensis sub ... | 2009 | 19478886 |
| in vivo reorganization of the actin cytoskeleton in leaves of nicotiana tabacum l. transformed with plastin-gfp. correlation with light-activated chloroplast responses. | the actin cytoskeleton is involved in the responses of plants to environmental signals. actin bundles play the role of tracks in chloroplast movements activated by light. chloroplasts redistribute in response to blue light in the mesophyll cells of nicotiana tabacum. the aim of this work was to study the relationship between chloroplast responses and the organization of actin cytoskeleton in living tobacco cells. chloroplast movements were measured photometrically as changes in light transmissio ... | 2009 | 19480655 |
| pleiotropic effects of the twin-arginine translocation system on biofilm formation, colonization, and virulence in vibrio cholerae. | the twin-arginine translocation (tat) system serves to translocate folded proteins, including periplasmic enzymes that bind redox cofactors in bacteria. the tat system is also a determinant of virulence in some pathogenic bacteria, related to pleiotropic effects including growth, motility, and the secretion of some virulent factors. the contribution of the tat pathway to vibrio cholerae has not been explored. here we investigated the functionality of the tat system in v. cholerae, the etiologic ... | 2009 | 19480715 |
| enzymatic assay of d-glucuronate using uronate dehydrogenase. | d-glucuronate is a key metabolite in the process of detoxification of xenobiotics and in a recently constructed synthetic pathway to produce d-glucaric acid, a "top value-added chemical" from biomass. a simple and specific assay of d-glucuronate would be useful for studying these processes, but existing assays are either time-consuming or nonspecific. using uronate dehydrogenase cloned from agrobacterium tumefaciens, we developed an assay for d-glucuronate with a detection limit of 5 microm. thi ... | 2009 | 19481054 |
| rna binding by the brome mosaic virus capsid protein and the regulation of viral rna accumulation. | viral capsid proteins (cps) can regulate gene expression and encapsulate viral rnas. low-level expression of the brome mosaic virus (bmv) cp was found to stimulate viral rna accumulation, while higher levels inhibited translation and bmv rna replication. regulation of translation acts through an rna element named the b box, which is also critical for the replicase assembly. the bmv cp has also been shown to preferentially bind to an rna element named slc that contains the core promoter for genom ... | 2009 | 19481091 |
| the transcription factor abi4 is a regulator of mitochondrial retrograde expression of alternative oxidase1a. | plant cells integrate signals from external sources and from organelles to regulate gene expression, referred to as anterograde and retrograde signaling, respectively. functional characterization of the promoter of alternative oxidase1a (aox1a) from arabidopsis (arabidopsis thaliana), a marker for mitochondrial retrograde response, was carried out by testing the ability of the aox1a promoter to drive expression of the reporter gene gus. this approach identified a strong repressor element, design ... | 2009 | 19482916 |
| negative regulation of systemic acquired resistance by replication factor c subunit3 in arabidopsis. | systemic acquired resistance (sar) is a plant immune response induced by local necrotizing pathogen infections. expression of sar in arabidopsis (arabidopsis thaliana) plants correlates with accumulation of salicylic acid (sa) and up-regulation of pathogenesis-related (pr) genes. sa is an essential and sufficient signal for sar. in a genetic screen to search for negative regulators of pr gene expression and sar, we found a new mutant that is hypersensitive to sa and exhibits enhanced induction o ... | 2009 | 19482917 |
| agrobacterium tumefaciens virc2 enhances t-dna transfer and virulence through its c-terminal ribbon-helix-helix dna-binding fold. | agrobacterium tumefaciens virc2 stimulates processing of single-stranded t-dna that is translocated into plants to induce tumor formation, but how virc2 functions is unclear. here, we report the 1.7-a x-ray crystal structure of its trypsin-resistant c-terminal domain, virc2(82-202), which reveals a form of the ribbon-helix-helix (rhh) dna-binding fold contained within a single polypeptide chain. dna-binding assays and mutagenesis indicate that virc2 uses this rhh fold to bind double-stranded dna ... | 2009 | 19482939 |
