Publications

elicitor-induced transcription factors for metabolic reprogramming of secondary metabolism in medicago truncatula.	exposure of medicago truncatula cell suspension cultures to pathogen or wound signals leads to accumulation of various classes of flavonoid and/or triterpene defense molecules, orchestrated via a complex signalling network in which transcription factors (tfs) are essential components.	2008	19102779
the poly(a)-dependent degradation pathway of rpso mrna is primarily mediated by rnase r.	polyadenylation is an important factor controlling rna degradation and rna quality control mechanisms. in this report we demonstrate for the first time that rnase r has in vivo affinity for polyadenylated rna and can be a key enzyme involved in poly(a) metabolism. rnase ii and pnpase, two major rna exonucleases present in escherichia coli, could not account for all the poly(a)-dependent degradation of the rpso mrna. rnase ii can remove the poly(a) tails but fails to degrade the mrna as it cannot ...	2009	19103951
phosphate availability alters lateral root development in arabidopsis by modulating auxin sensitivity via a mechanism involving the tir1 auxin receptor.	the survival of plants, as sessile organisms, depends on a series of postembryonic developmental events that determine the final architecture of plants and allow them to contend with a continuously changing environment. modulation of cell differentiation and organ formation by environmental signals has not been studied in detail. here, we report that alterations in the pattern of lateral root (lr) formation and emergence in response to phosphate (pi) availability is mediated by changes in auxin ...	2008	19106375
genomic resources and tools for gene function analysis in potato.	potato, a highly heterozygous tetraploid, is undergoing an exciting phase of genomics resource development. the potato research community has established extensive genomic resources, such as large expressed sequence tag (est) data collections, microarrays and other expression profiling platforms, and large-insert genomic libraries. moreover, potato will now benefit from a global potato physical mapping effort, which is serving as the underlying resource for a full potato genome sequencing projec ...	2008	19107214
regulation of cyclic lipopeptide biosynthesis in pseudomonas fluorescens by the clpp protease.	cyclic lipopeptides produced by pseudomonas species exhibit potent surfactant and broad-spectrum antibiotic properties. their biosynthesis is governed by large multimodular nonribosomal peptide synthetases, but little is known about the genetic regulatory network. this study provides, for the first time, evidence that the serine protease clpp regulates the biosynthesis of massetolides, cyclic lipopeptides involved in swarming motility, biofilm formation, and antimicrobial activity of pseudomonas ...	2009	19114474
regulation of cyclic lipopeptide biosynthesis in pseudomonas fluorescens by the clpp protease.	cyclic lipopeptides produced by pseudomonas species exhibit potent surfactant and broad-spectrum antibiotic properties. their biosynthesis is governed by large multimodular nonribosomal peptide synthetases, but little is known about the genetic regulatory network. this study provides, for the first time, evidence that the serine protease clpp regulates the biosynthesis of massetolides, cyclic lipopeptides involved in swarming motility, biofilm formation, and antimicrobial activity of pseudomonas ...	2009	19114474
essential role of the sycp chaperone in type iii secretion of the yspp effector.	the ysa type iii secretion (t3s) system enhances gastrointestinal infection by yersinia enterocolitica bv. 1b. one effector protein targeted into host cells is yspp, a protein tyrosine phosphatase. it was determined in this study that the secretion of yspp requires a chaperone, sycp. genetic analysis showed that deletion of sycp completely abolished the secretion of yspp without affecting the secretion of other ysps by the ysa t3s system. analysis of the secretion and translocation signals of ys ...	2009	19114483
essential role of the sycp chaperone in type iii secretion of the yspp effector.	the ysa type iii secretion (t3s) system enhances gastrointestinal infection by yersinia enterocolitica bv. 1b. one effector protein targeted into host cells is yspp, a protein tyrosine phosphatase. it was determined in this study that the secretion of yspp requires a chaperone, sycp. genetic analysis showed that deletion of sycp completely abolished the secretion of yspp without affecting the secretion of other ysps by the ysa t3s system. analysis of the secretion and translocation signals of ys ...	2009	19114483
functional characterization of the type iii secretion atpase hrcn from the plant pathogen xanthomonas campestris pv. vesicatoria.	many gram-negative plant and animal pathogenic bacteria employ a type iii secretion (t3s) system to inject effector proteins into the cytosol of eukaryotic host cells. the membrane-spanning t3s apparatus is associated with an atpase that presumably provides the energy for the secretion process. here, we describe the role of the predicted atpase hrcn from the plant pathogenic bacterium xanthomonas campestris pathovar vesicatoria. we show that hrcn hydrolyzes atp in vitro and is essential for t3s ...	2009	19114489
functional characterization of the type iii secretion atpase hrcn from the plant pathogen xanthomonas campestris pv. vesicatoria.	many gram-negative plant and animal pathogenic bacteria employ a type iii secretion (t3s) system to inject effector proteins into the cytosol of eukaryotic host cells. the membrane-spanning t3s apparatus is associated with an atpase that presumably provides the energy for the secretion process. here, we describe the role of the predicted atpase hrcn from the plant pathogenic bacterium xanthomonas campestris pathovar vesicatoria. we show that hrcn hydrolyzes atp in vitro and is essential for t3s ...	2009	19114489
a rapid biosensor-based method for quantification of free and glucose-conjugated salicylic acid.	abstract:	2008	19117519
an integrated genomics approach to define niche establishment by rhodococcus fascians.	rhodococcus fascians is a gram-positive phytopathogen that induces shooty hyperplasia on its hosts through the secretion of cytokinins. global transcriptomics using microarrays combined with profiling of primary metabolites on infected arabidopsis (arabidopsis thaliana) plants revealed that this actinomycete modulated pathways to convert its host into a niche. the transcript data demonstrated that r. fascians leaves a very characteristic mark on arabidopsis with a pronounced cytokinin response i ...	2009	19118125
nramp genes function in arabidopsis thaliana resistance to erwinia chrysanthemi infection.	atnramp3 and atnramp4 are two arabidopsis metal transporters sharing about 50% sequence identity with mouse nramp1. the nramp1/slc11a1 metal ion transporter plays a crucial role in the innate immunity of animal macrophages targeted by intracellular bacterial pathogens. atnramp3 and atnramp4 localize to the vacuolar membrane. we found that atnramp3 is upregulated in leaves challenged with the bacterial pathogens pseudomonas syringae and erwinia chrysanthemi, whereas atnramp4 expression is not mod ...	2009	19121106
