Publications

clonal population structure of pseudomonas avellanae strains of different origin based on multilocus enzyme electrophoresis.	to assess the genetic diversity and genetic relationships of pseudomonas avellanae, the causative agent of hazelnut decline, a total of 102 strains, obtained from central italy (provinces of viterbo and rome) and northern greece, were studied using multilocus enzyme electrophoresis (mlee). their allelic variation in 10 loci was determined. all loci were polymorphic and 53 electrophoretic types (ets) were identified from the total sample. the mean genetic diversity (h) was 0.65 and this value ran ...	2003	14523121
rps4-mediated disease resistance requires the combined presence of rps4 transcripts with full-length and truncated open reading frames.	arabidopsis rps4 belongs to the toll/interleukin-1 receptor (tir)-nucleotide binding site (nbs)-leu-rich repeat (lrr) class of disease resistance (r) genes. like other family members in different plant species, rps4 produces alternative transcripts with truncated open reading frames. the dominant alternative rps4 transcripts are generated by retention of intron 3 or introns 2 and 3, which contain in-frame stop codons and lie downstream of the nbs-encoding exon. we analyzed the biological signifi ...	2003	14523247
cleavage of the pseudomonas syringae type iii effector avrrpt2 requires a host factor(s) common among eukaryotes and is important for avrrpt2 localization in the host cell.	many phytopathogenic bacteria use a type iii secretion system to deliver type iii effector proteins into the host plant cell. the pseudomonas syringae type iii effector avrrpt2 is cleaved at a specific site when translocated into the host cell. in this study, we first demonstrate that the factor(s) required for avrrpt2 cleavage is present in extracts from animal and yeast cells, as well as plant cells. the cleavage factor in animal and plant cell extracts was heat labile but relatively insensiti ...	2003	14526114
molecular basis of pto-mediated resistance to bacterial speck disease in tomato.	the pto gene in tomato confers gene-for-gene resistance to pseudomonas syringae pv. tomato, the causative agent of bacterial speck disease. pto was first introgressed from a wild species of tomato into cultivated tomato varieties over 60 years ago and is now widely used to control speck disease. cloning of the pto gene revealed that it encodes a cytoplasmically localized serine-threonine protein kinase. the molecular basis of gene-for-gene recognition in this pathosystem is the direct physical i ...	2003	14527329
conditional survival as a selection strategy to identify plant-inducible genes of pseudomonas syringae.	a novel strategy termed habitat-inducible rescue of survival (hirs) was developed to identify genes of pseudomonas syringae that are induced during growth on bean leaves. this strategy is based on the complementation of metxw, two cotranscribed genes that are necessary for methionine biosynthesis and required for survival of p. syringae on bean leaves exposed to conditions of low humidity. we constructed a promoter trap vector, ptrap, containing a promoterless version of the wild-type p. syringa ...	2003	14532027
characterization of a salicylic acid- and pathogen-induced lipase-like gene in chinese cabbage.	a cdna clone for a salicylic acid-induced gene in chinese cabbage (brassica rapa subsp. pekinensis) was isolated and characterized. the cabbage gene, designated br-sil1 (for brassica rapa salicylate-induced lipase-like 1 gene), encodes a putative lipase that has the family ii lipase motif gdsxxdxg around the active site serine. a database search showed that plant genomes have a large number of genes that contain the family ii lipase motif. the lipase-like proteins include a myrosinase-associated ...	2003	14536025
multiple hormones act sequentially to mediate a susceptible tomato pathogen defense response.	phytohormones regulate plant responses to a wide range of biotic and abiotic stresses. how a limited number of hormones differentially mediate individual stress responses is not understood. we have used one such response, the compatible interaction of tomato (lycopersicon esculentum) and xanthomonas campestris pv vesicatoria (xcv), to examine the interactions of jasmonic acid (ja), ethylene, and salicylic acid (sa). the role of ja was assessed using an antisense allene oxide cyclase transgenic l ...	2003	14551324
bacterial cell surface display for epitope mapping of hepatitis c virus core antigen.	cell surface expression of protein has been widely used to display enzymes and antigens. here we show that pseudomonas syringae ice nucleation protein with a deletion of internal repeating domain (inc) can be used in escherichia coli to display peptide in a conformationally active form on the outside of the folded protein by fusing to the c-terminus of inc. diagnostic potential of this technology was demonstrated by effective mapping of antigenic epitopes derived from hepatitis c virus (hcv) cor ...	2003	14553932
the botrytis susceptible1 gene encodes an r2r3myb transcription factor protein that is required for biotic and abiotic stress responses in arabidopsis.	the molecular and cellular mechanisms involved in plant resistance to the necrotrophic fungal pathogen botrytis cinerea and their genetic control are poorly understood. botrytis causes severe disease in a wide range of plant species, both in the field and in postharvest situations, resulting in significant economic losses. we have isolated the bos1 (botrytis-susceptible1) gene of arabidopsis based on a t-dna insertion allele that resulted in increased susceptibility to botrytis infection. the bo ...	2003	14555693
tertiary structure of thiopurine methyltransferase from pseudomonas syringae, a bacterial orthologue of a polymorphic, drug-metabolizing enzyme.	in humans, the enzyme thiopurine methyltransferase (tpmt) metabolizes 6-thiopurine (6-tp) medications, including 6-thioguanine, 6-mercaptopurine and azathioprine, commonly used for immune suppression and for the treatment of hematopoietic malignancies. s-methylation by tpmt prevents the intracellular conversion of these drugs into active 6-thioguanine nucleotides (6-tgns). genetic polymorphisms in the tpmt protein sequence have been associated with decreased tissue enzymatic activities and an in ...	2003	14556746
the is1111 family members is4321 and is5075 have subterminal inverted repeats and target the terminal inverted repeats of tn21 family transposons.	is5075 and is4321 are closely related (93.1% identical) members of the is1111 family that target a specific position in the 38-bp terminal inverted repeats of tn21 family transposons and that are inserted in only one orientation. they are 1,327 bp long and have identical ends consisting of short inverted repeats of 12 bp with an additional 7 bp (taatgag) or 6 bp (aatgag) to the left of the left inverted repeats and 3 bp (aga) or 4 bp (agat) to the right of the right inverted repeat. circular for ...	2003	14563872
analysis of specific binding involved in genomic packaging of the double-stranded-rna bacteriophage phi6.	the genomes of bacteriophage phi6 and its relatives are packaged through a mechanism that involves the recognition and translocation of the three different plus-strand transcripts of the segmented double-stranded-rna genomes into preformed polyhedral structures called procapsids or inner cores. the packaging requires the hydrolysis of nucleoside triphosphates and takes place in the order segment s-segment m, segment l. packaging is dependent upon unique sequences of about 200 nucleotides near th ...	2003	14563876
