Publications

hydrogen peroxide acts as a second messenger for the induction of defense genes in tomato plants in response to wounding, systemin, and methyl jasmonate.	the systemic accumulation of both hydrogen peroxide (h(2)o(2)) and proteinase inhibitor proteins in tomato leaves in response to wounding was inhibited by the nadph oxidase inhibitors diphenylene iodonium (dpi), imidazole, and pyridine. the expression of several defense genes in response to wounding, systemin, oligosaccharides, and methyl jasmonate also was inhibited by dpi. these genes, including those of four proteinase inhibitors and polyphenol oxidase, are expressed within 4 to 12 hr after w ...	2001	11158538
tomato allene oxide synthase and fatty acid hydroperoxide lyase, two cytochrome p450s involved in oxylipin metabolism, are targeted to different membranes of chloroplast envelope.	allene oxide synthase (aos) and hydroperoxide lyase (hpl) are related cytochrome p450s that metabolize a common fatty acid hydroperoxide substrate to different classes of bioactive oxylipins within chloroplasts. here, we report the use of in vitro import assays to investigate the targeting of tomato (lycopersicon esculentum) aos (leaos) and hpl (lehpl) to isolated chloroplasts. leaos, which contains a typical n-terminal transit peptide, was targeted to the inner envelope membrane by a route that ...	2001	11154338
freezing of barley studied by infrared video thermography.	freezing of barley (hordeum vulgare), hordeum murinum, and holcus lanatus was studied using infrared video thermography. in the field, ice could enter h. lanatus leaves through hydathodes. in laboratory tests with barley, initially 0.4% of the leaf water froze, spreading in alternate strips of high and low freezing intensity longitudinally at 1 to 4 cm s(-1), and simultaneously spreading laterally at 0.3 cm s(-1). similar results were obtained in the field with h. lanatus. a distinct second, mor ...	2001	11154332
a gain-of-function mutation in an arabidopsis toll interleukin1 receptor-nucleotide binding site-leucine-rich repeat type r gene triggers defense responses and results in enhanced disease resistance.	in a screen for suppressors of npr1-5-based salicylic acid (sa) insensitivity, we isolated a semidominant gain-of-function mutation, designated ssi4, that confers constitutive expression of several pr (pathogenesis-related) genes, induces sa accumulation, triggers programmed cell death, and enhances resistance to bacterial and oomycete pathogens. through map-based cloning, ssi4 was identified and found to encode a putative protein belonging to the tir-nbs-lrr (toll interleukin1 receptor-nucleoti ...	2002	12468733
a novel nucleus-targeted protein is expressed in barley leaves during senescence and pathogen infection.	the barley (hordeum vulgare) cdna hvs40 represents a gene with enhanced mrna level during leaf senescence. biolistic transformation of onion (allium cepa) epidermal cell layers with a glucuronidase fusion protein construct provided evidence that the 15.4-kd protein encoded by hvs40 is localized to the nucleus. expression of the gene is induced by jasmonate and salicylic acid; both are known to act as signaling compounds during senescence and defense toward pathogens. transcript levels of hvs40 w ...	2002	12427984
analysis and effects of cytosolic free calcium increases in response to elicitors in nicotiana plumbaginifolia cells.	cell suspensions obtained from nicotiana plumbaginifolia plants stably expressing the apoaequorin gene were used to analyze changes in cytosolic free calcium concentrations ([ca(2+)](cyt)) in response to elicitors of plant defenses, particularly cryptogein and oligogalacturonides. the calcium signatures differ in lag time, peak time, intensity, and duration. the intensities of both signatures depend on elicitor concentration and extracellular calcium concentration. cryptogein signature is charac ...	2002	12368509
plant disease susceptibility genes?		2002	12215498
signature of balancing selection in arabidopsis.	natural selection and genetic linkage cause dna segments to have genealogical histories resembling those of the selected sites. when a polymorphism maintained by selection is old, it will have an island of enhanced sequence variability surrounding it, which represents a detectable "signature of selection." we investigate the structure of single-nucleotide polymorphisms (snps) in a 20-kb interval containing the arabidopsis thaliana disease resistance gene rps5, a locus containing common alleles f ...	2002	12172007
the role of auxin, ph, and stress in the activation of embryogenic cell division in leaf protoplast-derived cells of alfalfa.	culturing leaf protoplast-derived cells of the embryogenic alfalfa (medicago sativa subsp. varia a2) genotype in the presence of low (1 microm) or high (10 microm) 2, 4-dichlorophenoxyacetic acid (2,4-d) concentrations results in different cell types. cells exposed to high 2,4-d concentration remain small with dense cytoplasm and can develop into proembryogenic cell clusters, whereas protoplasts cultured at low auxin concentration elongate and subsequently die or form undifferentiated cell colon ...	2002	12177494
reactive oxygen species in the elongation zone of maize leaves are necessary for leaf extension.	the production and role of reactive oxygen species (ros) in the expanding zone of maize (zea mays) leaf blades were investigated. ros release along the leaf blade was evaluated by embedding intact seedlings in 2',7'-dichlorofluorescein-containing agar and examining the distribution of 2',7'-dichlorofluorescein fluorescence along leaf 4, which was exposed by removing the outer leaves before embedding the seedling. fluorescence was high in the expanding region, becoming practically non-detectable ...	2002	12177475
using genomic resources to guide research directions. the arabinogalactan protein gene family as a test case.	arabinogalactan proteins (agps) are extracellular hydroxyproline-rich proteoglycans implicated in plant growth and development. the protein backbones of agps are rich in proline/hydroxyproline, serine, alanine, and threonine. most family members have less than 40% similarity; therefore, finding family members using basic local alignment search tool searches is difficult. as part of our systematic analysis of agp function in arabidopsis, we wanted to make sure that we had identified most of the m ...	2002	12177459
the subtilisin-like serine protease sdd1 mediates cell-to-cell signaling during arabidopsis stomatal development.	wild-type stomata are distributed nonrandomly, and their density is controlled by endogenous and exogenous factors. in the arabidopsis mutant stomatal density and distribution1-1 (sdd1-1), the establishment of the stomatal pattern is disrupted, resulting in stomata clustering and twofold to fourfold increases in stomatal density. the sdd1 gene that encodes a subtilisin-like ser protease is expressed strongly in stomatal precursor cells (meristemoids and guard mother cells), and the sdd1 promoter ...	2002	12119372
two immediate-early pathogen-responsive members of the atcmpg gene family in arabidopsis thaliana and the w-box-containing elicitor-response element of atcmpg1.	the arabidopsis thaliana genome contains at least 50 predicted atcmpg genes. the encoded protein family is defined by a common domain possessing four strictly conserved amino acid residues [cys, met, pro, and gly (cmpg)] that designate the family. two members, atcmpg1 and atcmpg2, with high sequence similarity to the previously described, immediate-early pathogen-responsive pccmpg1 gene from petroselinum crispum were selected for analysis of their expression modes and defense-related promoter el ...	2002	12084942