| identification and expression analysis of wrky transcription factor genes in canola (brassica napus l.) in response to fungal pathogens and hormone treatments. | members of plant wrky transcription factor families are widely implicated in defense responses and various other physiological processes. for canola (brassica napus l.), no wrky genes have been described in detail. because of the economic importance of this crop, and its evolutionary relationship to arabidopsis thaliana, we sought to characterize a subset of canola wrky genes in the context of pathogen and hormone responses. | 2009 | 19493335 |
| activation of beta-glucan synthases by wall-bound purple acid phosphatase in tobacco cells. | wall-bound purple acid phosphatases have been shown to be potentially involved in the regulation of plant cell growth. the aim of this work was to further investigate the function of one of these phosphatases in tobacco (nicotiana tabacum), ntpap12, using transgenic cells overexpressing the enzyme. the transgenic cells exhibited a higher level of phosphatase activity in their walls. the corresponding protoplasts regenerating a cell wall exhibited a higher rate of beta-glucan synthesis and cellul ... | 2009 | 19493971 |
| characterization of the covalent and noncovalent adducts of agp1 phytochrome assembled with biliverdin and phycocyanobilin by circular dichroism and flash photolysis. | the functional role of the covalent attachment of the bilin chromophores biliverdin (bv) and phycocyanobilin (pcb) was investigated for phytochrome agp1 from agrobacterium tumefaciens using circular dichroism (cd) and transient absorption spectroscopy. covalent and noncovalent adducts with these chromophores were prepared by using wild-type (wt) agp1 (covalent bv and noncovalent pcb binding), mutant c20a in which the covalent bv binding site is eliminated, and mutant v249c in which the covalent ... | 2009 | 19496558 |
| quorum sensing differentially regulates pseudomonas aeruginosa type vi secretion locus i and homologous loci ii and iii, which are required for pathogenesis. | pseudomonas aeruginosa harbours three type vi secretion (t6s) loci. although hsi-i has been partially studied, limited knowledge is available on the homologous loci hsi-ii and hsi-iii. we show that quorum sensing (qs) differentially regulates the expression of genes at all three loci. hsi-i-associated gene expression is suppressed by both the homoserine lactone transcription factor lasr and the 4-hydroxy-2-alkylquinoline (haq) transcriptional regulator mvfr. conversely, both hsi-ii and hsi-iii l ... | 2009 | 19497948 |
| an alternative succinate (2-oxoglutarate) transport system in rhizobium tropici is induced in nodules of phaseolus vulgaris. | the rhizobial dcta permease is essential for the development of effective nitrogen-fixing bacteroids, which was correlated with its requirement for growth on c(4)-dicarboxylates. a previously described dcta mutant of rhizobium tropici ciat899, strain ga1 (dcta), however, was unexpectedly still able to grow on succinate as a sole carbon source but less efficiently than ciat899. like other rhizobial dcta mutants, ga1 was unable to grow on fumarate or malate as a carbon source and induced the forma ... | 2009 | 19502401 |
| functional and expression analyses of the cop operon, required for copper resistance in agrobacterium tumefaciens. | the copper resistance determinant coparz, which encodes a cpx-type copper atpase efflux protein, a transcriptional regulator, and a putative intracellular copper chaperone, was functionally characterized for the phytopathogenic bacterium agrobacterium tumefaciens. these genes are transcribed as an operon, and their expression is induced in response to increasing copper and silver ion concentrations in a copr-dependent fashion. analysis of the coparz promoter revealed a putative copr binding box ... | 2009 | 19502402 |