the effect of antifreeze proteins and poly(vinyl alcohol) on the nucleation of ice: a preliminary study.	three substances have been tested for ice nucleation inhibition. these were an antifreeze protein afp iii from the fish macrozoarces americanus, an antifreeze glycoprotein afgp from the fish dissostichus mawsoni, and an 80% hydrolysed poly(vinyl alcohol) with a molecular weight of 9 to 10 kd. a nucleation spectrometer was used to test nucleation inhibition at a range of concentrations against two types of ice nuclei: those present in tap water and a bacterial nucleator from pseudomonas syringae. ...	2003	14566392
knockout analysis of arabidopsis transcription factors tga2, tga5, and tga6 reveals their redundant and essential roles in systemic acquired resistance.	arabidopsis nonexpresser of pathogenesis-related (pr) genes (npr1) is the sole positive regulator that has been shown to be essential for the induction of systemic acquired resistance. in npr1 mutant plants, salicylic acid (sa)-mediated pr gene expression and pathogen resistance are abolished completely. npr1 has been shown to interact with three closely related tga transcription factors-tga2, tga5, and tga6-in yeast two-hybrid assays. to elucidate the biological functions of these three tga tra ...	2003	14576289
a gain-of-function mutation in a plant disease resistance gene leads to constitutive activation of downstream signal transduction pathways in suppressor of npr1-1, constitutive 1.	plants have evolved sophisticated defense mechanisms against pathogen infections, during which resistance (r) genes play central roles in recognizing pathogens and initiating defense cascades. most of the cloned r genes share two common domains: the central domain, which encodes a nucleotide binding adaptor shared by apaf-1, certain r proteins, and ced-4 (nb-arc), plus a c-terminal region that encodes leu-rich repeats (lrr). in arabidopsis, a dominant mutant, suppressor of npr1-1, constitutive 1 ...	2003	14576290
the pseudomonas fluorescens algg protein, but not its mannuronan c-5-epimerase activity, is needed for alginate polymer formation.	bacterial alginates are produced as 1-4-linked beta-d-mannuronan, followed by epimerization of some of the mannuronic acid residues to alpha-l-guluronic acid. here we report the isolation of four different epimerization-defective point mutants of the periplasmic pseudomonas fluorescens mannuronan c-5-epimerase algg. all mutations affected amino acids conserved among algg-epimerases and were clustered in a part of the enzyme also sharing some sequence similarity to a group of secreted epimerases ...	2003	12775688
ferredoxin from sweet pepper (capsicum annuum l.) intensifying harpin(pss)-mediated hypersensitive response shows an enhanced production of active oxygen species (aos).	the hypersensitive response (hr) is a form of cell death associated with plant resistance to pathogen infection. harpin(pss), an elicitor from the bacterium pseudomonas syringae pv. syringae, induces a hr in non-host plants. previously, we reported an amphipathic protein from sweet pepper interfering with harpin(pss)-mediated hr. in this report, we isolated and characterized a cdna clone encoded that amphipathic protein from sweet pepper. this protein is designated as pflp (plant ferredoxin-like ...	2003	12777051
nutritional similarity between leaf-associated nonpathogenic bacteria and the pathogen is not predictive of efficacy in biological control of bacterial spot of tomato.	it has been demonstrated that for a nonpathogenic, leaf-associated bacterium, effectiveness in the control of bacterial speck of tomato is correlated with the similarity in the nutritional needs of the nonpathogenic bacterium and the pathogen pseudomonas syringae pv. tomato. this relationship was investigated further in this study by using the pathogen xanthomonas campestris pv. vesicatoria, the causal agent of bacterial spot of tomato, and a collection of nonpathogenic bacteria isolated from to ...	2003	12788754
physical interaction between rrs1-r, a protein conferring resistance to bacterial wilt, and popp2, a type iii effector targeted to the plant nucleus.	rrs1-r confers broad-spectrum resistance to several strains of the causal agent of bacterial wilt, ralstonia solanacearum. although genetically defined as recessive, this r gene encodes a protein whose structure combines the tir-nbs-lrr domains found in several r proteins and a wrky motif characteristic of some plant transcriptional factors and behaves as a dominant gene in transgenic susceptible plants. here we show that popp2, a r. solanacearum type iii effector, which belongs to the yopj/avrr ...	2003	12788974
novel exchangeable effector loci associated with the pseudomonas syringae hrp pathogenicity island: evidence for integron-like assembly from transposed gene cassettes.	pseudomonas syringae strains use a type iii secretion system (ttss) to translocate effector proteins that assist in the parasitism of host plant cells. some genes for effector proteins are clustered in the exchangeable effector locus (eel) associated with the hrp pathogenicity island. a polymerase chain reaction-based screen was developed to amplify the eel from p. syringae strains. of the 86 strains screened, the eel was successfully amplified from 30 predominately north american p. syringae pv ...	2003	12795376
a strategy for the nmr characterization of type ii copper(ii) proteins: the case of the copper trafficking protein copc from pseudomonas syringae.	copc from pseudomonas syringae was found to be a protein capable of binding both cu(i) and cu(ii) at two different sites. the solution structure of the apo protein is available, and structural information has been obtained on the cu(i) bound form. we attempt here to set the limits for the determination of the solution structure of a cu(ii) protein, such as the cu(ii) bound form of copc, in which the cu(ii) ion takes a type ii coordination. the electron relaxation time is estimated from nmrd meas ...	2003	12797793
characterization of the early response of arabidopsis to alternaria brassicicola infection using expression profiling.	all tested accessions of arabidopsis are resistant to the fungal pathogen alternaria brassicicola. resistance is compromised by pad3 or coi1 mutations, suggesting that it requires the arabidopsis phytoalexin camalexin and jasmonic acid (ja)-dependent signaling, respectively. this contrasts with most well-studied arabidopsis pathogens, which are controlled by salicylic acid-dependent responses and do not benefit from absence of camalexin or ja. here, mutants with defects in camalexin synthesis (p ...	2003	12805591
the pattern of systemic acquired resistance induction within the arabidopsis rosette in relation to the pattern of translocation.	local leaf infections by a necrogenic pathogen can lead to systemic acquired resistance (sar) in untreated leaves. we reasoned that, whatever the nature of the long-distance signal, if it is transported in the phloem, the pattern of sar induced within the plant by treatment of a single leaf should match the pattern of translocation out of that leaf. the source-sink relationships (orthostichies) in the arabidopsis rosette were established with [14c]suc or phloem-mobile 3-aminotriazole at herbicid ...	2003	12805614
systemic gene expression in arabidopsis during an incompatible interaction with alternaria brassicicola.	pathogen challenge can trigger an integrated set of signal transduction pathways, which ultimately leads to a state of "high alert," otherwise known as systemic or induced resistance in tissue remote to the initial infection. although large-scale gene expression during systemic acquired resistance, which is induced by salicylic acid or necrotizing pathogens has been previously reported using a bacterial pathogen, the nature of systemic defense responses triggered by an incompatible necrotrophic ...	2003	12805628