transcriptional profiling reveals novel interactions between wounding, pathogen, abiotic stress, and hormonal responses in arabidopsis.	mechanical wounding not only damages plant tissues, but also provides pathways for pathogen invasion. to understand plant responses to wounding at a genomic level, we have surveyed the transcriptional response of 8,200 genes in arabidopsis plants. approximately 8% of these genes were altered by wounding at steady-state mrna levels. studies of expression patterns of these genes provide new information on the interactions between wounding and other signals, including pathogen attack, abiotic stres ...	2002	12068110
induced instability of two arabidopsis constitutive pathogen-response alleles.	paramutation is an example of a non-mendelian-directed allelic interaction that results in the epigenetic alteration of one allele. we describe a paramutation-like interaction between two alleles, bal and cpr1-1 (constitutive expressor of pr genes 1), which map to a complex r-like gene cluster on arabidopsis chromosome 4. both alleles cause dwarfing and constitutive defense responses, similar to another dwarf variant, ssi1 (suppressor of sa-insensitivity 1). previous work has demonstrated that t ...	2002	12032362
induced systemic resistance (isr) against pathogens in the context of induced plant defences.	induced systemic resistance (isr) of plants against pathogens is a widespread phenomenon that has been intensively investigated with respect to the underlying signalling pathways as well as to its potential use in plant protection. elicited by a local infection, plants respond with a salicylic-dependent signalling cascade that leads to the systemic expression of a broad spectrum and long-lasting disease resistance that is efficient against fungi, bacteria and viruses. changes in cell wall compos ...	2002	12099523
rar1 and ndr1 contribute quantitatively to disease resistance in arabidopsis, and their relative contributions are dependent on the r gene assayed.	plant disease resistance (r) genes mediate specific pathogen recognition, leading to a successful immune response. downstream responses include ion fluxes, an oxidative burst, transcriptional reprogramming, and, in many cases, hypersensitive cell death at the infection site. we used a transgenic arabidopsis line carrying the bacterial avirulence gene avrrpm1 under the control of a steroid-inducible promoter to select for mutations in genes required for rpm1-mediated recognition and signal transd ...	2002	12034893
arabidopsis rar1 exerts rate-limiting control of r gene-mediated defenses against multiple pathogens.	we have identified the arabidopsis ortholog of barley rar1 as a component of resistance specified by multiple nucleotide binding/leu-rich repeat resistance (r) genes recognizing different bacterial and oomycete pathogen isolates. characterization of partially and fully defective rar1 mutations revealed that wild-type rar1 acts as a rate-limiting regulator of early r gene-triggered defenses, determining the extent of pathogen containment, hypersensitive plant cell death, and an oxidative burst at ...	2002	12034891
transcriptional regulation: a genomic overview.	the availability of the arabidopsis thaliana genome sequence allows a comprehensive analysis of transcriptional regulation in plants using novel genomic approaches and methodologies. such a genomic view of transcription first necessitates the compilation of lists of elements. transcription factors are the most numerous of the different types of proteins involved in transcription in eukaryotes, and the arabidopsis genome codes for more than 1,500 of them, or approximately 6% of its total number o ...	2002	22303220
ecology and evolutionary biology of arabidopsis.	arabidopsis thaliana is now widely used as a model system in molecular and developmental biology, as well as in physiology and cell biology. however, ecologists and evolutionary biologists have turned their attention to the mouse ear cress only much more recently and almost reluctantly. the reason for this is the perception that a. thaliana is not particularly interesting ecologically and that it represents an oddity from an evolutionary standpoint. while there is some truth in both these attitu ...	2002	22303188
multigene engineering: dawn of an exciting new era in biotechnology.	development of a rice variety enriched in provitamin a, the accumulation of polyhydroxybutyrate polyester in arabidopsis nuclear transgenic plants (with enzymes targeted to chloroplasts in both), and the expression of bacterial operons via the chloroplast genome are recent landmark achievements in multigene engineering. hyper-expression of transgenes has resulted in the formation of insecticidal protein crystals or inclusion bodies of pharmaceutical proteins in transgenic chloroplasts, achieving ...	2002	11950565
altering the expression of the chlorophyllase gene athcor1 in transgenic arabidopsis caused changes in the chlorophyll-to-chlorophyllide ratio.	the arabidopsis gene athcor1, which encodes the cori1 (coronatine-induced) protein, was expressed in bacterial cells. soluble recombinant cori1 was purified and shown to possess chlorophyllase (chlase) activity in vitro. to determine its activity in vivo, wild-type arabidopsis and coi1 mutant, which lacks athcor1 transcripts, were transformed with sense and antisense forms of the gene. wild-type and coi1 plants overexpressing athcor1 showed increased contents of chlorophyllide (chlide) without a ...	2002	11950974
distribution of spontaneous mutants and inferences about the replication mode of the rna bacteriophage phi6.	when a parent virus replicates inside its host, it must first use its own genome as the template for replication. however, once progeny genomes are produced, the progeny can in turn act as templates. depending on whether the progeny genomes become templates, the distribution of mutants produced by an infection varies greatly. while information on the distribution is important for many population genetic models, it is also useful for inferring the replication mode of a virus. we have analyzed the ...	2002	11884552
expression profile matrix of arabidopsis transcription factor genes suggests their putative functions in response to environmental stresses.	numerous studies have shown that transcription factors are important in regulating plant responses to environmental stress. however, specific functions for most of the genes encoding transcription factors are unclear. in this study, we used mrna profiles generated from microarray experiments to deduce the functions of genes encoding known and putative arabidopsis transcription factors. the mrna levels of 402 distinct transcription factor genes were examined at different developmental stages and ...	2002	11910004
