Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| E622, a miniature, virulence-associated mobile element. | Miniature inverted terminal repeat elements (MITEs) are nonautonomous mobile elements that have a significant impact on bacterial evolution. Here we characterize E622, a 611-bp virulence-associated MITE from Pseudomonas syringae, which contains no coding region but has almost perfect 168-bp inverted repeats. Using an antibiotic coupling assay, we show that E622 is transposable and can mobilize an antibiotic resistance gene contained between its borders. Its predicted parent element, designated T ... | 2012 | 22081398 |
| antibacterial compounds from the mushroom ganoderma colossum from nigeria. | three colossolactones (colossolactone e, colossolactone b and 23-hydroxycolossolactone e) were isolated and characterized from an n-hexane:dichloromethane (2:7) extract of ganoderma colossum using chromatographic techniques. the antimicrobial activity of the three compounds was then tested against gram-positive and gram-negative bacteria. the activity was evaluated by the thin-layer chromatography agar overlay method. the results showed that colossolactone e and 23-hydroxycolossolactone e were a ... | 2011 | 22084057 |
| Extensive Genomic Variation within Clonal Complexes of Neisseria meningitidis. | Meningococcal disease is a widely distributed complex disease affecting all age categories. It can cause severe meningitis and septicemia, especially in unvaccinated infants and young children. The causative agent, Neisseria meningitidis (Nm), can be phenotypically and genetically differentiated into serogroups and sequence types (STs) and has a highly dynamic population structure. To obtain a deeper understanding of the epidemiology of Nm, we sequenced seven Nm genomes. Large-scale genomic anal ... | 2011 | 22084315 |
| Direct Infusion Mass Spectrometry of Oxylipin-Containing Arabidopsis thaliana Membrane Lipids Reveals Varied Patterns in Different Stress Responses. | Direct infusion electrospray ionization triple quadrupole precursor scanning for three oxidized fatty acyl anions revealed 86 mass spectral peaks representing polar membrane lipids in extracts from Arabidopsis thaliana infected with Pseudomonas syringae pv tomato DC3000 expressing AvrRpt2 (PstAvr). Quadrupole time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the presence of membrane lipids containing one or more oxidized acyl chains. The membra ... | 2011 | 22086419 |
| Direct Infusion Mass Spectrometry of Oxylipin-Containing Arabidopsis thaliana Membrane Lipids Reveals Varied Patterns in Different Stress Responses. | Direct infusion electrospray ionization triple quadrupole precursor scanning for three oxidized fatty acyl anions revealed 86 mass spectral peaks representing polar membrane lipids in extracts from Arabidopsis thaliana infected with Pseudomonas syringae pv tomato DC3000 expressing AvrRpt2 (PstAvr). Quadrupole time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the presence of membrane lipids containing one or more oxidized acyl chains. The membra ... | 2011 | 22086419 |
| brassinosteroids modulate the efficiency of plant immune responses to microbe-associated molecular patterns. | metazoans and plants use pattern recognition receptors (prrs) to sense conserved microbial-associated molecular patterns (mamps) in the extracellular environment. in plants, the bacterial mamps flagellin and elongation factor tu (ef-tu) activate distinct, phylogenetically related cell surface pattern recognition receptors of the leucine-rich repeat receptor kinase (lrr-rk) family called fls2 and ef-tu receptor, respectively. bak1 is an lrr-rk coreceptor for both fls2 and ef-tu receptor. bak1 is ... | 2011 | 22087001 |
| brassinosteroids modulate the efficiency of plant immune responses to microbe-associated molecular patterns. | metazoans and plants use pattern recognition receptors (prrs) to sense conserved microbial-associated molecular patterns (mamps) in the extracellular environment. in plants, the bacterial mamps flagellin and elongation factor tu (ef-tu) activate distinct, phylogenetically related cell surface pattern recognition receptors of the leucine-rich repeat receptor kinase (lrr-rk) family called fls2 and ef-tu receptor, respectively. bak1 is an lrr-rk coreceptor for both fls2 and ef-tu receptor. bak1 is ... | 2011 | 22087001 |
| brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent of the receptor kinase bak1. | plants and animals use innate immunity as a first defense against pathogens, a costly yet necessary tradeoff between growth and immunity. in arabidopsis, the regulatory leucine-rich repeat receptor-like kinase (lrr-rlk) bak1 combines with the lrr-rlks fls2 and efr in pathogen-associated molecular pattern (pamp)-triggered immunity (pti) and the lrr-rlk bri1 in brassinosteroid (br)-mediated growth. therefore, a potential tradeoff between these pathways mediated by bak1 is often postulated. here, w ... | 2011 | 22087006 |
| brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent of the receptor kinase bak1. | plants and animals use innate immunity as a first defense against pathogens, a costly yet necessary tradeoff between growth and immunity. in arabidopsis, the regulatory leucine-rich repeat receptor-like kinase (lrr-rlk) bak1 combines with the lrr-rlks fls2 and efr in pathogen-associated molecular pattern (pamp)-triggered immunity (pti) and the lrr-rlk bri1 in brassinosteroid (br)-mediated growth. therefore, a potential tradeoff between these pathways mediated by bak1 is often postulated. here, w ... | 2011 | 22087006 |
| the 'green revolution' dwarfing genes play a role in disease resistance in triticum aestivum and hordeum vulgare. | the green revolution dwarfing genes, rht-b1b and rht-d1b, encode mutant forms of della proteins and are present in most modern wheat varieties. della proteins have been implicated in the response to biotic stress in the model plant, arabidopsis thaliana. using defined wheat rht near-isogenic lines and barley sln1 gain of function (gof) and loss of function (lof) lines, the role of della in response to biotic stress was investigated in pathosystems representing contrasting trophic styles (biotrop ... | 2011 | 22090435 |
| the 'green revolution' dwarfing genes play a role in disease resistance in triticum aestivum and hordeum vulgare. | the green revolution dwarfing genes, rht-b1b and rht-d1b, encode mutant forms of della proteins and are present in most modern wheat varieties. della proteins have been implicated in the response to biotic stress in the model plant, arabidopsis thaliana. using defined wheat rht near-isogenic lines and barley sln1 gain of function (gof) and loss of function (lof) lines, the role of della in response to biotic stress was investigated in pathosystems representing contrasting trophic styles (biotrop ... | 2011 | 22090435 |
| Pseudomonas syringae pv. phaseolicola effector HopF1 inhibits pathogen-associated molecular pattern-triggered immunity in a RIN4-independent manner in common bean (Phaseolus vulgaris). | Plant pathogens usually promote pathogenesis by secreting effector proteins into host plant cells. One of the secreted effectors of Pseudomonas syringae pv. phaseolicola, the causative agent of halo-blight disease in common bean (Phaseolus vulgaris), HopF1, activates effector-triggered immunity (ETI) in a bean cultivar containing R1 resistance gene, but displays virulence function in a bean cultivar without the R1 gene. The virulence mechanism of the effector remained unknown, although it was id ... | 2011 | 22092678 |