| structure-based rational design of a phosphotriesterase. | in silico substrate docking of both stereoisomers of the pesticide chlorfenvinphos (cvp) in the phosphotriesterase from agrobacterium radiobacter identified two residues (f131 and w132) that prevent productive substrate binding and cause stereospecificity. a variant (w131h/f132a) was designed that exhibited ca. 480-fold and 8-fold increases in the rate of z-cvp and e-cvp hydrolysis, respectively, eliminating stereospecificity. | 2009 | 19502439 |
| agrobacterium-mediated transient gene expression and silencing: a rapid tool for functional gene assay in potato. | potato is the third most important food crop worldwide. however, genetic and genomic research of potato has lagged behind other major crops due to the autopolyploidy and highly heterozygous nature associated with the potato genome. reliable and technically undemanding techniques are not available for functional gene assays in potato. here we report the development of a transient gene expression and silencing system in potato. gene expression or rnai-based gene silencing constructs were delivered ... | 2009 | 19503835 |
| optimization of the bioprocessing conditions for scale-up of transient production of a heterologous protein in plants using a chemically inducible viral amplicon expression system. | use of transient expression for the rapid, large-scale production of recombinant proteins in plants requires optimization of existing methods to facilitate scale-up of the process. we have demonstrated that the techniques used for agroinfiltration and induction greatly impact transient production levels of heterologous protein. a cucumber mosaic virus inducible viral amplicon (cmviva) expression system was used to transiently produce recombinant alpha-1-antitrypsin (raat) by co-infiltrating harv ... | 2009 | 19504593 |
| ethylene insensitivity conferred by a mutated arabidopsis ethylene receptor gene alters nodulation in transgenic lotus japonicus. | transgenics are used to demonstrate a causal relationship between ethylene insensitivity of a seedling legume plant, the level of ethylene receptor gene expression, lateral root growth and mesorhizobium loti-induced nodule initiation. | 2009 | 19505874 |
| identification of a new rice blast resistance gene, pid3, by genomewide comparison of paired nucleotide-binding site--leucine-rich repeat genes and their pseudogene alleles between the two sequenced rice genomes. | rice blast, caused by magnaporthe oryzae, is one of the most devastating diseases. the two major subspecies of asian cultivated rice (oryza sativa l.), indica and japonica, have shown obvious differences in rice blast resistance, but the genomic basis that underlies the difference is not clear. we performed a genomewide comparison of the major class of resistant gene family, the nucleotide-binding site-leucine-rich repeat (nbs-lrr) gene family, between 93-11 (indica) and nipponbare (japonica) wi ... | 2009 | 19506306 |
| expression of the psmta1 gene in white poplar engineered with the mat system is associated with heavy metal tolerance and protection against 8-hydroxy-2'-deoxyguanosine mediated-dna damage. | marker-free transgenic white poplar (populus alba l., cv 'villafranca') plants, expressing the psmt (a1) gene from pisum sativum for a metallothionein-like protein, were produced by agrobacterium tumefaciens-mediated transformation. the 35scamv-psmt (a1)-nost cassette was inserted into the ipt-type vector pmat22. the occurrence of the abnormal ipt-shooty phenotype allowed the visual selection of transformants, while the yeast site-specific recombination r/rs system was responsible for the excisi ... | 2009 | 19506883 |
| synthesis and assembly of porphyromonas gingivalis fimbrial protein in potato tissues. | periodontal disease caused by the gram-negative oral anaerobic bacterium porphyromonas gingivalis is thought to be initiated by the binding of p. gingivalis fimbrial protein to saliva-coated oral surfaces. to assess whether biologically active fimbrial antigen can be synthesized in edible plants, a cdna fragment encoding the c-terminal binding portion of p. gingivalis fimbrial protein, fima (amino acids 266-337), was cloned behind the mannopine synthase promoter in plant expression vector ppcv70 ... | 2009 | 19507071 |