myb72, a node of convergence in induced systemic resistance triggered by a fungal and a bacterial beneficial microbe.	colonisation of plant roots by selected beneficial trichoderma fungi or pseudomonas bacteria can result in the activation of a systemic defence response that is effective against a broad spectrum of pathogens. in arabidopsis thaliana, induced systemic resistance (isr) triggered by the rhizobacterial strain pseudomonas fluorescens wcs417r is regulated by a jasmonic acid- and ethylene-dependent defence signalling pathway. jasmonic acid and ethylene also play a role in trichoderma-induced resistanc ...	2009	19121118
induction of systemic resistance in arabidopsis thaliana in response to a culture filtrate from a plant growth-promoting fungus, phoma sp. gs8-3.	the plant growth-promoting fungus (pgpf), phoma sp. gs8-3, isolated from a zoysia grass rhizosphere, is capable of protecting cucumber plants against virulent pathogens. this fungus was investigated in terms of the underlying mechanisms and ability to elicit systemic resistance in arabidopsis thaliana. root treatment of arabidopsis plants with a culture filtrate (cf) from phoma sp. gs8-3 elicited systemic resistance against the bacterial speck pathogen pseudomonas syringae pv. tomato dc3000 (pst ...	2009	19121119
novel expression hosts for complex secondary metabolite megasynthetases: production of myxochromide in the thermopilic isolate corallococcus macrosporus gt-2.	abstract: although many secondary metabolites with diverse biological activities have been isolated from myxobacteria, most strains of these biotechnologically important gliding prokaryotes remain difficult to handle genetically. in this study we describe the new fast growing myxobacterial thermophilic isolate gt-2 as a heterologous host for the expression of natural product biosynthetic pathways isolated from other myxobacteria. according to the results of sequence analysis of the 16s rdna, thi ...	2009	19126236
forca, a promoter element that responds to crosstalk between defense and light signaling.	recognition of pathogenic microorganisms triggers in plants comprehensive transcriptional reprogramming. in order to identify transcriptome-level control elements required for plant immune responses we are examining several sets of genes found by microarray experiments to be co-activated in arabidopsis thaliana (arabidopsis) seedlings infected with the oomycete hyaloperonospora parasitica. promoter motifs conserved in clusters of co-expressed genes may be involved in mediating coordinated gene a ...	2009	19128484
use of a synthetic salicylic acid analog to investigate the roles of methyl salicylate and its esterases in plant disease resistance.	we previously demonstrated that salicylic acid-binding protein 2 (sabp2) of tobacco is an integral component of systemic acquired resistance (sar). sabp2 is a methyl salicylate (mesa) esterase that has high affinity for sa, which feedback inhibits its esterase activity. mesa esterase activity is required in distal, healthy tissue of pathogen-infected plants to hydrolyze mesa, which functions as a long-distance, phloem-mobile sar signal; this hydrolysis releases the biologically active defense ho ...	2009	19131332
allelic variants of the pseudomonas syringae type iii effector hopz1 are differentially recognized by plant resistance systems.	the bacterial plant pathogen pseudomonas syringae depends on the type iii secretion system and type iii-secreted effectors to cause disease in plants. hopz is a diverse family of type iii effectors widely distributed in p. syringae isolates. among the hopz homologs, hopz1 is ancient to p. syringae and has been shown to be under strong positive selection driven by plant resistance-imposed selective pressure. here, we characterized the virulence and avirulence functions of the three hopz1 alleles ...	2009	19132870
conservation in the face of diversity: multistrain analysis of an intracellular bacterium.	with the recent completion of numerous sequenced bacterial genomes, notable advances have been made in understanding the level of conservation between various species. however, relatively little is known about the genomic diversity among strains. we determined the complete genome sequence of the florida strain of anaplasma marginale, and near complete (>96%) sequences for an additional three strains, for comparative analysis with the previously fully sequenced st. maries strain genome.	2009	19134224
arginine racemization by coupled catabolic and anabolic dehydrogenases.	d-amino acids exist in living organisms as specialized components of many different machineries. biosynthesis of d-amino acids from racemization of predominant l-enantiomers is catalyzed by a single enzyme. here, we report the finding of a novel 2-component amino acid racemase for d-to-l inversion in d-arginine metabolism of pseudomonas aeruginosa. from dna microarray analysis, the putative daubar operon (for d-arginine utilization) of unknown functions was found to be highly induced by d-argini ...	2009	19139398
genetic analysis of acd6-1 reveals complex defense networks and leads to identification of novel defense genes in arabidopsis.	pathogen infection leads to the activation of defense signaling networks in plants. to study these networks and the relationships between their components, we introduced various defense mutations into acd6-1, a constitutive gain-of-function arabidopsis mutant that is highly disease resistant. acd6-1 plants show spontaneous cell death, reduced stature, and accumulate high levels of camalexin (an anti-fungal compound) and salicylic acid (sa; a signaling molecule). disruption of several defense gen ...	2009	19144005
mobile genetic elements in the genome of the beneficial rhizobacterium pseudomonas fluorescens pf-5.	pseudomonas fluorescens pf-5 is a plant-associated bacterium that inhabits the rhizosphere of a wide variety of plant species and and produces secondary metabolites suppressive of fungal and oomycete plant pathogens. the pf-5 genome is rich in features consistent with its commensal lifestyle, and its sequence has revealed attributes associated with the strain's ability to compete and survive in the dynamic and microbiologically complex rhizosphere habitat. in this study, we analyzed mobile genet ...	2009	19144133
the effector repertoire of enteropathogenic e. coli: ganging up on the host cell.	diarrhoeal disease caused by enteropathogenic e. coli (epec) is dependent on a delivery system that injects numerous bacterial 'effector' proteins directly into host cells. the best-described epec effectors are encoded together on the locus of enterocyte effacement (lee) pathogenicity island and display high levels of multifunctionality and cooperativity within the host cell. more recently, effectors encoded outside the lee (non-lee effectors) have been discovered and their functions are beginni ...	2009	19144561
oxidative stress-induced peptidoglycan deacetylase in helicobacter pylori.	structural modification of peptidoglycan (pg) is one of the mechanisms that pathogenic bacteria use to evade the host innate immune system. for the noninvasive human gastric pathogen helicobacter pylori, pg delivery to the host cells is one trigger of the immune response. h. pylori hp310 was markedly up-expressed upon cell exposure to oxidative stress. however, disruption of hp310 did not produce a phenotype distinguishable from the parent, including oxidative stress resistance characteristics. ...	2009	19147492
imbalanced lignin biosynthesis promotes the sexual reproduction of homothallic oomycete pathogens.	lignin is incorporated into plant cell walls to maintain plant architecture and to ensure long-distance water transport. lignin composition affects the industrial value of plant material for forage, wood and paper production, and biofuel technologies. industrial demands have resulted in an increase in the use of genetic engineering to modify lignified plant cell wall composition. however, the interaction of the resulting plants with the environment must be analyzed carefully to ensure that there ...	2009	19148278
