| small heat-shock protein hspl is induced by virb protein(s) and promotes virb/d4-mediated dna transfer in agrobacterium tumefaciens. | agrobacterium tumefaciens is a gram-negative plant-pathogenic bacterium that causes crown gall disease by transferring and integrating its transferred dna (t-dna) into the host genome. we characterized the chromosomally encoded alpha-crystallin-type small heat-shock protein (alpha-hsp) hspl, which was induced by the virulence (vir) gene inducer acetosyringone (as). the transcription of hspl but not three other alpha-hsp genes (hspc, hspat1, hspat2) was upregulated by as. further expression analy ... | 2009 | 19556291 |
| detailed characterization of mirafiori lettuce virus-resistant transgenic lettuce. | lettuce big-vein disease is caused by mirafiori lettuce virus (milv), which is vectored by the soil-borne fungus olpidium brassicae. a milv-resistant transgenic lettuce line was developed through introducing inverted repeats of the milv coat protein (cp) gene. here, a detailed characterization study of this lettuce line was conducted by comparing it with the parental, non-transformed 'kaiser' cultivar. there were no significant differences between transgenic and non-transgenic lettuce in terms o ... | 2010 | 19557540 |
| glycosides of arylnaphthalene lignans from acanthus mollis having axial chirality. | glycosides of arylnaphthalene lignans having axial chirality were isolated from acanthus mollis. owing to the axial chirality, their structure, including absolute configuration, was determined by means of extensive spectroscopic data such as uv, ir, ms, 1d and 2d nmr spectra, and computational chiroptical methods. a compound, 2',4-dihydroxyretrohelioxanthin (2'-hydroxy-justirumalin), has a structure containing two aromatic moieties with substituents hindering rotation about the biaryl axis. the ... | 2009 | 19559451 |
| a membrane-bound matrix-metalloproteinase from nicotiana tabacum cv. by-2 is induced by bacterial pathogens. | plant matrix metalloproteinases (mmp) are conserved proteolytic enzymes found in a wide range of monocotyledonous and dicotyledonous plant species. acting on the plant extracellular matrix, they play crucial roles in many aspects of plant physiology including growth, development and the response to stresses such as pathogen attack. | 2009 | 19563670 |
| cdna-aflp analysis reveals differential gene expression in compatible interaction of wheat challenged with puccinia striiformis f. sp. tritici. | puccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. the fungus is strictly biotrophic and thus, completely dependent on living host cells for its reproduction, which makes it difficult to study genes of the pathogen. in spite of its economic importance, little is known about the molecular basis of compatible interaction between the pathogen and wheat host. in this study, we identified wheat and p. striiformis genes ass ... | 2009 | 19566949 |
| attrp1 encodes a novel tpr protein that interacts with the ethylene receptor ers1 and modulates development in arabidopsis. | arabidopsis attrp1 is an orthologue of sltpr1, a tomato tetratricopeptide repeat protein that interacts with the tomato ethylene receptors leetr1 and nr in yeast 2-hybrid assays and in vitro, and modulates plant development. attrp1 is encoded by a single copy gene in the arabidopsis genome, and is related to tcc1, a human protein that competes with raf-1 for ras binding, and distantly related to the immunophilin-like fk-binding proteins twd1 and pas1. the former is involved in auxin transport an ... | 2009 | 19567478 |
| establishment of the winter-annual growth habit via frigida-mediated histone methylation at flowering locus c in arabidopsis. | in arabidopsis thaliana, flowering-time variation exists among accessions, and the winter-annual (late-flowering without vernalization) versus rapid-cycling (early flowering) growth habit is typically determined by allelic variation at frigida (fri) and flowering locus c (flc). fri upregulates the expression of flc, a central floral repressor, to levels that inhibit flowering, resulting in the winter-annual habit. here, we show that fri promotes histone h3 lysine-4 trimethylation (h3k4me3) in fl ... | 2009 | 19567704 |
| broad-range pcr, cloning and sequencing of the full 16s rrna gene for detection of bacterial dna in synovial fluid samples of tunisian patients with reactive and undifferentiated arthritis. | broad-range rdna pcr provides an alternative, cultivation-independent approach for identifying bacterial dna in reactive and other form of arthritis. the aim of this study was to use broad-range rdna pcr targeting the 16s rrna gene in patients with reactive and other forms of arthritis and to screen for the presence of dna from any given bacterial species in synovial fluid (sf) samples. | 2009 | 19570210 |
| maintenance of an old world betasatellite by a new world helper begomovirus and possible rapid adaptation of the betasatellite. | begomoviruses (family geminiviridae) cause major losses to crops throughout the tropical regions of the world. begomoviruses originating from the new world (nw) and the old world (ow) are genetically distinct. whereas the majority of ow begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as betasatellites), the genomes of nw begomoviruses are exclusively bipartite and do not associate with satellites. here, we show for t ... | 2009 | 19570867 |
| subcellular localization of the barley stripe mosaic virus triple gene block proteins. | barley stripe mosaic virus (bsmv) spreads from cell to cell through the coordinated actions of three triple gene block (tgb) proteins (tgb1, tgb2, and tgb3) arranged in overlapping open reading frames (orfs). our previous studies (d. m. lawrence and a. o. jackson, j. virol. 75:8712-8723, 2001; d. m. lawrence and a. o. jackson, mol. plant pathol. 2:65-75, 2001) have shown that each of these proteins is required for cell-to-cell movement in monocot and dicot hosts. we recently found (h.-s. lim, j. ... | 2009 | 19570874 |
| comparative large-scale analysis of interactions between several crop species and the effector repertoires from multiple pathovars of pseudomonas and ralstonia. | bacterial plant pathogens manipulate their hosts by injection of numerous effector proteins into host cells via type iii secretion systems. recognition of these effectors by the host plant leads to the induction of a defense reaction that often culminates in a hypersensitive response manifested as cell death. genes encoding effector proteins can be exchanged between different strains of bacteria via horizontal transfer, and often individual strains are capable of infecting multiple hosts. host p ... | 2009 | 19571308 |
| abscisic acid has a key role in modulating diverse plant-pathogen interactions. | we isolated an activation-tagged arabidopsis (arabidopsis thaliana) line, constitutive disease susceptibility2-1d (cds2-1d), that showed enhanced bacterial growth when challenged with various pseudomonas syringae strains. systemic acquired resistance and systemic pathogenesis-related gene1 induction were also compromised in cds2-1d. the t-dna insertion adjacent to nine-cis-epoxycarotenoid dioxygenase5 (nced5), one of six genes encoding the abscisic acid (aba) biosynthetic enzyme nced, caused a m ... | 2009 | 19571312 |
| dimethyltin(iv) derivatives of biologically potent substituted phenylacrylic acids: synthesis, chemical characterization and inhibitory effects on agrobacterium tumefaciens. | effect of dimethyltin(iv) complexes of different substituted phenyl acrylic acids on the ability of agrobacterium tumefaciens to cause tumours in plants was studied by using potato discs. the results demonstrated significant inhibition of tumours formation. all the compounds were synthesized and characterized by using analytical techniques, i.e. ftir, multinuclear nmr ((1)h, (13)c, (19)f and (119)sn) and mass spectrometry. these studies explain that dimethyltin(iv) derivatives exist in a deforme ... | 2009 | 19573076 |
