Publications

the roles of aba in plant-pathogen interactions.	defence against abiotic and biotic stresses is crucial for the fitness and survival of plants under adverse or suboptimal growth conditions. the phytohormone abscisic acid (aba) is not only important for mediating abiotic stress responses, but also plays a multifaceted and pivotal role in plant immunity. this review presents examples demonstrating the importance of crosstalk between aba and the key biotic stress phytohormone salicylic acid in determining the outcome of plant--pathogen interactio ...	2011	21380629
insights from molecular modeling and dynamics simulation of pathogen resistance (r) protein from brinjal.	resistance (r) protein recognizes molecular signature of pathogen infection and activates downstream hypersensitive response signalling in plants. r protein works as a molecular switch for pathogen defence signalling and represent one of the largest plant gene family. hence, understanding molecular structure and function of r proteins has been of paramount importance for plant biologists. the present study is aimed at predicting structure of r proteins signalling domains (cc-nbs) by creating a h ...	2011	21383919
overexpression of arabidopsis eceriferum1 promotes wax very-long-chain alkane biosynthesis and influences plant response to biotic and abiotic stresses.	land plant aerial organs are covered by a hydrophobic layer called the cuticle that serves as a waterproof barrier protecting plants against desiccation, ultraviolet radiation, and pathogens. cuticle consists of a cutin matrix as well as cuticular waxes in which very-long-chain (vlc) alkanes are the major components, representing up to 70% of the total wax content in arabidopsis (arabidopsis thaliana) leaves. however, despite its major involvement in cuticle formation, the alkane-forming pathway ...	2011	21386033
deubiquitinating enzymes atubp12 and atubp13 and their tobacco homologue ntubp12 are negative regulators of plant immunity.	ôçó signalling by ubiquitination is implicated in diverse aspects of the plant lifecycle, and enzymes of ubiquitin metabolism are overrepresented in the arabidopsis genome compared with other model eukaryotes. despite the importance of ubiquitination in the regulation of signalling, little is known about deubiquitinating enzymes, which reverse the process of ubiquitination. ôçó transgenic rna interference-based cosuppression and the isolation of atubp12/13 double mutants collectively provides th ...	2011	21388379
triclosan-resistant bacteria isolated from feedlot and residential soils.	triclosan is an antimicrobial agent that is currently incorporated into hundreds of consumer and medical products. it can be either a bacteriostatic or bactericidal agent, depending on its formulation. it has activity against gram-positive and gram-negative bacteria, as well as some viruses and protists. the purpose of this study was to determine whether triclosan-resistant bacteria could be isolated from the soil. soils from cattle feedlots and residential lawns were collected and assayed for t ...	2011	21391038
the hrpz gene of pseudomonas syringae pv. phaseolicola enhances resistance to rhizomania disease in transgenic nicotiana benthamiana and sugar beet.	to explore possible sources of transgenic resistance to the rhizomania-causing beet necrotic yellow vein virus (bnyvv), nicotiana benthamiana plants were constructed to express the harpin of pseudomonas syringae pv. phaseolicola (hrpz(psph)). the hrpz protein was expressed as an n-terminal fusion to the pr1 signal peptide (sp/hrpz) to direct harpin accumulation to the plant apoplast. transgene integration was verified by mpcr in all primary transformants (t0), while immunoblot analysis confirmed ...	2011	21394206
arabidopsis metacaspase 2d is a positive mediator of cell death induced during biotic and abiotic stresses.	cysteine proteases such as caspases play important roles in programmed cell death (pcd) of metazoans. plant metacaspases (mcps), a family of cysteine proteases structurally related to caspases, have been hypothesized to be ancestors of metazoan caspases, despite their different substrate specificity. arabidopsis thaliana contains six type ii mcp genes (atmcp2a-f). whether and how these individual members are involved in controlling pcd in plants remains largely unknown. here we investigated the ...	2011	21395887
comparative genomics reveals diversity among xanthomonads infecting tomato and pepper.	bacterial spot of tomato and pepper is caused by four xanthomonas species and is a major plant disease in warm humid climates. the four species are distinct from each other based on physiological and molecular characteristics. the genome sequence of strain 85-10, a member of one of the species, xanthomonas euvesicatoria (xcv) has been previously reported. to determine the relationship of the four species at the genome level and to investigate the molecular basis of their virulence and differing ...	2011	21396108
indole-3-acetic acid biosynthesis in the biocontrol strain pseudomonas fluorescens psd and plant growth regulation by hormone overexpression.	pseudomonas fluorescens is an important biological component of agricultural soils that bestows a number of direct and indirect beneficial attributes to the plants. we analyzed the biocontrol strain p. fluorescens psd for indole-3-acetic acid (iaa) biosynthesis and studied the effect of its consequent manipulation on its plant-growth-promoting (pgp) potential. while the indole pyruvic acid (ipya) pathway commonly associated with pgp bacteria was lacking, the indole acetamide (iam) pathway genera ...	2011	21397014
tomato rav transcription factor is a pivotal modulator involved in the ap2/erebp-mediated defense pathway.	ralstonia solanacearum is the causal agent of bacterial wilt (bw), one of the most important bacterial diseases worldwide. we used cdna microarray to survey the gene expression profile in transgenic tomato (solanum lycopersicum) overexpressing arabidopsis (arabidopsis thaliana) cbf1 (atcbf1), which confers tolerance to bw. the disease-resistant phenotype is correlated with constitutive expression of the related-to-abi3/vp1 (rav) transcription factor, ethylene-responsive factor (erf) family genes ...	2011	21398258
arabidopsis ndr1 is an integrin-like protein with a role in fluid loss and plasma membrane-cell wall adhesion.	arabidopsis (arabidopsis thaliana) non-race-specific disease resistance1 (ndr1), a plasma membrane-localized protein, plays an essential role in resistance mediated by the coiled-coil-nucleotide-binding site-leucine-rich repeat class of resistance (r) proteins, which includes resistance to pseudomonas syringae2 (rps2), resistance to pseudomonas syringae pv maculicola1, and rps5. infection with pseudomonas syringae pv tomato dc3000 expressing the bacterial effector proteins avrrpt2, avrb, and avr ...	2011	21398259
involvement of the smeab multidrug efflux pump in resistance to plant antimicrobials and contribution to nodulation competitiveness in sinorhizobium meliloti.	the contributions of multicomponent-type multidrug efflux pumps to antimicrobial resistance and nodulation ability in sinorhizobium meliloti were comprehensively analyzed. computational searches identified genes in the s. meliloti strain 1021 genome encoding 1 pump from the atp-binding cassette family, 3 pumps from the major facilitator superfamily, and 10 pumps from the resistance-nodulation-cell division family, and subsequently, these genes were deleted either individually or simultaneously. ...	2011	21398477