biotic and abiotic stress down-regulate mir398 expression in arabidopsis.	microrna398 targets two cu/zn superoxide dismutases (csd1 and csd2) in higher plants. previous investigations revealed both decreased mir398 expression during high cu(2+) or paraquat stress and increased expression under low cu(2+) or high sucrose in the growth medium. here, we show that additional abiotic stresses such as ozone and salinity also affect mir398 levels. ozone fumigation decreased mir398 levels that were gradually restored to normal levels after relieved from the stress. furthermor ...	2009	19148671
a critical role for the tify motif in repression of jasmonate signaling by a stabilized splice variant of the jasmonate zim-domain protein jaz10 in arabidopsis.	jasmonate zim-domain (jaz) proteins act as repressors of jasmonate (ja) signaling. perception of bioactive jas by the f-box protein coronatine insensitive1 (coi1) causes degradation of jazs via the ubiquitin-proteasome pathway, which in turn activates the expression of genes involved in plant growth, development, and defense. jaz proteins contain two highly conserved sequence regions: the jas domain that interacts with coi1 to destabilize the repressor and the zim domain of unknown function. her ...	2009	19151223
rice pi5-mediated resistance to magnaporthe oryzae requires the presence of two coiled-coil-nucleotide-binding-leucine-rich repeat genes.	rice blast, caused by the fungus magnaporthe oryzae, is one of the most devastating diseases of rice. to understand the molecular basis of pi5-mediated resistance to m. oryzae, we cloned the resistance (r) gene at this locus using a map-based cloning strategy. genetic and phenotypic analyses of 2014 f2 progeny from a mapping population derived from a cross between ir50, a susceptible rice cultivar, and the ril260 line carrying pi5 enabled us to narrow down the pi5 locus to a 130-kb interval. seq ...	2009	19153255
salmonella takes control: effector-driven manipulation of the host.	salmonella pathogenesis relies upon the delivery of over thirty specialised effector proteins into the host cell via two distinct type iii secretion systems. these effectors act in concert to subvert the host cell cytoskeleton, signal transduction pathways, membrane trafficking and pro-inflammatory responses. this allows salmonella to invade non-phagocytic epithelial cells, establish and maintain an intracellular replicative niche and, in some cases, disseminate to cause systemic disease. this r ...	2009	19157959
environmental control in tea fields to reduce infection by pseudomonas syringae pv. theae.	bacterial shoot blight (bsb) disease, caused by pseudomonas syringae pv. theae, is a major bacterial disease of tea plants in japan. bsb mainly occurs in the low-temperature season, and lesion formation by p. syringae pv. theae is enhanced by both low temperature and the presence of ice nucleation-active xanthomonas campestris (inax), which catalyzes ice formation at -2 to -4 degrees c and is frequently co-isolated with p. syringae pv. theae from tea plants. low temperature is thus the most impo ...	2009	19159313
identification of new type iii effectors and analysis of the plant response by competitive index.	in recent years, many efforts have been directed towards the identification of new type iii-secreted effectors, and the completion of the secretomes of several pseudomonas syringae pathovars. several functional and bioinformatic screenings have been used to search for candidates, which have been tested for translocation into the plant cell, an essential criterion for the identification of new type iii effector proteins. the most common translocation assay is based on the use of deltaavrrpt2 as a ...	2009	19161354
differential effectiveness of serratia plymuthica ic1270-induced systemic resistance against hemibiotrophic and necrotrophic leaf pathogens in rice.	induced resistance is a state of enhanced defensive capacity developed by a plant reacting to specific biotic or chemical stimuli. over the years, several forms of induced resistance have been characterized, including systemic acquired resistance, which is induced upon localized infection by an avirulent necrotizing pathogen, and induced systemic resistance (isr), which is elicited by selected strains of nonpathogenic rhizobacteria. however, contrary to the relative wealth of information on indu ...	2009	19161601
pseudomonas syringae type iii secretion system effectors: repertoires in search of functions.	the ability of pseudomonas syringae to grow and cause diseases in plants is dependent on the injection of multiple effector proteins into plant cells via the type iii secretion system (t3ss). genome-enabled bioinformatic/experimental methods have comprehensively identified the repertoires of effectors and related t3ss substrates for p. syringae pv. tomato dc3000 and three other sequenced strains. the effector repertoires are diverse and internally redundant. insights into effector functions are ...	2009	19168384
copper acquisition is mediated by ycnj and regulated by ycnk and csor in bacillus subtilis.	copper is an essential cofactor for many enzymes, and at over a threshold level, it is toxic for all organisms. to understand the mechanisms underlying copper homeostasis of the gram-positive bacterium bacillus subtilis, we have performed microarray studies under copper-limiting conditions. these studies revealed that the ycnj gene encodes a protein that plays an important role in copper metabolism, as it shows a significant, eightfold upregulation under copper-limiting conditions and its disrup ...	2009	19168619
infection and genotype remodel the entire soybean transcriptome.	high throughput methods, such as high density oligonucleotide microarray measurements of mrna levels, are popular and critical to genome scale analysis and systems biology. however understanding the results of these analyses and in particular understanding the very wide range of levels of transcriptional changes observed is still a significant challenge. many researchers still use an arbitrary cut off such as two-fold in order to identify changes that may be biologically significant. we have use ...	2009	19171053
coordinations between gene modules control the operation of plant amino acid metabolic networks.	being sessile organisms, plants should adjust their metabolism to dynamic changes in their environment. such adjustments need particular coordination in branched metabolic networks in which a given metabolite can be converted into multiple other metabolites via different enzymatic chains. in the present report, we developed a novel "gene coordination" bioinformatics approach and use it to elucidate adjustable transcriptional interactions of two branched amino acid metabolic networks in plants in ...	2009	19171064
apoplastic effectors secreted by two unrelated eukaryotic plant pathogens target the tomato defense protease rcr3.	current models of plant-pathogen interactions stipulate that pathogens secrete effector proteins that disable plant defense components known as virulence targets. occasionally, the perturbations caused by these effectors trigger innate immunity via plant disease resistance proteins as described by the "guard hypothesis." this model is nicely illustrated by the interaction between the fungal plant pathogen cladosporium fulvum and tomato. c. fulvum secretes a protease inhibitor avr2 that targets t ...	2009	19171904