| composite medicago truncatula plants harbouring agrobacterium rhizogenes-transformed roots reveal normal mycorrhization by glomus intraradices. | composite plants consisting of a wild-type shoot and a transgenic root are frequently used for functional genomics in legume research. although transformation of roots using agrobacterium rhizogenes leads to morphologically normal roots, the question arises as to whether such roots interact with arbuscular mycorrhizal (am) fungi in the same way as wild-type roots. to address this question, roots transformed with a vector containing the fluorescence marker dsred were used to analyse am in terms o ... | 2009 | 19574251 |
| oxi1 protein kinase is required for plant immunity against pseudomonas syringae in arabidopsis. | expression of the arabidopsis oxidative signal-inducible1 (oxi1) serine/threonine protein kinase gene (at3g25250) is induced by oxidative stress. the kinase is required for root hair development and basal defence against the oomycete pathogen hyaloperonospora parasitica, two separate h(2)o(2)-mediated processes. in this study, the role of oxi1 during pathogenesis was characterized further. null oxi1 mutants are more susceptible to both virulent and avirulent strains of the biotrophic bacterial p ... | 2009 | 19574254 |
| identification and characterization of maize and barley lsi2-like silicon efflux transporters reveals a distinct silicon uptake system from that in rice. | silicon (si) uptake has been extensively examined in rice (oryza sativa), but it is poorly understood in other gramineous crops. we identified low silicon rice 2 (lsi2)-like si efflux transporters from two important gramineous crops: maize (zea mays) and barley (hordeum vulgare). both maize and barley lsi2 expressed in xenopus laevis oocytes showed si efflux transport activity. furthermore, barley lsi2 was able to recover si uptake in a rice mutant defective in si efflux. maize and barley lsi2 w ... | 2009 | 19574435 |
| generation and identification of dna sequence flanking t-dna integration site of trichoderma atroviride mutants with high dichlorvos-degrading capacity. | a protocol for efficient agrobacterium tumefaciens-mediated transformation (atmt) of biocontrol fungus trichoderma atroviride strain t23 was developed to construct mutants with improved dichlorvos-degradation ability. a transformation frequency of 5x10(-6) was achieved. among 110 genetically stable t-dna transformants of t. atroviride t23, two transformants, amt-12 and amt-28, confirmed by southern blot analysis to have single-copy inserts of t-dna, showed an increase in dichlorvos-degradation a ... | 2009 | 19577921 |
| run-off replication of host-adaptability genes is associated with gene transfer agents in the genome of mouse-infecting bartonella grahamii. | the genus bartonella comprises facultative intracellular bacteria adapted to mammals, including previously recognized and emerging human pathogens. we report the 2,341,328 bp genome sequence of bartonella grahamii, one of the most prevalent bartonella species in wild rodents. comparative genomics revealed that rodent-associated bartonella species have higher copy numbers of genes for putative host-adaptability factors than the related human-specific pathogens. many of these gene clusters are loc ... | 2009 | 19578403 |
| sexually mature transgenic american chestnut trees via embryogenic suspension-based transformation. | the availability of a system for direct transfer of anti-fungal candidate genes into american chestnut (castanea dentata), devastated by a fungal blight in the last century, would offer an alternative or supplemental approach to conventional breeding for production of chestnut trees resistant to the blight fungus and other pathogens. by taking advantage of the strong ability of embryogenic american chestnut cultures to proliferate in suspension, a high-throughput agrobacterium tumefaciens-mediat ... | 2009 | 19578855 |
| genetic transformation of nepalese spring wheat (triticum aestivum l.) cultivars with ipt gene under the regulation of a senescence enhanced promoter from maize. | two nepalese spring wheat cultivars were transformed with an ipt gene from agrobacterium tumefaciens under the control of the senescence inducible promoter psee1 from maize using biolistic method. the resulting transgenic lines, one from pasang lahmu and seven from annapurna-1, were studied for the expression of the transgene and the phenotype characters like chlorophyll content, chlorophyll a/b ratio, ps ii quantum yield and other parameters of agronomic importance. analysis of transgene expres ... | 2009 | 19579929 |
| detection of a histidine kinase mrna in extraradical mycelium of pisolithus tinctorius induced by the plant metabolites. | the aim of this study was to test the effect of acetosyringone (as) on the accumulation of the histidine kinase coding mrna, using in vitro propagated pisolithus tinctorius. in the precontact phase of the ectomycorrhizal symbiosis, it is hypothesized that the plants releases chemicals, which are sensed by the fungal mycelium and in turn trigger the start of the symbiosis. the nature of such molecules is largely unknown; however, plant metabolite and their structural analogues have been widely us ... | 2009 | 19579944 |
| bacterial chemotaxis to atrazine and related s-triazines. | pseudomonas sp. strain adp utilizes the human-made s-triazine herbicide atrazine as the sole nitrogen source. the results reported here demonstrate that atrazine and the atrazine degradation intermediates n-isopropylammelide and cyanuric acid are chemoattractants for strain adp. in addition, the nonmetabolized s-triazine ametryn was also an attractant. the chemotactic response to these s-triazines was not specifically induced during growth with atrazine, and atrazine metabolism was not required ... | 2009 | 19581468 |
| establishment of agrobacterium tumefaciens-mediated transformation of an oleaginous fungus, mortierella alpina 1s-4, and its application for eicosapentaenoic acid producer breeding. | gene manipulation tools for an arachidonic-producing filamentous fungus, mortierella alpina 1s-4, have not been sufficiently developed. in this study, agrobacterium tumefaciens-mediated transformation (atmt) was investigated for m. alpina 1s-4 transformation, using the uracil-auxotrophic mutant (ura5(-) strain) of m. alpina 1s-4 as a host strain and the homologous ura5 gene as a selectable marker gene. furthermore, the gene for omega3-desaturase, catalyzing the conversion of n-6 fatty acid to n- ... | 2009 | 19581481 |
| repression of flowering by the mir172 target smz. | a small mobile protein, encoded by the flowering locus t (ft) locus, plays a central role in the control of flowering. ft is regulated positively by constans (co), the output of the photoperiod pathway, and negatively by flc, which integrates the effects of prolonged cold exposure. here, we reveal the mechanisms of regulation by the microrna mir172 target schlafmutze (smz), a potent repressor of flowering. whole-genome mapping of smz binding sites demonstrates not only direct regulation of ft, b ... | 2009 | 19582143 |
| agrobacterium-mediated gene transfer to cereal crop plants: current protocols for barley, wheat, triticale, and maize. | the development of powerful "omics" technologies has enabled researchers to identify many genes of interest for which comprehensive functional analyses are highly desirable. however, the production of lines which ectopically express recombinant genes, or those in which endogenous genes are knocked down via stable transformation, remains a major bottleneck for the association between genetics and gene function in monocotyledonous crops. methods of effective dna transfer into regenerable cells of ... | 2009 | 19584907 |