| rapid in vivo analysis of synthetic promoters for plant pathogen phytosensing. | we aimed to engineer transgenic plants for the purpose of early detection of plant pathogen infection, which was accomplished by employing synthetic pathogen inducible promoters fused to reporter genes for altered phenotypes in response to the pathogen infection. toward this end, a number of synthetic promoters consisting of inducible regulatory elements fused to a red fluorescent protein (rfp) reporter were constructed for use in phytosensing. | 2011 | 22093754 |
| Contrasting recombination patterns and demographic histories of the plant pathogen Ralstonia solanacearum inferred from MLSA. | We used multilocus sequence analysis (MLSA) on a worldwide collection of the plant pathogenic Ralstonia solanacearum (Betaproteobacteria) to retrace its complex evolutionary history. Using genetic imprints left during R. solanacearum evolution, we were able to delineate distinct evolutionary complex displaying contrasting dynamics. Among the phylotypes already described (I, IIA, IIB, III, IV), eight groups of strains with distinct evolutionary patterns, named clades, were identified. From our re ... | 2011 | 22094345 |
| Contrasting recombination patterns and demographic histories of the plant pathogen Ralstonia solanacearum inferred from MLSA. | We used multilocus sequence analysis (MLSA) on a worldwide collection of the plant pathogenic Ralstonia solanacearum (Betaproteobacteria) to retrace its complex evolutionary history. Using genetic imprints left during R. solanacearum evolution, we were able to delineate distinct evolutionary complex displaying contrasting dynamics. Among the phylotypes already described (I, IIA, IIB, III, IV), eight groups of strains with distinct evolutionary patterns, named clades, were identified. From our re ... | 2011 | 22094345 |
| Antibiotics shaping bacterial genome: deletion of an IS91 flanked virulence determinant upon exposure to subinhibitory antibiotic concentrations. | The nucleoid-associated proteins Hha and YdgT repress the expression of the toxin a-hemolysin. An Escherichia coli mutant lacking these proteins overexpresses the toxin a-hemolysin encoded in the multicopy recombinant plasmid pANN202-312R. Unexpectedly, we could observe that this mutant generated clones that no further produced hemolysin (Hly(-)). Generation of Hly(-) clones was dependent upon the presence in the culture medium of the antibiotic kanamycin (km), a marker of the hha allele (hha::T ... | 2011 | 22096603 |
| transcriptional analysis of late ripening stages of grapevine berry. | the composition of grapevine berry at harvest is a major determinant of wine quality. optimal oenological maturity of berries is characterized by a high sugar/acidity ratio, high anthocyanin content in the skin, and low astringency. however, harvest time is still mostly determined empirically, based on crude biochemical composition and berry tasting. in this context, it is interesting to identify genes that are expressed/repressed specifically at the late stages of ripening and which may be used ... | 2011 | 22098939 |
| Caenorhabditis elegans: a model to monitor bacterial air quality. | ABSTRACT: BACKGROUND: Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards of chemicals and particles contrary to micro-orga ... | 2011 | 22099854 |
| high-throughput analysis of growth differences among phage strains. | although methods such as spectrophotometry are useful for identifying growth differences among bacterial strains, it is currently difficult to similarly determine whether bacteriophage strains differ in growth using high throughput methods. here we use automated spectrophotometry to develop an in vitro method for indirectly distinguishing fitness (growth) differences among virus strains, based on direct measures of their infected bacterial hosts. we used computer simulations of a mathematical mo ... | 2012 | 22101310 |
| phytophthora sojae avirulence effector avr3b is a secreted nadh and adp-ribose pyrophosphorylase that modulates plant immunity. | plants have evolved pathogen-associated molecular pattern (pamp)-triggered immunity (pti) and effector-triggered immunity (eti) to protect themselves from infection by diverse pathogens. avirulence (avr) effectors that trigger plant eti as a result of recognition by plant resistance (r) gene products have been identified in many plant pathogenic oomycetes and fungi. however, the virulence functions of oomycete and fungal avr effectors remain largely unknown. here, we combined bioinformatics and ... | 2011 | 22102810 |
| discovery of a potent and highly β1 specific proteasome inhibitor from a focused library of urea-containing peptide vinyl sulfones and peptide epoxyketones. | syringolins, a class of natural products, potently and selectively inhibit the proteasome and show promising antitumour activity. to gain insight in the mode of action of syringolins, the ureido structural element present in syringolins is incorporated in oligopeptide vinyl sulfones and peptide epoxyketones yielding a focused library of potent new proteasome inhibitors. the distance of the ureido linkage with respect to the electrophilic trap strongly influences subunit selectivity within the pr ... | 2011 | 22105930 |
| discovery of a potent and highly β1 specific proteasome inhibitor from a focused library of urea-containing peptide vinyl sulfones and peptide epoxyketones. | syringolins, a class of natural products, potently and selectively inhibit the proteasome and show promising antitumour activity. to gain insight in the mode of action of syringolins, the ureido structural element present in syringolins is incorporated in oligopeptide vinyl sulfones and peptide epoxyketones yielding a focused library of potent new proteasome inhibitors. the distance of the ureido linkage with respect to the electrophilic trap strongly influences subunit selectivity within the pr ... | 2011 | 22105930 |
| arabidopsis lysin-motif proteins lym1 lym3 cerk1 mediate bacterial peptidoglycan sensing and immunity to bacterial infection. | recognition of microbial patterns by host pattern recognition receptors is a key step in immune activation in multicellular eukaryotes. peptidoglycans (pgns) are major components of bacterial cell walls that possess immunity-stimulating activities in metazoans and plants. here we show that pgn sensing and immunity to bacterial infection in arabidopsis thaliana requires three lysin-motif (lysm) domain proteins. lym1 and lym3 are plasma membrane proteins that physically interact with pgns and medi ... | 2011 | 22106285 |
| experimental sink removal induces stress responses, including shifts in amino acid and phenylpropanoid metabolism, in soybean leaves. | the repeated removal of flower, fruit, or vegetative buds is a common treatment to simulate sink limitation. these experiments usually lead to the accumulation of specific proteins, which are degraded during later stages of seed development, and have thus been designated as vegetative storage proteins. we used oligonucleotide microarrays to assess global effects of sink removal on gene expression patterns in soybean leaves and found an induction of the transcript levels of hundreds of genes with ... | 2011 | 22109846 |
| experimental sink removal induces stress responses, including shifts in amino acid and phenylpropanoid metabolism, in soybean leaves. | the repeated removal of flower, fruit, or vegetative buds is a common treatment to simulate sink limitation. these experiments usually lead to the accumulation of specific proteins, which are degraded during later stages of seed development, and have thus been designated as vegetative storage proteins. we used oligonucleotide microarrays to assess global effects of sink removal on gene expression patterns in soybean leaves and found an induction of the transcript levels of hundreds of genes with ... | 2011 | 22109846 |