the genome reverse compiler: an explorative annotation tool.	as sequencing costs have decreased, whole genome sequencing has become a viable and integral part of biological laboratory research. however, the tools with which genes can be found and functionally characterized have not been readily adapted to be part of the everyday biological sciences toolkit. most annotation pipelines remain as a service provided by large institutions or come as an unwieldy conglomerate of independent components, each requiring their own setup and maintenance.	2009	19173744
ethylene modulates the role of nonexpressor of pathogenesis-related genes1 in cross talk between salicylate and jasmonate signaling.	the plant hormones salicylic acid (sa), jasmonic acid (ja), and ethylene (et) play crucial roles in the signaling network that regulates induced defense responses against biotic stresses. antagonism between sa and ja operates as a mechanism to fine-tune defenses that are activated in response to multiple attackers. in arabidopsis (arabidopsis thaliana), nonexpressor of pathogenesis-related genes1 (npr1) was demonstrated to be required for sa-mediated suppression of ja-dependent defenses. because ...	2009	19176718
trichoderma virens, a plant beneficial fungus, enhances biomass production and promotes lateral root growth through an auxin-dependent mechanism in arabidopsis.	trichoderma species belong to a class of free-living fungi beneficial to plants that are common in the rhizosphere. we investigated the role of auxin in regulating the growth and development of arabidopsis (arabidopsis thaliana) seedlings in response to inoculation with trichoderma virens and trichoderma atroviride by developing a plant-fungus interaction system. wild-type arabidopsis seedlings inoculated with either t. virens or t. atroviride showed characteristic auxin-related phenotypes, incl ...	2009	19176721
temporal global expression data reveal known and novel salicylate-impacted processes and regulators mediating powdery mildew growth and reproduction on arabidopsis.	salicylic acid (sa) is a critical mediator of plant innate immunity. it plays an important role in limiting the growth and reproduction of the virulent powdery mildew (pm) golovinomyces orontii on arabidopsis (arabidopsis thaliana). to investigate this later phase of the pm interaction and the role played by sa, we performed replicated global expression profiling for wild-type and sa biosynthetic mutant isochorismate synthase1 (ics1) arabidopsis from 0 to 7 d after infection. we found that ics1- ...	2009	19176722
tracking costs of virulence in natural populations of the wheat pathogen, puccinia striiformis f.sp.tritici.	costs of adaptation play an important role in host-parasite coevolution. for parasites, evolving the ability to circumvent host resistance may trade off with subsequent growth or transmission. such costs of virulence (sensu plant pathology) limit the spread of all-infectious genotypes and thus facilitate the maintenance of genetic polymorphism in both host and parasite. we investigated costs of three virulence factors in puccinia striiformis f.sp.tritici, a fungal pathogen of wheat (triticum aes ...	2009	19183485
arabidopsis gh3.12 (pbs3) conjugates amino acids to 4-substituted benzoates and is inhibited by salicylate.	salicylate (sa, 2-hydroxybenzoate) is a phytohormone best known for its role as a critical mediator of local and systemic plant defense responses. in response to pathogens such as pseudomonas syringae, sa is synthesized and activates widespread gene expression. in gh3.12/pbs3 mutants of arabidopsis thaliana, induced total sa accumulation is significantly compromised as is sa-dependent gene expression and plant defense. atgh3 subfamily i and ii members have been shown to conjugate phytohormone ac ...	2009	19189963
polyamines as a common source of hydrogen peroxide in host- and nonhost hypersensitive response during pathogen infection.	the hypersensitive response (hr) is a powerful resistance system that plants have developed against pathogen attack. there are two major pathways for hr induction; one is through recognition of the pathogen by a specific host protein, and is known as the host hr. the other is through common biochemical changes upon infection--the nonhost hr. we previously demonstrated that hydrogen peroxide derived from polyamine degradation by polyamine oxidase triggers the typical host hr in tobacco plants upo ...	2009	19190986
genetic background of host-pathogen interaction between cucumis sativus l. and pseudomonas syringae pv. lachrymans.	the interplay of plant resistance mechanisms and bacterial pathogenicity is very complex. this applies also to the interaction that takes place between the pathogen pseudomonas syringae pv. lachrymans (smith et bryan) and the cucumber (cucumis sativus l.) as its host plant. research on p. syringae pv. lachrymans has led to the discovery of specific factors produced during pathogenesis, i.e. toxins or enzymes. similarly, studies on cucumber have identified the specific types of plant resistance e ...	2009	19193976
transposition-based method for the rapid generation of gene-targeting vectors to produce cre/flp-modifiable conditional knock-out mice.	conditional gene targeting strategies are progressively used to study gene function tissue-specifically and/or at a defined time period. instrumental to all of these strategies is the generation of targeting vectors, and any methodology that would streamline the procedure would be highly beneficial. we describe a comprehensive transposition-based strategy to produce gene-targeting vectors for the generation of mouse conditional alleles. the system employs a universal cloning vector and two custo ...	2009	19194496
rickettsia phylogenomics: unwinding the intricacies of obligate intracellular life.	completed genome sequences are rapidly increasing for rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and rocky mountain spotted fever. in light of phylogeny, the establishment of orthologous groups (ogs) of open reading frames (orfs) will distinguish the core rickettsial genes and other group specific genes (class 1 ogs or c1ogs) from those distributed indiscriminately throughout the rickettsial tree (class 2 og or c2ogs) ...	2008	19194535
early genomic responses to salicylic acid in arabidopsis.	salicylic acid (sa) is a stress-induced hormone involved in the activation of defense genes. here we analyzed the early genetic responses to sa of wild type and npr1-1 mutant arabidopsis seedlings, using complete arabidopsis transcriptome microarray (catmav2) chip. we identified 217 genes rapidly induced by sa (early saigs); 193 by a npr1-dependent and 24 by a npr1-independent pathway. these two groups of genes also differed in their functional classification, expression profiles and over-repres ...	2009	19199050
cascade reactions during coronafacic acid biosynthesis: elongation, cyclization, and functionalization during cfa7-catalyzed condensation.	herein, the biogenesis of the hydrindane ring system within coronafacic acid (cfa) has been investigated. these studies reveal that in addition to the canonical polyketide chain elongation and functionalization encoded by type i polyketide synthase (pkss), cascade reactions can take place during assembly line-like biosynthesis. indeed, upon cfa7-catalyzed claisen condensation between enzyme-bound malonate and an n-acetylcysteamine (snac) thioester, latent reactivity within the elongated enzyme-b ...	2009	19199623