| domain swapping reveals that the n-terminal domain of the sensor kinase kdpd in escherichia coli is important for signaling. | the kdpd/kdpe two-component system of escherichia coli regulates expression of the kdpfabc operon encoding the high affinity k+ transport system kdpfabc. the input domain of kdpd comprises a domain that belongs to the family of universal stress proteins (usp). it has been previously demonstrated that uspc binds to this domain, resulting in kdpd/kdpe scaffolding under salt stress. however the mechanistic significance of this domain for signaling remains unclear. here, we employed a "domain swappi ... | 2009 | 19589130 |
| genome-scale identification of legionella pneumophila effectors using a machine learning approach. | a large number of highly pathogenic bacteria utilize secretion systems to translocate effector proteins into host cells. using these effectors, the bacteria subvert host cell processes during infection. legionella pneumophila translocates effectors via the icm/dot type-iv secretion system and to date, approximately 100 effectors have been identified by various experimental and computational techniques. effector identification is a critical first step towards the understanding of the pathogenesis ... | 2009 | 19593377 |
| regulation of hydantoin-hydrolyzing enzyme expression in agrobacterium tumefaciens strain ru-ae01. | optically pure d-: amino acids, like d-: hydroxyphenylglycine, are used in the semi-synthetic production of pharmaceuticals. they are synthesized industrially via the biocatalytic hydrolysis of p-hydroxyphenylhydantoin using enzymes derived from agrobacterium tumefaciens strains. the reaction proceeds via a three-step pathway: (a) the ring-opening cleavage of the hydantoin ring by a d-: hydantoinase (encoded by hyuh), (b) conversion of the resultant d-: n-carbamylamino acid to the corresponding ... | 2009 | 19597814 |
| identification of amino acid residues of the pheromone-binding domain of the transcription factor trar that are required for positive control. | genes required for replication and for conjugal transfer of the agrobacterium tumefaciens ti plasmid are regulated by the quorum sensing transcription factor trar, whose n-terminal domain binds to the pheromone 3-oxo-octanoylhomoserine lactone (oohl) and whose c-terminal domain binds to specific dna sequences called tra boxes. here, we constructed 117 mutants, altering 103 surface-exposed amino acid residues of the trar n-terminal domain. each mutant was tested for activation of the trai promote ... | 2009 | 19602141 |
| agrobacterium-mediated transformation of meadow fescue (festuca pratensis huds.). | meadow fescue (festuca pratensis huds.) is an important cool-season forage grass in europe and asia. we developed a protocol for producing meadow fescue transgenic plants mediated by agrobacterium tumefaciens transformation. embryogenic calli derived from mature embryos were transformed with a. tumefaciens strain agl1 carrying the binary vector pdm805, coding for the phosphinothricin acetyltransferase (bar) and beta-glucuronidase (uida) genes. bialaphos was used as the selective agent throughout ... | 2009 | 19603171 |
| genomic resources of magnaporthe oryzae (gromo): a comprehensive and integrated database on rice blast fungus. | magnaporthe oryzae, rice blast fungus, is the most devastating pathogen of rice. it has emerged as a model phytopathogen for the study of host-pathogen interactions. a large body of data has been generated on different aspects of biology of this fungus and on host-pathogen interactions. however, most of the data is scattered and is not available as a single resource for researchers in this field. | 2009 | 19604367 |
| identification of beijerinckia fluminensis strains cip 106281t and uqm 1685t as rhizobium radiobacter strains, and proposal of beijerinckia doebereinerae sp. nov. to accommodate beijerinckia fluminensis lmg 2819. | during the course of a research project with free-living, nitrogen-fixing bacteria, we determined the 16s rrna gene sequence of beijerinckia fluminensis strains uqm 1685t and cip 106281t and discovered that they were only 90.6-91.2% similar to the sequences of strains of other beijerinckia species and subspecies. moreover, the highest similarity to these sequences (99.7%) corresponded to strains of rhizobium radiobacter (including agrobacterium tumefaciens). other diagnostic features confirmed t ... | 2009 | 19620377 |
| [genetic transformation of bt gene into sorghum (sorghum bicolor l.) mediated by agrobacterium tumefaciens]. | sorghum (sorghum bicolor l.) was one of the most important crops in the world next to wheat, rice, maize, soybean and barley. using the callus derived from immature inflorescence as the recipients, we efficiently transformed sorghum varieties 115, ics21b and 5-27 with the insecticidal bacillus thuringiensis (bt) cry1ab gene carried in the t-dna of binary vectors which contained hygromycin resistance gene and gus gene via agrobacterium tumefaciens. after gradient selection with hygromycin, a tota ... | 2009 | 19621584 |
| downy mildew resistance in arabidopsis by mutation of homoserine kinase. | plant disease resistance is commonly triggered by early pathogen recognition and activation of immunity. an alternative form of resistance is mediated by recessive downy mildew resistant 1 (dmr1) alleles in arabidopsis thaliana. map-based cloning revealed that dmr1 encodes homoserine kinase (hsk). six independent dmr1 mutants each carry a different amino acid substitution in the hsk protein. amino acid analysis revealed that dmr1 mutants contain high levels of homoserine that is undetectable in ... | 2009 | 19622802 |
| interaction of the tobacco mosaic virus replicase protein with a nac domain transcription factor is associated with the suppression of systemic host defenses. | an interaction between the helicase domain of the tobacco mosaic virus (tmv) 126-/183-kda replicase protein(s) and the arabidopsis thaliana nac domain transcription factor ataf2 was identified via yeast two-hybrid and in planta immunoprecipitation assays. ataf2 is transcriptionally induced in response to tmv infection, and its overexpression significantly reduces virus accumulation. proteasome inhibition studies suggest that ataf2 is targeted for degradation during virus infection. the transcrip ... | 2009 | 19625399 |
| the arabidopsis resurrection1 gene regulates a novel antagonistic interaction in plant defense to biotrophs and necrotrophs. | we report a role for the arabidopsis (arabidopsis thaliana) resurrection1 (rst1) gene in plant defense. the rst1 mutant exhibits enhanced susceptibility to the biotrophic fungal pathogen erysiphe cichoracearum but enhanced resistance to the necrotrophic fungal pathogens botrytis cinerea and alternaria brassicicola. rst1 encodes a novel protein that localizes to the plasma membrane and is predicted to contain 11 transmembrane domains. disease responses in rst1 correlate with higher levels of jasm ... | 2009 | 19625635 |
| the novel genes emmabc are associated with exopolysaccharide production, motility, stress adaptation, and symbiosis in sinorhizobium meliloti. | the nitrogen-fixing symbiont sinorhizobium meliloti senses and responds to constantly changing environmental conditions as it makes its way through the soil in search of its leguminous plant host, medicago sativa (alfalfa). as a result, this bacterium regulates various aspects of its physiology in order to respond appropriately to stress, starvation, and competition. for example, exopolysaccharide production, which has been shown to play an important role in the ability of s. meliloti to success ... | 2009 | 19633078 |
