Publications

the map kinase kinase mkk2 affects disease resistance in arabidopsis.	the arabidopsis mitogen-activated protein kinase (mapk) kinase 2 (mkk2) was shown to mediate cold and salt stress responses through activation of the two map kinases mpk4 and mpk6. transcriptome analysis of plants expressing constitutively active mkk2 (mkk2-ee plants) showed altered expression of genes induced by abiotic stresses but also a significant number of genes involved in defense responses. both mpk4 and mpk6 became rapidly activated upon pseudomonas syringae pv. tomato dc3000 infection ...	2007	17506336
signaling via the trichoderma atroviride mitogen-activated protein kinase tmk 1 differentially affects mycoparasitism and plant protection.	trichoderma atroviride is a mycoparasite of a number of plant pathogenic fungi thereby employing morphological changes and secretion of cell wall degrading enzymes and antibiotics. the function of the tmk 1 gene encoding a mitogen-activated protein kinase (mapk) during fungal growth, mycoparasitic interaction, and biocontrol was examined in t. atroviride. deltatmk 1 mutants exhibited altered radial growth and conidiation, and displayed de-regulated infection structure formation in the absence of ...	2007	17509915
yscu recognizes translocators as export substrates of the yersinia injectisome.	yscu is an essential component of the export apparatus of the yersinia injectisome. it consists of an n-terminal transmembrane domain and a long cytoplasmic c-terminal domain, which undergoes auto-cleavage at a npth site. substitutions n263a and p264a prevented cleavage of yscu and abolished export of lcrv, yopb and yopd but not of yop effectors. as a consequence, yscu(n263a) mutant bacteria made needles without the lcrv tip complex and they could not form translocation pores. the graft of the e ...	2007	17510628
aba is an essential signal for plant resistance to pathogens affecting ja biosynthesis and the activation of defenses in arabidopsis.	analyses of arabidopsis thaliana defense response to the damping-off oomycete pathogen pythium irregulare show that resistance to p. irregulare requires a multicomponent defense strategy. penetration represents a first layer, as indicated by the susceptibility of pen2 mutants, followed by recognition, likely mediated by erecta receptor-like kinases. subsequent signaling of inducible defenses is predominantly mediated by jasmonic acid (ja), with insensitive coi1 mutants showing extreme susceptibi ...	2007	17513501
arabidopsis gh3-like defense gene 1 is required for accumulation of salicylic acid, activation of defense responses and resistance to pseudomonas syringae.	in arabidopsis, the gh3-like gene family consists of 19 members, several of which have been shown to adenylate the plant hormones jasmonic acid, indole acetic acid and salicylic acid (sa). in some cases, this adenylation has been shown to catalyze hormone conjugation to amino acids. here we report molecular characterization of the gh3-like defense gene 1 (gdg1), a member of the gh3-like gene family, and show that gdg1 is an important component of sa-mediated defense against the bacterial pathoge ...	2007	17521413
identification of pseudomonas syringae pv. syringae 61 type iii secretion system hrp proteins that can travel the type iii pathway and contribute to the translocation of effector proteins into plant cells.	pseudomonas syringae translocates effector proteins into plant cells via an hrp1 type iii secretion system (t3ss). t3ss components hrpb, hrpd, hrpf, and hrpp were shown to be pathway substrates and to contribute to elicitation of the plant hypersensitive response and to translocation and secretion of the model effector avrpto1.	2007	17526708
physical association of the nb-lrr resistance protein rx with a ran gtpase-activating protein is required for extreme resistance to potato virus x.	nucleotide binding leucine-rich repeat (nb-lrr) proteins play an important role in plant and mammalian innate immunity. in plants, these resistance proteins recognize specific pathogen-derived effector proteins. recognition subsequently triggers a rapid and efficient defense response often associated with the hypersensitive response and other poorly understood processes that suppress the pathogen. to investigate mechanisms associated with the activation of disease resistance responses, we invest ...	2007	17526750
ecological genomics of marine roseobacters.	bacterioplankton of the marine roseobacter clade have genomes that reflect a dynamic environment and diverse interactions with marine plankton. comparative genome sequence analysis of three cultured representatives suggests that cellular requirements for nitrogen are largely provided by regenerated ammonium and organic compounds (polyamines, allophanate, and urea), while typical sources of carbon include amino acids, glyoxylate, and aromatic metabolites. an unexpectedly large number of genes are ...	2007	17526795
molecular identification and characterization of the tomato flagellin receptor lefls2, an orthologue of arabidopsis fls2 exhibiting characteristically different perception specificities.	bacterial flagellin is known to stimulate host immune responses in mammals and plants. in arabidopsis thaliana, the receptor kinase fls2 mediates flagellin perception through physical interaction with a highly conserved epitope in the n-terminus of flagellin, represented by the peptide flg22 derived from pseudomonas syringae. the peptide flg22 is highly active as an elicitor in many plant species. in contrast, a shortened version of the same epitope derived from escherichia coli, flg15(e coli), ...	2007	17530419
cmae: a transferase shuttling aminoacyl groups between carrier protein domains in the coronamic acid biosynthetic pathway.	during the biosynthesis of the cyclopropyl amino acid coronamic acid from l-allo-ile by the phytotoxic pseudomonas syringae, the aminoacyl group covalently attached to the pantetheinyl arm of cmaa is shuttled to the hs-pantetheinyl arm of the protein cmad by the aminoacyltransferase cmae. cmae will only recognize deacylated cmaa for initial complexation. the aminoacyl group becomes covalently attached to the active site cys of cmae and can then be transferred out to the holo pantetheinylated for ...	2007	17530782
proteolysis of the barley receptor-like protein kinase rpg1 by a proteasome pathway is correlated with rpg1-mediated stem rust resistance.	in plants, disease resistance mediated by the gene-for-gene mechanism involves the recognition of specific effector molecules produced by the pathogen either directly or indirectly by the resistance-gene products. this recognition triggers a series of signals, thereby serving as a molecular switch in regulating defense mechanisms by the plants. to understand the mechanism of action of the barley stem rust resistance gene rpg1, we investigated the fate of the rpg1 protein in response to infection ...	2007	17548826
production of surfactin from bacillus subtilis mz-7 grown on pharmamedia commercial medium.	commercial medium (pharmamedia) was investigated for the production of surfactin by bacillus subtilis mz-7. different media (defined, semi-defined, and complex media) were compared for the production of surfactin after fixing the least influential variables in standardized fermentation conditions. carbohydrate and nitrogen supplements were also tried to improve production in pharmamedia.	2007	17550616
