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transplastomic nicotiana benthamiana plants expressing multiple defence genes encoding protease inhibitors and chitinase display broad-spectrum resistance against insects, pathogens and abiotic stresses.plastid engineering provides several advantages for the next generation of transgenic technology, including the convenient use of transgene stacking and the generation of high expression levels of foreign proteins. with the goal of generating transplastomic plants with multiresistance against both phytopathogens and insects, a construct containing a monocistronic patterned gene stack was transformed into nicotiana benthamiana plastids harbouring sweet potato sporamin, taro cystatin and chitinase ...201424479648
[antitumor activity of l-asparaginase from erwinia carotovora from against different leukemic and solid tumours cell lines].we have studied dose- and time-dependent antitumor and cytotoxic effects of erwinia carotovora l-asparaginase (ecar lans) and escherichia coli l-asparaginase (medac) on human leukemic cells and human and animal solid tumor cells. we determined the sensitivity of tumor cells to l-asparaginases, as well the effect l-asparaginases on cell growth rate, protein and dna synthesis per se and with addition of different cytostatics. the data obtained demonstrated that ecar lans l-asparaginase suppressed ...201424479339
a secreted ustilago maydis effector promotes virulence by targeting anthocyanin biosynthesis in maize.the biotrophic fungus ustilago maydis causes smut disease in maize with characteristic tumor formation and anthocyanin induction. here, we show that anthocyanin biosynthesis is induced by the virulence promoting secreted effector protein tin2. tin2 protein functions inside plant cells where it interacts with maize protein kinase zmttk1. tin2 masks a ubiquitin-proteasome degradation motif in zmttk1, thus stabilizing the active kinase. active zmttk1 controls activation of genes in the anthocyanin ...201424473076
global analysis of the burkholderia thailandensis quorum sensing-controlled regulon.burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional luxr homologs. to identify b. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (rna-seq) analyses of quorum sensing mutants and their parent. the analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. we also found that genes c ...201424464461
role of duox in gut inflammation: lessons from drosophila model of gut-microbiota interactions.it is well-known that certain bacterial species can colonize the gut epithelium and induce inflammation in the mucosa, whereas other species are either benign or beneficial to the host. deregulation of the gut-microbe interactions may lead to a pathogenic condition in the host, such as chronic inflammation, tissue injuries, and even cancer. however, our current understanding of the molecular mechanisms that underlie gut-microbe homeostasis and pathogenesis remains limited. recent studies have us ...201324455491
role of duox in gut inflammation: lessons from drosophila model of gut-microbiota interactions.it is well-known that certain bacterial species can colonize the gut epithelium and induce inflammation in the mucosa, whereas other species are either benign or beneficial to the host. deregulation of the gut-microbe interactions may lead to a pathogenic condition in the host, such as chronic inflammation, tissue injuries, and even cancer. however, our current understanding of the molecular mechanisms that underlie gut-microbe homeostasis and pathogenesis remains limited. recent studies have us ...201324455491
[properties of pectolitic phytopathogenic bacteria isolates obtained in ukraine].bacteria obtained from potato tubers having symptoms of soft rot and grown in different regions of ukraine are identified as pectobacterium carotovorum subsp. carotovorum. these bacteria strains are able to produce bacteriocines. their killer activity in respect of p. carotovorum and esherichia coli has been studied. the sensitivity to bactericines has been shown. purified fractions of bacteriocines having high molecular weight (mctv) have been obtained. the difference in composition of proteins ...201424450188
the global response regulator expa controls virulence gene expression through rsma-mediated and rsma-independent pathways in pectobacterium wasabiae scc3193.expa (gaca) is a global response regulator that controls the expression of major virulence genes, such as those encoding plant cell wall-degrading enzymes (pcwdes) in the model soft rot phytopathogen pectobacterium wasabiae scc3193. several studies with pectobacteria as well as related phytopathogenic gammaproteobacteria, such as dickeya and pseudomonas, suggest that the control of virulence by expa and its homologues is executed partly by modulating the activity of rsma, an rna-binding posttran ...201424441162
pgrp-sc2 promotes gut immune homeostasis to limit commensal dysbiosis and extend lifespan.interactions between commensals and the host impact the metabolic and immune status of metazoans. their deregulation is associated with age-related pathologies like chronic inflammation and cancer, especially in barrier epithelia. maintaining a healthy commensal population by preserving innate immune homeostasis in such epithelia thus promises to promote health and longevity. here, we show that, in the aging intestine of drosophila, chronic activation of the transcription factor foxo reduces exp ...201424439372