milestones in chloroplast genetic engineering: an environmentally friendly era in biotechnology.	chloroplast genomes defied the laws of mendelian inheritance at the dawn of plant genetics, and continue to defy the mainstream approach to biotechnology, leading the field in an environmentally friendly direction. recent success in engineering the chloroplast genome for resistance to herbicides, insects, disease and drought, and for production of biopharmaceuticals, has opened the door to a new era in biotechnology. the successful engineering of tomato chromoplasts for high-level transgene expr ...	2002	11832280
epigenetic variation in arabidopsis disease resistance.	plant pathogen resistance is mediated by a large repertoire of resistance (r) genes, which are often clustered in the genome and show a high degree of genetic variation. here, we show that an arabidopsis thaliana r-gene cluster is also subject to epigenetic variation. we describe a heritable but metastable epigenetic variant bal that overexpresses the r-like gene at4g16890 from a gene cluster on chromosome 4. the bal variant and arabidopsis transgenics overexpressing the at4g16890 gene are dwarf ...	2002	11799061
specificity and cross-talk in plant signal transduction: january 2002 keystone symposium.		2002	12045267
the jasmonate signal pathway.		2002	12045275
ethylene biosynthesis and signaling networks.		2002	12045274
the arabidopsis xylem peptidase xcp1 is a tracheary element vacuolar protein that may be a papain ortholog.	xcp1 is a xylem-specific papain-like cysteine peptidase in arabidopsis. to determine whether xcp1 could be involved in tracheary element autolysis, promoter activity and localization of xcp1 were investigated using xcp1 promoter-beta-glucuronidase fusions and immunofluorescence confocal microscopy. a tracheary element expression pattern was detected for xcp1. results from confocal microscopy and biochemical subcellular fractionation indicated that xcp1 was localized in the vacuole. ectopic expre ...	2002	11788755
cross-talk between jasmonate and salicylate plant defense pathways: effects on several plant parasites.	plants are often attacked by many herbivorous insects and pathogens at the same time. two important suites of responses to attack are mediated by plant hormones, jasmonate and salicylate, which independently provide resistance to herbivorous insects and pathogens, respectively. several lines of evidence suggest that there is negative cross-talk between the jasmonate and salicylate response pathways. this biochemical link between general plant defense strategies means that deploying defenses agai ...	2002	28547690
copper resistance in pseudomonas syringae strains isolated from mango is encoded mainly by plasmids.	abstract bacterial apical necrosis of mango, elicited by pseudomonas syringae pv. syringae, limits fruit production in southern spain and portugal. examination of a collection of p. syringae pv. syringae isolates for copper resistance showed that 59% were resistant to cupric sulfate. the survey of a mango orchard revealed an increase in frequencies of copper-resistant bacteria after repeated treatments with bordeaux mixture. these data suggest that selection of copper-resistant strains could be ...	2002	18942971
biological control of bacterial speck of tomato under field conditions at several locations in north america.	abstract bacterial speck of tomato, caused by pseudomonas syringae pv. tomato, continues to be a problem for tomato growers worldwide. a collection of nonpathogenic bacteria from tomato leaves plus p. syringae strains tlp2 and cit7, p. fluorescens strain a506, and p. syringae pv. tomato dc3000 hrp mutants were examined in a greenhouse bioassay for the ability to reduce foliar bacterial speck disease severity. while several of these strains significantly reduced disease severity, p. syringae cit7 ...	2002	18943882
comparative dynamics of adherent and nonadherent bacterial populations on maize leaves.	abstract the dynamics of the adherent and nonadherent populations of three bacterial species on maize leaves were examined to identify the extent to which bacteria adhere to leaves and the importance of this adhesion to leaf colonization. pantoea agglomerans strain brt98, clavibacter michiganensis subsp. nebraskensis strain gh2390, and pseudomonas syringae pv. syringae strain hs191r all rapidly adhered to maize leaves following inoculation, but differed in the percentage of cells that adhered to ...	2002	18944027
rapid diagnosis of pseudomonas syringae pv. papulans, the causal agent of blister spot of apple, by polymerase chain reaction using specifically designed hrpl gene primers.	abstract the identification and detection of pseudomonas syringae pv. papulans, the causal agent of blister spot of apple, on apple leaves and fruit was achieved by polymerase chain reaction amplification of a specific dna fragment of the hrpl sequence. the consensus primers hrpl(1) and hrpl(2) were designed based on the alignment of pseudomonad hrpl gene sequences available in nucleic acid data banks. this primer set produced a 631-bp amplicon from 37 of the 57 pseudomonads strains tested. thes ...	2002	18944218
location and activity of members of a family of virppha homologues in pathovars of pseudomonas syringae and p. savastanoi.	summary virppha is a major determinant of the pathogenicity of pseudomonas savastanoi pv. phaseolicola to phaseolus bean. a family of homologues of virppha was detected in pathovars of p. savastanoi and p. syringae. we examined the structure and activity of alleles designated virppha, virppha(pgy), and virppha(psv) from p. savastanoi pathovars phaseolicola, glycinea, and savastanoi, respectively, and avrptob from p. syringae pv. tomato. sequencing showed that the virppha(pgy) homologue had a 48- ...	2002	20569328
primary structure and tissue-specific expression of the pathogenesis-related protein pr-1b in potatodagger.	summary the infection of potato (solanum tuberosum) leaves with the late blight pathogen phytophthora infestans, or treatment with fungal elicitor, leads to the massive accumulation of pathogenesis-related (pr) proteins in the extracellular leaf space. the most abundant of these proteins was purified to apparent homogeneity and identified as a new, basic member of the pr-1 family of defence proteins, designated pr-1b. antibodies raised against the protein and a cdna isolated by differential scre ...	2002	20569341
localization of hrpa-induced pseudomonas syringae pv. tomato dc3000 in infected tomato leaves.	summary pseudomonas syringae pv. tomato is the causative agent of bacterial speck of tomato. the key virulence determinant of p. syringae is the hrp gene cluster, which encodes a type iii secretion system. the type iii system is used by a wide variety of pathogenic bacteria for transporting virulence proteins from the bacteria directly into the eukaryotic host cell. hrp pilus, which is composed of hrpa pilin subunits, is an indispensable component of the type iii secretion system in p. syringae. ...	2002	20569352
targets of atwrky6 regulation during plant senescence and pathogen defense.	in arabidopsis, wrky factors comprise a large gene family of plant-specific transcriptional regulators controlling several types of plant stress responses. to understand the regulatory role of wrky proteins during such processes, we identified targets of the senescence- and defense-associated wrky6 factor. wrky6 was found to suppress its own promoter activity as well as that of a closely related wrky family member, indicating negative autoregulation. on the other hand, wrky6 positively influence ...	2002	12000796