| potential role of group iic-attc introns in integron cassette formation. | integrons are natural expression vectors in which gene cassettes are integrated downstream of a promoter region by a site-specific recombinase. gene cassettes usually consist of a single gene followed by a recombination site designated attc. a major unanswered question is how a gene becomes associated with an attc site. here, we investigate the potential role of a specific lineage of group iic introns, named group iic-attc, in cassette formation. group iic-attc introns preferentially target attc ... | 2009 | 19633079 |
| molecular basis of chve function in sugar binding, sugar utilization, and virulence in agrobacterium tumefaciens. | chve is a chromosomally encoded protein in agrobacterium tumefaciens that mediates a sugar-induced increase in virulence (vir) gene expression through the activities of the vira/virg two-component system and has also been suggested to be involved in sugar utilization. the chve protein has homology to several bacterial periplasmic sugar-binding proteins, such as the ribose-binding protein and the galactose/glucose-binding protein of escherichia coli. in this study, we provide direct evidence that ... | 2009 | 19633083 |
| diversity and evolution of effector loci in natural populations of the plant pathogen melampsora lini. | genetic variation for pathogen infectivity is an important driver of disease incidence and prevalence in both natural and managed systems. here, we use the interaction between the rust pathogen, melampsora lini, and two host plants, linum marginale and linum usitatissimum, to examine how host-pathogen interactions influence the maintenance of polymorphism in genes underlying pathogen virulence. extensive sequence variation at two effector loci (avrp123, avrp4) was found in m. lini isolates colle ... | 2009 | 19633228 |
| molecular and biochemical characterization of atpap15, a purple acid phosphatase with phytase activity, in arabidopsis. | purple acid phosphatase (pap) catalyzes the hydrolysis of phosphate monoesters and anhydrides to release phosphate within an acidic ph range. among the 29 pap-like proteins in arabidopsis (arabidopsis thaliana), atpap15 (at3g07130) displays a greater degree of amino acid identity with soybean (glycine max; gmphy) and tobacco (nicotiana tabacum) pap (ntpap) with phytase activity than the other atpaps. in this study, transgenic arabidopsis that expressed an atpap15 promoterbeta-glucuronidase (gus) ... | 2009 | 19633233 |
| [high expression of thymosin alpha 1 by injecting recombinant pvx vector into the tomato fruit]. | for expression of foreign genes in plant, plant virus vector provides many advantages, such as high expression level, short expression period and wider plant hosts. in the present study, we report the expression of thymosin alpha 1 (talpha1) in tomato fruits by potato virus x (pvx) vector. talpha1 gene fragment from plasmid pgem-t containing talpha1 gene was cloned into plant virus vector pgr107 and the resulting pgr107-talpha1 plasmid was confirmed by digestion with sal i and cla i. to express ... | 2009 | 19637628 |
| a polarity probe for monitoring light-induced structural changes at the entrance of the chromophore pocket in a bacterial phytochrome. | light-induced structural changes at the entrance of the chromophore pocket of agp1 phytochrome were investigated by using a thiol-reactive fluorescein derivative that is covalently attached to the genuine chromophore binding site (cys-20) and serves as a polarity probe. in the apoprotein, the absorption spectrum of bound fluorescein is red-shifted with respect to that of the free label suggesting that the probe enters the hydrophobic chromophore pocket. assembly of this construct with the chromo ... | 2009 | 19640848 |
| rapid real-time pcr assays for detection of klebsiella pneumoniae with the rmpa or maga genes associated with the hypermucoviscosity phenotype: screening of nonhuman primates. | the relationship of mucoviscosity-associated (maga) and/or regulator of mucoid phenotype (rmpa) genes to the klebsiella pneumoniae hypermucoviscosity (hmv) phenotype has been reported. we previously demonstrated that rmpa+ k. pneumoniae can cause serious disease in african green monkeys and isolated rmpa+ and maga+ hmv k. pneumoniae from other species of non-human primates. to rapidly screen african green monkeys/non-human primates for these infections, we developed three real-time pcr assays. t ... | 2009 | 19644019 |
| a quorum-sensing antagonist targets both membrane-bound and cytoplasmic receptors and controls bacterial pathogenicity. | quorum sensing is a process of bacterial communication involving production and detection of secreted molecules called autoinducers. gram-negative bacteria use acyl-homoserine lactone (ahl) autoinducers, which are detected by one of two receptor types. first, cytoplasmic luxr-type receptors bind accumulated intracellular ahls. ahl-luxr complexes bind dna and alter gene expression. second, membrane-bound luxn-type receptors bind accumulated extracellular ahls. ahl-luxn complexes relay information ... | 2009 | 19647512 |
| integrative and sequence characteristics of a novel genetic element, ice6013, in staphylococcus aureus. | a survey of chromosomal variation in the st239 clonal group of methicillin-resistant staphylococcus aureus (mrsa) revealed a novel genetic element, ice6013. the element is 13,354 bp in length, excluding a 6,551-bp tn552 insertion. ice6013 is flanked by 3-bp direct repeats and is demarcated by 8-bp imperfect inverted repeats. the element was present in 6 of 15 genome-sequenced s. aureus strains, and it was detected using genetic markers in 19 of 44 diverse mrsa and methicillin-susceptible strains ... | 2009 | 19648240 |
| mutational analysis of burkholderia thailandensis quorum sensing and self-aggregation. | acyl-homoserine lactone (acyl-hsl) quorum-sensing signaling is common to many proteobacteria. acyl-hsls are synthesized by the luxi family of synthases, and the signal response is mediated by members of the luxr family of transcriptional regulators. burkholderia thailandensis is a member of a closely related cluster of three species, including the animal pathogens burkholderia mallei and burkholderia pseudomallei. members of this group have similar luxi and luxr homologs, and these genes contrib ... | 2009 | 19648250 |
| partitioning the apical domain of the arabidopsis embryo requires the bobber1 nudc domain protein. | the apical domain of the embryo is partitioned into distinct regions that will give rise to the cotyledons and the shoot apical meristem. in this article, we describe a novel screen to identify arabidopsis thaliana embryo arrest mutants that are defective in this partitioning, and we describe the phenotype of one such mutant, bobber1. bobber1 mutants arrest at the globular stage of development, they express the meristem-specific shootmeristemless gene throughout the top half of the embryo, and t ... | 2009 | 19648297 |
| the structure of a putative s-formylglutathione hydrolase from agrobacterium tumefaciens. | the structure of the atu1476 protein from agrobacterium tumefaciens was determined at 2 a resolution. the crystal structure and biochemical characterization of this enzyme support the conclusion that this protein is an s-formylglutathione hydrolase (atusfgh). the three-dimensional structure of atusfgh contains the alpha/beta hydrolase fold topology and exists as a homo-dimer. contacts between the two monomers in the dimer are formed both by hydrogen bonds and salt bridges. biochemical characteri ... | 2009 | 19653299 |