mutation of lon protease differentially affects the expression of pseudomonas syringae type iii secretion system genes in rich and minimal media and reduces pathogenicity.	the bacterial lon protease participates in a variety of biological processes. in pseudomonas syringae, mutation of lon is known to activate hrpl and a few hrpl-regulated genes in rich medium. the elevated expression of hrpl and hrpl-regulated genes results from increased stability of hrpr, the transcriptional activator of hrpl, in the lon mutant. here, we conducted a microarray analysis to identify genes that are differentially expressed in a lon- mutant of p. syringae pv. tomato dc3000 grown in ...	2007	17555276
constitutive activation of a plasma membrane h(+)-atpase prevents abscisic acid-mediated stomatal closure.	light activates proton (h(+))-atpases in guard cells, to drive hyperpolarization of the plasma membrane to initiate stomatal opening, allowing diffusion of ambient co(2) to photosynthetic tissues. light to darkness transition, high co(2) levels and the stress hormone abscisic acid (aba) promote stomatal closing. the overall h(+)-atpase activity is diminished by aba treatments, but the significance of this phenomenon in relationship to stomatal closure is still debated. we report two dominant mut ...	2007	17557075
complementation analysis of the cold-sensitive phenotype of the escherichia coli csda deletion strain.	the cold shock response of escherichia coli is elicited by downshift of temperature from 37 degrees c to 15 degrees c and is characterized by induction of several cold shock proteins, including csda, during the acclimation phase. csda, a dead-box protein, has been proposed to participate in a variety of processes, such as ribosome biogenesis, mrna decay, translation initiation, and gene regulation. it is not clear which of the functions of csda play a role in its essential cold shock function or ...	2007	17557820
a pseudomonas syringae pv. tomato dc3000 mutant lacking the type iii effector hopq1-1 is able to cause disease in the model plant nicotiana benthamiana.	the model pathogen pseudomonas syringae pv. tomato dc3000 causes bacterial speck in tomato and arabidopsis, but nicotiana benthamiana, an important model plant, is considered to be a non-host. strain dc3000 injects approximately 28 effector proteins into plant cells via the type iii secretion system (t3ss). these proteins were individually delivered into n. benthamiana leaf cells via t3ss-proficient pseudomonas fluorescens, and eight, including hopq1-1, showed some capacity to cause cell death i ...	2007	17559511
attenuation of the hypersensitive response by an atpase associated with various cellular activities (aaa) protein through suppression of a small gtpase, adp ribosylation factor, in tobacco plants.	atpase associated with various cellular activities (aaa) proteins are commonly distributed among eukaryotes, and are involved in a multitude of cellular functions. ntaaa1 is one such example, being involved in pathogen response in tobacco plants. when its activity was suppressed in rnai transgenic tobacco plants, an elevated resistance to the pathogenic bacterium pseudomonas syringae was observed in comparison with the wild type. as aaa proteins function through interaction with specific partner ...	2007	17559512
pcd mutants of streptomyces clavuligerus still produce cephamycin c.	biosynthesis of cephamycin c in streptomyces clavuligerus involves the initial conversion of lysine to alpha-aminoadipic acid. lysine-6-aminotransferase and piperideine-6-carboxylate dehydrogenase carry out this two-step reaction, and genes encoding each of these enzymes are found within the cephamycin c gene cluster. however, while mutation of the lat gene causes complete loss of cephamycin production, pcd mutants still produce cephamycin at 30% to 70% of wild-type levels. cephamycin production ...	2007	17573474
identification of genes in xanthomonas campestris pv. vesicatoria induced during its interaction with tomato.	xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease of tomato and pepper. the disease process is interactive and very intricate and involves a plethora of genes in the pathogen and in the host. in the pathogen, different genes are activated in response to the changing environment to enable it to survive, adapt, evade host defenses, propagate, and damage the host. to understand the disease process, it is imperative to broaden our understanding of the gene machiner ...	2007	17573477
pseudomonas aeruginosa type iv pilus expression in neisseria gonorrhoeae: effects of pilin subunit composition on function and organelle dynamics.	type iv pili (tfp) play central roles in the expression of many phenotypes including motility, multicellular behavior, sensitivity to bacteriophages, natural genetic transformation, and adherence. in neisseria gonorrhoeae, these properties require ancillary proteins that act in conjunction with tfp expression and influence organelle dynamics. here, the intrinsic contributions of the pilin protein itself to tfp dynamics and associated phenotypes were examined by expressing the pseudomonas aerugin ...	2007	17573479
arabidopsis cytochrome p450 monooxygenase 71a13 catalyzes the conversion of indole-3-acetaldoxime in camalexin synthesis.	camalexin (3-thiazol-2-yl-indole) is an indole alkaloid phytoalexin produced by arabidopsis thaliana that is thought to be important for resistance to necrotrophic fungal pathogens, such as alternaria brassicicola and botrytis cinerea. it is produced from trp, which is converted to indole acetaldoxime (iaox) by the action of cytochrome p450 monooxygenases cyp79b2 and cyp79b3. the remaining biosynthetic steps are unknown except for the last step, which is conversion of dihydrocamalexic acid to ca ...	2007	17573535
resistance to botrytis cinerea in sitiens, an abscisic acid-deficient tomato mutant, involves timely production of hydrogen peroxide and cell wall modifications in the epidermis.	plant defense mechanisms against necrotrophic pathogens, such as botrytis cinerea, are considered to be complex and to differ from those that are effective against biotrophs. in the abscisic acid-deficient sitiens tomato (solanum lycopersicum) mutant, which is highly resistant to b. cinerea, accumulation of hydrogen peroxide (h(2)o(2)) was earlier and stronger than in the susceptible wild type at the site of infection. in sitiens, h(2)o(2) accumulation was observed from 4 h postinoculation (hpi) ...	2007	17573540
the n-terminal region of pseudomonas type iii effector avrptob elicits pto-dependent immunity and has two distinct virulence determinants.	resistance to bacterial speck disease in tomato is activated by the physical interaction of the host pto kinase with either of the sequence-dissimilar type iii effector proteins avrpto or avrptob (hopab2) from pseudomonas syringae pv. tomato. pto-mediated immunity requires prf, a protein with a nucleotide-binding site and leucine-rich repeats. the n-terminal 307 amino acids of avrptob were previously reported to interact with the pto kinase, and we show here that this region (avrptob(1-307)) is ...	2007	17764515
virulence and prodigiosin antibiotic biosynthesis in serratia are regulated pleiotropically by the ggdef/eal domain protein, pigx.	gram-negative bacteria of the genus serratia are opportunistic human, plant, and insect pathogens. serratia sp. strain atcc 39006 secretes pectinases and cellulases and produces the secondary metabolites carbapenem and prodigiosin. mutation of a gene (pigx) resulted in an extremely pleiotropic phenotype: prodigiosin antibiotic biosynthesis, plant virulence, and pectinase production were all elevated. pigx controlled secondary metabolism by repressing the transcription of the target prodigiosin b ...	2007	17766413