sites of interaction between the feca and fecr signal transduction proteins of ferric citrate transport in escherichia coli k-12.	transcription of the fecabcde ferric citrate transport genes of escherichia coli k-12 is initiated by a signaling cascade from the cell surface into the cytoplasm. fecr receives the signal in the periplasm from the outer membrane protein feca loaded with ferric citrate, transmits the signal across the cytoplasmic membrane, and converts feci in the cytoplasm to an active sigma factor. in this study, it was shown through the use of a bacterial two-hybrid system that, in the periplasm, the c-termin ...	2003	12813067
molecular analysis of the copper-transporting efflux system cuscfba of escherichia coli.	the cus determinant of escherichia coli encodes the cuscfba proteins that mediate resistance to copper and silver by cation efflux. cusa and cusb were essential for copper resistance, and cusc and cusf were required for full resistance. replacements of methionine residues 573, 623, and 672 with isoleucine in cusa resulted in loss of copper resistance, demonstrating their functional importance. substitutions for several other methionine residues of this protein did not have any effect. the small ...	2003	12813074
a pseudomonas syringae type iii effector suppresses cell wall-based extracellular defense in susceptible arabidopsis plants.	bacterial effector proteins secreted through the type iii secretion system (ttss) play a crucial role in causing plant and human diseases. although the ability of type iii effectors to trigger defense responses in resistant plants is well understood, the disease-promoting functions of type iii effectors in susceptible plants are largely enigmatic. previous microscopic studies suggest that in susceptible plants the ttss of plant-pathogenic bacteria transports suppressors of a cell wall-based plan ...	2003	12817082
functional similarities between the icm/dot pathogenesis systems of coxiella burnetii and legionella pneumophila.	coxiella burnetii, the etiological agent of q fever, is an obligate intracellular pathogen, whereas legionella pneumophila, the causative agent of legionnaires' disease, is a facultative intracellular pathogen. during infection of humans both of these pathogens multiply in alveolar macrophages inside a closed phagosome. l. pneumophila intracellular multiplication was shown to be dependent on the icm/dot system, which probably encodes a type iv-related translocation apparatus. recently, genes hom ...	2003	12819052
characterization of a pathogen-induced calmodulin-binding protein: mapping of four ca2+-dependent calmodulin-binding domains.	ca2+ and calmodulin (cam), a key ca2+ sensor in all eukaryotes, have been implicated in defense responses in plants. to elucidate the role of ca2+ and cam in defense signaling, we used 35s-labeled cam to screen expression libraries prepared from tissues that were either treated with an elicitor derived from phytophthora megasperma or infected with pseudomonas syringae pv. tabaci. nineteen cdnas that encode the same protein, pathogen-induced cam-binding protein (picbp), were isolated. the picbp f ...	2003	12825696
the pseudomonas syringae type iii-secreted protein hopptod2 possesses protein tyrosine phosphatase activity and suppresses programmed cell death in plants.	the bacterial plant pathogen pseudomonas syringae possesses a type iii protein secretion system that delivers many virulence proteins into plant cells. a subset of these proteins (called avr proteins) is recognized by the plant's innate immune system and triggers defences. one defence-associated response is the hypersensitive response (hr), a programmed cell death (pcd) of plant tissue. we have previously identified hopptod2 as a type iii secreted protein from p. s. pv. tomato dc3000. sequence a ...	2003	12828636
a translocated protein tyrosine phosphatase of pseudomonas syringae pv. tomato dc3000 modulates plant defence response to infection.	pseudomonas syringae strains translocate effector proteins into host cells via the hrp-encoded type iii protein secretion system (ttss) to facilitate pathogenesis in susceptible plants. however, the mechanisms by which pathogenesis is favoured by these effectors are not well understood. individual strains express multiple effectors with apparently distinct activities that are co-ordinately regulated by the alternative sigma factor hrpl. genes for several effectors were identified in the p. syrin ...	2003	12828637
characterization of salicylic acid-induced genes in chinese cabbage.	salicylic acid is a messenger molecule in the activation of defense responses in plants. in this study, we isolated four cdna clones representing salicylic acid-induced genes in chinese cabbage (brassica rapa subsp. pekinensis) by subtractive hybridization. of the four clones, the bc5-2 clone encodes a putative glucosyltransferase protein. the bc5-3 clone is highly similar to an arabidopsis gene encoding a putative metal-binding farnesylated protein. the bc6-1 clone is a chitinase gene with simi ...	2003	12835914
freshwater bacteria can methylate selenium through the thiopurine methyltransferase pathway.	involvement of the bacterial thiopurine methyltransferase (btpmt) in natural selenium methylation by freshwater was investigated. a freshwater environment that had no known selenium contamination but exhibited reproducible emission of dimethyl selenide (dmse) or dimethyl diselenide (dmdse) when it was supplemented with an organic form of selenium [(methyl)selenocysteine] or an inorganic form of selenium (sodium selenite) was used. the distribution of the btpmt gene (tpm) in the microflora was st ...	2003	12839745
identification of two-component regulatory systems in bifidobacterium infantis by functional complementation and degenerate pcr approaches.	two-component signal transduction systems (2css) are widely used by bacteria to sense and adapt to changing environmental conditions. with two separate approaches, three different 2css were identified on the chromosome of the probiotic bacterium bifidobacterium infantis ucc 35624. one locus was identified by means of functional complementation of an escherichia coli mutant. another two were identified by pcr with degenerate primers corresponding to conserved regions of one protein component of t ...	2003	12839803
detection and diversity assessment of xylella fastidiosa in field-collected plant and insect samples by using 16s rrna and gyrb sequences.	the causal agent of diseases in many economically important plants is attributed to the xylem-limited bacterium xylella fastidiosa. the detection of this plant pathogen has been hampered due to its difficult isolation and slow growth on plates. nearly complete nucleotide sequences of the 16s rrna gene and partial sequences of the gyrb gene were determined for 18 strains of x. fastidiosa isolated from different plant hosts. a phylogenetic analysis, based on gyrb, grouped strains in three clusters ...	2003	12839807
ethylene and jasmonic acid signaling affect the npr1-independent expression of defense genes without impacting resistance to pseudomonas syringae and peronospora parasitica in the arabidopsis ssi1 mutant.	salicylic acid (sa), ethylene, and jasmonic acid (ja) are important signaling molecules in plant defense to biotic stress. an intricate signaling network involving sa, ethylene, and ja fine tunes plant defense responses. sa-dependent defense responses in arabidopsis thaliana are mediated through npr1-dependent and -independent mechanisms. we have previously shown that activation of an npr1-independent defense mechanism confers enhanced disease resistance and constitutive expression of the pathog ...	2003	12848424
the lower cell density of leaf parenchyma in the arabidopsis thaliana mutant lcd1-1 is associated with increased sensitivity to ozone and virulent pseudomonas syringae.	under optimal growth conditions (120 micro mol photons m-2 sec-1 photosynthetically active radiation (par), 16-h photoperiod), the recessive ozone-sensitive arabidopsis thaliana l. heynh. mutant lcd1-1 exhibits a pale phenotype compared to the wild type. confocal and multiphoton microscopy revealed that the paleness of lcd1-1 is because of a lower cell density in the leaf palisade parenchyma, resulting in decreased chlorophyll content. when exposed to ozone, lcd1-1 leaves become paler and contai ...	2003	12848826