| the majority of the type iii effector inventory of pseudomonas syringae pv. tomato dc3000 can suppress plant immunity. | the pseudomonas syringae type iii protein secretion system (t3ss) and the type iii effectors it injects into plant cells are required for plant pathogenicity and the ability to elicit a hypersensitive response (hr). the hr is a programmed cell death that is associated with effector-triggered immunity (eti). a primary function of p. syringae type iii effectors appears to be the suppression of eti and pathogen-associated molecular pattern-triggered immunity (pti), which is induced by conserved mol ... | 2009 | 19656042 |
| systemic acquired resistance in soybean is regulated by two proteins, orthologous to arabidopsis npr1. | systemic acquired resistance (sar) is induced in non-inoculated leaves following infection with certain pathogenic strains. sar is effective against many pathogens. salicylic acid (sa) is a signaling molecule of the sar pathway. the development of sar is associated with the induction of pathogenesis related (pr) genes. arabidopsis non-expressor of pr1 (npr1) is a regulatory gene of the sa signal pathway 123. sar in soybean was first reported following infection with colletotrichum trancatum that ... | 2009 | 19656407 |
| reconstitution of authentic nanovirus from multiple cloned dnas. | we describe a new plant single-stranded dna (ssdna) virus, a nanovirus isolate originating from the faba bean in ethiopia. we applied rolling circle amplification (rca) to extensively copy the individual circular dnas of the nanovirus genome. by sequence analyses of more than 208 individually cloned genome components, we obtained a representative sample of eight polymorphic swarms of circular dnas, each about 1 kb in size. from these heterogeneous dna populations after rca, we inferred consensus ... | 2009 | 19656882 |
| turnip mosaic virus rna replication complex vesicles are mobile, align with microfilaments, and are each derived from a single viral genome. | nicotiana benthamiana plants were agroinoculated with an infectious cdna clone of turnip mosaic virus (tumv) that was engineered to express a fluorescent protein (green fluorescent protein [gfp] or mcherry) fused to the viral 6k2 protein known to induce vesicle formation. cytoplasmic fluorescent discrete protein structures were observed in infected cells, corresponding to the vesicles containing the viral rna replication complex. the vesicles were motile and aligned with microfilaments. intracel ... | 2009 | 19656892 |
| involvement of a broccoli coq5 methyltransferase in the production of volatile selenium compounds. | selenium (se) is an essential micronutrient for animals and humans but becomes toxic at high dosage. biologically based se volatilization, which converts se into volatile compounds, provides an important means for cleanup of se-polluted environments. to identify novel genes whose products are involved in se volatilization from plants, a broccoli (brassica oleracea var italica) cdna encoding coq5 methyltransferase (bocoq5-2) in the ubiquinone biosynthetic pathway was isolated. its function was au ... | 2009 | 19656903 |
| modulation of the poly(adp-ribosyl)ation reaction via the arabidopsis adp-ribose/nadh pyrophosphohydrolase, atnudx7, is involved in the response to oxidative stress. | here, we assessed modulation of the poly(adp-ribosyl)ation (par) reaction by an arabidopsis (arabidopsis thaliana) adp-ribose (rib)/nadh pyrophosphohydrolase, atnudx7 (for arabidopsis nudix hydrolase 7), in atnudx7-overexpressed (pro(35s):atnudx7) or atnudx7-disrupted (ko-nudx7) plants under normal conditions and oxidative stress caused by paraquat treatment. levels of nadh and adp-rib were decreased in the pro(35s):atnudx7 plants but increased in the ko-nudx7 plants under normal conditions and ... | 2009 | 19656905 |
| pestilence, persistence and pathogenicity: infection strategies of bartonella. | it has been nearly two decades since the discovery of bartonella as an agent of bacillary angiomatosis in aids patients and persistent bacteremia and 'nonculturable' endocarditis in homeless people. since that time, the number of bartonella species identified has increased from one to 24, and 10 of these bacteria are associated with human disease. although bartonella is the only genus that infects human erythrocytes and triggers pathological angiogenesis in the vascular bed, the group remains un ... | 2009 | 19659429 |
| enhanced gene replacements in ku80 disruption mutants of the dermatophyte, trichophyton mentagrophytes. | the frequency of targeted gene disruption via homologous recombination is low in the clinically important dermatophyte, trichophyton mentagrophytes. the ku genes, ku70 and ku80, encode key components of the nonhomologous end-joining pathway involved in dna double-strand break repair. their deletion increases the homologous recombination frequency, facilitating targeted gene disruption. to improve the homologous recombination frequency in t. mentagrophytes, the ku80 ortholog was inactivated. the ... | 2009 | 19659498 |
| copper acquisition by the senc protein regulates aerobic respiration in pseudomonas aeruginosa pao1. | aerobic respiration of pseudomonas aeruginosa involves four terminal oxidases belonging to the heme-copper family (that is, three cytochrome c oxidases and one quinol oxidase) plus one copper-independent, cyanide-insensitive quinol oxidase (cio). the pa0114 gene encoding an sco1/senc-type protein, which is known to be important for copper delivery to cytochrome c in yeast, rhodobacter spp. and agrobacterium tumefaciens, was found to be important for copper acquisition and aerobic respiration in ... | 2009 | 19659575 |
| quantitative fitness effects of infection in a gene-for-gene system. | * it is often assumed that pathogen infection decreases plant fitness, thereby driving the evolution of plant resistance (r) genes. however, the impact of bacterial pathogens on fitness has been shown to be relatively subtle, ranging from positive to negative. * in this study, we focus on the rps5-mediated resistance in arabidopsis thaliana and examine the fitness effects of resistance by experimentally infecting resistant (r) and susceptible (s) plants with a natural avirulent pseudomonas syrin ... | 2009 | 19659661 |
| mini-tn7 vectors as genetic tools for gene cloning at a single copy number in an industrially important and phytopathogenic bacteria, xanthomonas spp. | transposon mini-tn7 vectors insert into the chromosome of several gram-negative bacteria in a site-specific manner. here, we showed the application of mini-tn7 as single copy site-specific integration vector system for xanthomonas campestris pv. campestris. the transposition of the mini-tn7 into the bacterial genome was detected at a tn7 attachment (atttn7) site located downstream of glms1. furthermore, using a newly constructed vector pbbr1flp2 containing the flipase (flp) recombinase for site- ... | 2009 | 19659730 |
| deletion of host histone acetyltransferases and deacetylases strongly affects agrobacterium-mediated transformation of saccharomyces cerevisiae. | agrobacterium tumefaciens is a plant pathogen that genetically transforms plant cells by transferring a part of its ti-plasmid, the t-strand, to the host cell. under laboratory conditions, it can also transform cells from many different nonplant organisms, including the yeast saccharomyces cerevisiae. collections of s. cerevisiae strains have been developed with systematic deletion of all coding sequences. here, we used these collections to identify genes involved in the agrobacterium-mediated t ... | 2009 | 19659745 |
| analysis of complete genome sequence of neorickettsia risticii: causative agent of potomac horse fever. | neorickettsia risticii is an obligate intracellular bacterium of the trematodes and mammals. horses develop potomac horse fever (phf) when they ingest aquatic insects containing encysted n. risticii-infected trematodes. the complete genome sequence of n. risticii illinois consists of a single circular chromosome of 879 977 bp and encodes 38 rna species and 898 proteins. although n. risticii has limited ability to synthesize amino acids and lacks many metabolic pathways, it is capable of making m ... | 2009 | 19661282 |