pseudomonas syringae lytic transglycosylases coregulated with the type iii secretion system contribute to the translocation of effector proteins into plant cells.	pseudomonas syringae translocates virulence effector proteins into plant cells via a type iii secretion system (t3ss) encoded by hrp (for hypersensitive response and pathogenicity) genes. three genes coregulated with the hrp t3ss system in p. syringae pv. tomato dc3000 have predicted lytic transglycosylase domains: pspto1378 (here designated hrph), pspto2678 (hopp1), and pspto852 (hopaj1). hrph is located between hrpr and avre1 in the hrp pathogenicity island and is carried in the functional clu ...	2007	17827286
physiological ecology of stenoxybacter acetivorans, an obligate microaerophile in termite guts.	stenoxybacter acetivorans is a newly described, obligately microaerophilic beta-proteobacterium that is abundant in the acetate-rich hindgut of reticulitermes. here we tested the hypotheses that cells are located in the hypoxic, peripheral region of reticulitermes flavipes hindguts and use acetate to fuel their o(2)-consuming respiratory activity in situ. physical fractionation of r. flavipes guts, followed by limited-cycle pcr with s. acetivorans-specific 16s rrna gene primers, indicated that c ...	2007	17827335
exoribonuclease r in mycoplasma genitalium can carry out both rna processing and degradative functions and is sensitive to rna ribose methylation.	mycoplasma genitalium, a small bacterium having minimal genome size, has only one identified exoribonuclease, rnase r (mgr). we have purified mgr to homogeneity, and compared its rna degradative properties to those of its escherichia coli homologs rnase r (ecr) and rnase ii (ecii). mgr is active on a number of substrates including oligoribonucleotides, poly(a), rrna, and precursors to trna. unlike ecr, which degrades rrna and pre-trna without formation of intermediate products, mgr appears sensi ...	2007	17872508
identification of harpins in pseudomonas syringae pv. tomato dc3000, which are functionally similar to hrpk1 in promoting translocation of type iii secretion system effectors.	harpins are a subset of type iii secretion system (t3ss) substrates found in all phytopathogenic bacteria that utilize a t3ss. pseudomonas syringae pv. tomato dc3000 was previously reported to produce two harpins, hrpz1 and hrpw1. dc3000 was shown here to deploy two additional proteins, hopak1 and hopp1, which have the harpin-like properties of lacking cysteine, eliciting the hypersensitive response (hr) when partially purified and infiltrated into tobacco leaves, and possessing a two-domain str ...	2007	17873033
the pseudomonas syringae type iii effector tyrosine phosphatase hopao1 suppresses innate immunity in arabidopsis thaliana.	the bacterial pathogen pseudomonas syringae pv. tomato (pst) strain dc3000 infects tomato and arabidopsis plants, and is a model for studying the molecular basis of bacterial disease. pst dc3000 secretes a battery of largely uncharacterized effector proteins into host cells via a type-iii secretion system (ttss). little is currently known about the molecular mechanisms by which individual ttss effectors promote virulence. the effector hopao1 has similarity to protein tyrosine phosphatases, inclu ...	2007	17877704
evaluation of reference genes for real-time rt-pcr expression studies in the plant pathogen pectobacterium atrosepticum.	real-time rt-pcr has become a powerful technique to monitor low-abundance mrna expression and is a useful tool when examining bacterial gene expression inside infected host tissues. however, correct evaluation of data requires accurate and reliable normalisation against internal standards. thus, the identification of reference genes whose expression does not change during the course of the experiment is of paramount importance. here, we present a study where manipulation of cultural growth condi ...	2007	17888160
the ralstonia solanacearum pathogenicity regulator hrpb induces 3-hydroxy-oxindole synthesis.	the transcriptional activator hrpb of the bacterial wilt causing betaproteobacterium ralstonia solanacearum represents a key regulator for pathogenicity. in particular, it drives expression of hrp genes encoding a type iii secretion system (t3ss) as well as effector molecules for delivery into the host cytosol to promote disease. however, the hrpb regulon extends beyond this t3ss. we describe here an hrpb-activated operon of six genes that is responsible for the synthesis of a fluorescent isatin ...	2007	17890323
a cluster of disease resistance genes in arabidopsis is coordinately regulated by transcriptional activation and rna silencing.	the rpp5 (for recognition of peronospora parasitica 5) locus in the arabidopsis thaliana columbia strain contains a cluster of paralogous disease resistance (r) genes that play important roles in innate immunity. among the r genes in this locus, rpp4 confers resistance to two races of the fungal pathogen hyaloperonospora parasitica, while activation of snc1 (for suppressor of npr1-1, constitutive 1) results in the resistance to another race of h. parasitica and to pathovars of the bacterial path ...	2007	17890374
rice pti1a negatively regulates rar1-dependent defense responses.	tomato (solanum lycopersicum) pto encodes a protein kinase that confers resistance to bacterial speck disease. a second protein kinase, pti1, physically interacts with pto and is involved in pto-mediated defense signaling. pti1-related sequences are highly conserved among diverse plant species, including rice (oryza sativa), but their functions are largely unknown. here, we report the identification of a null mutant for the pti1 homolog in rice and the functional characterization of os pti1a. th ...	2007	17890377
deinococcus geothermalis: the pool of extreme radiation resistance genes shrinks.	bacteria of the genus deinococcus are extremely resistant to ionizing radiation (ir), ultraviolet light (uv) and desiccation. the mesophile deinococcus radiodurans was the first member of this group whose genome was completely sequenced. analysis of the genome sequence of d. radiodurans, however, failed to identify unique dna repair systems. to further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second deinococcus species, the thermophile de ...	2007	17895995
wounding induces resistance to pathogens with different lifestyles in tomato: role of ethylene in cross-protection.	many reports point to the existence of a network of regulatory signalling occurring in plants during the interaction with micro-organisms (biotic stress) and abiotic stresses such as wounding. however, the focus is on shared intermediates/components and/or common molecular outputs in differently triggered signalling pathways, and not on the degree and modes of effective influence between abiotic and biotic stresses nor the range of true plant-pathogen interactions open to such influence. we repo ...	2007	17897407
the pseudomonas putida lon protease is involved in n-acyl homoserine lactone quorum sensing regulation.	in pseudomonas putida and pseduomonas aeruginosa, the similar ppur/rsal/ppui and lasr/rsal/lasi acyl homoserine lactones (ahls) quorum sensing (qs) systems have been shown to be under considerable regulation by other global regulators. a major regulator is the rsal protein which strongly directly represses the transcription of the p. putida ppui and p. aeruginosa lasi ahl synthases. in this study we screened a transposon mutant bank of p. putida in order to identify if any other regulators were ...	2007	17655747