regulation of arabidopsis copine 1 gene expression in response to pathogens and abiotic stimuli.	the copines are a widely distributed class of calcium-dependent, phospholipid-binding proteins of undetermined biological function. mutation of the arabidopsis cpn1 (copine 1) gene causes a humidity-sensitive lesion mimic phenotype with increased resistance to a bacterial and an oomyceteous pathogen, constitutive pathogenesis-related gene expression, and an accelerated hypersensitive cell death defense response. here, we show that the disease resistance phenotype of the cpn1-1 mutant was also te ...	2003	12857819
molecular characterization and quantitative analysis of superoxide dismutases in virulent and avirulent strains of aeromonas salmonicida subsp. salmonicida.	aeromonas salmonicida subsp. salmonicida is a facultatively intracellular gram-negative bacterium that is the etiological agent of furunculosis, a bacterial septicemia of salmonids that causes significant economic loss to the salmon farming industry. the mechanisms by which a. salmonicida evades intracellular killing may be relevant in understanding virulence and the eventual design of appropriate treatment strategies for furunculosis. we have identified two open reading frames (orfs) and relate ...	2003	12867441
isolation and analysis of mutants of double-stranded-rna bacteriophage phi6 with altered packaging specificity.	the genomes of bacteriophage phi6 and its relatives are packaged through a mechanism that involves the recognition and translocation of the three different plus strand transcripts of the segmented double-stranded rna genomes into preformed polyhedral structures called procapsids or inner cores. this packaging requires hydrolysis of nucleoside triphosphates and takes place in the order s-m-l. packaging is dependent on unique sequences of about 200 nucleotides near the 5' ends of plus strand trans ...	2003	12867467
simultaneous analysis of phytohormones, phytotoxins, and volatile organic compounds in plants.	phytohormones regulate the protective responses of plants against both biotic and abiotic stresses by means of synergistic or antagonistic actions referred to as signaling crosstalk. a bottleneck in crosstalk research is the quantification of numerous interacting phytohormones and regulators. the chemical analysis of salicylic acid, jasmonic acid, indole-3-acetic acid, and abscisic acid is typically achieved by using separate and complex methodologies. moreover, pathogen-produced phytohormone mi ...	2003	12874387
the rapid induction of glutathione s-transferases atgstf2 and atgstf6 by avirulent pseudomonas syringae is the result of combined salicylic acid and ethylene signaling.	the expression of two members of the glutathione s-transferase (gst) multigene family was studied in arabidopsis plants inoculated with an avirulent strain of pseudomonas syringae pv. tomato (pst). accumulation of atgstf2 and atgstf6 transcripts started 4 and 2 h after inoculation, respectively, and clearly preceded the induction of the pathogenesis-related pr-1 gene. the aim of this work was to find the reason for the faster induction of the two gsts compared with classical salicylic acid (sa)- ...	2003	12881503
electroporation and stable maintenance of plasmid dnas in a biocontrol strain of pseudomonas syringae.	transformation efficiencies as high as 10(7) transformants microg(-1) dna have been previously reported for pseudomonads using electroporation protocols established for e. coli with plasmid dnas prepared from methylation proficient e. coli hosts. we report here a protocol for electroporation of plasmid dnas into a biocontrol strain of pseudomonas syringae which could not be electroporated by standard e. coli methods. transformation efficiencies of 10(7) or higher were obtained with dna recovered ...	2003	12882571
an arabidopsis mutant resistant to thaxtomin a, a cellulose synthesis inhibitor from streptomyces species.	thaxtomin a is a phytotoxin produced by streptomyces scabies and other streptomyces species, the causative agents of common scab disease in potato and other taproot crops. at nanomolar concentrations, thaxtomin causes dramatic cell swelling, reduced seedling growth, and inhibition of cellulose synthesis in arabidopsis. we identified a mutant of arabidopsis, designated txr1, that exhibits increased resistance to thaxtomin as a result of a decrease in the rate of toxin uptake. the txr1 gene was id ...	2003	12897252
p-coumaroylnoradrenaline, a novel plant metabolite implicated in tomato defense against pathogens.	the avr9 peptide elicitor from the fungus cladosporium fulvum, the bacterial pathogen pseudomonas syringae pathovar tomato carrying the avirulence gene avrpto (pst (avrpto)), and the organophosphorous insecticide fenitrothion induce resistance-related responses in tomato lines carrying the cf-9, pto, and fen genes, respectively. these responses were associated with synthesis of p-coumaroyloctopamine and p-coumaroylnoradrenaline, a novel compound for plants. in susceptible near isogenic tomato li ...	2003	12900412
colonization of arabidopsis thaliana with salmonella enterica and enterohemorrhagic escherichia coli o157:h7 and competition by enterobacter asburiae.	enteric pathogens, such as salmonella enterica and escherichia coli o157:h7, have been shown to contaminate fresh produce. under appropriate conditions, these bacteria will grow on and invade the plant tissue. we have developed arabidopsis thaliana (thale cress) as a model system with the intention of studying plant responses to human pathogens. under sterile conditions and at 100% humidity, s. enterica serovar newport and e. coli o157:h7 grew to 10(9) cfu g(-1) on a. thaliana roots and to 2 x 1 ...	2003	12902287
analysis of the argk-tox gene cluster in nontoxigenic strains of pseudomonas syringae pv. phaseolicola.	the analysis of 46 isolates obtained directly from different and distant common bean fields from the northwestern part of spain revealed that they do not produce phaseolotoxin. the isolates were classified as race 5, and their analysis revealed that they do not carry the argk-tox gene cluster involved in the biosynthesis of the phaseolotoxin.	2003	12902295
identifying the methyltransferases for m(5)u747 and m(5)u1939 in 23s rrna using maldi mass spectrometry.	there are three sites of m(5)u modification in escherichia coli stable rnas: one at the invariant trna position u54 and two in 23s rrna at the phylogenetically conserved positions u747 and u1939. each of these sites is modified by its own methyltransferase, and the trna methyltransferase, trma, is well-characterised. two open reading frames, ybjf and ygca, are approximately 30% identical to trma, and here we determine the functions of these candidate methyltransferases using maldi mass spectrome ...	2003	12907714
overexpression of the disease resistance gene pto in tomato induces gene expression changes similar to immune responses in human and fruitfly.	the pto gene encodes a serine/threonine protein kinase that confers resistance in tomato (lycopersicon esculentum) to pseudomonas syringae pv tomato strains that express the type iii effector protein avrpto. constitutive overexpression of pto in tomato, in the absence of avrpto, activates defense responses and confers resistance to several diverse bacterial and fungal plant pathogens. we have used a series of gene discovery and expression profiling methods to examine the effect of pto overexpres ...	2003	12913147