| induction of protein body formation in plant leaves by elastin-like polypeptide fusions. | elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'vpgxg' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. in addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. this study's main objectives were to determine the g ... | 2009 | 19664215 |
| bell-like homeodomain selectively regulates the high-irradiance response of phytochrome a. | plant responses mediated by phytochrome a display a first phase saturated by transient light signals and a second phase requiring sustained excitation with far-red light (fr). these discrete outcomes, respectively so-called very-low-fluence response (vlfr) and high-irradiance response (hir), are appropriate in different environmental and developmental contexts but the mechanisms that regulate the switch remain unexplored. promoter analysis of a light-responsive target gene revealed a motif neces ... | 2009 | 19666535 |
| identification of tyrosylprotein sulfotransferase in arabidopsis. | tyrosine sulfation is a posttranslational modification common in peptides and proteins synthesized by the secretory pathway in most eukaryotes. in plants, this modification is critical for the biological activities of a subset of peptide hormones such as psk and psy1. in animals, tyrosine sulfation is catalyzed by golgi-localized type ii transmembrane proteins called tyrosylprotein sulfotransferases (tpsts). however, no orthologs of animal tpst genes have been found in plants, suggesting that pl ... | 2009 | 19666544 |
| surface colonization by marine roseobacters: integrating genotype and phenotype. | the roseobacter clade is a broadly distributed, abundant, and biogeochemically relevant group of marine bacteria. representatives are often associated with organic surfaces in disparate marine environments, suggesting that a sessile lifestyle is central to the ecology of lineage members. the importance of surface association and colonization has been demonstrated recently for select strains, and it has been hypothesized that production of antimicrobial agents, cell density-dependent regulatory m ... | 2009 | 19666726 |
| intra- and interspecies conjugal transfer of tn916-like elements from lactococcus lactis in vitro and in vivo. | tetracycline-resistant lactococcus lactis strains originally isolated from polish raw milk were analyzed for the ability to transfer their antibiotic resistance genes in vitro, using filter mating experiments, and in vivo, using germfree rats. four of six analyzed l. lactis isolates were able to transfer tetracycline resistance determinants in vitro to l. lactis bu2-60, at frequencies ranging from 10(-5) to 10(-7) transconjugants per recipient. three of these four strains could also transfer res ... | 2009 | 19666731 |
| the reversed terminator of octopine synthase gene on the agrobacterium ti plasmid has a weak promoter activity in prokaryotes. | agrobacterium tumefaciens transfers dna from its ti plasmid to plant host cells. the genes located within the transferred dna of ti plasmid including the octopine synthase gene (ocs) are expressed in plant host cells. the 3'-flanking region of ocs gene, known as ocs terminator, is widely used as a transcriptional terminator of the transgenes in plant expression vectors. in this study, we found the reversed ocs terminator (3'-ocs-r) could drive expression of hygromycin phosphotransferase ii gene ... | 2010 | 19669666 |
| the mediator complex subunit pft1 is a key regulator of jasmonate-dependent defense in arabidopsis. | jasmonate signaling plays an important role in both plant defense and development. here, we have identified a subunit of the mediator complex as a regulator of the jasmonate signaling pathway in arabidopsis thaliana. the mediator complex is a conserved multiprotein complex that acts as a universal adaptor between transcription factors and the rna polymerase ii transcriptional machinery. we report that the phytochrome and flowering time1 (pft1) gene, which encodes the mediator25 subunit of mediat ... | 2009 | 19671879 |
| proteolysis of a negative regulator of innate immunity is dependent on resistance genes in tomato and nicotiana benthamiana and induced by multiple bacterial effectors. | rpm1-interacting protein 4 (rin4), a negative regulator of the basal defense response in plants, is targeted by multiple bacterial virulence effectors. we show that rin4 degradation is induced by the effector avrpto from pseudomonas syringae and that this degradation in solanaceous plants is dependent on the resistance protein, pto, a protein kinase, and prf, a nucleotide binding site-leucine-rich repeat protein. our data demonstrate overlap between two of the best-characterized pathways for rec ... | 2009 | 19671880 |
| multiple antibiotic resistance in arabidopsis is conferred by mutations in a chloroplast-localized transport protein. | widespread antibiotic resistance is a major public health concern, and plants represent an emerging antibiotic exposure route. recent studies indicate that crop plants fertilized with antibiotic-laden animal manure accumulate antibiotics; however, the molecular mechanisms of antibiotic entry and subcellular partitioning within plant cells remain unknown. here, we report that mutations in the arabidopsis (arabidopsis thaliana) locus multiple antibiotic resistance1 (mar1) confer resistance, while ... | 2009 | 19675150 |
| arabidopsis actin-related protein arp5 in multicellular development and dna repair. | actin-related protein 5 (arp5) is a conserved subunit of the ino80 chromatin-remodeling complex in yeast and mammals. we have characterized the expression and subcellular distribution of arabidopsis thaliana arp5 and explored its role in the epigenetic control of multicellular development and dna repair. arp5-specific monoclonal antibodies localized arp5 protein to the nucleoplasm of interphase cells in arabidopsis and nicotiana tabacum. arp5 promoter-reporter fusions and the arp5 protein are ub ... | 2009 | 19679120 |
| global position analysis of the pseudomonas aeruginosa quorum-sensing transcription factor lasr. | in pseudomonas aeruginosa quorum sensing (qs), the transcriptional regulator lasr controls the expression of more than 300 genes. several of these genes are activated indirectly via a second, subordinate qs regulator, rhlr. conserved sequence elements upstream of individual other genes have been shown to bind lasr in vitro. to comprehensively identify all regions that are bound by lasr in vivo, we employed chromatin immunoprecipitation in conjunction with microarray analysis. we identified 35 pu ... | 2009 | 19682264 |
| cell-free escherichia coli-based system to screen for quorum-sensing molecules interacting with quorum receptor proteins of streptomyces coelicolor. | quorum sensing (qs) is mediated by small molecules and involved in diverse cellular functions, such as virulence, biofilm formation, secondary metabolism, and cell differentiation. in this study, we developed a rapid and effective screening tool based on a cell-free escherichia coli-based expression system to identify qs molecules of streptomyces. the binding of qs molecules to gamma-butyrolactone receptor scbr was monitored by changes in the expression levels of the green fluorescent protein re ... | 2009 | 19684180 |