pathogens drop the hint: don't forget phytoalexin pathways.	many effectors secreted by pathogenic bacteria suppress host signal transduction pathways that activate host defense responses. in this issue of cell host & microbe, zhou et al. (2011) now broaden that theme by demonstrating that hopz1b from pseudomonas syringae pv. glycinea causes degradation of a host enzyme directly involved in the synthesis of antimicrobial phytoalexin compounds.	2011	21402353
pseudomonas syringae type iii effector hopz1 targets a host enzyme to suppress isoflavone biosynthesis and promote infection in soybean.	type iii secreted effectors (t3ses), such as pseudomonas syringae hopz1, are essential bacterial virulence proteins injected into the host cytosol to facilitate infection. however, few direct targets of t3ses are known. investigating the target(s) of hopz1 in soybean, a natural p. syringae host, we find that hopz1 physically interacts with the isoflavone biosynthesis enzyme, 2-hydroxyisoflavanone dehydratase (gmhid1). p. syringae infection induces gmhid1 expression and production of daidzein, a ...	2011	21402357
comprehensive identification of protein substrates of the dot/icm type iv transporter of legionella pneumophila.	a large number of proteins transferred by the legionella pneumophila dot/icm system have been identified by various strategies. with no exceptions, these strategies are based on one or more characteristics associated with the tested proteins. given the high level of diversity exhibited by the identified proteins, it is possible that some substrates have been missed in these screenings. in this study, we took a systematic method to survey the l. pneumophila genome by testing hypothetical orfs lar ...	2011	21408005
reactive oxygen species scavenging by catalase is important for female lutzomyia longipalpis fecundity and mortality.	the phlebotomine sand fly lutzomyia longipalpis is the most important vector of american visceral leishmaniasis (avl), the disseminated and most serious form of the disease in central and south america. in the natural environment, most female l. longipalpis are thought to survive for less than 10 days and will feed on blood only once or twice during their lifetime. successful transmission of parasites occurs when a leishmania-infected female sand fly feeds on a new host. knowledge of factors aff ...	2011	21408075
structure-function analysis of the hrpb2-hrcu interaction in the xanthomonas citri type iii secretion system.	bacterial type iii secretion systems deliver protein virulence factors to host cells. here we characterize the interaction between hrpb2, a small protein secreted by the xanthomonas citri subsp. citri type iii secretion system, and the cytosolic domain of the inner membrane protein hrcu, a paralog of the flagellar protein flhb. we show that a recombinant fragment corresponding to the c-terminal cytosolic domain of hrcu produced in e. coli suffers cleavage within a conserved asn264-pro265-thr266- ...	2011	21408079
genetic dissection of basal defence responsiveness in accessions of arabidopsis thaliana.	basal resistance involves a multitude of pathogen- and herbivore-inducible defence mechanisms, ranging from localized callose deposition to systemic defence gene induction by salicylic acid (sa) and jasmonic acid (ja). in this study, we have explored and dissected genetic variation in the responsiveness of basal defence mechanisms within a selection of arabidopsis accessions. responsiveness of ja-induced pdf1.2 gene expression was associated with enhanced basal resistance against the necrotrophi ...	2011	21414016
the cyclic nucleotide-gated channels atcngc11 and 12 are involved in multiple ca²?-dependent physiological responses and act in a synergistic manner.	arabidopsis cyclic nucleotide-gated ion channels (atcngcs) form a large family consisting of 20 members. these channels have so far been reported to be involved in a diverse range of physiological phenomena. for example, atcngc18 was reported to play an important role in pollen tube growth, while atcngc2, 4, 11, and 12 were implicated in mediating pathogen defence. to identify additional functions for atcngc11 and 12, various physiological aspects were analysed using both atcngc11 and 12 single ...	2011	21414958
composition and conservation of the mrna-degrading machinery in bacteria.	rna synthesis and decay counteract each other and therefore inversely regulate gene expression in pro- and eukaryotic cells by controlling the steady-state level of individual transcripts. genetic and biochemical data together with recent in depth annotation of bacterial genomes indicate that many components of the bacterial rna decay machinery are evolutionarily conserved and that their functional analogues exist in organisms belonging to all kingdoms of life. here we briefly review biological ...	2011	21418661
expression of aspartyl protease and c3hc4-type ring zinc finger genes are responsive to ascorbic acid in arabidopsis thaliana.	ascorbate (asa) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. the aim was to identify genes whose transcript levels respond to changes in leaf asa. the asa-deficient arabidopsis mutant vtc2-1 was incubated with the asa precursor l-galactono-1,4-lactone (l-gall) to increase leaf asa concentration. differentially expressed genes screened by dna microarray were further characterized for asa responsiveness in wild-type plants. the analysis of 1 ...	2011	21421703
protection of arabidopsis thaliana against leaf-pathogenic pseudomonas syringae by sphingomonas strains in a controlled model system.	diverse bacterial taxa live in association with plants without causing deleterious effects. previous analyses of phyllosphere communities revealed the predominance of few bacterial genera on healthy dicotyl plants, provoking the question of whether these commensals play a particular role in plant protection. here, we tested two of them, methylobacterium and sphingomonas, with respect to their ability to diminish disease symptom formation and the proliferation of the foliar plant pathogen pseudom ...	2011	21421777
emerging roles in plant defense for cis-jasmone-induced cytochrome p450 cyp81d11.	cis-jasmone is a volatile organic compound emitted constitutively by flowers or leaves of several plant species where it acts as an attractant for pollinators and as a chemical cue for host localisation (or avoidance) for insects. ( 1-3) it is also released by some plant species after feeding damage inflicted by herbivorous insects and in this case might serve as a chemical cue for parasitoids to guide them to their prey (so called "indirect defense"). ( 4,5) moreover, we have recently shown tha ...	2011	21422824
the homogentisate and homoprotocatechuate central pathways are involved in 3- and 4-hydroxyphenylacetate degradation by burkholderia xenovorans lb400.	genome characterization of the model pcb-degrading bacterium burkholderia xenovorans lb400 revealed the presence of eleven central pathways for aromatic compounds degradation, among them, the homogentisate and the homoprotocatechuate pathways. however, the functionality of these central pathways in strain lb400 has not been assessed and related peripheral pathways has not been described.	2011	21423751
jasmonate signaling involves the abscisic acid receptor pyl4 to regulate metabolic reprogramming in arabidopsis and tobacco.	the phytohormones jasmonates (jas) constitute an important class of elicitors for many plant secondary metabolic pathways. however, jas do not act independently but operate in complex networks with crosstalk to several other phytohormonal signaling pathways. here, crosstalk was detected between the ja and abscisic acid (aba) signaling pathways in the regulation of tobacco (nicotiana tabacum) alkaloid biosynthesis. a tobacco gene from the pyr/pyl/rcar family, ntpyl4, the expression of which is re ...	2011	21436041