riboflavin-induced priming for pathogen defense in arabidopsis thaliana.	riboflavin (vitamin b(2)) participates in a variety of redox processes that affect plant defense responses. previously we have shown that riboflavin induces pathogen resistance in the absence of hypersensitive cell death (hcd) in plants. herein, we report that riboflavin induces priming of defense responses in arabidopsis thaliana toward infection by virulent pseudomonas syringae pv. tomato dc3000 (pst). induced resistance was mechanistically connected with the expression of defense response gen ...	2009	19200155
role of acinetobacter baylyi crc in catabolite repression of enzymes for aromatic compound catabolism.	here, we describe for the first time the crc (catabolite repression control) protein from the soil bacterium acinetobacter baylyi. expression of a. baylyi crc varied according to the growth conditions. a strain with a disrupted crc gene showed the same growth as the wild type on a number of carbon sources. carbon catabolite repression by acetate and succinate of protocatechuate 3,4-dioxygenase, the key enzyme of protocatechuate breakdown, was strongly reduced in the crc strain, whereas in the wi ...	2009	19201803
disentangling the complexity of mitogen-activated protein kinases and reactive oxygen species signaling.		2009	19201916
pea aphid as both host and vector for the phytopathogenic bacterium pseudomonas syringae.	aphids are widespread agricultural pests that are capable of disseminating plant viral diseases; however, despite coming into frequent contact with epiphytic bacteria, aphids are considered to have no role in bacterial transmission. here, we demonstrate the ability of pea aphids to vector the phytopathogen pseudomonas syringae pv. syringae b728a (psyb728a). while feeding on plants colonized by epiphytic bacteria, aphids acquire the bacteria, which colonize the digestive tract, multiply, and are ...	2009	19201955
irre, a global regulator of extreme radiation resistance in deinococcus radiodurans, enhances salt tolerance in escherichia coli and brassica napus.	globally, about 20% of cultivated land is now affected by salinity. salt tolerance is a trait of importance to all crops in saline soils. previous efforts to improve salt tolerance in crop plants have met with only limited success. bacteria of the genus deinococcus are known for their ability to survive highly stressful conditions, and therefore possess a unique pool of genes conferring extreme resistance. in deinococcus radiodurans, the irre gene encodes a global regulator responsible for extre ...	2009	19204796
minimum contradiction matrices in whole genome phylogenies.	minimum contradiction matrices are a useful complement to distance-based phylogenies. a minimum contradiction matrix represents phylogenetic information under the form of an ordered distance matrix y(i) (,) (j) (n). a matrix element corresponds to the distance from a reference vertex n to the path (i, j). for an x-tree or a split network, the minimum contradiction matrix is a robinson matrix. it therefore fulfills all the inequalities defining perfect order: y(i) (,) (j) (n) >or= y(i) (,) (k) (n ...	2008	19204821
identification of a post-targeting step required for efficient cotranslational translocation of proteins across the escherichia coli inner membrane.	recent studies have shown that cytoplasmic proteins are exported efficiently in escherichia coli only if they are attached to signal peptides that are recognized by the signal recognition particle and are thereby targeted to the secyeg complex cotranslationally. the evidence suggests that the entry of these proteins into the secretory pathway at an early stage of translation is necessary to prevent them from folding into a translocation-incompetent conformation. we found, however, that several g ...	2009	19211555
the 7b-1 mutation in tomato (solanum lycopersicum l.) confers a blue light-specific lower sensitivity to coronatine, a toxin produced by pseudomonas syringae pv. tomato.	the spontaneous mutant 7b-1 in tomato (solanum lycopersicum=lycopersicon esculentum) is a photoperiod-dependent male-sterile mutant previously reported as resistant to various abiotic stresses specifically under blue light. since this finding improved the potential of 7b-1's use in breeding programmes, its susceptibility to stress induced by coronatine (cor), the phytotoxine produced by several pseudomonas syringae strains, was assessed in this study. the 7b-1 mutant was found to be less sensiti ...	2009	19213807
arabidopsis cam binding protein cbp60g contributes to mamp-induced sa accumulation and is involved in disease resistance against pseudomonas syringae.	salicylic acid (sa)-induced defense responses are important factors during effector triggered immunity and microbe-associated molecular pattern (mamp)-induced immunity in plants. this article presents evidence that a member of the arabidopsis cbp60 gene family, cbp60g, contributes to mamp-triggered sa accumulation. cbp60g is inducible by both pathogen and mamp treatments. pseudomonas syringae growth is enhanced in cbp60g mutants. expression profiles of a cbp60g mutant after mamp treatment are si ...	2009	19214217
differential expression of eight defensin genes of n. benthamiana following biotic stress, wounding, ethylene, and benzothiadiazole treatments.	eight nicotiana benthamiana defensin genes were identified that could be divided into two classes with class ii defensins being longer than class i defensins due to an additional acidic c-terminal domain. class i defensins were nbdef1.1, nbdef1.2, nbdef1.3, nbdef1.4, nbdef1.5, and nbdef1.6, and class ii were nbdef2.1 and nbdef2.2. relative rt-pcr showed that nbdef1.1, nbdef1.2, and nbdef1.4 had relatively similar expression levels in healthy leaves, stems, roots, flowers, and seeds. however, nbd ...	2009	19214516
rna degradation in archaea and gram-negative bacteria different from escherichia coli.	exoribonucleolytic and endoribonucleolytic activities are important for controlled degradation of rna and contribute to the regulation of gene expression at the posttranscriptional level by influencing the half-lives of specific messenger rnas. the rna half-lives are determined by the characteristics of the rna substrates and by the availability and the properties of the involved proteins-ribonucleases and assisting polypeptides. much is known about rna degradation in eukarya and bacteria, but t ...	2009	19215775
engineered polyamine catabolism preinduces tolerance of tobacco to bacteria and oomycetes.	polyamine oxidase (pao) catalyzes the oxidative catabolism of spermidine and spermine, generating hydrogen peroxide. in wild-type tobacco (nicotiana tabacum 'xanthi') plants, infection by the compatible pathogen pseudomonas syringae pv tabaci resulted in increased pao gene and corresponding pao enzyme activities; polyamine homeostasis was maintained by induction of the arginine decarboxylase pathway and spermine was excreted into the apoplast, where it was oxidized by the enhanced apoplastic pao ...	2009	19218362
characterization of regulatory pathways in xylella fastidiosa: genes and phenotypes controlled by gaca.	the xylem-limited, insect-transmitted bacterium xylella fastidiosa causes pierce's disease in grapes through cell aggregation and vascular clogging. gaca controls various physiological processes and pathogenicity factors in many gram-negative bacteria, including biofilm formation in pseudomonas syringae pv. tomato dc3000. cloned gaca of x. fastidiosa was found to restore the hypersensitive response and pathogenicity in gaca mutants of p. syringae pv. tomato dc3000 and erwinia amylovora. a gaca m ...	2009	19218414