| expression of pyrococcus furiosus superoxide reductase in arabidopsis enhances heat tolerance. | plants produce reactive oxygen species (ros) in response to environmental stresses sending signaling cues, which, if uncontrolled, result in cell death. like other aerobic organisms, plants have ros-scavenging enzymes, such as superoxide dismutase (sod), which removes superoxide anion radical (o(2)(-)) and prevents the production and buildup of toxic free radicals. however, increasing the expression of cytosolic sods is complex, and increasing their production in vivo has proven to be challengin ... | 2009 | 19684226 |
| mate transporters facilitate vacuolar uptake of epicatechin 3'-o-glucoside for proanthocyanidin biosynthesis in medicago truncatula and arabidopsis. | expression of the arabidopsis thaliana myb transcription factor transparent testa 2 (tt2) in medicago trunculata hairy roots induces both proanthocyanidin accumulation and the atp-dependent vacuolar/vesicular uptake of epicatechin 3'-o-glucoside; neither process is active in control roots that do, however, possess anthocyanidin 3-o-glucoside vacuolar uptake activity. a vacuolar membrane-localized multidrug and toxic compound extrusion (mate) transporter, medicago mate1, was identified at the mol ... | 2009 | 19684242 |
| bacterial quorum-sensing network architectures. | quorum sensing is a cell-cell communication process in which bacteria use the production and detection of extracellular chemicals called autoinducers to monitor cell population density. quorum sensing allows bacteria to synchronize the gene expression of the group, and thus act in unison. here, we review the mechanisms involved in quorum sensing with a focus on the vibrio harveyi and vibrio cholerae quorum-sensing systems. we discuss the differences between these two quorum-sensing systems and t ... | 2009 | 19686078 |
| protein mislocalization in plant cells using a gfp-binding chromobody. | a key challenge in cell biology is to directly link protein localization to function. the green fluorescent protein (gfp)-binding protein, gbp, is a 13-kda soluble protein derived from a llama heavy chain antibody that binds with high affinity to gfp as well as to some gfp variants such as yellow fluorescent protein (yfp). a gbp fusion to the red fluorescent protein (rfp), a molecule termed a chromobody, was previously used to trace in vivo the localization of various animal antigens. in this st ... | 2009 | 19686537 |
| osmotic shock improves tnt1 transposition frequency in medicago truncatula cv jemalong during in vitro regeneration. | insertion mutant collections are powerful tools for genetic studies in plants. although large-scale insertional mutagenesis using t-dna is not feasible in legumes, the tnt1 tobacco retrotransposon can be used as a very efficient mutagen in the medicago truncatula r108 genotype. in this article, we show that tnt1 can also be exploited to create insertional mutants via transformation and/or regeneration in the reference cultivar jemalong. tnt1 insertional mutagenesis in jemalong following agrobact ... | 2009 | 19688215 |
| modification of tobacco plant development by sense and antisense expression of the tomato viroid-induced agc viiia protein kinase pkv suggests involvement in gibberellin signaling. | the serine-threonine protein kinase gene, designated pkv (protein kinase- viroid induced) was previously found to be transcriptionally activated in tomato plants infected with the plant pathogen potato spindle tuber viroid (pstvd). these plants exhibited symptoms of stunting, and abnormal development of leaf, root, and vascular tissues. the encoded protein, pkv, is a novel member of the agc viiia group of signal-transducing protein kinases; however, the role of pkv in plant development is unknow ... | 2009 | 19689802 |
| expression of a plant defensin in rice confers resistance to fungal phytopathogens. | transgenic rice (oryza sativa l. cv. pusa basmati 1), overexpressing the rs-afp2 defensin gene from the raphanus sativus was generated by agrobacterium tumefaciens-mediated transformation. expression levels of rs-afp2 ranged from 0.45 to 0.53% of total soluble protein in transgenic plants. it was observed that constitutive expression of rs-afp2 suppresses the growth of magnaporthe oryzae and rhizoctonia solani by 77 and 45%, respectively. no effect on plant morphology was observed in the rs-afp2 ... | 2010 | 19690975 |
| magnetic circular dichroism study of a dicobalt(ii) complex with mixed 5- and 6-coordination: a spectroscopic model for dicobalt(ii) hydrolases. | the magnetic circular dichroism (mcd) study of [co(2)(mu-oh)(mu-ph(4)dba)(tmeda)(2)(otf)], in which ph(4)dba is the dinucleating bis(carboxylate) ligand dibenzofuran-4,6-bis(diphenylacetate) and tmeda is n,n,n',n'-tetramethylethylenediamine, is presented. this complex serves as an excellent spectroscopic model for a number of dicobalt(ii) enzymes and proteins that have both the mu-hydroxo, mu-carboxylato bridging and asymmetric 6- and 5-coordination. the low-temperature mcd spectrum of the model ... | 2009 | 19691327 |
| microarray comparative genomic hybridisation analysis incorporating genomic organisation, and application to enterobacterial plant pathogens. | microarray comparative genomic hybridisation (acgh) provides an estimate of the relative abundance of genomic dna (gdna) taken from comparator and reference organisms by hybridisation to a microarray containing probes that represent sequences from the reference organism. the experimental method is used in a number of biological applications, including the detection of human chromosomal aberrations, and in comparative genomic analysis of bacterial strains, but optimisation of the analysis is desi ... | 2009 | 19696881 |
| elimination of the mycotoxin citrinin production in the industrial important strain monascus purpureus sm001. | the application of the high-producing pigments industrial strain monascus purpureus sm001 has been greatly limited by the synchronous production of mycotoxin citrinin. here we have tried both traditional mutagenesis and metabolic engineering methods to eliminate the production of citrinin. traditional chemical and physical mutagens were applied to induce mutagenesis, and a bio-screening method based on the antibacterial activity of citrinin against bacillus subtilis was designed to select mutant ... | 2010 | 19699814 |
| organophosphate hydrolase in brevundimonas diminuta is targeted to the periplasmic face of the inner membrane by the twin arginine translocation pathway. | a twin arginine translocation (tat) motif, involved in transport of folded proteins across the inner membrane, was identified in the signal peptide of the membrane-associated organophosphate hydrolase (oph) of brevundimonas diminuta. expression of the precursor form of oph carrying a c-terminal his tag in an opd-negative background and subsequent immunoblotting with anti-his antibodies showed that only the mature form of oph associated with the membrane and that the precursor form of oph was ent ... | 2009 | 19700527 |
| recovery of nonpathogenic mutant bacteria from tumors caused by several agrobacterium tumefaciens strains: a frequent event? | we have evaluated the interaction that bacterial genotypes and plant hosts have with the loss of pathogenicity in tumors, using seven agrobacterium tumefaciens strains inoculated on 12 herbaceous and woody hosts. we performed a screening of the agrobacteria present inside the tumors, looking for nonpathogenic strains, and found a high variability of those strains in this niche. to verify the origin of the putative nonpathogenic mutant bacteria, we applied an efficient, reproducible, and specific ... | 2009 | 19700547 |
| a pair of allelic wrky genes play opposite roles in rice-bacteria interactions. | although allelic diversity of genes has been reported to play important roles in different physiological processes, information on allelic diversity of defense-responsive genes in host-pathogen interactions is limited. here, we report that a pair of allelic genes, oswrky45-1 and oswrky45-2, which encode proteins with a 10-amino acid difference, play opposite roles in rice (oryza sativa) resistance against bacterial pathogens. bacterial blight caused by xanthomonas oryzae pv oryzae (xoo), bacteri ... | 2009 | 19700558 |