| bacterial type iv secretion systems in human disease. | type iv secretion (t4s) systems are versatile machines involved in many processes relevant to bacterial virulence, such as horizontal dna transfer and effector translocation into human cells. a recent workshop organized by the international university of andalousia in baeza, spain, covered most aspects of bacterial t4s relevant to human disease, ranging from the structural and mechanistic analysis of the t4s systems to the physiological roles of the translocated effector proteins in subverting c ... | 2009 | 19508287 |
| polyamine accumulation in transgenic tomato enhances the tolerance to high temperature stress. | polyamines play an important role in plant response to abiotic stress. s-adenosyl-l-methionine decarboxylase (samdc) is one of the key regulatory enzymes in the biosynthesis of polyamines. in order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, samdc cdna isolated from saccharomyces cerevisiae was introduced into tomato genome by means of agrobacterium tumefaciens through leaf disc transformation. transgene and expre ... | 2009 | 19508360 |
| the t-dna integration pattern in arabidopsis transformants is highly determined by the transformed target cell. | transgenic loci obtained after agrobacterium tumefaciens-mediated transformation can be simple, but fairly often they contain multiple t-dna copies integrated into the plant genome. to understand the origin of complex t-dna loci, floral-dip and root transformation experiments were carried out in arabidopsis thaliana with mixtures of a. tumefaciens strains, each harboring one or two different t-dna vectors. upon floral-dip transformation, 6-30% of the transformants were co-transformed by multiple ... | 2009 | 19508426 |
| crystal structure of the complex between pseudomonas effector avrptob and the tomato pto kinase reveals both a shared and a unique interface compared with avrpto-pto. | resistance to bacterial speck disease in tomato (solanum lycopersicum) is activated upon recognition by the host pto kinase of either one of two sequence-unrelated effector proteins, avrpto or avrptob, from pseudomonas syringae pv tomato (pst). pto induces pst immunity by acting in concert with the prf protein. the recently reported structure of the avrpto-pto complex revealed that interaction of avrpto with pto appears to relieve an inhibitory effect of pto, allowing pto to activate prf. here, ... | 2009 | 19509331 |
| cytokinin induces expansin gene expression in melilotus alba desr. wild-type and the non-nodulating, non-mycorrhizal (nodmyc) mutant masym3. | we previously showed that applying 10(-6) m of the cytokinin 6-benzylaminopurine (bap) to uninoculated roots of masym3, a nod(-)myc(-)melilotus alba (desr.) mutant, resulted in the accumulation of maenod40 transcripts to levels similar to bap-treated wild-type roots. in contrast, inoculation with a nod(-)s. meliloti mutant expressing the trans-zeatin synthase gene of agrobacterium tumefaciens (nod(-)/ptzs(+)) did not induce maenod40 transcript accumulation in either wild-type or masym3 roots. ho ... | 2008 | 19513217 |
| arabidopsis gh3.5 regulates salicylic acid-dependent and both npr1-dependent and independent defense responses. | the cross-talk between plant disease resistance and development is fundamental to understanding systemic physiological processes during pathogen attack. our previous study showed that the arabidopsis gh3.5 gene acts as a bifunctional modulator of the salicylic acid (sa)-mediated resistance and the auxin-mediated susceptibility during the arabidopsis-pseudomonas syringae interaction as well as development. here, we further study the role and mechanism of gh3.5 involved in the sa-dependent defense ... | 2008 | 19513247 |
| agrobacterium aiming for the host chromatin: host and bacterial proteins involved in interactions between t-dna and plant nucleosomes. | agrobacterium genetically transforms its hosts by transferring a segment of dna (t-dna) into the host cell and integrating it into the host genome. integration requires a close interaction between t-dna, which is packaged into a nucleoprotein complex (t-complex) by bacterial virulence (vir) proteins, and the host chromatin. this interaction is facilitated by the host protein vip 1, which binds both to the major protein component of the t-complex, vire2, and to the core histones. recently, vip1 h ... | 2009 | 19513263 |