evidence that wapb is a 1,2-glucosyltransferase of pseudomonas aeruginosa involved in lipopolysaccharide outer core biosynthesis.	pseudomonas aeruginosa is an important opportunistic pathogen infecting debilitated individuals. one of the major virulence factors expressed by p. aeruginosa is lipopolysaccharide (lps), which is composed of lipid a, core oligosaccharide (os), and o-antigen polysaccharide. the core os is divided into inner and outer regions. although the structure of the outer core os has been elucidated, the functions and mechanisms of the glycosyltransferases involved in core os biogenesis are currently unkno ...	2011	21441506
the phytopathogen pseudomonas syringae pv. tomato dc3000 has three high-affinity iron-scavenging systems functional under iron limitation conditions but dispensable for pathogenesis.	high-affinity iron scavenging through the use of siderophores is a well-established virulence determinant in mammalian pathogenesis. however, few examples have been reported for plant pathogens. here, we use a genetic approach to investigate the role of siderophores in pseudomonas syringae pv. tomato dc3000 (dc3000) virulence in tomato. dc3000, an agronomically important pathogen, has two known siderophores for high-affinity iron scavenging, yersiniabactin and pyoverdin, and we uncover a third s ...	2011	21441525
unwinding activity of cold shock proteins and rna metabolism.	temperature downshift from 37 (o) c to 15 (o) c results in the exertion of cold shock response in escherichia coli, which induces cold shock proteins, such as csda. previously, we showed that the helicase activity of csda is critical for its function in the cold acclimation of cells and its primary role is mrna degradation. only rhle (helicase), cspa (rna chaperone) and rnase r (exoribonuclease) were found to complement the cold shock function of csda. rnase r has two independent activities, hel ...	2011	21445001
arabidopsis map kinase phosphatase 1 (atmkp1) negatively regulates mpk6-mediated pamp responses and resistance against bacteria.	a primary component of plant defense is the detection of pathogen-associated molecular patterns (pamps) by plasma membrane-localized pathogen recognition receptors. pamp perception results in rapid and transient activation of phosphorylation-dependent signaling pathways that lead to a wide array of defense-related responses, including extensive changes in gene expression. in arabidopsis, several kinases, including the mitogen-activated protein kinases (mapks) mpk6 and mpk3, are rapidly activated ...	2011	21447069
identification of outer membrane proteins from an antarctic bacterium pseudomonas syringae lz4w.	subcellular fractionation of proteins is a preferred method of choice for detection and identification of proteins from complex mixtures such as bacterial cells. to characterize the membrane proteins of the antarctic bacterium pseudomonas syringae lz4w, the membrane fractions were prepared using three different methods, namely triton x-100 solubilization, sucrose density gradient, and carbonate extraction methods. the proteins were separated on one-dimensional polyacrylamide gels and analyzed us ...	2011	21447709
circadian clock-regulated phosphate transporter pht4;1 plays an important role in arabidopsis defense.	the arabidopsis accelerated cell death 6-1 (acd6-1) mutant shows constitutive defense, cell death, and extreme dwarf phenotypes. in a screen for acd6-1 suppressors, we identified a mutant that was disrupted by a t-dna in the phosphate transporter 4;1 (pht4;1) gene. the suppressor mutant pht4;1-1 is dominant, expresses truncated pht4;1 transcripts, and is more susceptible to virulent pseudomonas syringae strains but not to several avirulent strains. treatment with a salicylic acid (sa) agonist in ...	2011	21447757
characterization of gdp-mannose dehydrogenase from the brown alga ectocarpus siliculosus providing the precursor for the alginate polymer.	alginate is a major cell wall polymer of brown algae. the precursor for the polymer is gdp-mannuronic acid, which is believed to be derived from a four-electron oxidation of gdp-mannose through the enzyme gdp-mannose dehydrogenase (gmd). so far no eukaryotic gmd has been biochemically characterized. we have identified a candidate gene in the ectocarpus siliculosus genome and expressed it as a recombinant protein in escherichia coli. the gmd from ectocarpus differs strongly from related enzymes i ...	2011	21454608
the structure of the elicitor cerato-platanin (cp), the first member of the cp fungal protein family, reveals a double ?ß-barrel fold and carbohydrate binding.	cerato-platanin (cp) is a secretion protein produced by the fungal pathogen ceratocystis platani, the causal agent of the plane canker disease and the first member of the cp family. cp is considered a pathogen-associated molecular pattern because it induces various defense responses in the host, including production of phytoalexins and cell death. although much is known about the properties of cp and related proteins as elicitors of plant defense mechanisms, its biochemical activity and host tar ...	2011	21454637
nitric oxide production is not required for dihydrosphingosine-induced cell death in tobacco by-2 cells.	sphinganine or dihydrosphingosine (d18:0, dhs), one of the most abundant free sphingoid long chain base (lcb) in plants, is known to induce a calcium dependent programmed cell death (pcd) in tobacco by-2 cells. in addition, we have recently shown that dhs triggers a production of h2o2, via the activation of nadph oxidase(s). however, this production of h2o2 is not correlated with the dhs-induced cell death but would rather be associated with basal cell defense mechanisms. in the present study, w ...	2011	21455022
nitric oxide is required for an optimal establishment of the medicago truncatula-sinorhizobium meliloti symbiosis.	nitric oxide (no) is a gaseous molecule that participates in numerous plant signalling pathways. it is involved in plant responses to pathogens and development processes such as seed germination, flowering and stomatal closure. using a permeable no-specific fluorescent probe and a bacterial reporter strain expressing the lacz gene under the control of a no-responsive promoter, we detected no production in the first steps, during infection threads growth, of the medicago truncatula-sinorhizobium ...	2011	21457261
diversity, evolution, and functionality of clustered regularly interspaced short palindromic repeat (crispr) regions in the fire blight pathogen erwinia amylovora.	the clustered regularly interspaced short palindromic repeat (crispr)/cas system confers acquired heritable immunity against mobile nucleic acid elements in prokaryotes, limiting phage infection and horizontal gene transfer of plasmids. in crispr arrays, characteristic repeats are interspersed with similarly sized nonrepetitive spacers derived from transmissible genetic elements and acquired when the cell is challenged with foreign dna. new spacers are added sequentially and the number and type ...	2011	21460108