| horizontal gene transfer in histophilus somni and its role in the evolution of pathogenic strain 2336, as determined by comparative genomic analyses. | abstract: background: pneumonia and myocarditis are the most commonly reported diseases due to histophilus somni, an opportunistic pathogen of the reproductive and respiratory tracts of cattle. thus far only a few genes involved in metabolic and virulence functions have been identified and characterized in h. somni using traditional methods. analyses of the genome sequences of several pasteurellaceae species have provided insights into their biology and evolution. in view of the economic and ec ... | 2011 | 22111657 |
| ntrc and chloroplast-generated reactive oxygen species regulate pseudomonas syringae pv. tomato disease development in tomato and arabidopsis. | coronatine (cor) producing pathovars of pseudomonas syringae including pvs. tomato, maculicola, and glycinea cause important diseases on tomato, crucifers and soybeans, respectively, and produces symptoms with necrotic lesions surrounded by chlorosis. the chlorosis is mainly attributed to cor. however, the significance of cor-induced chlorosis in localized lesion development and the molecular basis of disease-associated cell death is largely unknown. to identify host (chloroplast) genes that pla ... | 2011 | 22112219 |
| sulfate supply influences compartment specific glutathione metabolism and confers enhanced resistance to tobacco mosaic virus during a hypersensitive response. | sufficient sulfate supply has been linked to the development of sulfur induced resistance or sulfur enhanced defense (sir/sed) in plants. in this study we investigated the effects of sulfate (s) supply on the response of genetically resistant tobacco (nicotiana tabacum cv. samsun nn) to tobacco mosaic virus (tmv). plants grown with sufficient sulfate (+s plants) developed significantly less necrotic lesions during a hypersensitive response (hr) when compared to plants grown without sulfate (-s p ... | 2011 | 22122784 |
| hopx1 in erwinia amylovora functions as an avirulence protein in apple and is regulated by hrpl. | fire blight is a devastating disease of rosaceous plants caused by the gram-negative bacterium erwinia amylovora. this pathogen delivers virulence proteins into host cells utilizing the type iii secretion system (t3ss). expression of the t3ss and of translocated and secreted substrates is activated by the alternative sigma factor hrpl, which recognizes hrp box promoters upstream of regulated genes. a collection of hidden markov model (hmm) profiles was used to identify putative hrp boxes in the ... | 2011 | 22123252 |
| bacterial-fungal interactions: hyphens between agricultural, clinical, environmental, and food microbiologists. | bacteria and fungi can form a range of physical associations that depend on various modes of molecular communication for their development and functioning. these bacterial-fungal interactions often result in changes to the pathogenicity or the nutritional influence of one or both partners toward plants or animals (including humans). they can also result in unique contributions to biogeochemical cycles and biotechnological processes. thus, the interactions between bacteria and fungi are of centra ... | 2011 | 22126995 |
| genomics of bacterial and archaeal viruses: dynamics within the prokaryotic virosphere. | prokaryotes, bacteria and archaea, are the most abundant cellular organisms among those sharing the planet earth with human beings (among others). however, numerous ecological studies have revealed that it is actually prokaryotic viruses that predominate on our planet and outnumber their hosts by at least an order of magnitude. an understanding of how this viral domain is organized and what are the mechanisms governing its evolution is therefore of great interest and importance. the vast majorit ... | 2011 | 22126996 |
| polyamines attenuate ethylene-mediated defense responses to abrogate resistance to botrytis cinerea in tomato. | transgenic tomato (solanum lycopersicum) lines over-expressing yeast spermidine synthase (yspdsyn), an enzyme involved in polyamine (pa) biosynthesis, were developed. these transgenic lines accumulate higher levels of spermidine (spd) than the wild type plants and were examined for responses to the fungal necrotrophs botrytis cinerea and alternaria solani, bacterial pathogen pseudomonas syringae pv. tomato dc3000, and larvae of the chewing insect tobacco hornworm manduca sexta. the spd-accumul ... | 2011 | 22128140 |
| polyamines attenuate ethylene-mediated defense responses to abrogate resistance to botrytis cinerea in tomato. | transgenic tomato (solanum lycopersicum) lines over-expressing yeast spermidine synthase (yspdsyn), an enzyme involved in polyamine (pa) biosynthesis, were developed. these transgenic lines accumulate higher levels of spermidine (spd) than the wild type plants and were examined for responses to the fungal necrotrophs botrytis cinerea and alternaria solani, bacterial pathogen pseudomonas syringae pv. tomato dc3000, and larvae of the chewing insect tobacco hornworm manduca sexta. the spd-accumul ... | 2011 | 22128140 |
| unraveling plant responses to bacterial pathogens through proteomics. | plant pathogenic bacteria cause diseases in important crops and seriously and negatively impact agricultural production. therefore, an understanding of the mechanisms by which plants resist bacterial infection at the stage of the basal immune response or mount a successful specific r-dependent defense response is crucial since a better understanding of the biochemical and cellular mechanisms underlying these interactions will enable molecular and transgenic approaches to crops with increased bio ... | 2011 | 22131803 |
| Pseudomonas syringae pv. actinidiae Draft Genomes Comparison Reveal Strain-Specific Features Involved in Adaptation and Virulence to Actinidia Species. | A recent re-emerging bacterial canker disease incited by Pseudomonas syringae pv. actinidiae (Psa) is causing severe economic losses to Actinidia chinensis and A. deliciosa cultivations in southern Europe, New Zealand, Chile and South Korea. Little is known about the genetic features of this pathovar. We generated genome-wide Illumina sequence data from two Psa strains causing outbreaks of bacterial canker on the A. deliciosa cv. Hayward in Japan (J-Psa, type-strain of the pathovar) and in Italy ... | 2011 | 22132095 |
| hybrid incompatibility in arabidopsis is determined by a multiple-locus genetic network. | the cross between arabidopsis thaliana and the closely related species arabidopsis arenosa results in postzygotic hybrid incompatibility, manifested as seed death. ecotypes of a. thaliana were tested for their ability to produce live seed when crossed to a. arenosa. the identified genetic variation was used to map quantitative trait loci (qtls) encoded by the a. thaliana genome that affect the frequency of postzygotic lethality and the phenotypes of surviving seeds. seven qtls affecting the a. t ... | 2011 | 22135429 |