export of functional streptomyces coelicolor alditol oxidase to the periplasm or cell surface of escherichia coli and its application in whole-cell biocatalysis.	streptomyces coelicolor a3(2) alditol oxidase (aldo) is a soluble monomeric flavoprotein in which the flavin cofactor is covalently linked to the polypeptide chain. aldo displays high reactivity towards different polyols such as xylitol and sorbitol. these characteristics make aldo industrially relevant, but full biotechnological exploitation of this enzyme is at present restricted by laborious and costly purification steps. to eliminate the need for enzyme purification, this study describes a w ...	2009	19224207
quantitative metabolomics reveals an epigenetic blueprint for iron acquisition in uropathogenic escherichia coli.	bacterial pathogens are frequently distinguished by the presence of acquired genes associated with iron acquisition. the presence of specific siderophore receptor genes, however, does not reliably predict activity of the complex protein assemblies involved in synthesis and transport of these secondary metabolites. here, we have developed a novel quantitative metabolomic approach based on stable isotope dilution to compare the complement of siderophores produced by escherichia coli strains associ ...	2009	19229321
impact of cry1ac-carrying brassica rapa subsp. pekinensis on leaf bacterial community.	the effects of chinese cabbage (brassica rapa subsp. pekinensis) carrying cry1ac derived from bacillus thuringiensis (bt) on leaf bacterial community were examined by analyzing the horizontal transfer of trans-gene fragments from plants to bacteria. the effect of plant pathogenic bacteria on the gene transfer was also examined using pseudomonas syringae pathovar. maculicola. the frequency of hygromycin-resistant bacteria did not alter in bt leaves, though slight increase was observed in pseudomo ...	2009	19229489
synthesis of (+)-coronafacic acid.	an enantioselective synthesis of (+)-coronafacic acid has been achieved. rhodium-catalyzed cyclization of an alpha-diazoester provided the intermediate cyclopentanone in high enantiomeric purity. subsequent fe-mediated cyclocarbonylation of a derived alkenyl cyclopropane gave a bicyclic enone that then was hydrogenated and carried on to the natural product.	2009	19231870
multidrug resistance in bacteria.	large amounts of antibiotics used for human therapy, as well as for farm animals and even for fish in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. multidrug resistance in bacteria may be generated by one of two mechanisms. first, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. this accumulation occurs typically on resistance (r) plasmids. second, multidrug resistance may also occur by t ...	2009	19231985
subcellular localization and functional analysis of the arabidopsis gtpase rabe.	membrane trafficking plays a fundamental role in eukaryotic cell biology. of the numerous known or predicted protein components of the plant cell trafficking system, only a relatively small subset have been characterized with respect to their biological roles in plant growth, development, and response to stresses. in this study, we investigated the subcellular localization and function of an arabidopsis (arabidopsis thaliana) small gtpase belonging to the rabe family. rabe proteins are phylogene ...	2009	19233904
structural evidence suggests that antiactivator exsd from pseudomonas aeruginosa is a dna binding protein.	the opportunistic pathogen p. aeruginosa utilizes a type iii secretion system (t3ss) to support acute infections in predisposed individuals. in this bacterium, expression of all t3ss-related genes is dependent on the arac-type transcriptional activator exsa. before host contact, the t3ss is inactive and exsa is repressed by the antiactivator protein exsd. the repression, thought to occur through direct interactions between the two proteins, is relieved upon opening of the type iii secretion (t3s ...	2009	19235906
features of basal and race-specific defences in photosynthetic arabidopsis thaliana suspension cultured cells.	plant suspension cell cultures display many features of the innate immune responses observed in planta and have been extensively applied to the study of basal and race-specific defences. however, no single model including photosynthetic cultured cells has been used for the exhaustive characterization of both basal and race-specific defences to date. in this article, we report the activation of basal and race-specific defences in green cultured cells from arabidopsis thaliana. inoculation of cult ...	2009	19236577
a rice gene of de novo origin negatively regulates pathogen-induced defense response.	how defense genes originated with the evolution of their specific pathogen-responsive traits remains an important problem. it is generally known that a form of duplication can generate new genes, suggesting that a new gene usually evolves from an ancestral gene. however, we show that a new defense gene in plants may evolve by de novo origination, resulting in sophisticated disease-resistant functions in rice. analyses of gene evolution showed that this new gene, osdr10, had homologs only in the ...	2009	19240804
substrate-triggered formation and remarkable stability of the c-h bond-cleaving chloroferryl intermediate in the aliphatic halogenase, syrb2.	aliphatic halogenases activate o(2), cleave alpha-ketoglutarate (alphakg) to co(2) and succinate, and form haloferryl [x-fe(iv)o; x = cl or br] complexes that cleave aliphatic c-h bonds to install halogens during the biosynthesis of natural products by non-ribosomal peptide synthetases (nrpss). for the related alphakg-dependent dioxygenases, it has been shown that reaction of the fe(ii) cofactor with o(2) to form the c-h bond-cleaving ferryl complex is "triggered" by binding of the target substr ...	2009	19245217
soluble plant cell signals induce the expression of the type iii secretion system of pseudomonas syringae and upregulate the production of pilus protein hrpa.	type iii protein secretion is essential for the pathogenicity of pseudomonas syringae on its host plants. expression of hrpa, a major component of the type iii secretion system (t3ss)-associated pilus, was studied both in plant leaves and in vitro using reporter genes. we found that induction of the hrpa promoter was stronger in plants than in vitro, and that the induction was enhanced by both host and nonhost plants of p. syringae pv. tomato. in vitro, the expression was enhanced by cell-free e ...	2009	19245322
mqo, a tricarboxylic acid cycle enzyme, is required for virulence of pseudomonas syringae pv. tomato strain dc3000 on arabidopsis thaliana.	plant pathogenic bacteria, such as pseudomonas syringae pv. tomato strain dc3000, the causative agent of tomato bacterial speck disease, grow to high levels in the apoplastic space between plant cells. colonization of plant tissue requires expression of virulence factors that modify the apoplast to make it more suitable for pathogen growth or facilitate adaptation of the bacteria to the apoplastic environment. to identify new virulence factors involved in these processes, dc3000 tn5 transposon i ...	2009	19251849