bwmk1, a rice mitogen-activated protein kinase, locates in the nucleus and mediates pathogenesis-related gene expression by activation of a transcription factor.	mitogen-activated protein kinase (mapk) cascades are known to transduce plant defense signals, but the downstream components of the mapk have as yet not been elucidated. here, we report an mapk from rice (oryza sativa), bwmk1, and a transcription factor, oserebp1, phosphorylated by the kinase. the mapk carries a tdy phosphorylation motif instead of the more common tey motif in its kinase domain and has an unusually extended c-terminal domain that is essential to its kinase activity and transloca ...	2003	12913152
the arabidopsis nhl3 gene encodes a plasma membrane protein and its overexpression correlates with increased resistance to pseudomonas syringae pv. tomato dc3000.	the arabidopsis genome contains a family of ndr1/hin1-like (nhl) genes that show homology to the nonrace-specific disease resistance (ndr1) and the tobacco (nicotiana tabacum) harpin-induced (hin1) genes. nhl3 is a pathogen-responsive member of this nhl gene family that is potentially involved in defense. in independent transgenic nhl3-overexpressing plant lines, a clear correlation between increased resistance to virulent pseudomonas syringae pv. tomato dc3000 and enhanced nhl3 transcript level ...	2003	12913158
molecular characterization of a novel lipase-like pathogen-inducible gene family of arabidopsis.	in a differential screening between arabidopsis plants pretreated with the resistance-inducer beta-aminobutyric acid and untreated control plants, we have identified a gene encoding a novel lipase-like protein, prlip1. the abundance of prlip1 mrnas in arabidopsis leaves was up-regulated by application of beta-aminobutyric acid, salicylic acid (sa), and ethylene as well as by various pathogens. induction of prlip1 depended on a functioning sa and ethylene signal transduction pathway but was indep ...	2003	12913177
application of comparative genomics in the identification and analysis of novel families of membrane-associated receptors in bacteria.	a great diversity of multi-pass membrane receptors, typically with 7 transmembrane (tm) helices, is observed in the eukaryote crown group. so far, they are relatively rare in the prokaryotes, and are restricted to the well-characterized sensory rhodopsins of various phototropic prokaryotes.	2003	12914674
polynucleotide phosphorylase-deficient mutants of pseudomonas putida.	in bacteria, polynucleotide phosphorylase (pnpase) is one of the main exonucleolytic activities involved in rna turnover and is widely conserved. in spite of this, pnpase does not seem to be essential for growth if the organisms are not subjected to special conditions, such as low temperature. we identified the pnpase-encoding gene (pnp) of pseudomonas putida and constructed deletion mutants that did not exhibit cold sensitivity. in addition, we found that the transcription pattern of pnp upon c ...	2003	12923102
regulation of the vitamin b12 metabolism and transport in bacteria by a conserved rna structural element.	cobalamin in the form of adenosylcobalamin (ado-cbl) is known to repress expression of genes for vitamin b(12) biosynthesis and be transported by a posttranscriptional regulatory mechanism, which involves direct binding of ado-cbl to 5'untranslated gene regions (5'utr). using comparative analysis of genes and regulatory regions, we identified a highly conserved rna structure, the b12-element, which is widely distributed in 5'utrs of vitamin b(12)-related genes in eubacteria. multiple alignment o ...	2003	12923257
the complete genome sequence of the arabidopsis and tomato pathogen pseudomonas syringae pv. tomato dc3000.	we report the complete genome sequence of the model bacterial pathogen pseudomonas syringae pathovar tomato dc3000 (dc3000), which is pathogenic on tomato and arabidopsis thaliana. the dc3000 genome (6.5 megabases) contains a circular chromosome and two plasmids, which collectively encode 5,763 orfs. we identified 298 established and putative virulence genes, including several clusters of genes encoding 31 confirmed and 19 predicted type iii secretion system effector proteins. many of the virule ...	2003	12928499
pseudomonas syringae pv. tomato dc3000 hopptom (cel orf3) is important for lesion formation but not growth in tomato and is secreted and translocated by the hrp type iii secretion system in a chaperone-dependent manner.	pseudomonas syringae pv. tomato dc3000 is a pathogen of tomato and arabidopsis that injects virulence effector proteins into host cells via a type iii secretion system (ttss). ttss-deficient mutants have a hrp- phenotype, that is, they cannot elicit the hypersensitive response (hr) in non-host plants or pathogenesis in host plants. mutations in effector genes typically have weak virulence phenotypes (apparently due to redundancy), but deletion of six open reading frames (orf) in the dc3000 conse ...	2003	12940984
direct delivery of bacterial avirulence proteins into resistant arabidopsis protoplasts leads to hypersensitive cell death.	many bacterial avirulence (avr) proteins, including the pseudomonas syringae proteins, avrrpt2 and avrb, appear to be recognized inside the host plant cell by resistance mechanisms mediated by the cognate resistance (r) genes. it is thought that avr proteins are either delivered directly into the host cell via the bacterial type iii secretion system (ttss) or taken up by the plant cell following secretion into the apoplast through the ttss. recently, it was shown that the xanthomonas campestris ...	2003	12943547
[effect of the lipopolysaccharide-protein complex of pseudomonas syringae pv. atrofaciens on the process of tumor formation caused by agrobacterium tumefaciens].	it has been found that the agent of bacterial spotting of rye p. syringae pv. atrofaciens 8281 has no antagonistic action on the strains 9052 and 9054 of agrobacterium tumefaciens--the agent of crown gall tumor. lipopolysaccharide-protein complex of p. syringae pv. atrofaciens 8281 when added to the culture medium does not affect the growth and development of a. tumefaciens bacteria. it has been experimentally established that the lipopolysaccharide-protein complex of p. syringae pv. atrofaciens ...	2003	12945188
cleavage of arabidopsis pbs1 by a bacterial type iii effector.	plant disease-resistance (r) proteins are thought to function as receptors for ligands produced directly or indirectly by pathogen avirulence (avr) proteins. the biochemical functions of most avr proteins are unknown, and the mechanisms by which they activate r proteins have not been determined. in arabidopsis, resistance to pseudomonas syringae strains expressing avrpphb requires rps5, a member of the class of r proteins that have a predicted nucleotide-binding site and leucine-rich repeats, an ...	2003	12947197
genetic and molecular evidence that the pseudomonas syringae type iii effector protein avrrpt2 is a cysteine protease.	upon delivery to the plant cell during infection, the pseudomonas syringae effector protein avrrpt2 undergoes proteolytic processing, enhances pathogen virulence and causes the elimination of the arabidopsis rin4 protein. a structure-prediction method was employed in order to investigate possible biochemical functions of avrrpt2. results of a secondary structure prediction algorithm suggest that the functional c-terminal portion of avrrpt2 is a cysteine protease. mutation of predicted catalytic ...	2003	12950919
colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of fusarium oxysporum.	fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. the objective of this study was to compare the abilities of a pathogenic strain (foln3) and a nonpathogenic strain (fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, a ...	2003	12957934