| molecular cloning and characterization of a novel glyoxalase i gene tagly i in wheat (triticum aestivum l.). | methylglyoxal is a kind of poisonous metabolite that can react with rna, dna and protein, which generally results in a number of side advert effects to cell. glyoxalase i is a member of glyoxalase system that can detoxify methylglyoxal. an est encoding a glyoxalase i was isolated from a ssh (suppression subtractive hybridization)-cdna library of wheat spike inoculated by fusarium graminearum. the corresponding full length gene, named tagly i, was cloned, sequenced and characterized. its genomic ... | 2010 | 19513813 |
| a novel di-acidic motif facilitates er export of the syntaxin syp31. | it is generally accepted that er protein export is largely influenced by the transmembrane domain (tmd). the situation is unclear for membrane-anchored proteins such as snares, which are anchored to the membrane by their tmd at the c-terminus. for example, in plants, sec22 and syp31 (a yeast sed5 homologue) have a 17 aa tmd but different locations (er/golgi and golgi), indicating that tmd length alone is not sufficient to explain their targeting. to establish the identity of factors that influen ... | 2009 | 19516076 |
| virus-induced gene silencing (vigs) in nicotiana benthamiana and tomato. | rna interference (rnai) is a highly specific gene-silencing phenomenon triggered by dsrna. this silencing mechanism uses two major classes of rna regulators: micrornas, which are produced from non-protein coding genes and short interfering rnas (sirnas). plants use rnai to control transposons and to exert tight control over developmental processes such as flower organ formation and leaf development. plants also use rnai to defend themselves against infection by viruses. consequently, many viruse ... | 2009 | 19516240 |
| enod40 gene expression and cytokinin responses in the nonnodulating, nonmycorrhizal (nodmyc) mutant, masym3, of melilotus alba desr. | several nonnodulating, nonmycorrhizal (nod(-)myc(-)) mutants of melilotus alba desr. (white sweetclover) have been described. however, the details of their responses to sinorhizobium meliloti have not been fully elucidated. we investigated rhizobial entry and colonization using confocal scanning laser microscopy on the masym1-5 mutants and isolated an early nodulin (enod40) gene from wild-type m. alba. we focused on masym3, the least responsive of the mutants to s. meliloti and va-fungi, to dete ... | 2007 | 19516966 |
| substrate-induced conformational changes in the essential peripheral membrane-associated mannosyltransferase pima from mycobacteria: implications for catalysis. | phosphatidyl-myo-inositol mannosyltransferase a (pima) is an essential glycosyltransferase (gt) involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (pims), which are key components of the mycobacterial cell envelope. pima is the paradigm of a large family of peripheral membrane-binding gts for which the molecular mechanism of substrate/membrane recognition and catalysis is still unknown. strong evidence is provided showing that pima undergoes significant conformational changes u ... | 2009 | 19520856 |
| sorting of gfp tagged ntsyr1, an aba related syntaxin. | exocytosis molecular mechanisms in plant cells are not fully understood. the full characterization of molecular determinants, such as snares, for the specificity in vesicles delivery to the plasma membrane should shed some light on these mechanisms. nicotiana tabacum syntaxin 1 (ntsyr1 or syp121) is a snare protein required for aba control of ion channels and appears involved in the exocytosis of exogenous markers.ntsyr1 is mainly localized on the plasma membrane, but when over expressed the pro ... | 2006 | 19521480 |
| agrobacterium-mediated transformation of ruta graveolens l. | agrobacterium tumefaciens is used to develop a genetic transformation method for a medicinal plant ruta graveolens. the direct plant regeneration strategy is preferred to callus line establishment. in vitro seedlings, 2- -to 3-wk-old, are used to excise hypocotyls and co-cultivated for 3 d with a. tumefaciens strain c58c1rif containing plasmid ptde4 harbouring neomycin phosphotransferase (npt ii, kanamycin resistance) and beta-glucuronidase encoding genes. the southern blot analysis has shown th ... | 2009 | 19521849 |