interactions between xanthomonas species and arabidopsis thaliana.	arabidopsis has been well studied as a model plant for plant pathogen interactions. while a large portion of the literature has been devoted to interactions between arabidopsis and pseudomonas and peronospora species, a small cadre of researchers have been making inroads on the response of arabidopsis to xanthomonas. differential responses of arabidopsis accessions to isolates of xanthomonas campestris pv campestris include tolerance, a hypersensitive response, resistance without a hypersensitiv ...	2002	22303203
preexisting systemic acquired resistance suppresses hypersensitive response-associated cell death in arabidopsis hrl1 mutant.	the hypersensitive response (hr) displayed by resistant plants against invading pathogens is a prominent feature of plant-pathogen interactions. the arabidopsis hypersensitive response like lesions1 (hrl1) mutant is characterized by heightened defense responses that make it more resistant to virulent pathogens. however, hrl1 suppresses avirulent pathogen-induced hr cell death. furthermore, the high pr-1 expression observed in hrl1 remains unaltered after avirulent and virulent pathogen infection ...	2002	11950972
the arabidopsis thaliana-pseudomonas syringae interaction.		2002	22303207
alpha-crystallin-type heat shock proteins: socializing minichaperones in the context of a multichaperone network.	alpha-crystallins were originally recognized as proteins contributing to the transparency of the mammalian eye lens. subsequently, they have been found in many, but not all, members of the archaea, bacteria, and eucarya. most members of the diverse alpha-crystallin family have four common structural and functional features: (i) a small monomeric molecular mass between 12 and 43 kda; (ii) the formation of large oligomeric complexes; (iii) the presence of a moderately conserved central region, the ...	2002	11875128
syringotoxin pore formation and inactivation in human red blood cell and model bilayer lipid membranes.	the effect of syringotoxin (st), a member of the cyclic lipodepsipeptides family (clps) produced by pseudomonas syringae pv. syringae on the membrane permeability of human red blood cells (rbcs) and model bilayer lipid membranes (blms) was studied and compared to that of two recently investigated clps, syringomycin e (sre) and syringopeptin 22a (sp22a) [biochim. biophys. acta 1466 (2000) 79 and bioelectrochemistry 52 (2000) 161]. the permeability-increasing effect of st on rbcs was the least amo ...	2002	12488047
bacteriocin serratine-p as a biological tool in the control of fire blight erwinia amylovora.	fire blight, caused by the bacterium erwinia amylovora (burill winslow et al.), is the most important bacterial disease in european pear growing. it can cause a lot of damage in some countries on apple and on pear trees in orchards and also in the fruit tree nurseries. in belgium, the disease is present since 1972. control of fire blight in belgian fruit orchards is made on a broad basis of measurements in and around the fruit trees. the use of an antibiotic is allowed for application only durin ...	2002	12701444
[aberrant development of pollen in transgenic tobacco expressing bacterial iaam gene driven by pollen- and tapetum-specific promoters].	microsporogenesis offers an ideal model for studying gene expression, cell division and cell to cell communication during development. the role of auxin in pollen development was investigated in transgenic tobacco plants expressing the coding region of the iaam gene from pseudomonas syringae, under control of the promoters lat-52 (pollen-specific) or ta-29 (tapetum-specific). iaa level in anther of transgenic plants increased significantly, and transgenic plants displayed morphological aberratio ...	2002	15344309
direct biochemical evidence for type iii secretion-dependent translocation of the avrbs2 effector protein into plant cells.	the calmodulin-dependent adenylate cyclase domain (cya) of the bordetella pertussis cyclolysin was used as a reporter protein to study the direct translocation of the xanthomonas effector protein, avrbs2, into the plant host cell. adenylate cyclase activity (production of camp) depends on the presence of eukaryotic plant calmodulin and is only active after translocation from the prokaryotic cell into the eukaryotic plant cell. here, we show that infection of pepper plants by xanthomonas campestr ...	2002	12060777
inhibition of bacterial ice nucleation by polyglycerol polymers.	the simple linear polymer polyglycerol (pgl) was found to apparently bind and inhibit the ice nucleating activity of proteins from the ice nucleating bacterium pseudomonas syringae. pgl of molecular mass 750 da was added to a solution consisting of 1 ppm freeze-dried p. syringae 31a in water. differential ice nucleator spectra were determined by measuring the distribution of freezing temperatures in a population of 98 drops of 1 microl volume. the mean freezing temperature was lowered from -6.8 ...	2002	12061844
an evolutionarily conserved mediator of plant disease resistance gene function is required for normal arabidopsis development.	plants recognize many pathogens through the action of a diverse family of proteins called disease resistance (r) genes. the arabidopsis r gene rpm1 encodes resistance to specific pseudomonas syringae strains. we describe an rpm1-interacting protein that is an ortholog of tip49a, previously shown to interact with the tata binding protein (tbp) complex and to modulate c-myc- and beta-catenin-mediated signaling in animals. reduction of arabidopsis tip49a (attip49a) mrna levels results in measurable ...	2002	12062092
two distinct pseudomonas effector proteins interact with the pto kinase and activate plant immunity.	the pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of pseudomonas syringae that express the protein avrpto. pto and avrpto physically interact, and this interaction is required for activation of host resistance. we identified a second pseudomonas protein, avrptob, that interacts specifically with pto and is widely distributed among plant pathogens. avrptob is delivered into the plant cell by the bacterial type iii secretion system, and it elicits ...	2002	12062102
the shca protein is a molecular chaperone that assists in the secretion of the hoppsya effector from the type iii (hrp) protein secretion system of pseudomonas syringae.	pseudomonas syringae uses a type iii protein secretion system encoded by the hrp pathogenicity island (pai) to translocate effector proteins into plant cells. one of these effector proteins is hoppsya. a small open reading frame (orf), named shca, precedes the hoppsya gene in the hrp pai of p. s. syringae 61. the predicted amino acid sequence of shca shares general characteristics with chaperones used in type iii protein secretion systems of animal pathogens. a functionally non-polar deletion of ...	2002	12067337
signals involved in arabidopsis resistance to trichoplusia ni caterpillars induced by virulent and avirulent strains of the phytopathogen pseudomonas syringae.	plants have evolved different but interconnected strategies to defend themselves against herbivorous insects and microbial pathogens. we used an arabidopsis/pseudomonas syringae pathosystem to investigate the impact of pathogen-induced defense responses on cabbage looper (trichoplusia ni) larval feeding. arabidopsis mutants [npr1, pad4, eds5, and sid2(eds16)] or transgenic plants (nahg) that are more susceptible to microbial pathogens and are compromised in salicylic acid (sa)-dependent defense ...	2002	12068100