local context finder (lcf) reveals multidimensional relationships among mrna expression profiles of arabidopsis responding to pathogen infection.	a major task in computational analysis of mrna expression profiles is definition of relationships among profiles on the basis of similarities among them. this is generally achieved by pattern recognition in the distribution of data points representing each profile in a high-dimensional space. some drawbacks of commonly used pattern recognition algorithms stem from their use of a globally linear space and/or limited degrees of freedom. a pattern recognition method called local context finder (lcf ...	2003	12960373
does lowering glutamine synthetase activity in nodules modify nitrogen metabolism and growth of lotus japonicus?	a cdna encoding cytosolic glutamine synthetase (gs) from lotus japonicus was fused in the antisense orientation relative to the nodule-specific lbc3 promoter of soybean (glycine max) and introduced into l. japonicus via transformation with agrobacterium tumefaciens. among the 12 independent transformed lines into which the construct was introduced, some of them showed diminished levels of gs1 mrna and lower levels of gs activity. three of these lines were selected and their t(1) progeny was furt ...	2003	12970491
a developmental response to pathogen infection in arabidopsis.	we present evidence that susceptible arabidopsis plants accelerate their reproductive development and alter their shoot architecture in response to three different pathogen species. we infected 2-week-old arabidopsis seedlings with two bacterial pathogens, pseudomonas syringae and xanthomonas campestris, and an oomycete, peronospora parasitica. infection with each of the three pathogens reduced time to flowering and the number of aerial branches on the primary inflorescence. in the absence of co ...	2003	12970499
genetic and physical localization of the soybean rpg1-b disease resistance gene reveals a complex locus containing several tightly linked families of nbs-lrr genes.	alleles or tightly linked genes at the soybean (glycine max l. merr.) rpg1 locus confer resistance to strains of pseudomonas syringae pv. glycinea that express the avirulence genes avrb or avrrpm1. we have previously mapped rpg1-b (the gene specific for avrb) to a cluster of resistance genes (r genes) with diverse specificities in molecular linkage group f. here, we describe the high-resolution physical and genetic mapping of rpg1-b to a 0.16-cm interval encompassed by two overlapping bac clones ...	2003	12971605
structure of the o polysaccharides and serological classification of pseudomonas syringae pv. porri from genomospecies 4.	strains of pseudomonas syringae pv. porri are characterized by a number of pathovar-specific phenotypic and genomic characters and constitute a highly homogeneous group. using monoclonal antibodies, they all were classified in a novel p. syringae serogroup o9. the o polysaccharides (ops) isolated from the lipopolysaccharides (lps) of p. syringae pv. porri ncppb 3365 and ncppb 3364t possess multiple oligosaccharide o repeats, some of which are linear and composed of l-rhamnose (l-rha), whereas th ...	2003	12492471
distribution and function of new bacterial intein-like protein domains.	hint protein domains appear in inteins and in the c-terminal region of hedgehog and hedgehog-like animal developmental proteins. intein hint domains are responsible and sufficient for protein-splicing of their host-protein flanks. in hedgehog proteins the hint domain autocatalyses its cleavage from the n-terminal domain of the hedgehog protein by attaching a cholesterol molecule to it. we identified two new types of hint domains. both types have active site sequence features of hint domains but ...	2003	12492854
complete sequence of virulence plasmid pjm1 from the marine fish pathogen vibrio anguillarum strain 775.	the virulence plasmid pjm1 enables the fish pathogen vibrio anguillarum, a gram-negative polarly flagellated comma-shaped rod bacterium, to cause a highly fatal hemorrhagic septicemic disease in salmonids and other fishes, leading to epizootics throughout the world. the pjm1 plasmid 65,009-nucleotide sequence, with an overall g+c content of 42.6%, revealed genes and open reading frames (orfs) encoding iron transporters, nonribosomal peptide enzymes, and other proteins essential for the biosynthe ...	2003	13129954
transcriptional organization of the pseudomonas putida tol-oprl genes.	proteins of the tol system play a key role in the maintenance of outer membrane integrity and cell morphology in gram-negative bacteria. in pseudomonas putida, the seven genes, orf1, tolq, tolr, tola, tolb, oprl, and orf2, which encode the proteins of this complex, are clustered in a 5.8-kb region of chromosomal dna. analysis of polar mutations, reverse transcriptase pcr assays, and transcriptional fusion constructs with a promoterless lacz gene revealed that the genes are arranged in two operon ...	2003	12486055
cytosolic hsp90 associates with and modulates the arabidopsis rpm1 disease resistance protein.	the arabidopsis protein rpm1 activates disease resistance in response to pseudomonas syringae proteins targeted to the inside of the host cell via the bacterial type iii delivery system. we demonstrate that specific mutations in the atp-binding domain of a single arabidopsis cytosolic hsp90 isoform compromise rpm1 function. these mutations do not affect the function of related disease resistance proteins. rpm1 associates with hsp90 in plant cells. the arabidopsis proteins rar1 and sgt1 are requi ...	2003	14592967
high throughput virus-induced gene silencing implicates heat shock protein 90 in plant disease resistance.	virus-induced gene silencing was used to assess the function of random nicotiana benthamiana cdnas in disease resistance. out of 4992 cdnas tested from a normalized library, there were 79 that suppressed a hypersensitive response (hr) associated with pto-mediated resistance against pseudomonas syringae. however, only six of these clones blocked the pto-mediated suppression of p.syringae growth. the three clones giving the strongest loss of pto resistance had inserts corresponding to hsp90 and al ...	2003	14592968
flagellin glycosylation island in pseudomonas syringae pv. glycinea and its role in host specificity.	the deduced amino acid sequences of the flagellins of pseudomonas syringae pv. tabaci and p. syringae pv. glycinea are identical; however, their abilities to induce a hypersensitive reaction are clearly different. the reason for the difference seems to depend on the posttranslational modification of the flagellins. to investigate the role of this posttranslational modification in the interactions between plants and bacterial pathogens, we isolated genes that are potentially involved in the postt ...	2003	14594840
nitric oxide does not trigger early programmed cell death events but may contribute to cell-to-cell signaling governing progression of the arabidopsis hypersensitive response.	nitric oxide (no) has been suggested to play a role in the hypersensitive response (hr). single- and double-label fluorescence microscopy experiments were conducted using arabidopsis leaves infected with pseudomonas syringae pv. tomato dc3000 carrying either avrb or avrrpt2. kinetics of no production were followed by measurement of green 4-amino-5-methylamino-2',7'-difluorofluorescein (daf-fm) triazole fluorescence in leaves coinfiltrated with daf-fm diacetate. kinetics of hypersensitive cell de ...	2003	14601664
population structure of alexandrium (dinophyceae) cyst formation-promoting bacteria in hiroshima bay, japan.	a total of 31 bacterial isolates that have potential alexandrium cyst formation-promoting activity (alex-cfpb) were isolated from hiroshima bay (japan), which is characterized by seasonal blooms of the toxic dinoflagellate alexandrium tamarense. the population structure of alex-cfpb was analyzed by means of restriction fragment length polymorphism analysis of the 16s rrna genes (16s rdna). fourteen ribotypes, a to n, were observed among the 31 isolates of alex-cfpb by using four restriction enzy ...	2003	14602614