chemotaxis to pyrimidines and identification of a cytosine chemoreceptor in pseudomonas putida.	we developed a high-throughput quantitative capillary assay and demonstrated that pseudomonas putida strains f1 and prs2000 were attracted to cytosine, but not thymine or uracil. in contrast, pseudomonas aeruginosa pao1 was not chemotactic to any pyrimidines. chemotaxis assays with a mutant strain of f1 in which the putative methyl-accepting chemotaxis protein-encoding gene pput_0623 was deleted revealed that this gene (designated mcpc) encodes a chemoreceptor for positive chemotaxis to cytosine ...	2009	19251854
a stenotrophomonas maltophilia multilocus sequence typing scheme for inferring population structure.	stenotrophomonas maltophilia is an opportunistic, highly resistant, and ubiquitous pathogen. strains have been assigned to genogroups using amplified fragment length polymorphism. hence, isolates of environmental and clinical origin predominate in different groups. a multilocus sequence typing (mlst) scheme was developed using a highly diverse selection of 70 strains of various ecological origins from seven countries on all continents including strains of the 10 previously defined genogroups. se ...	2009	19251858
identification and analyses of candidate genes for rpp4-mediated resistance to asian soybean rust in soybean.	asian soybean rust is a formidable threat to soybean (glycine max) production in many areas of the world, including the united states. only five sources of resistance have been identified (resistance to phakopsora pachyrhizi1 [rpp1], rpp2, rpp3, rpp4, and rpp5). rpp4 was previously identified in the resistant genotype pi459025b and mapped within 2 centimorgans of satt288 on soybean chromosome 18 (linkage group g). using simple sequence repeat markers, we developed a bacterial artificial chromoso ...	2009	19251904
synergistic effects of the membrane actions of cecropin-melittin antimicrobial hybrid peptide bp100.	bp100 (kklfkkilkyl-nh(2)) is a short cecropin a-melittin hybrid peptide, obtained through a combinatorial chemistry approach, which is highly effective in inhibiting both the in vitro and in vivo growth of economically important plant pathogenic gram-negatives. the intrinsic tyr fluorescence of bp100 was taken advantage of to study the peptide's binding affinity and damaging effect on phospholipid bilayers modeling the bacterial and mammalian cytoplasmic membranes. in vitro cytotoxic effects of ...	2009	19254540
properties of pasp: a pseudomonas protease capable of mediating corneal erosions.	to analyze pasp in terms of its gene distribution and expression, its corneal pathologic effects, its enzymatic properties, and the protectiveness of the immune response to this protease.	2009	19255155
development and evaluation of a structural model for sf1b helicase dda.	helicases are proteins that unwind double-stranded nucleic acids. dda helicase from bacteriophage t4 has served as an excellent model for understanding the molecular mechanism of this class of enzymes. study of the structure of dda may reveal why some helicases translocate in a 5' to 3' direction on dna, while others translocate in a 3' to 5' direction. attaining a structure of dda has proven difficult because the protein fails to readily form crystals and is too large for current nmr technologi ...	2009	19256528
characterization of citrus sinensis type 1 mitochondrial alternative oxidase and expression analysis in biotic stress.	the higher plant mitochondrial electron transport chain contains an alternative pathway that ends with the aox (alternative oxidase). the aox proteins are encoded by a small gene family composed of two discrete gene subfamilies. aox1 is present in both monocot and eudicot plants, whereas aox2 is only present in eudicot plants. we isolated a genomic clone from citrus sinensis containing the aox1a gene. the orange aox1a consists of four exons interrupted by three introns and its promoter harbours ...	2009	19257856
characterization of pr-10 genes from eight betula species and detection of bet v 1 isoforms in birch pollen.	bet v 1 is an important cause of hay fever in northern europe. bet v 1 isoforms from the european white birch (betula pendula) have been investigated extensively, but the allergenic potency of other birch species is unknown. the presence of bet v 1 and closely related pr-10 genes in the genome was established by amplification and sequencing of alleles from eight birch species that represent the four subgenera within the genus betula. q-tof lc-mse was applied to identify which pr-10/bet v 1 genes ...	2009	19257882
effects of inducers of systemic acquired resistance on reproduction of meloidogyne javanica and rotylenchulus reniformis in pineapple.	the potency of the inducers of systemic acquired resistance (sar), acibenzolar-s-methyl, dl-alpha-amino-n-butyric acid (aaba), dl-beta-amino-n-butyric acid (baba), gamma-amino-n-butyric acid (gaba), p-aminobenzoic acid (paba), riboflavin, and salicylic acid (sa), in reducing reproduction of meloidogyne javanica and rotylenchulus reniformis in pineapple was investigated. all inducers were applied as foliar sprays to 1-mon-old pineapple plants (20 ml/plant) grown in 22-cm-diam. pots in the greenho ...	2006	19259535
the cinnamyl alcohol dehydrogenase gene family in populus: phylogeny, organization, and expression.	lignin is a phenolic heteropolymer in secondary cell walls that plays a major role in the development of plants and their defense against pathogens. the biosynthesis of monolignols, which represent the main component of lignin involves many enzymes. the cinnamyl alcohol dehydrogenase (cad) is a key enzyme in lignin biosynthesis as it catalyzes the final step in the synthesis of monolignols. the cad gene family has been studied in arabidopsis thaliana, oryza sativa and partially in populus. this ...	2009	19267902
pseudomonas syringae hrpp is a type iii secretion substrate specificity switch domain protein that is translocated into plant cells but functions atypically for a substrate-switching protein.	pseudomonas syringae delivers virulence effector proteins into plant cells via an hrp1 type iii secretion system (t3ss). p. syringae pv. tomato dc3000 hrpp has a c-terminal, putative t3ss substrate specificity switch domain, like yersinia yscp. a deltahrpp dc3000 mutant could not cause disease in tomato or elicit a hypersensitive response (hr) in tobacco, but the hr could be restored by expression of hrpp in trans. though hrpp is a relatively divergent protein in the t3ss of different p. syringa ...	2009	19270091
effect of iron concentration on the growth rate of pseudomonas syringae and the expression of virulence factors in hrp-inducing minimal medium.	although chemically defined media have been developed and widely used to study the expression of virulence factors in the model plant pathogen pseudomonas syringae, it has been difficult to link specific medium components to the induction response. using a chemostat system, we found that iron is the limiting nutrient for growth in the standard hrp-inducing minimal medium and plays an important role in inducing several virulence-related genes in pseudomonas syringae pv. tomato dc3000. with variou ...	2009	19270129
regulation of tomato prf by pto-like protein kinases.	tomato prf encodes a nucleotide-binding domain shared by apaf-1, certain r proteins, and ced-4 fused to c-terminal leucine-rich repeats (nbarc-lrr) protein that is required for bacterial immunity to pseudomonas syringae and sensitivity to the organophosphate fenthion. the signaling pathways involve two highly related protein kinases. pto kinase mediates direct recognition of the bacterial effector proteins avrpto or avrptob. fen kinase is required for fenthion sensitivity and recognition of bact ...	2009	19271954