| hybrid incompatibility in arabidopsis is determined by a multiple-locus genetic network. | the cross between arabidopsis thaliana and the closely related species arabidopsis arenosa results in postzygotic hybrid incompatibility, manifested as seed death. ecotypes of a. thaliana were tested for their ability to produce live seed when crossed to a. arenosa. the identified genetic variation was used to map quantitative trait loci (qtls) encoded by the a. thaliana genome that affect the frequency of postzygotic lethality and the phenotypes of surviving seeds. seven qtls affecting the a. t ... | 2011 | 22135429 |
| silencing mpk4 in nicotiana attenuata enhances photosynthesis and seed production but compromises abscisic acid-induced stomatal closure and guard cell-mediated resistance to pseudomonas syringae pv. tomato dc3000. | mitogen-activated protein kinases (mapks) play pivotal roles in development and environmental interactions in eukaryotes. here we studied the function of a mapk, nampk4, in a wild tobacco species nicotiana attenuata. the nampk4-silenced n. attenuata (irnampk4) attained somewhat smaller statures, delayed senescence, and greatly enhanced stomatal conductance and photosynthetic rate, especially during late developmental stages. all these changes were associated with highly increased seed production ... | 2011 | 22147519 |
| silencing mpk4 in nicotiana attenuata enhances photosynthesis and seed production but compromises abscisic acid-induced stomatal closure and guard cell-mediated resistance to pseudomonas syringae pv. tomato dc3000. | mitogen-activated protein kinases (mapks) play pivotal roles in development and environmental interactions in eukaryotes. here we studied the function of a mapk, nampk4, in a wild tobacco species nicotiana attenuata. the nampk4-silenced n. attenuata (irnampk4) attained somewhat smaller statures, delayed senescence, and greatly enhanced stomatal conductance and photosynthetic rate, especially during late developmental stages. all these changes were associated with highly increased seed production ... | 2011 | 22147519 |
| Next Generation Systemic Acquired Resistance. | Systemic acquired resistance (SAR) is a plant immune response to pathogen attack. Recent evidence suggests that plant immunity involves regulation by chromatin remodeling and DNA methylation. We have investigated whether SAR can be inherited epigenetically following disease pressure by Pseudomonas syringae pv. tomato DC3000 (PstDC3000). Compared to progeny from control-treated Arabidopsis (C1), progeny from PstDC3000-inoculated Arabidopsis (P1) were primed to activate salicylic acid (SA)-inducib ... | 2011 | 22147520 |
| Next Generation Systemic Acquired Resistance. | Systemic acquired resistance (SAR) is a plant immune response to pathogen attack. Recent evidence suggests that plant immunity involves regulation by chromatin remodeling and DNA methylation. We have investigated whether SAR can be inherited epigenetically following disease pressure by Pseudomonas syringae pv. tomato DC3000 (PstDC3000). Compared to progeny from control-treated Arabidopsis (C1), progeny from PstDC3000-inoculated Arabidopsis (P1) were primed to activate salicylic acid (SA)-inducib ... | 2011 | 22147520 |
| separating significant matches from spurious matches in dna sequences. | word matches are widely used to compare genomic sequences. complete genome alignment methods often rely on the use of matches as anchors for building their alignments, and various alignment-free approaches that characterize similarities between large sequences are based on word matches. among matches that are retrieved from the comparison of two genomic sequences, a part of them may correspond to spurious matches (sms), which are matches obtained by chance rather than by homologous relationships ... | 2012 | 22149632 |
| The Arabidopsis short-chain dehydrogenase/reductase 3, an ABSCISIC ACID DEFICIENT 2 homolog, is involved in plant defense responses but not in ABA biosynthesis. | ABSCISIC ACID DEFICIENT2 (ABA2) encodes a short-chain dehydrogenase/reductase1 (SDR1) that catalyzes the multi-step conversion of xanthoxin to abscisic aldehyde during abscisic acid (ABA) biosynthesis in Arabidopsis thaliana. In this study, AtSDR2 and AtSDR3, the two closest homologs to AtABA2, were investigated for their potential role in ABA biosynthesis. AtSDR2 showed undetectable transcription in plants grown under normal conditions or under stress. AtSDR3 and AtABA2 have different spatial a ... | 2012 | 22153241 |
| HrpZ harpins from different Pseudomonas syringae pathovars differ in molecular interactions and in induction of anion channel responses in Arabidopsis thaliana suspension cells. | HrpZ, a type three secretion system helper protein from the plant-pathogen Pseudomonas syringae, can be recognized by many plants as a defence elicitor. Responses of Arabidopsis thaliana suspension cells to different HrpZ variants were studied by electrophysiological methods and cell death assay. Purified HrpZ originating from a compatible pathogen P. syringae pv. tomato DC3000 (HrpZ(Pto)) and incompatible P. syringae pv. phaseolicola (HrpZ(Pph)) both promoted Arabidopsis cell death. As an early ... | 2012 | 22153254 |
| Inhibition of Pseudomonas aeruginosa Virulence: Characterization of the AprA-AprI Interface and Species Selectivity. | Pseudomonas aeruginosa secretes the virulence factor alkaline protease (AprA) to enhance its survival. AprA cleaves one of the key microbial recognition molecules, monomeric flagellin, and thereby diminishes Toll-like receptor 5 activation. In addition, AprA degrades host proteins such as complement proteins and cytokines. P. aeruginosa encodes a highly potent inhibitor of alkaline protease (AprI) that is solely located in the periplasm where it is presumed to protect periplasmic proteins agains ... | 2011 | 22154939 |
| carbapenem-hydrolyzing ges-5-encoding gene on different plasmid types from a sewage treatment plant. | plasmids prsb113 and prsb115 were recovered from an activated sludge bacterial community of a municipal wastewater treatment plant in germany. both plasmids carry the same bla(ges-5) carbapenemase gene that is located within two distinct class 1 integrons. these plasmids have different backbones, belong to different incompatibility groups and could replicate in both pseudomonas aeruginosa and escherichia coli. | 2011 | 22156421 |
| giant dna virus mimivirus encodes pathway for biosynthesis of unusual sugar 4-amino-4,6-dideoxy-d-glucose (viosamine). | mimivirus is one the largest dna virus identified so far, infecting several acanthamoeba species. analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. all of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. among them, we identified the l136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. this enzyme was shown to ... | 2011 | 22157758 |
| giant dna virus mimivirus encodes pathway for biosynthesis of unusual sugar 4-amino-4,6-dideoxy-d-glucose (viosamine). | mimivirus is one the largest dna virus identified so far, infecting several acanthamoeba species. analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. all of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. among them, we identified the l136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. this enzyme was shown to ... | 2011 | 22157758 |
| arabidopsis deficient in cutin ferulate encodes a transferase required for feruloylation of ω-hydroxy fatty acids in cutin polyester. | the cuticle is a complex aliphatic polymeric layer connected to the cell wall and covers surfaces of all aerial plant organs. the cuticle prevents nonstomatal water loss, regulates gas exchange, and acts as a barrier against pathogen infection. the cuticle is synthesized by epidermal cells and predominantly consists of an aliphatic polymer matrix (cutin) and intracuticular and epicuticular waxes. cutin monomers are primarily c(16) and c(18) unsubstituted, ω-hydroxy, and α,ω-dicarboxylic fatty ac ... | 2011 | 22158675 |