the plant host pathogen interface: cell wall and membrane dynamics of pathogen-induced responses.	perception of pathogens by their hosts is the outcome of a highly coordinated and sophisticated surveillance network, tightly regulated by both host and pathogen elicitors, effectors, and signaling processes. in this article, we focus on two relatively well-studied host-pathogens systems, one involving a bacterial-plant interaction (pseudomonas syringae-arabidopsis) and the other involving an oomycete-plant interaction (phytophthora sojae-soybean). we discuss the status of current research relat ...	2007	17656566
characterization of the osmoprotectant transporter opuc from pseudomonas syringae and demonstration that cystathionine-beta-synthase domains are required for its osmoregulatory function.	the plant pathogen pseudomonas syringae may cope with osmotic stress on plants, in part, by importing osmoprotective compounds. in this study, we found that p. syringae pv. tomato strain dc3000 was distinct from most bacterial species in deriving greater osmoprotection from exogenous choline than from glycine betaine. this superior osmoprotection was correlated with a higher capacity for uptake of choline than for uptake of glycine betaine. of four putative osmoregulatory abc transporters in dc3 ...	2007	17660277
salicylic acid, yersiniabactin, and pyoverdin production by the model phytopathogen pseudomonas syringae pv. tomato dc3000: synthesis, regulation, and impact on tomato and arabidopsis host plants.	a genetically tractable model plant pathosystem, pseudomonas syringae pv. tomato dc3000 on tomato and arabidopsis thaliana hosts, was used to investigate the role of salicylic acid (sa) and iron acquisition via siderophores in bacterial virulence. pathogen-induced sa accumulation mediates defense in these plants, and dc3000 contains the genes required for the synthesis of sa, the sa-incorporated siderophore yersiniabactin (ybt), and the fluorescent siderophore pyoverdin (pvd). we found that dc30 ...	2007	17660289
atnudt7, a negative regulator of basal immunity in arabidopsis, modulates two distinct defense response pathways and is involved in maintaining redox homeostasis.	plants have evolved complicated regulatory systems to control immune responses. both positive and negative signaling pathways interplay to coordinate development of a resistance response with the appropriate amplitude and duration. atnudt7, a nudix domain-containing protein in arabidopsis (arabidopsis thaliana) that hydrolyzes nucleotide derivatives, was found to be a negative regulator of the basal defense response, and its loss-of-function mutation results in enhanced resistance to infection b ...	2007	17660350
a novel insertion sequence, ispa26, in oprd of pseudomonas aeruginosa is associated with carbapenem resistance.		2007	17682099
identification of discriminative characteristics for clusters from biologic data with inforbio software.	there are a number of different methods for generation of trees and algorithms for phylogenetic analysis in the study of bacterial taxonomy. genotypic information, such as ssu rrna gene sequences, now plays a more prominent role in microbial systematics than does phenotypic information. however, the integration of genotypic and phenotypic information for polyphasic studies is necessary for the classification and identification of microbes. thus, we devised an algorithm that objectively identifie ...	2007	17683520
an "electronic fluorescent pictograph" browser for exploring and analyzing large-scale biological data sets.	the exploration of microarray data and data from other high-throughput projects for hypothesis generation has become a vital aspect of post-genomic research. for the non-bioinformatics specialist, however, many of the currently available tools provide overwhelming amounts of data that are presented in a non-intuitive way.	2007	17684564
the structural basis for activation of plant immunity by bacterial effector protein avrpto.	pathogenic microbes use effectors to enhance susceptibility in host plants. however, plants have evolved a sophisticated immune system to detect these effectors using cognate disease resistance proteins, a recognition that is highly specific, often elicits rapid and localized cell death, known as a hypersensitive response, and thus potentially limits pathogen growth. despite numerous genetic and biochemical studies on the interactions between pathogen effector proteins and plant resistance prote ...	2007	17694048
dual regulation role of gh3.5 in salicylic acid and auxin signaling during arabidopsis-pseudomonas syringae interaction.	salicylic acid (sa) plays a central role in plant disease resistance, and emerging evidence indicates that auxin, an essential plant hormone in regulating plant growth and development, is involved in plant disease susceptibility. gh3.5, a member of the gh3 family of early auxin-responsive genes in arabidopsis (arabidopsis thaliana), encodes a protein possessing in vitro adenylation activity on both indole-3-acetic acid (iaa) and sa. here, we show that gh3.5 acts as a bifunctional modulator in bo ...	2007	17704230
athipm, an ortholog of the apple hrpn-interacting protein, is a negative regulator of plant growth and mediates the growth-enhancing effect of hrpn in arabidopsis.	hrpn (harpin) protein is critical to the virulence of the fire blight pathogen erwinia amylovora in host plants like apple (malus x domestica). moreover, exogenous treatment of arabidopsis (arabidopsis thaliana), a nonhost plant, with partially purified hrpn enhances growth. to address the bases of the effects of hrpn in disease, we sought a hrpn-interacting protein(s) in apple, using a yeast two-hybrid assay. a single positive clone, designated hipm (hrpn-interacting protein from malus), was fo ...	2007	17704235
pseudomonas syringae type iii effector avrptob is phosphorylated in plant cells on serine 258, promoting its virulence activity.	the pseudomonas syringae pv. tomato protein avrptob is translocated into plant cells via the bacterial type iii secretion system. in resistant tomato leaves, avrptob acts as an avirulence protein by interacting with the host pto kinase and eliciting the host immune response. pto-mediated immunity requires prf, a pto-interacting protein with a putative nucleotide-binding site and a region of leucine-rich repeats. in susceptible tomato plants, which lack either pto or prf, avrptob acts as a virule ...	2007	17711844
characterization of arabidopsis thaliana genes encoding functional homologues of the yeast metal chaperone cox19p, involved in cytochrome c oxidase biogenesis.	the arabidopsis thaliana genome contains two nearly identical genes which encode proteins showing similarity with the yeast metal chaperone cox19p, involved in cytochrome c oxidase biogenesis. one of these genes (atcox19-1) produces two transcript forms that arise from an alternative splicing event and encode proteins with different n-terminal portions. both atcox19 isoforms are imported into mitochondria in vitro and are found attached to the inner membrane facing the intermembrane space. the s ...	2007	17712601
blue-light-activated histidine kinases: two-component sensors in bacteria.	histidine kinases, used for environmental sensing by bacterial two-component systems, are involved in regulation of bacterial gene expression, chemotaxis, phototaxis, and virulence. flavin-containing domains function as light-sensory modules in plant and algal phototropins and in fungal blue-light receptors. we have discovered that the prokaryotes brucella melitensis, brucella abortus, erythrobacter litoralis, and pseudomonas syringae contain light-activated histidine kinases that bind a flavin ...	2007	17717187