| increased vincristine production from agrobacterium tumefaciens c58 induced shooty teratomas of catharanthus roseus g. don. | dimeric indole alkaloids are used extensively for cancer therapy. agrobacterium tumefaciens c58 strain was used for induction of shooty teratoma in catharanthus roseus using epicotyl and stem node explants. the transformed nature of shooty teratomas was confirmed by nopaline assay. growth kinetics of shooty teratomas depicted maximum growth during 21-24 days of culture. dimeric alkaloid vincristine in the transformed cultures was present at a concentration of 0.011 that was tenfold higher compar ... | 2009 | 19521912 |
| expression of a gfp gene in penicillium nordicum under control of the promoter of the ochratoxin a polyketide synthase gene. | a gfp reporter gene strain of penicillium nordicum was constructed in order to be able to study the influence of environmental parameters on ochratoxin a biosynthesis. to introduce the gfp gene an agrobacterium tumefaciens mediated transformation system (atmt) for p. nordicum was established resulting in a transformation efficiency of about 60 transformants per microg of dna. the selection principle was based on the hygromycin b resistance gene located on the ti-dna fragment of the binary vector ... | 2009 | 19525025 |
| identification of an aox system that requires cytochrome c in the highly arsenic-resistant bacterium ochrobactrum tritici scii24. | microbial biotransformations have a major impact on environments contaminated with toxic elements, including arsenic, resulting in an increasing interest in strategies responsible for how bacteria cope with arsenic. in the present work, we investigated the metabolism of this metalloid in the bacterium ochrobactrum tritici scii24. this heterotrophic organism contains two different ars operons and is able to oxidize arsenite to arsenate. the presence of arsenite oxidase genes in this organism was ... | 2009 | 19525272 |
| a novel cation-dependent o-methyltransferase involved in anthocyanin methylation in grapevine. | anthocyanins are major pigments in colored grape (vitis vinifera) berries, and most of them are monomethoxylated or dimethoxylated. we report here the functional characterization of an anthocyanin o-methyltransferase (aomt) from grapevine. the expression pattern in two cultivars with different anthocyanin methylation profiles (syrah and nebbiolo) showed a peak at start ripening (véraison), when the concentrations of all methylated anthocyanins begin to increase. the purified recombinant aomt pro ... | 2009 | 19525322 |
| resistance to the pseudomonas syringae effector hopa1 is governed by the tir-nbs-lrr protein rps6 and is enhanced by mutations in srfr1. | the pseudomonas syringae-arabidopsis (arabidopsis thaliana) interaction is an extensively studied plant-pathogen system. arabidopsis possesses approximately 150 putative resistance genes encoding nucleotide binding site (nbs) and leucine-rich repeat (lrr) domain-containing proteins. the majority of these belong to the toll/interleukin-1 receptor (tir)-nbs-lrr (tnl) class. comparative studies with the coiled-coil-nbs-lrr genes rps2, rpm1, and rps5 and isogenic p. syringae strains expressing singl ... | 2009 | 19525323 |
| the role of acidocalcisomes in parasitic protists. | acidocalcisomes are acidic organelles with a high concentration of phosphorus present as pyrophosphate (pp(i)) and polyphosphate (poly p) complexed with calcium and other cations. the acidocalcisome membrane contains a number of pumps (ca(2+)-atpase, v-h(+)-atpase, h(+)-ppase), exchangers (na(+)/h(+), ca(2+)/h(+)), and channels (aquaporins), while its matrix contains enzymes related to pp(i) and poly p metabolism. acidocalcisomes have been observed in pathogenic, as well as non-pathogenic prokar ... | 2009 | 19527347 |
| cloning of a high-affinity k+ transporter gene puthkt2;1 from puccinellia tenuiflora and its functional comparison with oshkt2;1 from rice in yeast and arabidopsis. | a high-affinity k+ transporter puthkt2;1 cdna was isolated from the salt-tolerant plant puccinellia tenuiflora. expression of puthkt2;1 was induced by both 300 mm nacl and k+-starvation stress in roots, but only slightly regulated by those stresses in shoots. puthkt2;1 transcript levels in 300 mm nacl were doubled by the depletion of potassium. yeast transformed with puthkt2;1, like those transformed with phahkt2;1 from salt-tolerant reed plants (phragmites australis), (i) were able to take up k ... | 2009 | 19528529 |