| arabidopsis deficient in cutin ferulate encodes a transferase required for feruloylation of ω-hydroxy fatty acids in cutin polyester. | the cuticle is a complex aliphatic polymeric layer connected to the cell wall and covers surfaces of all aerial plant organs. the cuticle prevents nonstomatal water loss, regulates gas exchange, and acts as a barrier against pathogen infection. the cuticle is synthesized by epidermal cells and predominantly consists of an aliphatic polymer matrix (cutin) and intracuticular and epicuticular waxes. cutin monomers are primarily c(16) and c(18) unsubstituted, ω-hydroxy, and α,ω-dicarboxylic fatty ac ... | 2011 | 22158675 |
| a deletion in nrt2.1 attenuates pseudomonas syringae-induced hormonal perturbation, resulting in primed plant defenses. | for an efficient defense response against pathogens, plants must coordinate rapid genetic reprogramming to produce an incompatible interaction. nrt2 gene family members are sentinels of nitrate availability. in this study, we present an additional role for nrt2.1 linked to plant resistance against pathogens. this gene antagonizes the priming of plant defenses against the bacterial pathogen pseudomonas syringae pv tomato dc3000 (pst). the nrt2 mutant (which is deficient in two genes, nrt2.1 and n ... | 2011 | 22158760 |
| a deletion in nrt2.1 attenuates pseudomonas syringae-induced hormonal perturbation, resulting in primed plant defenses. | for an efficient defense response against pathogens, plants must coordinate rapid genetic reprogramming to produce an incompatible interaction. nrt2 gene family members are sentinels of nitrate availability. in this study, we present an additional role for nrt2.1 linked to plant resistance against pathogens. this gene antagonizes the priming of plant defenses against the bacterial pathogen pseudomonas syringae pv tomato dc3000 (pst). the nrt2 mutant (which is deficient in two genes, nrt2.1 and n ... | 2011 | 22158760 |
| 3d structure of the yersinia entomophaga toxin complex and implications for insecticidal activity. | toxin complex (tc) proteins are a class of bacterial protein toxins that form large, multisubunit complexes. comprising tca, b, and c components, they are of great interest because many exhibit potent insecticidal activity. here we report the structure of a novel tc, yen-tc, isolated from the bacterium yersinia entomophaga mh96, which differs from the majority of bacterially derived tcs in that it exhibits oral activity toward a broad range of insect pests, including the diamondback moth (plutel ... | 2011 | 22158901 |
| Genomes and Virulence Factors of Novel Bacterial Pathogens Causing Bleaching Disease in the Marine Red Alga Delisea pulchra. | Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolys ... | 2011 | 22162749 |
| transcriptional regulation of ribosome components are determined by stress according to cellular compartments in arabidopsis thaliana. | plants have to coordinate eukaryotic ribosomes (cytoribosomes) and prokaryotic ribosomes (plastoribosomes and mitoribosomes) production to balance cellular protein synthesis in response to environmental variations. we identified 429 genes encoding potential ribosomal proteins (rp) in arabidopsis thaliana. because cytoribosome proteins are encoded by small nuclear gene families, plastid rp by nuclear and plastid genes and mitochondrial rp by nuclear and mitochondrial genes, several transcriptiona ... | 2011 | 22164228 |
| Phage-based biocontrol strategies to reduce foodborne pathogens in foods. | There has been much recent interest in the use of phages as biocontrol agents of foodborne pathogens in animals used for food production, and in the food products themselves. This interest seems to be driven by consumers' request for more natural foods, as well as the fact that foodborne outbreaks continue to occur, globally, in many foods, some of which (such as fresh produce), lack adequate methods to control any pathogenic contamination present. Also, the many successes with respect to regula ... | 2011 | 22164346 |
| gaca directly regulates expression of several virulence genes in pseudomonas syringae pv. tabaci 11528. | a two-component system comprising gacs and gaca affects a large number of traits in many gram-negative bacteria. however, the signals to which gacs responds, the regulation mechanism for gaca expression, and the genes gaca controls are not yet clear. in this study, several phenotypic tests and tobacco-leaf pathogenicity assays were conducted using a gaca deletion mutant strain (bl473) of pseudomonas syringae pv. tabaci 11528. to determine the regulation mechanism for gaca gene expression and to ... | 2011 | 22166197 |
| structural analysis of pseudomonas syringae avrptob bound to host bak1 reveals two similar kinase-interacting domains in a type iii effector. | to infect plants, pseudomonas syringae pv. tomato delivers ∼30 type iii effector proteins into host cells, many of which interfere with pamp-triggered immunity (pti). one effector, avrptob, suppresses pti using a central domain to bind host bak1, a kinase that acts with several pattern recognition receptors to activate defense signaling. a second avrptob domain binds and suppresses the pti-associated kinase bti9 but is conversely recognized by the protein kinase pto to activate effector-triggere ... | 2011 | 22169508 |
| occurrence of putative virulence genes in arcobacter species isolated from humans and animals. | interest for arcobacters in veterinary and human public health has increased since the first report of the isolation of arcobacters from food of animal origin. since then, studies worldwide have reported the occurrence of arcobacters on food and in food-production animals and have highlighted the possible transmission of especially a. butzleri to the human population. in humans, arcobacters are associated with enteritis and septicemia. to assess their clinical relevance for humans and animals, e ... | 2011 | 22170914 |
| the costs of evolving resistance in heterogeneous parasite environments. | the evolution of host resistance to parasites, shaped by associated fitness costs, is crucial for epidemiology and maintenance of genetic diversity. selection imposed by multiple parasites could be a particularly strong constraint, as hosts either accumulate costs of multiple specific resistances or evolve a more costly general resistance mechanism. we used experimental evolution to test how parasite heterogeneity influences the evolution of host resistance. we show that bacterial host populatio ... | 2011 | 22171085 |
| the costs of evolving resistance in heterogeneous parasite environments. | the evolution of host resistance to parasites, shaped by associated fitness costs, is crucial for epidemiology and maintenance of genetic diversity. selection imposed by multiple parasites could be a particularly strong constraint, as hosts either accumulate costs of multiple specific resistances or evolve a more costly general resistance mechanism. we used experimental evolution to test how parasite heterogeneity influences the evolution of host resistance. we show that bacterial host populatio ... | 2011 | 22171085 |