microbes in high arctic snow and implications for the cold biosphere.	we applied molecular, microscopic, and culture techniques to characterize the microbial communities in snow and air at remote sites in the canadian high arctic (ward hunt island, ellesmere island, and cornwallis island, latitudes 74 to 83(o)n). members of the bacteria and eukarya were prevalent in the snow, and their small subunit (ssu) rrna gene signatures indicated strong local aerial transport within the region over the preceding 8 months of winter snowpack accumulation. many of the operation ...	2011	21460114
proteomic analysis of defense response of wildtype arabidopsis thaliana and plants with impaired no- homeostasis.	in recent years, nitric oxide (no) has been recognized as a signalling molecule of plants, being involved in diverse processes like germination, root growth, stomatal closing, and responses to various stresses. a mechanism of how no can regulate physiological processes is the modulation of cysteine residues of proteins (s-nitrosylation) by s-nitrosoglutathione (gsno), a physiological no donor. the concentration of gsno and the level of s-nitrosylated proteins are regulated by gsno reductase, whi ...	2011	21462345
the hrpn effector of erwinia amylovora, which is involved in type iii translocation, contributes directly or indirectly to callose elicitation on apple leaves.	erwinia amylovora is responsible for fire blight of apple and pear trees. its pathogenicity depends on a type iii secretion system (t3ss) mediating the translocation of effectors into the plant cell. the dspa/e effector suppresses callose deposition on apple leaves. we found that e. amylovora and pseudomonas syringae dc3000 tts mutants or peptide flg22 do not trigger callose deposition as strongly as the dspa/e mutant on apple leaves. this suggests that, on apple leaves, callose deposition is po ...	2011	21463207
extracellular leucine-rich repeats as a platform for receptor/coreceptor complex formation.	receptor kinases with leucine-rich repeat (lrr) extracellular domains form the largest family of receptors in plants. in the few cases for which there is mechanistic information, ligand binding in the extracellular domain often triggers the recruitment of a lrr-coreceptor kinase. the current model proposes that this recruitment is mediated by their respective kinase domains. here, we show that the extracellular lrr domain of bri1-associated kinase1 (bak1), a coreceptor involved in the disparate ...	2011	21464298
analysis of the host microrna response to salmonella uncovers the control of major cytokines by the let-7 family.	micrornas have well-established roles in eukaryotic host responses to viruses and extracellular bacterial pathogens. in contrast, microrna responses to invasive bacteria have remained unknown. here, we report cell type-dependent microrna regulations upon infection of mammalian cells with the enteroinvasive pathogen, salmonella typhimurium. murine macrophages strongly upregulate nf-?b associated micrornas; strikingly, these regulations which are induced by bacterial lipopolysaccharide (lps) occur ...	2011	21468030
pectobacterium carotovorum elicits plant cell death with dspe/f but the p. carotovorum dspe does not suppress callose or induce expression of plant genes early in plant-microbe interactions.	the broad-host-range bacterial soft rot pathogen pectobacterium carotovorum causes a dspe/f-dependent plant cell death on nicotiana benthamiana within 24 h postinoculation (hpi) followed by leaf maceration within 48 hpi. p. carotovorum strains with mutations in type iii secretion system (t3ss) regulatory and structural genes, including the dspe/f operon, did not cause hypersensitive response (hr)-like cell death and or leaf maceration. a strain with a mutation in the type ii secretion system cau ...	2011	21469936
phytobacterial type iii effectors hopx1, hopab1 and hopf2 enhance sense-post transcriptional gene silencing independently of plant r gene-effector recognition.	plant and animal pathogenic bacteria deploy a variable arsenal of type iii effector proteins (t3eps) to manipulate host defense. specific biochemical functions and molecular/sub-cellular targets have been demonstrated or proposed for a growing number of t3eps, but remain unknown for the majority of them. here we show that transient expression of genes coding certain bacterial t3eps (hopab1, hopx1 and hopf2), which did not elicit hypersensitive response (hr) in transgenic gfp nicotiana benthamian ...	2011	21469938
gaba accumulation causes cell elongation defects and a decrease in expression of genes encoding secreted and cell wall-related proteins in arabidopsis thaliana.	gaba (γ-aminobutyric acid), a non-protein amino acid, is a signaling factor in many organisms. in plants, gaba is known to accumulate under a variety of stresses. however, the consequence of gaba accumulation, especially in vegetative tissues, remains poorly understood. moreover, gene expression changes as a consequence of gaba accumulation in plants are largely unknown. the pop2 mutant, which is defective in gaba catabolism and accumulates gaba, is a good model to examine the effects of gaba ac ...	2011	21471118
programmed cell death in the plant immune system.	cell death has a central role in innate immune responses in both plants and animals. besides sharing striking convergences and similarities in the overall evolutionary organization of their innate immune systems, both plants and animals can respond to infection and pathogen recognition with programmed cell death. the fact that plant and animal pathogens have evolved strategies to subvert specific cell death modalities emphasizes the essential role of cell death during immune responses. the hyper ...	2011	21475301
a mathematical model of quorum sensing regulated eps production in biofilm communities.	biofilms are microbial communities encased in a layer of extracellular polymeric substances (eps). the eps matrix provides several functional purposes for the biofilm, such as protecting bacteria from environmental stresses, and providing mechanical stability. quorum sensing is a cell-cell communication mechanism used by several bacterial taxa to coordinate gene expression and behaviour in groups, based on population densities.	2011	21477365
hpa2 required by hrpf to translocate xanthomonas oryzae transcriptional activator-like effectors into rice for pathogenicity.	xanthomonas oryzae pv. oryzicola, the causative agent of bacterial leaf streak, injects a plethora of effectors through the type iii secretion system (t3ss) into rice cells to cause disease. the t3ss, encoded by the hrp genes, is essential for the pathogen to elicit the hypersensitive response (hr) in nonhost tobacco and for pathogenicity in host rice. whether or not a putative lytic transglycosylase, hpa2, interacts with a translocon protein, hrpf, to facilitate bacterial pathogenicity remains ...	2011	21478322
roles of three transporters, cbcxwv, bett1, and bett3, in pseudomonas aeruginosa choline uptake for catabolism.	pseudomonas aeruginosa uses the quaternary amine choline as a carbon source, osmoprotectant, and macromolecular precursor. the importance of choline in p. aeruginosa physiology is highlighted by the presence of multiple known and putative choline transporters encoded within its genome. this report describes the relative roles of three choline transporters, the abc transporter cbcxwv and two symporters, bett1 and bett3, in p. aeruginosa growth on choline under osmotic conditions that are physiolo ...	2011	21478341
hierarchy and roles of pathogen-associated molecular pattern-induced responses in nicotiana benthamiana.	our current understanding of pathogen-associated molecular pattern (pamp)-triggered immunity signaling pathways in plants is limited due to the redundancy of several components or the lethality of mutants in arabidopsis (arabidopsis thaliana). to overcome this, we used a virus-induced gene silencing-based approach in combination with pharmacological studies to decipher links between early pamp-triggered immunity events and their roles in immunity following pamp perception in nicotiana benthamian ...	2011	21478366