role of phages in the pathogenesis of burkholderia, or 'where are the toxin genes in burkholderia phages?'.	most bacteria of the genus burkholderia are soil- and rhizosphere-associated, and rhizosphere associated, noted for their metabolic plasticity in the utilization of a wide range of organic compounds as carbon sources. many burkholderia species are also opportunistic human and plant pathogens, and the distinction between environmental, plant, and human pathogens is not always clear. burkholderia phages are not uncommon and multiple cryptic prophages are identifiable in the sequenced burkholderia ...	2007	17719265
ethylene is one of the key elements for cell death and defense response control in the arabidopsis lesion mimic mutant vad1.	although ethylene is involved in the complex cross talk of signaling pathways regulating plant defense responses to microbial attack, its functions remain to be elucidated. the lesion mimic mutant vad1-1 (for vascular associated death), which exhibits the light-conditional appearance of propagative hypersensitive response-like lesions along the vascular system, is a good model for studying the role of ethylene in programmed cell death and defense. here, we demonstrate that expression of genes as ...	2007	17720753
inhibition of fungal and bacterial plant pathogens in vitro and in planta with ultrashort cationic lipopeptides.	plant diseases constitute an emerging threat to global food security. many of the currently available antimicrobial agents for agriculture are highly toxic and nonbiodegradable and cause extended environmental pollution. moreover, an increasing number of phytopathogens develop resistance to them. recently, we have reported on a new family of ultrashort antimicrobial lipopeptides which are composed of only four amino acids linked to fatty acids (a. makovitzki, d. avrahami, and y. shai, proc. natl ...	2007	17720828
molecular evolution of pathogenicity-island genes in pseudomonas viridiflava.	the bacterial pathogen pseudomonas viridiflava possesses two pathogenicity islands (pais) that share many gene homologs, but are structurally and phenotypically differentiated (t-pai and s-pai). these pais are paralogous, but only one is present in each isolate. while this dual presence/absence polymorphism has been shown to be maintained by balancing selection, little is known about the molecular evolution of individual genes on the pais. here we investigate genetic variation of 12 pai gene loc ...	2007	17720907
the phytotoxin coronatine contributes to pathogen fitness and is required for suppression of salicylic acid accumulation in tomato inoculated with pseudomonas syringae pv. tomato dc3000.	the roles of the phytotoxin coronatine (cor) and salicylic acid (sa)-mediated defenses in the interaction of pseudomonas syringae pv. tomato dc3000 and tomato (solanum lycopersicum) were investigated. unlike findings reported for arabidopsis thaliana, dc3000 mutants impaired for production of cor or one of its components, coronafacic acid (cfa) or coronamic acid (cma), induced distinctly different disease lesion phenotypes in tomato. tomato plants inoculated with the cfa- cma- mutant db29 showed ...	2007	17722699
the relationship of within-host multiplication and virulence in a plant-virus system.	virulence does not represent any obvious advantage to parasites. most models of virulence evolution assume that virulence is an unavoidable consequence of within-host multiplication of parasites, resulting in trade-offs between within-host multiplication and between-host transmission fitness components. experimental support for the central assumption of this hypothesis, i.e., for a positive correlation between within-host multiplication rates and virulence, is limited for plant-parasite systems.	2007	17726516
hydrogen peroxide generation by the pepper extracellular peroxidase capo2 activates local and systemic cell death and defense response to bacterial pathogens.	reactive oxygen species (ros) are responsible for mediating cellular defense responses in plants. controversy has existed over the origin of ros in plant defense. we have isolated a novel extracellular peroxidase gene, capo2, from pepper (capsicum annuum). local or systemic expression of capo2 is induced in pepper by avirulent xanthomonas campestris pv vesicatoria (xcv) infection. we examined the function of the capo2 gene in plant defense using the virus-induced gene silencing technique and gai ...	2007	17905862
linear osmoregulated periplasmic glucans are encoded by the opggh locus of pseudomonas aeruginosa.	osmoregulated periplasmic glucans (opgs) are produced by many proteobacteria and are important for bacterial-host interactions. the opgg and opgh genes involved in the synthesis of opgs are the most widely distributed genes in proteobacterial genomes. two other non-homologous genes, both named ndvb, are also involved in opg biosynthesis in several species. the pseudomonas aeruginosa genome possesses two orfs, pa5077 and pa5078, that show similarity to opgh and opgg of pseudomonas syringae, respe ...	2007	17906125
overexpression of arabidopsis map kinase kinase 7 leads to activation of plant basal and systemic acquired resistance.	there is a growing body of evidence indicating that mitogen-activated protein kinase (mapk) cascades are involved in plant defense responses. analysis of the completed arabidopsis thaliana genome sequence has revealed the existence of 20 mapks, 10 mapkks and 60 mapkkks, implying a high level of complexity in mapk signaling pathways, and making the assignment of gene functions difficult. the map kinase kinase 7 (mkk7) gene of arabidopsis has previously been shown to negatively regulate polar auxi ...	2007	17908155
medicinal smoke reduces airborne bacteria.	this study represents a comprehensive analysis and scientific validation of our ancient knowledge about the effect of ethnopharmacological aspects of natural products' smoke for therapy and health care on airborne bacterial composition and dynamics, using the biolog microplate panels and microlog database. we have observed that 1h treatment of medicinal smoke emanated by burning wood and a mixture of odoriferous and medicinal herbs (havan sámagri=material used in oblation to fire all over india) ...	2007	17913417
absence of the endo-beta-1,4-glucanases cel1 and cel2 reduces susceptibility to botrytis cinerea in tomato.	cel1 and cel2 are members of the tomato (solanum lycopersicum mill) endo-beta-1,4-glucanase (egase) family that may play a role in fruit ripening and organ abscission. this work demonstrates that cel1 protein is present in other vegetative tissues and accumulates during leaf development. we recently reported the downregulation of both the cel1 mrna and protein upon fungal infection, suggesting the involvement of egases in plant-pathogen interactions. this hypothesis was confirmed by assessing th ...	2007	17916112
a key role for the arabidopsis win3 protein in disease resistance triggered by pseudomonas syringae that secrete avrrpt2.	effector proteins injected by the pathogenic bacteria pseudomonas syringae into plants can have profound effects on the pathogen-host interaction due to their efficient recognition by plants and the subsequent triggering of defenses. the avrrpt2 effector triggers strong local and systemic defense (called systemic acquired resistance [sar]) responses in arabidopsis thaliana plants that harbor a functional rps2 gene that encodes an r protein in the coiled-coil, nucleotide-binding domain, leucine-r ...	2007	17918621
distribution and replication of the pathogenicity plasmid ppath in diverse populations of the gall-forming bacterium pantoea agglomerans.	pantoea agglomerans has been transformed from a commensal bacterium into two related gall-forming pathovars by acquisition of ppath plasmids containing a pathogenicity island (pai). this pai harbors an hrp/hrc gene cluster, type iii effectors, and phytohormone biosynthetic genes. dna typing by pulsed-field gel electrophoresis revealed two major groups of p. agglomerans pv. gypsophilae and one group of p. agglomerans pv. betae. the ppath plasmids of the different groups had nearly identical repli ...	2007	17921271