| characterization of mtfa, a novel regulatory output signal protein of the glucose-phosphotransferase system in e. coli k-12. | the glucose phosphotransferase system (pts) in escherichia coli k-12 is a complex sensory and regulatory system. in addition to its central role in glucose uptake, it informs other global regulatory networks about carbohydrate availability and the physiological status of the cell. the expression of the ptsg gene encoding the glucose pts transporter eiicb(glc) is primarily regulated via the repressor mlc, whose inactivation is glucose dependent. during transport of glucose and dephosphorylation o ... | 2011 | 22178967 |
| glycoalkaloid metabolism1 is required for steroidal alkaloid glycosylation and prevention of phytotoxicity in tomato. | steroidal alkaloids (sas) are triterpene-derived specialized metabolites found in members of the solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. their biosynthesis involves the action of glycosyltransferases to form steroidal glycoalkaloids (sgas). to elucidate the metabolism of sgas in the solanaceae family, we examined the tomato (solanum lycopersicum) glycoalkaloid metabolism1 (game1) gene. our findings imply that game1 is a galactosyltransfer ... | 2011 | 22180624 |
| bacteriophage φ6--structure investigated by fluorescence stokes shift spectroscopy. | the stokes shift of tryptophan (trp) fluorescence from layers of the lipid-containing bacteriophage φ6 is compared to determine the relative effect of the layers on virus hydrophobicity. in the inner most layer, the empty procapsid (pc) which contains 80-90% of the virion trp residues, λ(max) = 339.8 nm. the pc emission is substantially more redshifted than the other φ6 layers and nearer to that of the pseudomonad host cell than the other φ6 layers. the trp emission from the nucleocapsid (nc) wi ... | 2011 | 22181691 |
| bacteriophage φ6--structure investigated by fluorescence stokes shift spectroscopy. | the stokes shift of tryptophan (trp) fluorescence from layers of the lipid-containing bacteriophage φ6 is compared to determine the relative effect of the layers on virus hydrophobicity. in the inner most layer, the empty procapsid (pc) which contains 80-90% of the virion trp residues, λ(max) = 339.8 nm. the pc emission is substantially more redshifted than the other φ6 layers and nearer to that of the pseudomonad host cell than the other φ6 layers. the trp emission from the nucleocapsid (nc) wi ... | 2011 | 22181691 |
| Gene order and chromosome dynamics coordinate spatiotemporal gene expression during the bacterial growth cycle. | In Escherichia coli crosstalk between DNA supercoiling, nucleoid-associated proteins and major RNA polymerase s initiation factors regulates growth phase-dependent gene transcription. We show that the highly conserved spatial ordering of relevant genes along the chromosomal replichores largely corresponds both to their temporal expression patterns during growth and to an inferred gradient of DNA superhelical density from the origin to the terminus. Genes implicated in similar functions are relat ... | 2011 | 22184251 |
| Gene order and chromosome dynamics coordinate spatiotemporal gene expression during the bacterial growth cycle. | In Escherichia coli crosstalk between DNA supercoiling, nucleoid-associated proteins and major RNA polymerase s initiation factors regulates growth phase-dependent gene transcription. We show that the highly conserved spatial ordering of relevant genes along the chromosomal replichores largely corresponds both to their temporal expression patterns during growth and to an inferred gradient of DNA superhelical density from the origin to the terminus. Genes implicated in similar functions are relat ... | 2011 | 22184251 |
| Increasing Nitric Oxide Content in Arabidopsis thaliana by Expressing Rat Neuronal Nitric Oxide Synthase Resulted in Enhanced Stress Tolerance. | Nitric oxide (NO) plays essential roles in many physiological and developmental processes in plants, including biotic and abiotic stresses, which cause adverse effect on agricultural production. However, for the lack of findings for nitric oxide synthase (NOS), it raises many difficulties to investigate the physiological roles of NO in vivo and thus its utilization for genetic engineering. Here, to explore the possibility of manipulating the endogenous NO level, the rat neuronal NOS (nNOS) was e ... | 2011 | 22186181 |
| The major volatile organic compound emitted from Arabidopsis thaliana flowers, the sesquiterpene (E)-ß-caryophyllene, is a defense against a bacterial pathogen. | • Flowers have a high risk of pathogen attack because of their rich nutrient and moisture content, and high frequency of insect visitors. We investigated the role of (E)-ß-caryophyllene in floral defense against a microbial pathogen. This sesquiterpene is a common volatile compound emitted from flowers, and is a major volatile released from the stigma of Arabidopsis thaliana flowers. • Arabidopsis thaliana lines lacking a functional (E)-ß-caryophyllene synthase or constitutively overexpressing t ... | 2011 | 22187939 |
| Emigration of the plant pathogen Pseudomonas syringae from leaf litter contributes to its population dynamics in alpine snowpack. | The recently discovered ubiquity of the plant pathogen Pseudomonas syringae in headwaters and alpine ecosystems worldwide elicits new questions about the ecology of this bacterium and subsequent consequences for disease epidemiology. Because of the major contribution of snow to river run-off during crop growth, we evaluated the population dynamics of P. syringae in snowpack and the underlying leaf litter during two years in the Southern French Alps. High population densities of P. syringae were ... | 2011 | 22188069 |
| structural analysis of hoppmal reveals the presence of a second adaptor domain common to the hopab family of pseudomonas syringae type iii effectors. | hoppmal is a member of the hopab family of type iii effectors present in the phytopathogen pseudomonas syringae. using both x-ray crystallography and solution nuclear magnetic resonance, we demonstrate that hoppmal contains two structurally homologous yet functionally distinct domains. the n-terminal domain corresponds to the previously described pto-binding domain, while the previously uncharacterised c-terminal domain spans residues 308-385. while structurally similar, these domains do not sha ... | 2011 | 22191472 |
| structural analysis of hoppmal reveals the presence of a second adaptor domain common to the hopab family of pseudomonas syringae type iii effectors. | hoppmal is a member of the hopab family of type iii effectors present in the phytopathogen pseudomonas syringae. using both x-ray crystallography and solution nuclear magnetic resonance, we demonstrate that hoppmal contains two structurally homologous yet functionally distinct domains. the n-terminal domain corresponds to the previously described pto-binding domain, while the previously uncharacterised c-terminal domain spans residues 308-385. while structurally similar, these domains do not sha ... | 2011 | 22191472 |
| bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins. | the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ... | 2012 | 22192777 |
| bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins. | the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ... | 2012 | 22192777 |
| widespread genetic switches and toxicity resistance proteins for fluoride. | most riboswitches are metabolite-binding rna structures located in bacterial messenger rnas where they control gene expression. we have discovered a riboswitch class in many bacterial and archaeal species whose members are selectively triggered by fluoride but reject other small anions, including chloride. these fluoride riboswitches activate expression of genes that encode putative fluoride transporters, enzymes that are known to be inhibited by fluoride, and additional proteins of unknown func ... | 2011 | 22194412 |