antagonistic role of 9-lipoxygenase-derived oxylipins and ethylene in the control of oxidative stress, lipid peroxidation and plant defence.	9-lipoxygenases (9-loxs) initiate fatty acid oxygenation in plant tissues, with formation of 9-hydroxy-10,12,15-octadecatrienoic acid (9-hot) from linolenic acid. a lox1 lox5 mutant, which is deficient in 9-lox activity, and two mutants noxy6 and noxy22 (non-responding to oxylipins), which are insensitive to 9-hot, have been used to investigate 9-hot signalling. map-based cloning indicated that the noxy6 and noxy22 mutations are located at the ctr1 (constitutive ethylene response1) and eto1 (eth ...	2011	21481031
the role of cellular objectives and selective pressures in metabolic pathway evolution.	evolution results from molecular-level changes in an organism, thereby producing novel phenotypes and, eventually novel species. however, changes in a single gene can lead to significant changes in biomolecular networks through the gain and loss of many molecular interactions. thus, significant insights into microbial evolution have been gained through the analysis and comparison of reconstructed metabolic networks. however, challenges remain from reconstruction incompleteness and the inability ...	2011	21481583
the stealth episome: suppression of gene expression on the excised genomic island pphgi-1 from pseudomonas syringae pv. phaseolicola.	pseudomonas syringae pv. phaseolicola is the causative agent of halo blight in the common bean, phaseolus vulgaris. p. syringae pv. phaseolicola race 4 strain 1302a contains the avirulence gene avrpphb (syn. hopar1), which resides on pphgi-1, a 106 kb genomic island. loss of pphgi-1 from p. syringae pv. phaseolicola 1302a following exposure to the hypersensitive resistance response (hr) leads to the evolution of strains with altered virulence. here we have used fluorescent protein reporter syste ...	2011	21483484
the lectin receptor kinase lecrk-i.9 is a novel phytophthora resistance component and a potential host target for a rxlr effector.	in plants, an active defense against biotrophic pathogens is dependent on a functional continuum between the cell wall (cw) and the plasma membrane (pm). it is thus anticipated that proteins maintaining this continuum also function in defense. the legume-like lectin receptor kinase lecrk-i.9 is a putative mediator of cw-pm adhesions in arabidopsis and is known to bind in vitro to the phytophthora infestans rxlr-deer effector ipi-o via a rgd cell attachment motif present in ipi-o. here we show th ...	2011	21483488
a conserved cysteine motif is critical for rice ceramide kinase activity and function.	ceramide kinase (cerk) is a key regulator of cell survival in dicotyledonous plants and animals. much less is known about the roles of cerk and ceramides in mediating cellular processes in monocot plants. here, we report the characterization of a ceramide kinase, oscerk, from rice (oryza sativa spp. japonica cv. nipponbare) and investigate the effects of ceramides on rice cell viability.	2011	21483860
toroidal surface complexes of bacteriophage ϕ12 are responsible for host-cell attachment.	cryo-electron tomography and subtomogram averaging are utilized to determine that the bacteriophage ϕ12, a member of the cystoviridae family, contains surface complexes that are toroidal in shape, are composed of six globular domains with six-fold symmetry, and have a discrete density connecting them to the virus membrane-envelope surface. the lack of this kind of spike in a reassortant of ϕ12 demonstrates that the gene for the hexameric spike is located in ϕ12's medium length genome segment, li ...	2011	21489589
plant intracellular innate immune receptor resistance to pseudomonas syringae pv. maculicola 1 (rpm1) is activated at, and functions on, the plasma membrane.	plants deploy intracellular innate immune receptors to recognize pathogens and initiate disease resistance. these nucleotide-binding, leucine-rich repeat (nb-lrr) proteins are activated by pathogen effector proteins that are delivered into the host cell to suppress host defense responses. little is known about the sites and mechanisms of nb-lrr activation, but some nb-lrr proteins can function inside the plant nucleus. we demonstrate that rpm1 is activated on the plasma membrane and does not rel ...	2011	21490299
aba-dependent amine oxidases-derived h2o2 affects stomata conductance.	recently we showed that aba is at least partly responsible for the induction of the polyamine exodus pathway in vitis vinifera plants. both sensitive and tolerant plants employ this pathway to orchestrate stress responses, differing between stress adaptation and programmed cell death. herein we show that aba is an upstream signal for the induction of the polyamine catabolic pathway in vitis vinifera. thus, amine oxidases are producing h2o2 which signals stomata closure. moreover, the previously ...	2010	21490422
plant immunity: evolutionary insights from pbs1, pto, and rin4.	two layers of plant immune systems are used by plants to defend against phytopathogens. the first layer is pathogen-associate molecular patterns (pamps)-triggered immunity (pti), which is activated by plant cell-surface pattern recognition receptors (prrs) upon perception of microbe general elicitors. the second layer is effector-triggered immunity (eti), which is initiated by specific recognition of pathogen type iii secreted effectors (t3ses) with plant intracellular resistance (r) proteins. c ...	2011	21494098
total (bio)synthesis: strategies of nature and of chemists.	the biosynthetic pathways to a number of natural products have been reconstituted in vitro using purified enzymes. many of these molecules have also been synthesized by organic chemists. here we compare the strategies used by nature and by chemists to reveal the underlying logic and success of each total synthetic approach for some exemplary molecules with diverse biosynthetic origins.	2010	21495259
differential disease resistance response in the barley necrotic mutant nec1.	abstract:	2011	21496226
phosphorylation of a wrky transcription factor by two pathogen-responsive mapks drives phytoalexin biosynthesis in arabidopsis.	plant sensing of invading pathogens triggers massive metabolic reprogramming, including the induction of secondary antimicrobial compounds known as phytoalexins. we recently reported that mpk3 and mpk6, two pathogen-responsive mitogen-activated protein kinases, play essential roles in the induction of camalexin, the major phytoalexin in arabidopsis thaliana. in search of the transcription factors downstream of mpk3/mpk6, we found that wrky33 is required for mpk3/mpk6-induced camalexin biosynthes ...	2011	21498677
glutathione signaling acts through npr1-dependent sa-mediated pathway to mitigate biotic stress.	glutathione (gsh) has widely been known to be a multifunctional molecule especially as an antioxidant uptill now, but has found a new role in plant defense signaling. research from the past three decades indicate that gsh is a player in pathogen defense in plants, but the mechanism underlying this has not been elucidated fully. we have recently shown that gsh acts as a signaling molecule and mitigates biotic stress through non-expressor of pr genes 1 (npr1)-dependent salicylic acid (sa)-mediated ...	2011	21499030