erwinia carotovora elicitors and botrytis cinerea activate defense responses in physcomitrella patens.	vascular plants respond to pathogens by activating a diverse array of defense mechanisms. studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. however, very little is known about the infection and defense responses of the bryophyte, physcomitrella patens, to well-studied phytopathogens. the purpose of this study was to determine: i) whether two representative broad host range pathogens, erwinia carot ...	2007	17922917
a novel relaxase homologue is involved in chromosomal dna processing for type iv secretion in neisseria gonorrhoeae.	the neisseria gonorrhoeae type iv secretion system secretes chromosomal dna that acts in natural transformation. to examine the mechanism of dna processing for secretion, we made mutations in the putative relaxase gene trai and used nucleases to characterize the secreted dna. the nuclease experiments demonstrated that the secreted dna is single-stranded and blocked at the 5' end. mutation of trai identified tyr93 as required for dna secretion, while substitution of tyr201 resulted in intermediat ...	2007	17927698
comparative and functional genomics reveals genetic diversity and determinants of host specificity among reference strains and a large collection of chinese isolates of the phytopathogen xanthomonas campestris pv. campestris.	xanthomonas campestris pathovar campestris (xcc) is the causal agent of black rot disease of crucifers worldwide. the molecular genetic diversity and host specificity of xcc are poorly understood.	2007	17927820
burkholderia cenocepacia c5424 produces a pigment with antioxidant properties using a homogentisate intermediate.	burkholderia cenocepacia is a gram-negative opportunistic pathogen that belongs to the burkholderia cepacia complex. b. cenocepacia can survive intracellularly within phagocytic cells, and some epidemic strains produce a brown melanin-like pigment that can scavenge free radicals, resulting in the attenuation of the host cell oxidative burst. in this work, we demonstrate that the brown pigment produced by b. cenocepacia c5424 is synthesized from a homogentisate (hga) precursor. the disruption of ...	2007	17933889
the arabidopsis mitogen-activated protein kinase kinase mkk3 is upstream of group c mitogen-activated protein kinases and participates in pathogen signaling.	although the arabidopsis thaliana genome contains genes encoding 20 mitogen-activated protein kinases (mapks) and 10 mapk kinases (mapkks), most of them are still functionally uncharacterized. in this work, we analyzed the function of the group b mapk kinase, mkk3. transgenic promkk3:gus lines showed basal expression in vascular tissues that was strongly induced by pseudomonas syringae pv tomato strain dc3000 (pst dc3000) infection but not by abiotic stresses. the growth of virulent pst dc3000 w ...	2007	17933903
anti-ice nucleation activity in xylem extracts from trees that contain deep supercooling xylem parenchyma cells.	boreal hardwood species, including japanese white birch (betula platyphylla sukat. var. japonica hara), japanese chestnut (castanea crenata sieb. et zucc.), katsura tree (cercidiphyllum japonicum sieb. et zucc.), siebold's beech (fagus crenata blume), mulberry (morus bombycis koidz.), and japanese rowan (sorbus commixta hedl.), had xylem parenchyma cells (xpcs) that adapt to subfreezing temperatures by deep supercooling. crude extracts from xylem in all these trees were found to have anti-ice nu ...	2007	17936742
cloning and characterization of the biosynthetic gene cluster for kutznerides.	kutznerides, actinomycete-derived cyclic depsipetides, consist of six nonproteinogenic residues, including a highly oxygenated tricyclic hexahydropyrroloindole, a chlorinated piperazic acid, 2-(1-methylcyclopropyl)-glycine, a beta-branched-hydroxy acid, and 3-hydroxy glutamic acid, for which biosynthetic logic has not been elucidated. herein we describe the biosynthetic gene cluster for the kutzneride family, identified by degenerate primer pcr for halogenating enzymes postulated to be involved ...	2007	17940045
comparative genomic analysis of two-component regulatory proteins in pseudomonas syringae.	pseudomonas syringae is a widespread bacterial plant pathogen, and strains of p. syringae may be assigned to different pathovars based on host specificity among different plant species. the genomes of p. syringae pv. syringae (psy) b728a, pv. tomato (pto) dc3000 and pv. phaseolicola (pph) 1448a have been recently sequenced providing a major resource for comparative genomic analysis. a mechanism commonly found in bacteria for signal transduction is the two-component system (tcs), which typically ...	2007	17971244
sensitivity and speed of induced defense of cabbage (brassica oleracea l.): dynamics of bolox expression patterns during insect and pathogen attack.	the lipoxygenase pathway is involved in the early steps of plant responses to herbivorous insects and phytopathogens. induced defenses in the crucifer brassica oleracea have been well documented. here, we have cloned a lipoxygenase (lox) from b. oleracea (bolox). the sequence reveals that the bolox protein has a transit peptide for chloroplast targeting, which is characteristic for class 2 loxs involved in jasmonic acid (ja) biosynthesis which takes place in the chloroplast. phylogenetic analysi ...	2007	17977145
basal resistance against pseudomonas syringae in arabidopsis involves wrky53 and a protein with homology to a nematode resistance protein.	basal resistance is the ultimately unsuccessful plant defense response to infection with a virulent pathogen. it is thought to be triggered by host recognition of pathogen-associated molecular patterns, with subsequent suppression of particular components by pathogen effectors. to identify novel components of arabidopsis basal resistance against the bacterial pathogen pseudomonas syringae pv. tomato, microarray expression profiling was carried out on the cirl mutant, which displays enhanced resi ...	2007	17977154
induction of p-coumaroyldopamine and feruloyldopamine, two novel metabolites, in tomato by the bacterial pathogen pseudomonas syringae.	inoculation of tomato plants (solanum lycopersicum cv. rutgers) with pseudomonas syringae pv. tomato led to the production of a hypersensitive-like response in this pathovar of tomato. accumulation of hydroxycinnamic acid amides (hcaa) of tyramine (p-coumaroyltyramine and feruloyltyramine) and dopamine (p-coumaroyldopamine and feruloyldopamine) was detected after bacterial infection. two of them, p-coumaroyldopamine and feruloyldopamine, are described for the first time. the accumulation of hcaa ...	2007	17977155
a library of linear undecapeptides with bactericidal activity against phytopathogenic bacteria.	a 125-member library of synthetic linear undecapeptides was prepared based on a previously described peptide h-k(1)klfkkilkf(10)l-nh(2) (bp76) that inhibited in vitro growth of the plant pathogenic bacteria erwinia amylovora, xanthomonas axonopodis pv. vesicatoria, and pseudomonas syringae pv. syringae at low micromolar concentrations. peptides were designed using a combinatorial chemistry approach by incorporating amino acids possessing various degrees of hydrophobicity and hydrophilicity at po ...	2007	17980935