| widespread genetic switches and toxicity resistance proteins for fluoride. | most riboswitches are metabolite-binding rna structures located in bacterial messenger rnas where they control gene expression. we have discovered a riboswitch class in many bacterial and archaeal species whose members are selectively triggered by fluoride but reject other small anions, including chloride. these fluoride riboswitches activate expression of genes that encode putative fluoride transporters, enzymes that are known to be inhibited by fluoride, and additional proteins of unknown func ... | 2011 | 22194412 |
| pseudomonas syringae coordinates production of a motility-enabling surfactant with flagellar assembly. | using a sensitive assay, we observed low levels of an unknown surfactant produced by pseudomonas syringae pv. syringae b728a that was undetectable with traditional methods yet enabled swarming motility in a strain that was deficient in production of syringafactin, the main characterized surfactant produced by p. syringae. random mutagenesis of the syringafactin-deficient strain revealed an acyltransferase with homology to rhla from p. aeruginosa that was required for production of this unidentif ... | 2011 | 22194459 |
| structural elucidation and functional characterization of the hyaloperonospora arabidopsidis effector protein atr13. | the oomycete hyaloperonospora arabidopsidis (hpa) is the causal agent of downy mildew on the model plant arabidopsis thaliana and has been adapted as a model system to investigate pathogen virulence strategies and plant disease resistance mechanisms. recognition of hpa infection occurs when plant resistance proteins (r-genes) detect the presence or activity of pathogen-derived protein effectors delivered to the plant host. this study examines the hpa effector atr13 emco5 and its recognition by r ... | 2011 | 22194684 |
| prediction of antibacterial activity from physicochemical properties of antimicrobial peptides. | consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. in addition, such thresholds observed in model membranes occur at local peptide concentrations close to full mem ... | 2011 | 22194847 |
| global analysis of arabidopsis/downy mildew interactions reveals prevalence of incomplete resistance and rapid evolution of pathogen recognition. | interactions between arabidopsis thaliana and its native obligate oomycete pathogen hyaloperonospora arabidopsidis (hpa) represent a model system to study evolution of natural variation in a host/pathogen interaction. both arabidopsis and hpa genomes are sequenced and collections of different sub-species are available. we analyzed ∼400 interactions between different arabidopsis accessions and five strains of hpa. we examined the pathogen's overall ability to reproduce on a given host, and perfor ... | 2011 | 22194907 |
| Syringolin B-inspired proteasome inhibitor analogue TIR-203 exhibits enhanced biological activity in multiple myeloma and neuroblastoma. | Context: The bacterium Pseudomonas syringae pv. syringae (Pss) is a pathogen of many plant species and causes, for example, brown spot disease in bean plants (Phaseolus vulgaris). Pss excretes the syringolins, natural product molecules that act as a virulence factors and inhibit the proteasome of the host plants. Objective: Proteasome inhibitors belong to an important class of anticancer agents and bortezomib (Velcade(®)) has been Food and Drug Administration-approved for the treatment of mult ... | 2012 | 22196580 |
| Peptidotriazoles with antimicrobial activity against bacterial and fungal plant pathogens. | We designed and prepared peptidotriazoles based on the antimicrobial peptide BP100 (LysLysLeuPheLysLysIleLeuLysTyrLeu-NH(2)) by introducing a triazole ring in the peptide backbone or onto the side chain of a selected residue. These compounds were screened for their in vitro growth inhibition of bacterial and fungal phytopathogens, and for their cytotoxic effects on eukaryotic cells and tobacco leaves. Their proteolytic susceptibility was also analyzed. The antibacterial activity and the hemolysi ... | 2011 | 22198367 |
| Role of 9-Lipoxygenase and a-Dioxygenase Oxylipin Pathways as Modulators of Local and Systemic Defense. | Plant 9-lipoxygenases (9-LOX) and a-dioxygenases (a-DOX) initiate the synthesis of oxylipins after bacterial infection. Here, the role of these enzymes in plants' defense was investigated using individual Arabidopsis thaliana lox1 and dox1 mutants and a double lox1 dox1 mutant. Studies with Pseudomonas syringae pv. tomato (Pst) revealed the enhanced susceptibility of lox1 to the virulent strain Pst DC3000 and the partial impairment of lox1 and dox1 mutants to activate systemic acquired resistanc ... | 2011 | 22199234 |
| Activation of the Arabidopsis thaliana mitogen-activated protein kinase MPK11 by the flagellin-derived elicitor peptide, flg22. | Mitogen-activated protein kinases (MAPKs) mediate cellular signal transduction during stress responses, as well as diverse growth and developmental processes in eukaryotes. Pathogen infection or treatments with conserved pathogen-associated molecular patterns (PAMPs) such as the bacterial flagellin-derived flg22 peptide are known to activate three Arabidopsis thaliana MAPKs, MPK3, MPK4 and MPK6. Several stresses, including flg22 treatment, are known to increase MPK11 expression but activation of ... | 2011 | 22204645 |
| descendants of primed arabidopsis plants exhibit resistance to biotic stress. | an attack of plants by pathogens or treatment with certain resistance-inducing compounds can lead to the establishment of a unique primed state of defense. primed plants show enhanced defense reactions upon further challenge with biotic or abiotic stress. here, we report that the primed state in arabidopsis thaliana is still functional in the next generation without additional treatment. we compared the reactions of arabidopsis plants that had been either primed with β-amino-butyric acid (baba) ... | 2011 | 22209872 |
| descendants of primed arabidopsis plants exhibit resistance to biotic stress. | an attack of plants by pathogens or treatment with certain resistance-inducing compounds can lead to the establishment of a unique primed state of defense. primed plants show enhanced defense reactions upon further challenge with biotic or abiotic stress. here, we report that the primed state in arabidopsis thaliana is still functional in the next generation without additional treatment. we compared the reactions of arabidopsis plants that had been either primed with β-amino-butyric acid (baba) ... | 2011 | 22209872 |
| herbivory in the previous generation primes plants for enhanced insect resistance. | inducible defenses, which provide enhanced resistance after initial attack, are nearly universal in plants. this defense signaling cascade is mediated by the synthesis, movement, and perception of jasmonic acid and related plant metabolites. to characterize the long-term persistence of plant immunity, we challenged arabidopsis (arabidopsis thaliana) and tomato (solanum lycopersicum) with caterpillar herbivory, application of methyl jasmonate, or mechanical damage during vegetative growth and ass ... | 2011 | 22209873 |