potentiation of developmentally regulated plant defense response by atwrky18, a pathogen-induced arabidopsis transcription factor.	atwrky18 is a pathogen- and salicylic acid-induced arabidopsis transcription factor containing the plant-specific wrky zinc finger dna-binding motif. in the present study, we have transformed arabidopsis plants with atwrky18 under control of the cauliflower mosaic virus 35s promoter. surprisingly, transgenic plants expressing high levels of atwrky18 were stunted in growth. when expressed at moderate levels, atwrky18 potentiated developmentally regulated defense responses in transgenic plants wit ...	2002	12068113
role of salicylic acid and nim1/npr1 in race-specific resistance in arabidopsis.	salicylic acid (sa) and the nim1/npr1 protein have both been demonstrated to be required for systemic acquired resistance (sar) and implicated in expression of race-specific resistance. in this work, we analyzed the role that each of these molecules play in the resistance response triggered by members of two subclasses of resistance (r) genes, members of which recognize unrelated pathogens. we tested the ability of tir and coiled-coil-class (also known as leucine-zipper-class) r genes to confer ...	2002	12072475
the barley stem rust-resistance gene rpg1 is a novel disease-resistance gene with homology to receptor kinases.	stem rust caused by puccinia graminis f. sp. tritici was among the most devastating diseases of barley in the northern great plains of the u.s. and canada before the deployment of the stem rust-resistance gene rpg1 in 1942. since then, rpg1 has provided durable protection against stem rust losses in widely grown barley cultivars (cvs.). extensive efforts to clone rpg1 by synteny with rice provided excellent flanking markers but failed to yield the gene because it does not seem to exist in rice. ...	2002	12077318
burkholderia thailandensis e125 harbors a temperate bacteriophage specific for burkholderia mallei.	burkholderia thailandensis is a nonpathogenic gram-negative bacillus that is closely related to burkholderia mallei and burkholderia pseudomallei. we found that b. thailandensis e125 spontaneously produced a bacteriophage, termed phie125, which formed turbid plaques in top agar containing b. mallei atcc 23344. we examined the host range of phie125 and found that it formed plaques on b. mallei but not on any other bacterial species tested, including b. thailandensis and b. pseudomallei. examinati ...	2002	12081973
in vivo interaction between npr1 and transcription factor tga2 leads to salicylic acid-mediated gene activation in arabidopsis.	the arabidopsis npr1 protein is a key regulator of salicylic acid (sa)-mediated gene expression in systemic acquired resistance. based on yeast two-hybrid analysis, npr1 has been suggested to interact with members of the tga family of transcription factors, including tga2 (ahbp-1b). however, genetic evidence demonstrating that the npr1-tga interaction occurs in planta is still lacking, and the role of this interaction in sa-mediated gene activation has yet to be determined. in this study, we exp ...	2002	12084833
cloning and heterologous expression of an enantioselective amidase from rhodococcus erythropolis strain mp50.	the gene for an enantioselective amidase was cloned from rhodococcus erythropolis mp50, which utilizes various aromatic nitriles via a nitrile hydratase/amidase system as nitrogen sources. the gene encoded a protein of 525 amino acids which corresponded to a protein with a molecular mass of 55.5 kda. the deduced complete amino acid sequence showed homology to other enantioselective amidases from different bacterial genera. the nucleotide sequence approximately 2.5 kb upstream and downstream of t ...	2002	12089004
survival of gacs/gaca mutants of the biological control bacterium pseudomonas aureofaciens 30-84 in the wheat rhizosphere.	gacs/gaca comprises a two-component regulatory system that controls the expression of secondary metabolites required for the control of plant diseases in many pseudomonads. high mutation frequencies of gacs and gaca have been observed in liquid culture. we examined whether gacs/gaca mutants could competitively displace the wild-type populations on roots and thus pose a threat to the efficacy of biological control. the survival of a gac mutant alone and in competition with the wild type on roots ...	2002	12089008
plant-dependent genotypic and phenotypic diversity of antagonistic rhizobacteria isolated from different verticillium host plants.	to study the effect of plant species on the abundance and diversity of bacterial antagonists, the abundance, the phenotypic diversity, and the genotypic diversity of rhizobacteria isolated from potato, oilseed rape, and strawberry and from bulk soil which showed antagonistic activity towards the soilborne pathogen verticillium dahliae kleb. were analyzed. rhizosphere and soil samples were taken five times over two growing seasons in 1998 and 1999 from a randomized field trial. bacterial isolates ...	2002	12089011
genotypic and phenotypic diversity within species of purple nonsulfur bacteria isolated from aquatic sediments.	to assess the extent of genotypic and phenotypic diversity within species of purple nonsulfur bacteria found in aquatic sediments, a total of 128 strains were directly isolated from agar plates that had been inoculated with sediment samples from haren and de biesbosch in the netherlands. all isolates were initially characterized by box-pcr genomic dna fingerprinting, and 60 distinct genotypes were identified. analyses of 16s rrna gene sequences of representatives of each genotype showed that fiv ...	2002	12089030
fitness of salmonella enterica serovar thompson in the cilantro phyllosphere.	the epiphytic fitness of salmonella enterica was assessed on cilantro plants by using a strain of s. enterica serovar thompson that was linked to an outbreak resulting from cilantro. salmonella serovar thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (clsm) at high densities on the veins and in natural lesions. the population sizes of two common colonizers of plant surfaces, pantoea agglomerans and pseudomonas chloro ...	2002	12089050
evidence of association of salmonellae with tomato plants grown hydroponically in inoculated nutrient solution.	the possibility of uptake of salmonellae by roots of hydroponically grown tomato plants was investigated. within 1 day of exposure of plant roots to hoagland nutrient solution containing 4.46 to 4.65 log(10) cfu of salmonellae/ml, the sizes of the pathogen populations were 3.01 cfu/g of hypocotyls and cotyledons and 3.40 log(10) cfu/g of stems for plants with intact root systems (control) and 2.55 log(10) cfu/g of hypocotyls and cotyledons for plants from which portions of the roots had been rem ...	2002	12089054
[activity of toxins produced by pseudomonas syringae pv. syringae in model and cell membranes].	we studied effects of toxins produced by a bacterium pseudomonas syringae pv. syringae on the conductance of bilayer lipid membranes (blm). the used toxins were as follows: syringopeptin 22a (sp22a), syringomycin e (spe), syringostatin a (ssa), syringotoxin b (stb), and methylated syringomycin e (ch3-sre). all toxins demonstrated channel-forming activity. the threshold sequence for toxin activity was sp22a > sre approximately equal to ssa > stb > ch3-sre, and this sequence was independent of lip ...	2002	12094768