stem-cell-triggered immunity through clv3p-fls2 signalling.	stem cells in the shoot apical meristem (sam) of plants are the self-renewable reservoir for leaf, stem and flower organogenesis. in nature, disease-free plants can be regenerated from sam despite infections elsewhere, which underlies a horticultural practice for decades. however, the molecular basis of the sam immunity remains unclear. here we show that the clavata3 peptide (clv3p), expressed and secreted from stem cells and functioning as a key regulator of stem-cell homeostasis in the sam of ...	2011	21499263
vitis vinifera vvnpr1.1 is the functional ortholog of atnpr1 and its overexpression in grapevine triggers constitutive activation of pr genes and enhanced resistance to powdery mildew.	studying grapevine (vitis vinifera) innate defense mechanisms is a prerequisite to the development of new protection strategies, based on the stimulation of plant signaling pathways to trigger pathogen resistance. two transcriptional coactivators (vvnpr1.1 and vvnpr1.2) with similarity to arabidopsis thaliana npr1 (non-expressor of pr genes 1), a well-characterized and key signaling element of the salicylic acid (sa) pathway, were recently isolated in vitis vinifera. in this study, functional ch ...	2011	21505863
using experimental evolution to explore natural patterns between bacterial motility and resistance to bacteriophages.	resistance of bacteria to phages may be gained by alteration of surface proteins to which phages bind, a mechanism that is likely to be costly as these molecules typically have critical functions such as movement or nutrient uptake. to address this potential trade-off, we combine a systematic study of natural bacteria and phage populations with an experimental evolution approach. we compare motility, growth rate and susceptibility to local phages for 80 bacteria isolated from horse chestnut leav ...	2011	21509046
two vacuole-mediated defense strategies in plants.	as plants lack immune cells, each cell has to defend itself against invading pathogens. plant cells have a large central vacuole that accumulates a variety of hydrolytic enzymes and antimicrobial compounds, raising the possibility that vacuoles play a role in plant defense. however, how plants use vacuoles to protect against invading pathogens is poorly understood. recently, we characterized two vacuole-mediated defense strategies associated with programmed cell death (pcd). in one strategy, vac ...	2010	21512325
molecular characterization of copper resistance genes from xanthomonas citri subsp. citri and xanthomonas alfalfae subsp. citrumelonis.	copper sprays have been widely used for control of endemic citrus canker caused by xanthomonas citri subsp. citri (xcc) in citrus-growing areas for more than two decades. xanthomonas alfalfae subsp. citrumelonis (xac) populations were also exposed to frequent sprays of copper for several years as a protective measure against citrus bacterial spot (cbs) in florida citrus nurseries. long term use of these bactericides has led to the development of copper resistant (cu(r)) strains in both xcc and x ...	2011	21515725
genomic analysis of xanthomonas oryzae from us rice reveals substantial divergence from known x. oryzae pathovars.	the species xanthomonas oryzae is comprised of two designated pathovars, both of which cause economically significant diseases of rice in asia and africa. although x. oryzae is not considered endemic to the united states, an x. oryzae-like bacterium was isolated from us rice and southern cutgrass in the late 1980s. the us strains were weakly pathogenic and genetically distinct from characterized x. oryzae pathovars. in the current study, draft genome sequence from two us xanthomonas strains reve ...	2011	21515727
bioinformatic characterization of the trimeric intracellular cation-specific channel protein family.	trimeric intracellular cation-specific (tric) channels are integral to muscle excitation-contraction coupling. tric channels provide counter-ionic flux when calcium is rapidly transported from intracellular stores to the cell cytoplasm. until recently, knowledge of the presence of these proteins was limited to animals. we analyzed the tric family and identified a profusion of prokaryotic family members with topologies and motifs similar to those of their eukaryotic counterparts. prokaryotic memb ...	2011	21519847
the lsd1-interacting protein gilp is a litaf domain protein that negatively regulates hypersensitive cell death in arabidopsis.	hypersensitive cell death, a form of avirulent pathogen-induced programmed cell death (pcd), is one of the most efficient plant innate immunity. however, its regulatory mechanism is poorly understood. atlsd1 is an important negative regulator of pcd and only two proteins, atbzip10 and atmc1, have been reported to interact with atlsd1.	2011	21526181
engineering microbial factories for synthesis of value-added products.	microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. in this review, we describe the recent progress on engineering microbial factor ...	2011	21526386
crystal structure of uroporphyrinogen iii synthase from pseudomonas syringae pv. tomato dc3000.	uroporphyrinogen iii synthase (u3s) is one of the key enzymes in the biosynthesis of tetrapyrrole compounds. it catalyzes the cyclization of the linear hydroxymethylbilane (hmb) to uroporphyrinogen iii (uro'gen iii). we have determined the crystal structure of u3s from pseudomonas syringae pv. tomato dc3000 (psu3s) at 2.5å resolution by the single wavelength anomalous dispersion (sad) method. each psu3s molecule consists of two domains interlinked by a two-stranded antiparallel β-sheet. the conf ...	2011	21527255
gene expression of pht cluster genes and a putative non-ribosomal peptide synthetase required for phaseolotoxin production is regulated by gacs/gaca in pseudomonas syringae pv. phaseolicola.	pseudomonas syringae pv. phaseolicola is the causal agent of halo blight disease of beans (phaseolus vulgaris l.), which is characterized by watersoaked lesions surrounded by a chlorotic halo resulting from the action of a non-host specific toxin known as phaseolotoxin. this toxin inhibits the enzyme ornithine carbamoyltransferase involved in the arginine biosynthesis pathway. it was previously reported that genes within the pht cluster were involved in the regulation and synthesis of phaseoloto ...	2011	21527339
alien introgressions represent a rich source of genes for crop improvement.		2011	21527718
a bacterial sub-family of luxr regulators that respond to plant compounds.	pseudomonas fluorescens are rhizobacteria known for their biocontrol properties; several antimicrobial functions are crucial for this process; experiments here investigate the modulation of their expression during the plant-bacterial interaction. the role of a luxr family regulator in interkingdom signalling has been investigated using genome-scale transcriptome analysis, gene promoter studies in vivo and in vitro, biocontrol assays and response to plant compounds. psor, a luxr solo or orphan re ...	2011	21531826
trans-repression of gene activity upstream of t-dna tagged rlk902 links arabidopsis root growth inhibition and downy mildew resistance.	receptor-like kinases (rlks) constitute a large family of signal perception molecules in arabidopsis. the largest group of rlks is the leucine-rich repeat (lrr) class that has been described to function in development and defense. of these, clavata1 (clv1) and erecta (er) receptors function in maintaining shoot meristem homeostasis and organ growth, but lrr rlks with similar function in the root remain unknown. for the interaction of arabidopsis with the oomycete pathogen hyaloperonospora arabid ...	2011	21532992