| hos3, an elo-like gene, inhibits effects of aba and implicates a s-1-p/ceramide control system for abiotic stress responses in arabidopsis thaliana. | a hyper-osmotically sensitive mutant of arabidopsis thaliana, designated hos3-1 (high expression of osmotically responsive genes), was identified based on its hyper-luminescence of rd29a:luc promoter fusion plants upon treatment with nacl and aba. these responses implicate the disrupted gene as a direct or indirect negative regulator of the rd29a stress-responsive pathway. by sequencing the flanking regions of the t-dna borders, it was determined that the disrupted gene is at locus at4g36830, an ... | 2009 | 19529829 |
| nucleotide substitutions in rolc and nptii gene sequences during long-term cultivation of panax ginseng cell cultures. | it has been shown previously that the rolc gene from agrobacterium tumefaciens gene was stably and highly expressed in 15-year-old panax ginseng transgenic cell cultures. in the present report, we analyze in detail the nucleotide composition of the rolc and nptii (neomycin phosphotransferase) genes, which is the selective marker used for transgenic cell cultures of p. ginseng. it has been established that the nucleotide sequences of the rolc and nptii genes underwent mutagenesis during cultivati ... | 2009 | 19529942 |
| fine-structured multi-scaling long-range correlations in completely sequenced genomes--features, origin, and classification. | the sequential organization of genomes, i.e. the relations between distant base pairs and regions within sequences, and its connection to the three-dimensional organization of genomes is still a largely unresolved problem. long-range power-law correlations were found using correlation analysis on almost the entire observable scale of 132 completely sequenced chromosomes of 0.5 x 10(6) to 3.0 x 10(7) bp from archaea, bacteria, arabidopsis thaliana, saccharomyces cerevisiae, schizosaccharomyces po ... | 2009 | 19533117 |
| transgenic ramie [boehmeria nivea (l.) gaud.]: factors affecting the efficiency of agrobacterium tumefaciens-mediated transformation and regeneration. | in the present study, an efficient agrobacterium-mediated gene transformation system was developed for ramie [boehmeria nivea (l.) gaud.] based on the examinations of several factors affecting plant transformation efficiency. the effects of agrobacterium cell density, acetosyringone, co-cultivation temperature, co-cultivation duration, co-cultivation photoperiod and ph on stable transformation were evaluated. agrobacterium at a concentration of od = 0.5-0.8 improved the efficiency of transformat ... | 2009 | 19533144 |
| ppor is a conserved unpaired luxr solo of pseudomonas putida which binds n-acyl homoserine lactones. | only a small number of pseudomonas putida strains possess the typical n-acyl homoserine lactone quorum sensing system (ahl qs) that consists of a modular luxr family protein and its cognate luxi homolog that produces the ahl signal. moreover, ahl qs systems in p. putida strains are diverse in the type of ahls they produce and the phenotypes that they regulate. | 2009 | 19534812 |
| molecular characterization of the plant virus genus ourmiavirus and evidence of inter-kingdom reassortment of viral genome segments as its possible route of origin. | ourmia melon virus (oumv), epirus cherry virus (epcv) and cassava virus c (csvc) are three species placed in the genus ourmiavirus. we cloned and sequenced their rna genomes. the sizes of the three genomic rnas of oumv, the type member of the genus, were 2814, 1064 and 974 nt and each had one open reading frame. rna1 potentially encoded a 97.5 kda protein carrying the gdd motif typical of rna-dependent rna polymerases (rdrps). the putative rdrps of ourmiaviruses are distantly related to known vi ... | 2009 | 19535502 |
| type iv secretion system of anaplasma phagocytophilum and ehrlichia chaffeensis. | the intracellular bacterial pathogens ehrlichia chaffeensis and anaplasma phagocytophilum have evolved to infect leukocytes and hijack biological compounds and processes of these host defensive cells. bacterial type iv secretion (t4s) system transports macromolecules across the membrane in an atp-dependent manner and is increasingly recognized as a virulence factor delivery mechanism that allows pathogens to modulate eukaryotic cell functions for their own benefit. genes encoding t4s system homo ... | 2009 | 19538269 |