altering plant-microbe interaction through artificially manipulating bacterial quorum sensing.	many bacteria regulate diverse physiological processes in concert with their population size. bacterial cell-to-cell communication utilizes small diffusible signal molecules, which the bacteria both produce and perceive. the bacteria couple gene expression to cell density by eliciting a response only when the signalling molecules reach a critical threshold (a point at which the population is said to be 'quorate'). the population as a whole is thus able to modify its behaviour as a single unit. a ...	2002	12096736
lymphopenia in the bb rat model of type 1 diabetes is due to a mutation in a novel immune-associated nucleotide (ian)-related gene.	the bb (biobreeding) rat is one of the best models of spontaneous autoimmune diabetes and is used to study non-mhc loci contributing to type 1 diabetes. type 1 diabetes in the diabetes-prone bb (bbdp) rat is polygenic, dependent upon mutations at several loci. iddm1, on chromosome 4, is responsible for a lymphopenia (lyp) phenotype and is essential to diabetes. in this study, we report the positional cloning of the iddm1/lyp locus. we show that lymphopenia is due to a frameshift deletion in a no ...	2002	12097339
phytochrome signalling modulates the sa-perceptive pathway in arabidopsis.	the interaction of phytochrome signalling with the sa signal transduction pathway has been investigated in arabidopsis using single and multiple mutants affected in light perception (phya and phyb deficient) and light-signal processing (psi2, phytochrome signalling). the induction of pr1 by sa and functional analogues has been found to strictly correlate with the activity of the signalling pathway controlled by both phya and phyb photoreceptors. in darkness as well as dim light, and independentl ...	2002	12100485
rsma and the quorum-sensing signal, n-[3-oxohexanoyl]-l-homoserine lactone, control the levels of rsmb rna in erwinia carotovora subsp. carotovora by affecting its stability.	rsma (for regulator of secondary metabolism), rsmc, and rsmb rna, the components of a posttranscriptional regulatory system, control extracellular protein production and pathogenicity in erwinia carotovora subsp. carotovora. rsma, an rna binding protein, acts as a negative regulator by promoting message decay. rsmb rna, on the other hand, acts as a positive regulator by neutralizing the effect of rsma. rsmc modulates the levels of rsma and rsmb rna by positively regulating rsma and negatively co ...	2002	12107125
effect of yeast cta1 gene expression on response of tobacco plants to tobacco mosaic virus infection.	the response of tobacco (nicotiana tabacum l. cv xanthi-nc) plants with elevated catalase activity was studied after infection by tobacco mosaic virus (tmv). these plants contain the yeast (saccharomyces cerevisiae) peroxisomal catalase gene cta1 under the control of the cauliflower mosaic virus 35s promoter. the transgenic lines exhibited 2- to 4-fold higher total in vitro catalase activity than untransformed control plants under normal growth conditions. cellular localization of the cta1 prote ...	2002	12114558
the role of ethylene and wound signaling in resistance of tomato to botrytis cinerea.	ethylene, jasmonate, and salicylate play important roles in plant defense responses to pathogens. to investigate the contributions of these compounds in resistance of tomato (lycopersicon esculentum) to the fungal pathogen botrytis cinerea, three types of experiments were conducted: (a) quantitative disease assays with plants pretreated with ethylene, inhibitors of ethylene perception, or salicylate; (b) quantitative disease assays with mutants or transgenes affected in the production of or the ...	2002	12114587
overexpression of pto induces a salicylate-independent cell death but inhibits necrotic lesions caused by salicylate-deficiency in tomato plants.	tomato plants overexpressing the disease resistance gene pto (35s::pto) exhibit spontaneous cell death, accumulation of salicylic acid (sa), elevated expression of pathogenesis-related genes, and enhanced resistance to a broad range of pathogens. because salicylate plays an important role in the cell death and defense activation in many lesion mimic mutants, we investigated the interaction of sa-mediated processes and the 35s::pto-mediated defense pathway by introducing the nahg transgene that e ...	2002	12118881
the presence of diverse is elements and an avrpphd homologue that acts as a virulence factor on the pathogenicity plasmid of erwinia herbicola pv. gypsophilae.	the pathogenicity of erwinia herbicola pv. gypsophilae (ehg) and erwinia herbicola pv. betae (ehb) is dependent on a native plasmid (ppath(ehg) or ppath(ehb)) that harbors the hrp gene cluster, genes encoding type iii effectors, phytohormones, biosynthetic genes, and several copies of is1327. sequence analysis of the hrp-flanking region in ppath(ehg) (cosmid pla150) revealed a cluster of four additional is elements designated as isehel, isehe2, isehe3, and isehe4. two copies of another is elemen ...	2002	12118887
arabidopsis son1 is an f-box protein that regulates a novel induced defense response independent of both salicylic acid and systemic acquired resistance.	one of several induced defense responses in plants is systemic acquired resistance (sar), which is regulated by salicylic acid and in arabidopsis by the nim1/npr1 protein. to identify additional components of the sar pathway or other genes that regulate sar-independent resistance, we performed genetic suppressor screens of mutagenized nim1-1 seedlings, which are highly susceptible to infection by peronospora parasitica. we isolated the son1 (suppressor of nim1-1) mutant, which shows full restora ...	2002	12119368
a r2r3-myb gene, atmyb30, acts as a positive regulator of the hypersensitive cell death program in plants in response to pathogen attack.	hypersensitive response (hr) is a programmed cell death that is commonly associated with disease resistance in plants. among the different hr-related early induced genes, the atmyb30 gene is specifically, rapidly, and transiently expressed during incompatible interactions between arabidopsis and bacterial pathogens. its expression was also shown to be deregulated in arabidopsis mutants affected in the control of cell death initiation. here, we demonstrate that overexpression in arabidopsis and t ...	2002	12119395
ubiquitin ligase-associated protein sgt1 is required for host and nonhost disease resistance in plants.	homologues of the yeast ubiquitin ligase-associated protein sgt1 are required for disease resistance in plants mediated by nucleotide-binding site/leucine-rich repeat (nbs-lrr) proteins. here, by silencing sgt1 in nicotiana benthamiana, we extend these findings and demonstrate that sgt1 has an unexpectedly general role in disease resistance. it is required for resistance responses mediated by nbs-lrr and other r proteins in which pathogen-derived elicitors are recognized either inside or outside ...	2002	12119413