development and application of a dapb-based in vivo expression technology system to study colonization of rice by the endophytic nitrogen-fixing bacterium pseudomonas stutzeri a15.	pseudomonas stutzeri a15 is a nitrogen-fixing bacterium isolated from paddy rice. strain a15 is able to colonize and infect rice roots. this strain may provide rice plants with fixed nitrogen and hence promote plant growth. in this article, we describe the use of dapb-based in vivo expression technology to identify p. stutzeri a15 genes that are specifically induced during colonization and infection (cii). we focused on the identification of p. stutzeri a15 genes that are switched on during rice ...	2003	14602651
virulence systems of pseudomonas syringae pv. tomato promote bacterial speck disease in tomato by targeting the jasmonate signaling pathway.	pseudomonas syringae pv. tomato strain dc3000 (pst dc3000) causes bacterial speck disease on tomato. the pathogenicity of pst dc3000 depends on both the type iii secretion system that delivers virulence effector proteins into host cells and the phytotoxin coronatine (cor), which is thought to mimic the action of the plant hormone jasmonic acid (ja). we found that a ja-insensitive mutant (jai1) of tomato was unresponsive to cor and highly resistant to pst dc3000, whereas host genotypes that are d ...	2003	14617079
genetic evidence that expression of nahg modifies defence pathways independent of salicylic acid biosynthesis in the arabidopsis-pseudomonas syringae pv. tomato interaction.	the salicylic acid (sa)-induction deficient (sid) mutants of arabidopsis, eds5 and sid2 accumulate normal amounts of camalexin after inoculation with pseudomonas syringae pv. tomato (pst), while transgenic nahg plants expressing an sa hydroxylase that degrades sa have reduced levels of camalexin and exhibit a higher susceptibility to different pathogens compared to the sid mutants. sid2 encodes an isochorismate synthase necessary for the synthesis of sa. nahg was shown to act epistatically to th ...	2003	14617091
translocated intimin receptor and its chaperone interact with atpase of the type iii secretion apparatus of enteropathogenic escherichia coli.	few interactions have been reported between effectors and components of the type iii secretion apparatus, although many interactions have been demonstrated between type iii effectors and their cognate chaperones. it is thought that chaperones may play a role in directing effectors to the type iii secretion apparatus. the atpase flii in the flagellar assembly apparatus plays a pivotal role in interacting with other components of the apparatus and with substrates of the flagellar system. we perfor ...	2003	14617638
purification and characterization of a phytase from pseudomonas syringae mok1.	a phytase (ec 3.1.3.8) from pseudomonas syringae mok1 was purified to apparent homogeneity in two steps employing cation and an anion exchange chromatography. the molecular weight of the purified enzyme was estimated to be 45 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. the optimal activity occurred at ph 5.5 and 40 degrees c. the michaelis constant (km) and maximum reaction rate (vmax) for sodium phytate were 0.38 mm and 769 u/mg of protein, respectively. the enzym ...	2003	14629009
structure and expression of phosphoenolpyruvate carboxylase kinase genes in solanaceae. a novel gene exhibits alternative splicing.	phosphorylation of phosphoenolpyruvate carboxylase (pepc; ec 4.1.1.31) plays an important role in the control of central metabolism in higher plants. two ppck (pepc kinase) genes have been identified in tomato (lycopersicon esculentum cv alicante), hereafter termed leppck1 and leppck2. the function of the gene products has been confirmed by transcription of full-length cdnas, translation, and in vitro assay of kinase activity. previously studied ppck genes contain a single intron. leppck2 also c ...	2003	14630963
the tomato transcription factor pti4 regulates defense-related gene expression via gcc box and non-gcc box cis elements.	the tomato transcription factor pti4, an ethylene-responsive factor (erf), interacts physically with the disease resistance protein pto and binds the gcc box cis element that is present in the promoters of many pathogenesis-related (pr) genes. we reported previously that arabidopsis plants expressing pti4 constitutively express several gcc box-containing pr genes and show reduced disease symptoms compared with wild-type plants after inoculation with pseudomonas syringae pv tomato or erysiphe oro ...	2003	14630974
the insecticidal toxin makes caterpillars floppy 2 (mcf2) shows similarity to hrma, an avirulence protein from a plant pathogen.	the photorhabdus luminescens w14 toxin encoding gene makes caterpillars floppy (mcf) was discovered due to its ability to kill caterpillars when expressed in escherichia coli. here we describe a homologue of mcf (renamed as mcf1), termed mcf2, discovered in the same genome. the mcf2 gene predicts another large toxin whose central domain, like mcf1, also shows limited homology to clostridium cytotoxin b. however, the n-terminus of mcf2 shows significant similarity to the type-iii secreted effecto ...	2003	14680709
photosynthetic acclimation is reflected in specific patterns of gene expression in drought-stressed loblolly pine.	because the product of a single gene can influence many aspects of plant growth and development, it is necessary to understand how gene products act in concert and upon each other to effect adaptive changes to stressful conditions. we conducted experiments to improve our understanding of the responses of loblolly pine (pinus taeda) to drought stress. water was withheld from rooted plantlets of to a measured water potential of -1 mpa for mild stress and -1.5 mpa for severe stress. net photosynthe ...	2003	14681533
a dna element recognised by the molybdenum-responsive transcription factor mode is conserved in proteobacteria, green sulphur bacteria and archaea.	the transition metal molybdenum is essential for life. escherichia coli imports this metal into the cell in the form of molybdate ions, which are taken up via an abc transport system. in e. coli and other proteobacteria molybdenum metabolism and homeostasis are regulated by the molybdate-responsive transcription factor mode.	2003	14641908
xopc and xopj, two novel type iii effector proteins from xanthomonas campestris pv. vesicatoria.	pathogenicity of the gram-negative plant pathogen xanthomonas campestris pv. vesicatoria depends on a type iii secretion (tts) system which translocates bacterial effector proteins into the plant cell. previous transcriptome analysis identified a genome-wide regulon of putative virulence genes that are coexpressed with the tts system. in this study, we characterized two of these genes, xopc and xopj. both genes encode xanthomonas outer proteins (xops) that were shown to be secreted by the tts sy ...	2003	14645268
pathways leading from bara/sira to motility and virulence gene expression in salmonella.	the bara and sira genes of salmonella enterica serovar typhimurium encode a two-component sensor kinase and a response regulator, respectively. this system increases the expression of virulence genes and decreases the expression of motility genes. in this study, we examined the pathways by which sira affects these genes. we found that the master regulator of flagellar genes, flhdc, had a positive regulatory effect on the primary regulator of intestinal virulence determinants, hila, but that hila ...	2003	14645287
gaca, the response regulator of a two-component system, acts as a master regulator in pseudomonas syringae pv. tomato dc3000 by controlling regulatory rna, transcriptional activators, and alternate sigma factors.	concerted investigations of factors affecting host-pathogen interactions are now possible with the model plant arabidopsis thaliana and its model pathogen pseudomonas syringae pv. tomato dc3000, as their whole genome sequences have become available. as a prelude to analysis of the regulatory genes and their targets, we have focused on gaca, the response regulator of a two-component system. the dc3000 gene was cloned by testing for the reversal of phenotypes of an erwinia gaca- mutant. a gaca- mu ...	2003	14651344