| control of nuclear and nucleolar localization of nuclear inclusion protein a of picorna-like potato virus a in nicotiana species. | the multifunctional nuclear inclusion protein a (nia) of potyviruses (genus potyvirus; potyviridae) accumulates in the nucleus of virus-infected cells for unknown reasons. in this study, two regions in the viral genome-linked protein (vpg) domain of nia in potato virus a (pva) were found to constitute nuclear and nucleolar localization signals (nls) in plant cells (nicotiana spp). amino acid substitutions in both nls i (residues 4 to 9) and nls ii (residues 41 to 50) prevented nuclear localizati ... | 2009 | 19700632 |
| borrelia burgdorferi small lipoprotein lp6.6 is a member of multiple protein complexes in the outer membrane and facilitates pathogen transmission from ticks to mice. | borrelia burgdorferi lipoprotein lp6.6 is a differentially produced spirochete antigen. an assessment of lp6.6 expression covering representative stages of the infectious cycle of spirochetes demonstrates that the gene is solely expressed during pathogen persistence in ticks. deletion of lp6.6 in infectious b. burgdorferi did not influence in vitro growth, or its ability to persist and induce inflammation in mice, migrate to larval or nymphal ticks or survive through the larval-nymphal molt. how ... | 2009 | 19703109 |
| gene silencing to investigate the roles of receptor-like proteins in arabidopsis. | receptor-like proteins (rlps) are cell surface receptors that play important roles in various processes. in several plant species rlps have been found to play a role in disease resistance, including the tomato cf and ve proteins and the apple hcrvf proteins that mediate resistance against the fungal pathogens cladosporium fulvum, verticillium spp., and venturia inaequalis, respectively. the arabidopsis genome contains 57 atrlp genes. two of these, clv2 (atrlp10) and tmm (atrlp17), have well-char ... | 2008 | 19704533 |
| a novel mapkk involved in cell death and defense signaling. | a high-throughput in planta overexpression screen of a nicotiana benthamiana cdna library identified a mitogen activated protein kinase kinase (mapkk), nbmkk1, as a potent inducer of hypersensitive response (hr)-like cell death. nbmkk1-mediated cell death was attenuated in plants whereby expression of nbsipk, an ortholog of tobacco sipk and arabidopsis atmpk6, was knocked down by virus-induced gene silencing (vigs), suggesting that nbmkk1 functions upstream of nbsipk. in accordance with this res ... | 2007 | 19704612 |
| study of free oligosaccharides derived from the bacterial n-glycosylation pathway. | the food-borne pathogen campylobacter jejuni is one of the leading causes of bacterial gastroenteritis worldwide and the most frequent antecedent in neuropathies such as the guillain-barré and miller fisher syndromes. c. jejuni was demonstrated to possess an n-linked protein glycosylation pathway that adds a conserved heptasaccharide to >40 periplasmic and membrane proteins. recently, we showed that c. jejuni also produces free heptasaccharides derived from the n-glycan pathway reminiscent of th ... | 2009 | 19706478 |
| proline antagonizes gaba-induced quenching of quorum-sensing in agrobacterium tumefaciens. | plants accumulate free l-proline (pro) in response to abiotic stresses (drought and salinity) and presence of bacterial pathogens, including the tumor-inducing bacterium agrobacterium tumefaciens. however, the function of pro accumulation in host-pathogen interaction is still unclear. here, we demonstrated that pro antagonizes plant gaba-defense in the a. tumefaciens c58-induced tumor by interfering with the import of gaba and consequently the gaba-induced degradation of the bacterial quorum-sen ... | 2009 | 19706545 |
| the colletotrichum orbiculare ssd1 mutant enhances nicotiana benthamiana basal resistance by activating a mitogen-activated protein kinase pathway. | plant basal resistance is activated by virulent pathogens in susceptible host plants. a colletotrichum orbiculare fungal mutant defective in the ssd1 gene, which regulates cell wall composition, is restricted by host basal resistance responses. here, we identified the nicotiana benthamiana signaling pathway involved in basal resistance by silencing the defense-related genes required for restricting the growth of the c. orbiculare mutant. only silencing of map kinase kinase2 or of both salicylic ... | 2009 | 19706796 |
| use of engineered enzymes to identify organophosphate and pyrethroid-related toxicity in toxicity identification evaluations. | engineered variants of a carboxylesterase from lucilia cuprina (e3) and a phosphotriesterase from agrobacterium radiobacter (opda) with enhanced hydrolytic activities against pyrethroid and organophosphate pesticides were evaluated as a toxicity identification evaluation (tie) manipulation. reduction in toxicity in the presence of the enzyme provides an indication that the toxicant is the enzyme's target substrate. carboxy/esterase e3 variants were evaluated to determine if the enzymes could mit ... | 2009 | 19708390 |
| symmetric signalling within asymmetric dimers of the staphylococcus aureus receptor histidine kinase agrc. | virulence in staphylococcus aureus is largely under control of the accessory gene regulator (agr) quorum-sensing system. the agrc receptor histidine kinase detects its autoinducing peptide (aip) ligand and generates an intracellular signal resulting in secretion of virulence factors. although agr is a well-studied quorum-sensing system, little is known about the mechanism of agrc activation. by co-immunoprecipitation analysis and intermolecular complementation of receptor mutants, we showed that ... | 2009 | 19708918 |
| identification and analysis of rhizobial plasmid origins of transfer. | twelve rhizobium leguminosarum isolates from france, germany and the uk, each carrying between four and seven plasmids, were screened by pcr using primers designed to amplify partial traa and trac genes and the intergenic spacer (igs) between them, which is expected to contain orit (the nick site for conjugal transfer). five strains, 1062, res-2, res-6, res-7 and res-9, generated orit-containing pcr fragments. sequencing identified three types that are related to but different from other rhizobi ... | 2002 | 19709282 |
| quorum sensing inhibition activity of garlic extract and p-coumaric acid. | the goal of this work was to investigate the influence of dmso, garlic extract and p-coumaric acid on bacterial quorum sensing (qs). | 2009 | 19709367 |
| spindle assembly checkpoint protein dynamics reveal conserved and unsuspected roles in plant cell division. | in eukaryotes, the spindle assembly checkpoint (sac) ensures that chromosomes undergoing mitosis do not segregate until they are properly attached to the microtubules of the spindle. | 2009 | 19710914 |
| detection of covalent and noncovalent intermediates in the polymerization reaction catalyzed by a c149s class iii polyhydroxybutyrate synthase. | polyhydroxybutyrate (phb) synthases catalyze the conversion of 3-hydroxybutyryl coenzyme a (hbcoa) to phb with a molecular mass of 1.5 mda. the class iii synthase from allochromatium vinosum is a tetramer of phaephac (each 40 kda). the polymerization involves covalent catalysis using c149 of phac with one phb chain per phaec dimer. two mechanisms for elongation have been proposed. the first involves an active site composed of two monomers in which the growing hydroxybutyrate (hb) chain alternate ... | 2009 | 19711985 |