lon protease functions as a negative regulator of type iii protein secretion in pseudomonas syringae.	the central conserved region of the pseudomonas syringae hrp pathogenicity island encodes a type iii protein secretion system (ttss) that is required for pathogenicity in plants. expression of the hrp ttss is controlled by the alternative sigma factor, hrpl, whose expression, in turn, is positively controlled by two truncated enhancer binding proteins, hrpr and hrps. although a number of environmental conditions are known to modulate hrp ttss expression, such as stringent conditions and pathogen ...	2002	12123452
cluster ii che genes from pseudomonas aeruginosa are required for an optimal chemotactic response.	pseudomonas aeruginosa, a gamma-proteobacterium, is motile by means of a single polar flagellum and is chemotactic to a variety of organic compounds and phosphate. p. aeruginosa has multiple homologues of escherichia coli chemotaxis genes that are organized into five gene clusters. previously, it was demonstrated that genes in cluster i and cluster v are essential for chemotaxis. a third cluster (cluster ii) contains a complete set of che genes, as well as two genes, mcpa and mcpb, encoding meth ...	2002	12142407
mutational analysis of the tola c-terminal domain of escherichia coli and genetic evidence for an interaction between tola and tolb.	the tol proteins are involved in the outer membrane stability of gram-negative bacteria. the c-terminal domain of tola was mutagenized to identify residues important for its functions. the isolation of suppressor mutants of tola mutations in the tolb gene confirmed an interaction between tolaiii and the n-terminal domain of tolb.	2002	12142433
sequence conservation in the chagasin family suggests a common trend in cysteine proteinase binding by unrelated protein inhibitors.	the recently described inhibitor of cysteine proteinases from trypanosoma cruzi, chagasin, was found to have close homologs in several eukaryotes, bacteria and archaea, the first protein inhibitors of cysteine proteases in prokaryotes. these previously uncharacterized 110-130 residue-long proteins share a well-conserved sequence motif that corresponds to two adjacent beta-strands and the short loop connecting them. chagasin-like proteins also have other conserved, mostly aromatic, residues, and ...	2002	12142451
role of pseudomonas putida indoleacetic acid in development of the host plant root system.	many plant-associated bacteria synthesize the phytohormone indoleacetic acid (iaa). while iaa produced by phytopathogenic bacteria, mainly by the indoleacetamide pathway, has been implicated in the induction of plant tumors, it is not clear whether iaa synthesized by beneficial bacteria, usually via the indolepyruvic acid pathway, is involved in plant growth promotion. to determine whether bacterial iaa enhances root development in host plants, the ipdc gene that encodes indolepyruvate decarboxy ...	2002	12147474
chlorxanthomycin, a fluorescent, chlorinated, pentacyclic pyrene from a bacillus sp.	a gram-positive bacillus sp. that fluoresces yellow under long-wavelength uv light on several common culture media was isolated from soil samples. on the basis of carbon source utilization studies, fatty acid methyl ester analysis, and 16s ribosomal dna analysis, this bacterium was most similar to bacillus megaterium. chemical extraction yielded a yellow-orange fluorescent pigment, which was characterized by x-ray crystallography, mass spectrometry, and nuclear magnetic resonance spectroscopy. t ...	2002	12147512
genetic variation for disease resistance and tolerance among arabidopsis thaliana accessions.	pathogens can be an important selective agent in plant evolution because they can severely reduce plant fitness and growth. however, the role of pathogen selection on plant evolution depends on the extent of genetic variation for resistance traits and their covariance with host fitness. although it is usually assumed that resistance traits will covary with plant fitness, this assumption has not been tested rigorously in plant-pathogen interactions. many plant species are tolerant to herbivores, ...	2002	12172004
nitrate efflux is an essential component of the cryptogein signaling pathway leading to defense responses and hypersensitive cell death in tobacco.	there is much interest in the transduction pathways by which avirulent pathogens or derived elicitors activate plant defense responses. however, little is known about anion channel functions in this process. the aim of this study was to reveal the contribution of anion channels in the defense response triggered in tobacco by the elicitor cryptogein. cryptogein induced a fast nitrate (no(3)(-)) efflux that was sensitive to anion channel blockers and regulated by phosphorylation events and ca(2+) ...	2002	12172032
in vitro freezing in microtitre plates applied to tobacco plants transformed with the inaz gene of pseudomonas syringae.	high throughput assays have been developed to measure the ice nucleation activity of transgenic tobacco, nicotiana tabacum l. cv. petit havana sr1 plants expressing the ice nucleation gene, inaz, from pseudomonas syringae at a young seedling stage, as well as in leaf tissue. both assays are carried out in 96-well microtitre plates. the first assay involves direct seeding in vitro, one seed per microtitre plate well containing murashige-skoog agar. when seedlings reach the two-leaf stage, they ar ...	2002	12177127
nitric oxide acts as an antioxidant and delays programmed cell death in barley aleurone layers.	nitric oxide (no) is a freely diffusible, gaseous free radical and an important signaling molecule in animals. in plants, no influences aspects of growth and development, and can affect plant responses to stress. in some cases, the effects of no are the result of its interaction with reactive oxygen species (ros). these interactions can be cytotoxic or protective. because gibberellin (ga)-induced programmed cell death (pcd) in barley (hordeum vulgare cv himalaya) aleurone layers is mediated by r ...	2002	12177477
atcox17, an arabidopsis homolog of the yeast copper chaperone cox17.	we have identified a new plant gene, atcox17, encoding a protein that shares sequence similarity to cox17, a cu-binding protein from yeast (saccharomyces cerevisiae) and vertebrates that mediates the delivery of cu to the mitochondria for the assembly of a functional cytochrome oxidase complex. the newly characterized arabidopsis protein has six cys residues at positions corresponding to those known to coordinate cu binding in the yeast homolog. moreover, we show that the arabidopsis cox17 cdna ...	2002	12177498
mitochondrial alternative oxidase is not a critical component of plant viral resistance but may play a role in the hypersensitive response.	transgenic tobacco (nicotiana tabacum) with altered levels of mitochondrial alternative oxidase (aox) were used to examine the potential role of this electron transport chain protein in resistance to tobacco mosaic virus. we examined the effect of aox expression on the salicylic acid-induced resistance in susceptible plants and the resistance responses of plants harboring the n-gene. a lack of aox did not compromise the ability of salicylic acid treatment to heighten the resistance of susceptibl ...	2002	12177499