novel candidate virulence factors in rice pathogen xanthomonas oryzae pv. oryzicola as revealed by mutational analysis.	bacterial leaf streak, caused by xanthomonas oryzae pv. oryzicola, is an important disease of rice. transposon-mediated mutational analysis of the pathogen with a quantitative assay revealed candidate virulence factors including genes involved in the pathogenesis of other phytopathogenic bacteria, virulence factors of animal pathogens, and genes not previously associated with virulence.	2007	17981946
a photosensory two-component system regulates bacterial cell attachment.	flavin-binding lov domains are blue-light photosensory modules that are conserved in a number of developmental and circadian regulatory proteins in plants, algae, and fungi. lov domains are also present in bacterial genomes, and are commonly located at the amino termini of sensor histidine kinases. genes predicted to encode lov-histidine kinases are conserved across a broad range of bacterial taxa, from aquatic oligotrophs to plant and mammalian pathogens. however, the function of these putative ...	2007	17986614
alternative splicing and mrna levels of the disease resistance gene rps4 are induced during defense responses.	the arabidopsis (arabidopsis thaliana) disease resistance protein resistance to pseudomonas syringae4 (rps4) activates defenses in response to bacterial pathogens expressing avrrps4 in a gene-for-gene specific manner. the rps4 gene produces multiple transcripts via alternative splicing of two regular introns flanking exon 3 and a cryptic intron within exon 3. we showed previously that rps4-mediated resistance requires the combined presence of transcripts encoding both full-length and truncated o ...	2007	17951452
oxo-phytodienoic acid-containing galactolipids in arabidopsis: jasmonate signaling dependence.	the jasmonate family of phytohormones, as represented by 12-oxo-phytodienoic acid (opda), dinor-phytodienoic acid (dn-opda), and jasmonic acid in arabidopsis (arabidopsis thaliana), has been implicated in a vast array of different developmental processes and stress responses. recent reports indicate that opda and dn-opda occur not only as free acids in arabidopsis, but also as esters with complex lipids, so-called arabidopsides. recently, we showed that recognition of the two bacterial effector ...	2007	17951463
the plant growth-promoting fungus penicillium simplicissimum gp17-2 induces resistance in arabidopsis thaliana by activation of multiple defense signals.	arabidopsis thaliana grown in soil amended with barley grain inocula of penicillium simplicissimum gp17-2 or receiving root treatment with its culture filtrate (cf) exhibited clear resistance to pseudomonas syringae pv. tomato dc3000 (pst). to assess the contribution of different defense pathways, arabidopsis genotypes implicated in salicylic acid (sa) signaling expressing the nahg transgene or carrying disruption in npr1 (npr1), jasmonic acid (ja) signaling (jar1) and ethylene (et) signaling (e ...	2007	17956859
functional analysis of polyphenol oxidases by antisense/sense technology.	polyphenol oxidases (ppos) catalyze the oxidation of phenolics to quinones, the secondary reactions of which lead to oxidative browning and postharvest losses of many fruits and vegetables. ppos are ubiquitous in angiosperms, are inducible by both biotic and abiotic stresses, and have been implicated in several physiological processes including plant defense against pathogens and insects, the mehler reaction, photoreduction of molecular oxygen by psi, regulation of plastidic oxygen levels, auron ...	2007	17960074
induction of a small heat shock protein and its functional roles in nicotiana plants in the defense response against ralstonia solanacearum.	in tobacco (nicotiana tabacum), ralstonia solanacearum oe1-1 (rsoe1-1) is pathogenic, whereas r. solanacearum 8107 (rs8107) is nonpathogenic and induces the hypersensitive response (hr). to elucidate the molecular mechanisms of plant-r. solanacearum interactions, we used differential display to isolate a cdna fragment, a6, regulated in tobacco by inoculation with rsoe1-1. the deduced amino acid sequence predicted from full-length a6-cdna showed similarity to small heat shock proteins from arabid ...	2007	17965181
novel hexamerization motif is discovered in a conserved cytoplasmic protein from salmonella typhimurium.	the cytoplasmic protein stm3548 of unknown function obtained from a strain of salmonella typhimurium was determined by x-ray crystallography at a resolution of 2.25 a. the asymmetric unit contains a hexamer of structurally identical monomers. the monomer is a globular domain with a long beta-hairpin protrusion that distinguishes this structure. this beta-hairpin occupies a central position in the hexamer, and its residues participate in the majority of interactions between subunits of the hexame ...	2007	17968677
argonaute4 is required for resistance to pseudomonas syringae in arabidopsis.	here, we report the characterization of the arabidopsis thaliana ocp11 (for overexpressor of cationic peroxidase11) mutant, in which a beta-glucuronidase reporter gene under the control of the h(2)o(2)-responsive ep5c promoter is constitutively expressed. ocp11 plants show enhanced disease susceptibility to the virulent bacterium pseudomonas syringae pv tomato dc3000 (p.s.t. dc3000) and also to the avirulent p.s.t. dc3000 carrying the effector avrrpm1 gene. in addition, ocp11 plants are also com ...	2007	17993621
separation of plant pathogens from different hosts and tissues by capillary electromigration techniques.	in this contribution capillary isoelectric focusing and capillary zone electrophoresis were applied for the separation and detection of different plant pathogens including pseudomonas syringae pv. syringae, p. syringae pv. lachrymans, pseudomonas savastanoi pv. fraxinus, p. savastanoi pv. olea, agrobacterium tumefaciens, a vitis, xanthomonas arboricola pv. juglandis, x. campestris pv. zinniae, and curtobacterium sp.. the uv detection and sensitive fluorescence detection of the native phytopathog ...	2007	17997525
regulation of tradeoffs between plant defenses against pathogens with different lifestyles.	plants activate distinct defense responses depending on the lifestyle of the attacker encountered. in these responses, salicylic acid (sa) and jasmonic acid (ja) play important signaling roles. sa induces defense against biotrophic pathogens that feed and reproduce on live host cells, whereas ja activates defense against necrotrophic pathogens that kill host cells for nutrition and reproduction. cross-talk between these defense signaling pathways has been shown to optimize the response against a ...	2007	17998535
a pseudomonas syringae effector inactivates mapks to suppress pamp-induced immunity in plants.	pathogen-associated molecular patterns (pamps) elicit basal defense responses in plants, and, in turn, pathogens have evolved mechanisms to overcome these pamp-induced defenses. to suppress immunity, the phytopathogenic bacterium pseudomonas syringae secretes effector proteins, the biochemical function and virulence targets of which remain largely unknown. we show that hopai1, an effector widely conserved in both plant and animal bacterial pathogens, inhibits the arabidopsis mitogen-activated pr ...	2007	18005697
a novel class of bacteria-induced small rnas in arabidopsis.	small rnas, including micrornas (mirnas) and small interfering rnas (sirnas), are essential regulatory molecules of many cellular processes. arabidopsis has at least three classes of endogenous sirnas--chromatin-associated sirnas, trans-acting sirnas (tasirnas), and natural antisense transcript (nat)-associated sirnas (nat-sirnas)--all 20-25 nucleotides (nt) in length. here, we identified a novel class of small rnas, long sirnas (lsirnas), which are 30-40 nt and share many common features with k ...	2007	18003861