the arabidopsis patatin-like protein 2 (plp2) plays an essential role in cell death execution and differentially affects biosynthesis of oxylipins and resistance to pathogens.	we previously reported that patatin-like protein 2 (plp2), a pathogen-induced patatin-like lipid acyl hydrolase, promotes cell death and negatively affects arabidopsis resistance to the fungus botrytis cinerea and to the bacteria pseudomonas syringae. we show here that, on the contrary, plp2 contributes to resistance to cucumber mosaic virus, an obligate parasite inducing the hypersensitive response. these contrasted impacts on different pathosystems were also reflected by differential effects o ...	2009	19271961
role of the histone variant h2a.z/htz1p in tbp recruitment, chromatin dynamics, and regulated expression of oleate-responsive genes.	the histone variant h2a.z (htz1p) has been implicated in transcriptional regulation in numerous organisms, including saccharomyces cerevisiae. genome-wide transcriptome profiling and chromatin immunoprecipitation studies identified a role for htz1p in the rapid and robust activation of many oleate-responsive genes encoding peroxisomal proteins, in particular pot1, pox1, fox2, and cta1. the swr1p-, gcn5p-, and chz1p-dependent association of htz1p with these promoters in their repressed states app ...	2009	19273605
the plant-associated microbe gene ontology (pamgo) consortium: community development of new gene ontology terms describing biological processes involved in microbe-host interactions.	all microbes that form beneficial, neutral, or pathogenic associations with hosts face similar challenges. they must physically adhere to and/or gain entry to host tissues; they must avoid, suppress, or tolerate host defenses; they must acquire nutrients from the host and successfully multiply. microbes that associate with hosts come from many kingdoms of life and include bacteria, fungi, oomycetes, and nematodes. the increasing numbers of full genome sequences from these diverse microbes provid ...	2009	19278549
protein secretion systems in bacterial-host associations, and their description in the gene ontology.	protein secretion plays a central role in modulating the interactions of bacteria with their environments. this is particularly the case when symbiotic bacteria (whether pathogenic, commensal or mutualistic) are interacting with larger host organisms. in the case of gram-negative bacteria, secretion requires translocation across the outer as well as the inner membrane, and a diversity of molecular machines have been elaborated for this purpose. a number of secreted proteins are destined to enter ...	2009	19278550
common and contrasting themes in host cell-targeted effectors from bacterial, fungal, oomycete and nematode plant symbionts described using the gene ontology.	a wide diversity of plant-associated symbionts, including microbes, produce proteins that can enter host cells, or are injected into host cells in order to modify the physiology of the host to promote colonization. these molecules, termed effectors, commonly target the host defense signaling pathways in order to suppress the defense response. others target the gene expression machinery or trigger specific modifications to host morphology or physiology that promote the nutrition and proliferation ...	2009	19278551
gene ontology annotation highlights shared and divergent pathogenic strategies of type iii effector proteins deployed by the plant pathogen pseudomonas syringae pv tomato dc3000 and animal pathogenic escherichia coli strains.	genome-informed identification and characterization of type iii effector repertoires in various bacterial strains and species is revealing important insights into the critical roles that these proteins play in the pathogenic strategies of diverse bacteria. however, non-systematic discipline-specific approaches to their annotation impede analysis of the accumulating wealth of data and inhibit easy communication of findings among researchers working on different experimental systems. the developme ...	2009	19278552
programmed cell death in host-symbiont associations, viewed through the gene ontology.	manipulation of programmed cell death (pcd) is central to many host microbe interactions. both plant and animal cells use pcd as a powerful weapon against biotrophic pathogens, including viruses, which draw their nutrition from living tissue. thus, diverse biotrophic pathogens have evolved many mechanisms to suppress programmed cell death, and mutualistic and commensal microbes may employ similar mechanisms. necrotrophic pathogens derive their nutrition from dead tissue, and many produce toxins ...	2009	19278553
arabidopsis gri is involved in the regulation of cell death induced by extracellular ros.	reactive oxygen species (ros) have important functions in plant stress responses and development. in plants, ozone and pathogen infection induce an extracellular oxidative burst that is involved in the regulation of cell death. however, very little is known about how plants can perceive ros and regulate the initiation and the containment of cell death. we have identified an arabidopsis thaliana protein, grim reaper (gri), that is involved in the regulation of cell death induced by extracellular ...	2009	19279211
an anomalous type iv secretion system in rickettsia is evolutionarily conserved.	bacterial type iv secretion systems (t4sss) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (dna and/or protein) translocation. thirteen genome sequences from rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced t4ss relative to the agrobacterium tumefaciens archetype (vir). however, the rickettsia t4ss has not been functionally characterized for its role in symbiosis/virulence, and none ...	2009	19279686
use of arabidopsis thaliana and pseudomonas syringae in the study of plant disease resistance and tolerance.	the interaction between arabidopsis thaliana and the bacterium pseudomonas syringae is being developed as a model experimental system for plant pathology research. race-specific ("gene-for-gene") resistance has been demonstrated for this interaction, and pathogen genes that determine avirulence have been isolated and characterized. because certain lines of both arabidopsis and soybean are resistant to bacteria carrying the avirulence genes avrrpt2 and avrb, extremely similar pathogen recognition ...	1993	19279805
molecular analysis of plant defense responses to plant pathogens.	a number of inducible plant responses are believed to contribute to disease resistance. these responses include the hypersensitive reaction, phytoalexin synthesis, and the production of chitinase, glucanase, and hydroxyproline-rich glycoproteins. because of the coordinate induction of these responses, it has been difficult to determine whether they are functional defense responses, and if they are, how they specifically contribute to disease resistance. recent developments in molecular biology h ...	1992	19283005
osmoadaptation among vibrio species and unique genomic features and physiological responses of vibrio parahaemolyticus.	vibrio parahaemolyticus is a moderately halophilic bacterium found in estuarine and marine coastal ecosystems worldwide. although the ability of v. parahaemolyticus to grow and proliferate in fluctuating saline environments is well known, the underlying molecular mechanisms of osmoadaptation are unknown. we performed an in silico analysis of v. parahaemolyticus strain rimd2210633 for genes homologous to osmotic stress response genes in other bacteria. we uncovered two putative compatible solute ...	2009	19286794