| herbivory in the previous generation primes plants for enhanced insect resistance. | inducible defenses, which provide enhanced resistance after initial attack, are nearly universal in plants. this defense signaling cascade is mediated by the synthesis, movement, and perception of jasmonic acid and related plant metabolites. to characterize the long-term persistence of plant immunity, we challenged arabidopsis (arabidopsis thaliana) and tomato (solanum lycopersicum) with caterpillar herbivory, application of methyl jasmonate, or mechanical damage during vegetative growth and ass ... | 2011 | 22209873 |
| coordination of a mitochondrial superoxide burst during the hypersensitive response to bacterial pathogen in nicotiana tabacum. | we characterized responses of nicotiana tabacum to pathovars of the bacterial pathogen pseudomonas syringae. these included a compatible response associated with necrotic cell death (pv tabaci), an incompatible response that included hypersensitive response (hr) cell death (pv maculicola) and an incompatible response that induced defenses but lacked the hr (pv phaseolicola). signaling molecules (salicylic acid [sa], nitric oxide [no], h(2) o(2) ) known to induce the stress responsive tobacco aox ... | 2011 | 22211396 |
| pseudomonas biofilm matrix composition and niche biology. | biofilms are a predominant form of growth for bacteria in the environment and in the clinic. critical for biofilm development are adherence, proliferation, and dispersion phases. each of these stages includes reinforcement by, or modulation of, the extracellular matrix. pseudomonas aeruginosa has been a model organism for the study of biofilm formation. additionally, other pseudomonas species utilize biofilm formation during plant colonization and environmental persistence. pseudomonads produce ... | 2012 | 22212072 |
| low antioxidant concentrations impact on multiple signalling pathways in arabidopsis thaliana partly through npr1. | production of reactive oxygen species (ros) is linked to signalling in both developmental and stress responses. the level of ros is controlled by both production and removal through various scavengers including ascorbic acid and glutathione. here, the role of low ascorbic acid or glutathione concentrations was investigated on ozone-induced cell death, defence signalling, and developmental responses. low ascorbic acid concentrations in vtc1 activated expression of salicylic acid (sa)-regulated ge ... | 2012 | 22213815 |
| determining degradation and synthesis rates of arabidopsis proteins using the kinetics of progressive 15n labeling of two-dimensional gel-separated protein spots. | the growth and development of plant tissues is associated with an ordered succession of cellular processes that are reflected in the appearance and disappearance of proteins. the control of the kinetics of protein turnover is central to how plants can rapidly and specifically alter protein abundance and thus molecular function in response to environmental or developmental cues. however, the processes of turnover are largely hidden during periods of apparent steady-state protein abundance, and ev ... | 2012 | 22215636 |
| quantitative proteomics reveals dynamic changes in the plasma membrane during arabidopsis immune signaling. | the plant plasma membrane is a crucial mediator of the interaction between plants and microbes. understanding how the plasma membrane proteome responds to diverse immune signaling events will lead to a greater understanding of plant immunity and uncover novel targets for crop improvement. here we report the results from a large scale quantitative proteomics study of plasma membrane-enriched fractions upon activation of the arabidopsis thaliana immune receptor rps2. more than 2300 proteins were i ... | 2012 | 22215637 |
| genome-wide identification of transcriptional start sites in the plant pathogen pseudomonas syringae pv. tomato str. dc3000. | rna-seq has provided valuable insights into global gene expression in a wide variety of organisms. using a modified rna-seq approach and illumina's high-throughput sequencing technology, we globally identified 5'-ends of transcripts for the plant pathogen pseudomonas syringae pv. tomato str. dc3000. a substantial fraction of 5'-ends obtained by this method were consistent with results obtained using global rna-seq and 5'race. as expected, many 5'-ends were positioned a short distance upstream of ... | 2011 | 22216251 |
| rootstock-regulated gene expression patterns associated with fire blight resistance in apple. | desirable apple varieties are clonally propagated by grafting vegetative scions onto rootstocks. rootstocks influence many phenotypic traits of the scion, including resistance to pathogens such as erwinia amylovora, which causes fire blight, the most serious bacterial disease of apple. the purpose of the present study was to quantify rootstock-mediated differences in scion fire blight susceptibility and to identify transcripts in the scion whose expression levels correlated with this response. | 2012 | 22229964 |
| quantitative interactor screening with next-generation sequencing (qis-seq) identifies arabidopsis thaliana mlo2 as a target of the pseudomonas syringae type iii effector hopz2. | identification of protein-protein interactions is a fundamental aspect of understanding protein function. a commonly used method for identifying protein interactions is the yeast two-hybrid system. | 2012 | 22230763 |
| stenotrophomonas maltophilia: an emerging global opportunistic pathogen. | summary: stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen. the increasing incidence of nosocomial and community-acquired s. maltophilia infections is of particular concern for immunocompromised individuals, as this bacterial pathogen is associated with a significant fatality/case ratio. s. maltophilia is an environmental bacterium found in aqueous habitats, including plant rhizospheres, animals, foods, and water sources. infections of s. maltophilia c ... | 2012 | 22232370 |
| a bacterial cysteine protease effector protein interferes with photosynthesis to suppress plant innate immune responses. | the bacterial pathogen pseudomonas syringae pv tomato dc3000 suppresses plant innate immunity with effector proteins injected by a type iii secretion system (t3ss). the cysteine protease effector hopn1, which reduces the ability of dc3000 to elicit programmed cell death in non-host tobacco, was found to also suppress the production of defence-associated reactive oxygen species (ros) and callose when delivered by pseudomonas fluorescens heterologously expressing a p. syringae t3ss. purified his(6 ... | 2012 | 22233353 |
| first description of natural and experimental conjugation between mycobacteria mediated by a linear plasmid. | in a previous study, we detected the presence of a mycobacterium avium species-specific insertion sequence, is1245, in mycobacterium kansasii. both species were isolated from a mixed m. avium-m. kansasii bone marrow culture from an hiv-positive patient. the transfer mechanism of this insertion sequence to m. kansasii was investigated here. | 2012 | 22235347 |
| pseudomonas syringae naturally lacking the canonical type iii secretion system are ubiquitous in nonagricultural habitats, are phylogenetically diverse and can be pathogenic. | the type iii secretion system (t3ss) is an important virulence factor of pathogenic bacteria, but the natural occurrence of variants of bacterial plant pathogens with deficiencies in their t3ss raises questions about the significance of the t3ss for fitness. previous work on t3ss-deficient plant pathogenic bacteria has focused on strains from plants or plant debris. here we have characterized t3ss-deficient strains of pseudomonas syringae from plant and nonplant substrates in pristine nonagricul ... | 2012 | 22237542 |