the phytotoxic lipodepsipeptide syringopeptin 25a from pseudomonas syringae pv syringae forms ion channels in sugar beet vacuoles.	syringopeptin 25a (sp(25)a) belongs to a family of cyclic lipodepsipeptides (ldps) produced by the gram-negative bacterium pseudomonas syringae, a phytopathogenic organism that affects several plants of agronomic interest. ldps increase the permeability of plasma and, possibly, intracellular membranes in plant cells. consistently, sp(25)a forms ion channels in planar lipid bilayers and other model membranes. here we used sugar beet tonoplasts as a new biological model system to study toxin actio ...	2002	12181614
constitutive expression of hrap gene in transgenic tobacco plant enhances resistance against virulent bacterial pathogens by induction of a hypersensitive response.	hypersensitive response-assisting protein (hrap) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpin(pss)-mediated hypersensitive response (hr). the hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. to assess the function of the hrap gene in plant disease resistance, the camv 35s promoter was used to express sweet pepper hrap in transgeni ...	2002	12182333
differential expression of genes encoding arabidopsis phospholipases after challenge with virulent or avirulent pseudomonas isolates.	phospholipase d (pld; ec 3.1.4.4) has been linked to a number of cellular processes, including tran membrane signaling and membrane degradation. four pld genes (alpha, beta, gamma1, and gamma2) have been cloned from arabidopsis thalami. they encode isoforms with distinct regulatory and catalytic properties but little is known about their physiological roles. using cdna amplified fragment length polymorphism display and rna blot analysis, we identified arabidopsis pldgamma1 and a gene encoding a ...	2002	12182338
antagonism between jasmonate- and salicylate-mediated induced plant resistance: effects of concentration and timing of elicitation on defense-related proteins, herbivore, and pathogen performance in tomato.	the jasmonate (ja) and salicylate (sa) signaling pathways in plants provide resistance to herbivorous insects and pathogens. it is known that these pathways interact, sometimes resulting in antagonism between the pathways. we tested how the timing and concentration of elicitation of each pathway influenced the interaction between the jasmonate and salicylate pathways measured in terms of five biochemical responses and biological resistance to caterpillars and bacteria. the salicylate pathway had ...	2002	12184393
biodegradation of the polyketide toxin cercosporin.	cercosporin is a non-host-specific polyketide toxin produced by many species of plant pathogens belonging to the genus cercospora. this red-pigmented, light-activated toxin is an important pathogenicity determinant for cercospora species. in this study, we screened 244 bacterial isolates representing 12 different genera for the ability to degrade cercosporin. cercosporin degradation was determined by screening for the presence of cleared zones surrounding colonies on cercosporin-containing cultu ...	2002	12200262
assessment of the importance of similarity in carbon source utilization profiles between the biological control agent and the pathogen in biological control of bacterial speck of tomato.	bacterial speck of tomato, caused by pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by ...	2002	12200291
lipopeptide production in pseudomonas sp. strain dss73 is regulated by components of sugar beet seed exudate via the gac two-component regulatory system.	pseudomonas sp. strain dss73 isolated from the sugar beet rhizosphere produces the cyclic lipopeptide amphisin, which inhibits the growth of plant-pathogenic fungi. by tn5::luxab mutagenesis, we obtained two nonproducing mutant strains, dss73-15c2 and dss73-12h8. the gene interrupted by the transposon in strain dss73-15c2 (amsy) encoded a protein with homology to peptide synthetases that was designated amphisin synthetase. dss73-12h8 carried the transposon in a regulatory gene encoding a protein ...	2002	12200307
construction and characterization of a prou-gfp transcriptional fusion that measures water availability in a microbial habitat.	we constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. this fusion between the prou promoter from escherichia coli and the reporter gene gfp was introduced into strains of e. coli, pantoea agglomerans, and pseudomonas syringae. the prou-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of nacl, na(2)so(4), kcl, or polyethylene glycol (molecular weight, 8000 ...	2002	12200319
novel domains and orthologues of eukaryotic transcription elongation factors.	the passage of rna polymerase ii across eukaryotic genes is impeded by the nucleosome, an octamer of histones h2a, h2b, h3 and h4 dimers. more than a dozen factors in the yeast saccharomyces cerevisiae are known to facilitate transcription elongation through chromatin. in order to better understand the evolution and function of these factors, their sequences have been compared with known protein, est and dna sequences. elongator subcomplex components elp4p and elp6p are shown to be homologues of ...	2002	12202748
complete characterisation of tn5530 from burkholderia cepacia strain 2a (pijb1) and studies of 2,4-dichlorophenoxyacetate uptake by the organism.	the complete genetic characterisation of tn5530 in burkholderia cepacia strain 2a (pijb1) has been accomplished, indicating that it is a tn3-like transposon with a complex structure bearing operons for the catabolism of 2,4-dichlorophenoxyacetate (2,4-d) and malonate. tn5530 is terminated at both ends by the is1071::is1471 element and the 2,4-d- and malonate-dissimilatory operons are separated by a region encoding a puta and lrp gene and a gene encoding a chloride channel protein. the chloride c ...	2002	12206751
identification of novel hrp-regulated genes through functional genomic analysis of the pseudomonas syringae pv. tomato dc3000 genome.	pseudomonas syringae pv. tomato (pst) strain dc3000 infects the model plants arabidopsis thaliana and tomato, causing disease symptoms characterized by necrotic lesions surrounded by chlorosis. one mechanism used by pst dc3000 to infect host plants is the type iii protein secretion system, which is thought to deliver multiple effector proteins to the plant cell. the exact number of type iii effectors in pst dc3000 or any other plant pathogenic bacterium is not known. all known type iii effector ...	2002	12207690
oxylipin profiling in pathogen-infected potato leaves.	plants respond to pathogen attack with a multicomponent defense response. synthesis of oxylipins via the lipoxygenase (lox) pathway appears to be an important factor for establishment of resistance in a number of pathosystems. in potato cells, pathogen-derived elicitors preferentially stimulate the 9-lox-dependent metabolism of polyunsaturated fatty acids (pufas). here we show by oxylipin profiling that potato plants react to pathogen infection with increases in the amounts of the 9-lox-derived ...	2002	12213493
pmr6, a pectate lyase-like gene required for powdery mildew susceptibility in arabidopsis.	the plant genes required for the growth and reproduction of plant pathogens are largely unknown. in an effort to identify these genes, we isolated arabidopsis mutants that do not support the normal growth of the powdery mildew pathogen erysiphe cichoracearum. here, we report on the cloning and characterization of one of these genes, pmr6. pmr6 encodes a pectate lyase-like protein with a novel c-terminal domain. consistent with its predicted gene function, mutations in pmr6 alter the composition ...	2002	12215508