| genetic determinants of symptoms on viral dna satellites. | begomovirus-dna-beta disease complexes induce different symptom phenotypes in their hosts. to investigate the genetic determinants of the phenotypic differences, nicotiana spp. and tomato plants were inoculated with infectious clones of tobacco curly shoot virus (tbcsv)/tbcsv dna-beta (tbcsb) and tomato yellow leaf curl china virus (tylccnv)/tylccnv dna-beta (tylccnb) pseudorecombinants and showed that tylccnb induced characteristic vein-thickening and enation symptoms, while tbcsb only slightly ... | 2009 | 19542327 |
| comparative genome-wide transcriptional profiling of azorhizobium caulinodans ors571 grown under free-living and symbiotic conditions. | the whole-genome sequence of the endosymbiotic bacterium azorhizobium caulinodans ors571, which forms nitrogen-fixing nodules on the stems and roots of sesbania rostrata, was recently determined. the sizes of the genome and symbiosis island are 5.4 mb and 86.7 kb, respectively, and these sizes are the smallest among the sequenced rhizobia. in the present study, a whole-genome microarray of a. caulinodans was constructed, and transcriptomic analyses were performed on free-living cells grown in ri ... | 2009 | 19542345 |
| virus-induced gene silencing, a post transcriptional gene silencing method. | virus-induced gene silencing (vigs) is one of the reverse genetics tools for analysis of gene function that uses viral vectors carrying a target gene fragment to produce dsrna which trigger rna-mediated gene silencing. there are a number of viruses which have been modified to silence the gene of interest effectively with a sequence-specific manner. therefore, different types of methodologies have been advanced and modified for vigs approach. virus-derived inoculations are performed on host plant ... | 2009 | 19547658 |
| detection of different quorum-sensing signal molecules in a virulent edwardsiella tarda strain ltb-4. | the aim of this study was to elucidate the potential quorum-sensing (qs) signal molecules of an emerging pathogen (edwardsiella tarda strain ltb-4) of cultured turbot (scophthalmus maximus). | 2010 | 19548884 |
| inactivation of a transgene due to transposition of insertion sequence (is136) of agrobacterium tumefaciens. | agrobacterium strains harbour insertion sequences, which are known to transpose into genomes as well as into ti plasmids. in this study we report the inactivation of a transgene due to transposition of the a. tumefaciens insertion sequence is136. the transposition was discovered following transformation of plant tissues, although the fidelity of the binary vector was confirmed following transformation into agrobacterium. such transpositions are rare but can occur and it is thus important to chec ... | 2009 | 19550035 |
| nodulation of sesbania species by rhizobium (agrobacterium) strain irbg74 and other rhizobia. | concatenated sequence analysis with 16s rrna, rpob and fusa genes identified a bacterial strain (irbg74) isolated from root nodules of the aquatic legume sesbania cannabina as a close relative of the plant pathogen rhizobium radiobacter (syn. agrobacterium tumefaciens). however, dna:dna hybridization with r. radiobacter, r. rubi, r. vitis and r. huautlense gave only 44%, 5%, 8% and 8% similarity respectively, suggesting that irbg74 is potentially a new species. additionally, it contained no vir ... | 2009 | 19555380 |
| agrobacterium rhizogenes-mediated transformation of superroot-derived lotus corniculatus plants: a valuable tool for functional genomics. | transgenic approaches provide a powerful tool for gene function investigations in plants. however, some legumes are still recalcitrant to current transformation technologies, limiting the extent to which functional genomic studies can be performed on. superroot of lotus corniculatus is a continuous root cloning system allowing direct somatic embryogenesis and mass regeneration of plants. recently, a technique to obtain transgenic l. corniculatus plants from superroot-derived leaves through a. tu ... | 2009 | 19555486 |