the developmental selector as1 is an evolutionarily conserved regulator of the plant immune response.	the myb-related gene asymmetric leaves 1 (as1) and its orthologs have an evolutionarily conserved role in specification of leaf cell identity. as1 is expressed in leaf founder cells, where it functions as a heterodimer with the structurally unrelated as2 proteins to repress activity of knotted 1-like homeobox (knox) genes. as1 therefore confines knox activity to the shoot apical meristem, where it promotes stem cell function through the regulation of phytohormone activities. here, we show that l ...	2007	18003921
preliminary investigations on inducing salt tolerance in maize through inoculation with rhizobacteria containing acc deaminase activity.	twenty rhizobacterial strains containing 1-aminocyclopropane-1-carboxylate deaminase were isolated from the rhizosphere of salt-affected maize fields. they were screened for their growth-promoting activities under axenic conditions at 1, 4, 8, and 12 ds x m-1 salinity levels. based upon the data of the axenic study, the 6 most effective strains were selected to conduct pot trials in the wire house. besides one original salinity level (1.6 ds x m-1), 3 other salinity levels (4, 8, and 12 ds x m-1 ...	2007	18026206
identification of prophages in bacterial genomes by dinucleotide relative abundance difference.	prophages are integrated viral forms in bacterial genomes that have been found to contribute to interstrain genetic variability. many virulence-associated genes are reported to be prophage encoded. present computational methods to detect prophages are either by identifying possible essential proteins such as integrases or by an extension of this technique, which involves identifying a region containing proteins similar to those occurring in prophages. these methods suffer due to the problem of l ...	2007	18030328
ectopic expression of apple mbr7 gene induced enhanced resistance to transgenic arabidopsis plant against a virulent pathogen.	a disease resistance related gene, mbr7, was identified in the wild apple species, malus baccata. the mbr7 gene has a single open reading frame (orf) of 3,288 nucleotides potentially encoding a 1,095-amino acid protein. its deduced amino acid sequence resembles the n protein of tobacco and the nl27 gene of potato and has several motifs characteristic of a tir-nbs-lrr r gene subclass. ectopic expression of mbr7 in arabidopsis enhanced the resistance against a virulent pathogen, pseudomonas syring ...	2007	18051364
a two-strain mixture of rhizobacteria elicits induction of systemic resistance against pseudomonas syringae and cucumber mosaic virus coupled to promotion of plant growth on arabidopsis thaliana.	we evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (pgpr) strains bacillus subtilis gb03 and b. amyloliquefaciens in937a formulated with the carrier chitosan (bioyield) for its capacity to elicit growth promotion and induced systemic resistance against infection by cucumber mosaic virus (cmv) and pseudomonas syringae pv. tomato dc3000 in arabidopsis thaliana. the biopreparation promoted plant growth of arabidopsis hormonal mutants, which included auxin, gibberellic ...	2007	18051759
pseudomonas syringae type iii effector avrrpt2 alters arabidopsis thaliana auxin physiology.	the pseudomonas syringae type iii effector avrrpt2 promotes bacterial virulence on arabidopsis thaliana plants lacking a functional rps2 gene (rps2 mutant plants). to investigate the mechanisms underlying the virulence activity of avrrpt2, we examined the phenotypes of transgenic a. thaliana rps2 seedlings constitutively expressing avrrpt2. these seedlings exhibited phenotypes reminiscent of a. thaliana mutants with altered auxin physiology, including longer primary roots, increased number of la ...	2007	18056646
interaction between sgt1 and cytosolic/nuclear hsc70 chaperones regulates arabidopsis immune responses.	the conserved eukaryotic protein sgt1 (for suppressor of g2 allele of skp1) has characteristics of an hsp90 (for heat shock protein 90 kd) cochaperone and in plants regulates hormone responses and resistance gene-triggered immunity. we affinity-purified sgt1-interacting proteins from arabidopsis thaliana leaf extracts and identified by mass spectrometry cytosolic heat shock cognate 70 (hsc70) chaperones as the major stable sgt1 interactors. arabidopsis sgt1a and sgt1b proteins associate with hsc ...	2007	18065690
modulation of bacterial type iii secretion system by a spermidine transporter dependent signaling pathway.	many gram-negative bacterial pathogens employ type iii secretion systems (t3ss) to inject effector proteins into host cells in infectious processes.	2007	18074016
natural variation in rps2-mediated resistance among arabidopsis accessions: correlation between gene expression profiles and phenotypic responses.	natural variation in gene expression (expression traits or e-traits) is increasingly used for the discovery of genes controlling traits. an important question is whether a particular e-trait is correlated with a phenotypic trait. here, we examined the correlations between phenotypic traits and e-traits among 10 arabidopsis thaliana accessions. we studied defense against pseudomonas syringae pv tomato dc3000 (pst), with a focus on resistance gene-mediated resistance triggered by the type iii effe ...	2007	18083910
rar1 and hsp90 form a complex with rac/rop gtpase and function in innate-immune responses in rice.	a rice (oryza sativa) rac/rop gtpase, os rac1, is involved in innate immunity, but its molecular function is largely unknown. rar1 (for required for mla12 resistance) and hsp90 (a heat shock protein 90 kd) are important components of r gene-mediated disease resistance, and their function is conserved in several plant species. hsp90 has also recently been shown to be important in mammalian innate immunity. however, their functions at the molecular level are not well understood. in this study, we ...	2007	18156216
bioinformatic evaluation of l-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of l-arginine catabolism in the cyanobacterium synechocystis sp. pcc 6803.	so far very limited knowledge exists on l-arginine catabolism in cyanobacteria, although six major l-arginine-degrading pathways have been described for prokaryotes. thus, we have performed a bioinformatic analysis of possible l-arginine-degrading pathways in cyanobacteria. further, we chose synechocystis sp. pcc 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on l-arginine catabolism with a transcript analysis.	2007	18045455
the complete genome sequence and analysis of the epsilonproteobacterium arcobacter butzleri.	arcobacter butzleri is a member of the epsilon subdivision of the proteobacteria and a close taxonomic relative of established pathogens, such as campylobacter jejuni and helicobacter pylori. here we present the complete genome sequence of the human clinical isolate, a. butzleri strain rm4018.	2007	18159241
the downy mildew effector proteins atr1 and atr13 promote disease susceptibility in arabidopsis thaliana.	the downy mildew (hyaloperonospora parasitica) effector proteins atr1 and atr13 trigger rpp1-nd/wsb- and rpp13-nd-dependent resistance, respectively, in arabidopsis thaliana. to better understand the functions of these effectors during compatible and incompatible interactions of h. parasitica isolates on arabidopsis accessions, we developed a novel delivery system using pseudomonas syringae type iii secretion via fusions of atrs to the n terminus of the p. syringae effector protein, avrrps4. atr ...	2007	18165328