analysis of the plant bos1 mutant highlights necrosis as an efficient defence mechanism during d. dadantii/arabidospis thaliana interaction.	dickeya dadantii is a broad host range phytopathogenic bacterium provoking soft rot disease on many plants including arabidopsis. we showed that, after d. dadantii infection, the expression of the arabidopsis bos1 gene was specifically induced by the production of the bacterial pelb/c pectinases able to degrade pectin. this prompted us to analyze the interaction between the bos1 mutant and d. dadantii. the phenotype of the infected bos1 mutant is complex. indeed, maceration symptoms occurred mor ...	2011	21533045
resistance to hemi-biotrophic f. graminearum infection is associated with coordinated and ordered expression of diverse defense signaling pathways.	fusarium species cause serious diseases in cereal staple food crops such as wheat and maize. currently, the mechanisms underlying resistance to fusarium-caused diseases are still largely unknown. in the present study, we employed a combined proteomic and transcriptomic approach to investigate wheat genes responding to f. graminearum infection that causes fusarium head blight (fhb). we found a total of 163 genes and 37 proteins that were induced by infection. these genes and proteins were associa ...	2011	21533105
towards establishment of a rice stress response interactome.	rice (oryza sativa) is a staple food for more than half the world and a model for studies of monocotyledonous species, which include cereal crops and candidate bioenergy grasses. a major limitation of crop production is imposed by a suite of abiotic and biotic stresses resulting in 30%-60% yield losses globally each year. to elucidate stress response signaling networks, we constructed an interactome of 100 proteins by yeast two-hybrid (y2h) assays around key regulators of the rice biotic and abi ...	2011	21533176
pepper asparagine synthetase 1 (caas1) is required for plant nitrogen assimilation and defense responses to microbial pathogens.	asparagine synthetase is a key enzyme in the production of the nitrogen-rich amino acid asparagine, which is crucial to primary nitrogen metabolism. despite its importance physiologically, the roles that asparagine synthetase plays during plant defense responses remain unknown. here, we determined that pepper (capsicum annuum) asparagine synthetase 1 (caas1) is essential for plant defense to microbial pathogens. infection with xanthomonas campestris pv. vesicatoria (xcv) induced early and strong ...	2011	21535260
a unified approach to the estimation and interpretation of resistance costs in plants.	plants exhibit a number of adaptive defence traits that endow resistance to past and current abiotic and biotic stresses. it is generally accepted that these adaptations will incur a cost when plants are not challenged by the stress to which they have become adapted--the so-called 'cost of adaptation'. the need to minimise or account for allelic variation at other fitness-related loci (genetic background control) is frequently overlooked when assessing resistance costs associated with plant defe ...	2011	21540885
the ehec type iii effector nlel is an e3 ubiquitin ligase that modulates pedestal formation.	enterohemorrhagic escherichia coli (ehec) o157:h7 causes hemorrhagic colitis and may result in potentially fatal hemolytic uremia syndrome in humans. ehec colonize the intestinal mucosa and promote the formation of actin-rich pedestals via translocated type iii effectors. two ehec type iii secreted effectors, tir and espfu/tccp, are key players for pedestal formation. we discovered that an ehec effector protein called non-lee-encoded ligase (nlel) is an e3 ubiquitin ligase. in vitro, we showed t ...	2011	21541301
active suppression of early immune response in tobacco by the human pathogen salmonella typhimurium.	the persistence of enteric pathogens on plants has been studied extensively, mainly due to the potential hazard of human pathogens such as salmonella enterica being able to invade and survive in/on plants. factors involved in the interactions between enteric bacteria and plants have been identified and consequently it was hypothesized that plants may be vectors or alternative hosts for enteric pathogens. to survive, endophytic bacteria have to escape the plant immune systems, which function at d ...	2011	21541320
use of a secretion trap screen in pepper following phytophthora capsici infection reveals novel functions of secreted plant proteins in modulating cell death.	in plants, the primary defense against pathogens is mostly inducible and associated with cell wall modification and defense-related gene expression, including many secreted proteins. to study the role of secreted proteins, a yeast-based signal-sequence trap screening was conducted with the rna from phytophthora capsici-inoculated root of capsicum annuum 'criollo de morelos 334' (cm334). in total, 101 capsicum annuum secretome (cas) clones were isolated and identified, of which 92 were predicted ...	2011	21542767
integration host factor (ihf) binds to the promoter region of the phtd operon involved in phaseolotoxin synthesis in p. syringae pv. phaseolicola nps3121.	abstract: background: pseudomonas syringae pv. phaseolicola, the causal agent of halo blight disease in beans, produces a toxin known as phaseolotoxin, in whose synthesis participate a group of genes organized within the genome in a region known as the "pht cluster". this region, which is thought to have been acquired by horizontal gene transfer, includes 5 transcriptional units, two monocistronic (argk, phtl) and three polycistronic (phta, phtd, phtm), whose expression is temperature dependent. ...	2011	21542933
characterization of a cryptic plasmid psm429 and its application for heterologous expression in psychrophilic pseudoalteromonas.	abstract: background: pseudoalteromonas is an important genus widespread in marine environment, and a lot of psychrophilic pseudoalteromonas strains thrive in deep sea and polar sea. by now, there are only a few genetic systems for pseudoalteromonas reported and no commercial pseudoalteromonas genetic system is available, which impedes the study of pseudoalteromonas, especially for psychrophilic strains. the aim of this study is to develop a heterologous expression system for psychrophilic pseud ...	2011	21542941
multiple roles of win3 in regulating disease resistance, cell death, and flowering time in arabidopsis.	the salicylic acid (sa) regulatory gene hopw1-1-interacting 3 (win3) was previously shown to confer resistance to the biotrophic pathogen pseudomonas syringae. here we report that win3 controls broad-spectrum disease resistance to the necrotrophic pathogen botrytis cinerae and contributes to basal defense induced by flg22, a 22-amino acid peptide derived from the conserved region of bacterial flagellin proteins. genetic analysis indicates that win3 acts additively with several known sa regulator ...	2011	21543726
cell wall damage-induced lignin biosynthesis is regulated by a reactive oxygen species- and jasmonic acid-dependent process in arabidopsis.	the plant cell wall is a dynamic and complex structure whose functional integrity is constantly being monitored and maintained during development and interactions with the environment. in response to cell wall damage (cwd), putatively compensatory responses, such as lignin production, are initiated. in this context, lignin deposition could reinforce the cell wall to maintain functional integrity. lignin is important for the plant's response to environmental stress, for reinforcement during secon ...	2011	21546454