new connections in the prokaryotic toxin-antitoxin network: relationship with the eukaryotic nonsense-mediated rna decay system.	several prokaryotic plasmids maintain themselves in their hosts by means of diverse post-segregational cell killing systems. recent findings suggest that chromosomally encoded copies of toxins and antitoxins of post-segregational cell killing systems - such as the rele system - might function as regulatory switches under stress conditions. the rele toxin cleaves ribosome-associated transcripts, whereas another post-segregational cell killing toxin, pare, functions as a gyrase inhibitor.	2003	14659018
efficient degradation of 2,4,6-trichlorophenol requires a set of catabolic genes related to tcp genes from ralstonia eutropha jmp134(pjp4).	2,4,6-trichlorophenol (2,4,6-tcp) is a hazardous pollutant. several aerobic bacteria are known to degrade this compound. one of these, ralstonia eutropha jmp134(pjp4), a well-known, versatile chloroaromatic compound degrader, is able to grow in 2,4,6-tcp by converting it to 2,6-dichlorohydroquinone, 6-chlorohydroxyquinol, 2-chloromaleylacetate, maleylacetate, and beta-ketoadipate. three enzyme activities encoded by tcp genes, 2,4,6-tcp monooxygenase (tcpa), 6-chlorohydroxyquinol 1,2-dioxygenase ...	2003	14660355
biochemical, genetic, and zoosporicidal properties of cyclic lipopeptide surfactants produced by pseudomonas fluorescens.	zoospores play an important role in the infection of plant and animal hosts by oomycetes and other zoosporic fungi. in this study, six fluorescent pseudomonas isolates with zoosporicidal activities were obtained from the wheat rhizosphere. zoospores of multiple oomycetes, including pythium species, albugo candida, and phytophthora infestans, were rendered immotile within 30 s of exposure to cell suspensions or cell culture supernatants of the six isolates, and subsequent lysis occurred within 60 ...	2003	14660362
characterization of the arga gene required for arginine biosynthesis and syringomycin production by pseudomonas syringae pv. syringae.	two types of necrosis-inducing lipodepsipeptide toxins, called syringomycin and syringopeptin, are major virulence factors of pseudomonas syringae pv. syringae strain b301d. a previous study showed that a locus, called syra, was required for both syringomycin production and plant pathogenicity, and the syra locus was speculated to encode a regulator of toxin production. in this study, sequence analysis of the 8-kb genomic dna fragment that complements the syra phenotype revealed high conservatio ...	2003	14660376
metagenome survey of biofilms in drinking-water networks.	most naturally occurring biofilms contain a vast majority of microorganisms which have not yet been cultured, and therefore we have little information on the genetic information content of these communities. therefore, we initiated work to characterize the complex metagenome of model drinking water biofilms grown on rubber-coated valves by employing three different strategies. first, a sequence analysis of 650 16s rrna clones indicated a high diversity within the biofilm communities, with the ma ...	2003	14660379
concomitant induction of systemic resistance to pseudomonas syringae pv. lachrymans in cucumber by trichoderma asperellum (t-203) and accumulation of phytoalexins.	most studies on the reduction of disease incidence in soil treated with trichoderma asperellum have focused on microbial interactions rather than on plant responses. this study presents conclusive evidence for the induction of a systemic response against angular leaf spot of cucumber (pseudomonas syringae pv. lachrymans) following application of t. asperellum to the root system. to ascertain that t. asperellum was the only microorganism present in the root milieu, plants were grown in an aseptic ...	2003	14660384
differential survival of solitary and aggregated bacterial cells promotes aggregate formation on leaf surfaces.	the survival of individual pseudomonas syringae cells was determined on bean leaf surfaces maintained under humid conditions or periodically exposed to desiccation stress. cells of p. syringae strain b728a harboring a gfp marker gene were visualized by epifluorescence microscopy, either directly in situ or after recovery from leaves, and dead cells were identified as those that were stained with propidium iodide in such populations. under moist, conducive conditions on plants, the proportion of ...	2003	14665692
efficiency of procedures for induction and cultivation of pseudomonas syringae pv. pisi l-form.	the l-form of pseudomonas syringae pv. phaseolicola has been proved to induce resistance to bean halo blight. various procedures were tested to induce the l-form of pseudomonas syringae pv. pisi for its potential use as biocontrol agent of pea bacterial blight. cell-wall deficient cells were induced in a liquid medium with penicillin following a protocol described for p. s. pv. phaseolicola. cell growth on solid induction medium developed as typical granular and vacuolated structures, and charac ...	2003	14717447
[serological heterogeneity of pseudomonas syringae pv. atrofaciens strains and their ecological niches].	the paper deals with a comparative analysis of the serological and ecological properties of pseudomonas syringae pv. atrofaciens strains from the collections of microbial cultures at the malkov institute for plant genetic resources and zabolotny institute of microbiology and virology. all of the strains from the bulgarian collection, except for one, fall into five serogroups (ii through vi) of the classification system of pastushenko and simonovich. the p. syringae pv. atrofaciens strains isolat ...	2003	14768551
construction and analysis of a recombinant cyanobacterium expressing a chromosomally inserted gene for an ethylene-forming enzyme at the psbai locus.	the coding sequence of a gene for a pseudomonas syringae ethylene-forming enzyme was inserted at the psbai locus in a cyanobacterium, synechococcus elongatus pcc 7942 via rps12-mediated gene replacement. the recombinant strain photoautotrophically produced ethylene at 451 nl ml(-1) h(-1) od730(-1), but showed a depressed specific growth rate as well as a yellow-green phenotype indicating a severe metabolic stress. the rate of ethylene production in the recombinant culture decreased as a result o ...	2003	16233410
[investigation of the mechanism of cell membrane-active cyclic lipodepsipeptides compounds].	the cyclic lipodepsipeptides produced by pseudomonas syringae pv. syringae possess fungicide properties. they inhibit much of the cell functions, presumably on the basis of their pore-forming activity. the syringomycin e, studied earlier by our research group, formed pores on human red blood cells (rbc), and caused also partially hemolysis. to reach selective toxicity, knowledge of the relationship between the structure and function of the clps is required. to fulfill this requirement, the pore ...	2003	15279038
two mapk cascades, npr1, and tga transcription factors play a role in pto-mediated disease resistance in tomato.	the tomato pto kinase confers resistance to the causative agent of bacterial speck disease, pseudomonas syringae pv. tomato, by recognizing the pathogen effector proteins avrpto or avrptob. pto-mediated resistance requires multiple signal transduction pathways and has been shown to activate many defense responses including an oxidative burst, rapid changes in the expression of over 400 genes, and localized cell death. we have tested the role in pto-mediated resistance in tomato of a set of 21 ge ...	2003	14675454