arabidopsis argonaute 2 regulates innate immunity via mirna393(∗)-mediated silencing of a golgi-localized snare gene, memb12.	argonaute (ago) proteins are critical components of rna silencing pathways that bind small rnas and mediate gene silencing at their target sites. we found that arabidopsis ago2 is highly induced by the bacterial pathogen pseudomonas syringae pv. tomato (pst). further genetic analysis demonstrated that ago2 functions in antibacterial immunity. one abundant species of ago2-bound small rna is mir393b(∗), which targets a golgi-localized snare gene, memb12. pst infection downregulates memb12 in a mir ...	2011	21549312
pseudomonas syringae colonizes distant tissues in nicotiana benthamiana through xylem vessels.	the ability to move from the primary infection site and colonize distant tissue in the leaf is an important property of bacterial plant pathogens, yet hardly investigated for model pathogens. here we show that gfp-expressing pseudomonas syringae pv. syringae dc3000 lacking the hopq1-1 effector (ptodc3000δhq) has a strong capacity to colonize distant leaf tissue from wound-inoculated sites in n. benthamiana. distant colonization occurs within one week after toothpick inoculation and is characteri ...	2011	21554458
vibrio cholerae requires the type vi secretion system virulence factor vasx to kill dictyostelium discoideum.	the type vi secretion system (t6ss) is recognized as an important virulence mechanism in several gram-negative pathogens. in vibrio cholerae, the causative agent of the diarrheal disease cholera, a minimum of three gene clusters-one main cluster and two auxiliary clusters-are required to form a functional t6ss apparatus capable of conferring virulence towards eukaryotic and prokaryotic hosts. despite an increasing understanding of the components that make up the t6ss apparatus, little is known a ...	2011	21555399
self/nonself perception in plants in innate immunity and defense.	the ability to distinguish 'self' from 'nonself' is the most fundamental aspect of any immune system. the evolutionary solution in plants to the problems of perceiving and responding to pathogens involves surveillance of nonself, damaged-self and altered-self as danger signals. this is reflected in basal resistance or non-host resistance, which is the innate immune response that protects plants against the majority of pathogens. in the case of surveillance of nonself, plants utilize receptor-lik ...	2010	21559176
organisation and regulation of the cytoskeleton in plant programmed cell death.	programmed cell death (pcd) involves precise integration of cellular responses to extracellular and intracellular signals during both stress and development. in recent years much progress in our understanding of the components involved in pcd in plants has been made. signalling to pcd results in major reorganisation of cellular components. the plant cytoskeleton is known to play a major role in cellular organisation, and reorganization and alterations in its dynamics is a well known consequence ...	2011	21566662
evolution of plant pathogenesis in pseudomonas syringae: a genomics perspective.	the phytopathogenic bacterium pseudomonas syringae causes serious diseases in a wide range of important crop plants, with recent severe outbreaks on the new zealand kiwifruit crop and among british horse chestnut trees. next-generation genome sequencing of over 25 new strains has greatly broadened our understanding of how this species adapts to a diverse range of plant hosts. not unexpectedly, the genomes were found to be highly dynamic, and extensive polymorphism was found in the distribution o ...	2010	21568703
regulatory subunit b'gamma of protein phosphatase 2a prevents unnecessary defense reactions under low light in arabidopsis.	light is an important environmental factor that modulates acclimation strategies and defense responses in plants. we explored the functional role of the regulatory subunit b'γ (b'γ) of protein phosphatase 2a (pp2a) in light-dependent stress responses of arabidopsis (arabidopsis thaliana). the predominant form of pp2a consists of catalytic subunit c, scaffold subunit a, and highly variable regulatory subunit b, which determines the substrate specificity of pp2a holoenzymes. mutant leaves of knock ...	2011	21571669
stars and symbiosis: microrna- and microrna*-mediated transcript cleavage involved in arbuscular mycorrhizal symbiosis.	the majority of plants are able to form the arbuscular mycorrhizal (am) symbiosis in association with am fungi. during symbiosis development, plant cells undergo a complex reprogramming resulting in profound morphological and physiological changes. micrornas (mirnas) are important components of the regulatory network of plant cells. to unravel the impact of mirnas and mirna-mediated mrna cleavage on root cell reprogramming during am symbiosis, we carried out high-throughput (illumina) sequencing ...	2011	21571671
identification of an african bacillus anthracis lineage that lacks expression of the spore surface associated anthrose containing oligosaccharide.	the surface of bacillus anthracis endospores exposes a pentasaccharide containing the monosaccharide anthrose which has been considered as vaccine or target for specific detection of the spores. in this study b. anthracis strains isolated from cattle carcasses in african countries where anthrax is endemic were tested for their cross-reactivity with monoclonal antibodies (mabs) specific for anthrose containing oligosaccharides. unexpectedly, none of the isolates collected in chad, cameroon and ma ...	2011	21571994
specific impact of tobamovirus infection on the arabidopsis small rna profile.	tobamoviruses encode a silencing suppressor that binds small rna (srna) duplexes in vitro and supposedly in vivo to counteract antiviral silencing. here, we used srna deep-sequencing combined with transcriptome profiling to determine the global impact of tobamovirus infection on arabidopsis srnas and their mrna targets. we found that infection of arabidopsis plants with oilseed rape mosaic tobamovirus causes a global size-specific enrichment of mirnas, ta-sirnas, and other phased sirnas. the obs ...	2011	21572953
identification of hyaloperonospora arabidopsidis transcript sequences expressed during infection reveals isolate-specific effectors.	biotrophic plant pathogens secrete effector proteins that are important for infection of the host. the aim of this study was to identify effectors of the downy mildew pathogen hyaloperonospora arabidopsidis (hpa) that are expressed during infection of its natural host arabidopsis thaliana. infection-related transcripts were identified from expressed sequence tags (ests) derived from leaves of the susceptible arabidopsis ws eds1-1 mutant inoculated with the highly virulent hpa isolate waco9. asse ...	2011	21573066
the molecular basis for antimicrobial activity of pore-forming cyclic peptides.	the mechanism of action of antimicrobial peptides is, to our knowledge, still poorly understood. to probe the biophysical characteristics that confer activity, we present here a molecular-dynamics and biophysical study of a cyclic antimicrobial peptide and its inactive linear analog. in the simulations, the cyclic peptide caused large perturbations in the bilayer and cooperatively opened a disordered toroidal pore, 1-2 nm in diameter. electrophysiology measurements confirm discrete poration even ...	2011	21575576