lytic peptidase l5 of lysobacter sp. xl1 with broad antimicrobial spectrum.the gram-negative bacterium lysobacter sp. xl1 secretes lytic enzymes (l1-l5) into the culture medium. enzyme l5 is the most recently found extracellular lytic enzyme of this bacterium. the paper presents the results of the isolation and characterization of some properties of this enzyme. thus, enzyme l5 of lysobacter sp. xl1 is a lytic serine protease. earlier, the enzyme was shown to be secreted into the culture medium by means of outer membrane vesicles, which possess a lytic effect towards l ...201424434599
pathogen virulence of phytophthora infestans: from gene to functional genomics.the oomycete, phytophthora infestans, is one of the most important plant pathogens worldwide. much of the pathogenic success of p. infestans, the potato late blight agent, relies on its ability to generate large amounts of sporangia from mycelia, which release zoospores that encyst and form infection structures. until recently, little was known about the molecular basis of oomycete pathogenicity by the avirulence molecules that are perceived by host defenses. to understand the molecular mechanis ...201224431484
pathogen virulence of phytophthora infestans: from gene to functional genomics.the oomycete, phytophthora infestans, is one of the most important plant pathogens worldwide. much of the pathogenic success of p. infestans, the potato late blight agent, relies on its ability to generate large amounts of sporangia from mycelia, which release zoospores that encyst and form infection structures. until recently, little was known about the molecular basis of oomycete pathogenicity by the avirulence molecules that are perceived by host defenses. to understand the molecular mechanis ...201224431484
plant rna binding proteins for control of rna virus infection.plant rna viruses have effective strategies to infect host plants through either direct or indirect interactions with various host proteins, thus suppressing the host immune system. when plant rna viruses enter host cells exposed rnas of viruses are recognized by the host immune system through processes such as sirna-dependent silencing. interestingly, some host rna binding proteins have been involved in the inhibition of rna virus replication, movement, and translation through rna-specific bind ...201324427141
in vitro characterization of a recombinant ahl-lactonase from bacillus cereus isolated from a striped catfish (pangasianodon hypophthalmus) pond.aiia gene encoding ahl-lactonase was isolated from bacillus cereus strain n26.2, originating from a striped catfish (pangasianodon hypophthalmus) pond in vietnam. this gene, abbreviated as aiia(n26.2), was cloned and expressed in a competent escherichia coli strain bl21(de3)plyss. the resulting protein, abbreviated as aiian26.2, was highly active in the ph range of 6-8 and could retain 80 % of the maximum activity under storage for 5 days at 4 °c or for 3 days at 20 °c. these properties of aiian ...201324426155
in vitro antibacterial activity of cysteine protease inhibitor from kiwifruit (actinidia deliciosa).the need for replacing traditional pesticides with alternative agents for the management of agricultural pathogens is rising worldwide. in this study, a cysteine proteinase inhibitor (cpi), 11 kda in size, was purified from green kiwifruit to homogeneity. we examined the growth inhibition of three plant pathogenic gram-negative bacterial strains by kiwi cpi and attempted to elucidate the potential mechanism of the growth inhibition. cpi influenced the growth of phytopathogenic bacteria agrobacte ...201224426085
in vitro antibacterial activity of cysteine protease inhibitor from kiwifruit (actinidia deliciosa).the need for replacing traditional pesticides with alternative agents for the management of agricultural pathogens is rising worldwide. in this study, a cysteine proteinase inhibitor (cpi), 11 kda in size, was purified from green kiwifruit to homogeneity. we examined the growth inhibition of three plant pathogenic gram-negative bacterial strains by kiwi cpi and attempted to elucidate the potential mechanism of the growth inhibition. cpi influenced the growth of phytopathogenic bacteria agrobacte ...201224426085
genome expression profile analysis of the maize sheath in response to inoculation to r. solani.currently, the molecular regulation mechanisms of disease-resistant involved in maize leaf sheaths infected by banded leaf and sheath blight (blsb) are poorly known. to gain insight into the transcriptome dynamics that are associated with their disease-resistant, genome-wide gene expression profiling was conducted by solexa sequencing. more than four million tags were generated from sheath tissues without any leaf or development leaf, including 193,222 and 204,824 clean tags in the two libraries ...201424420865
identification and characterization of the carbapenem mm 4550 and its gene cluster in streptomyces argenteolus atcc 11009.nearly 50 naturally occurring carbapenem β-lactam antibiotics, most produced by streptomyces, have been identified. the structural diversity of these compounds is limited to variance of the c-2 and c-6 side chains as well as the stereochemistry at c-5/c-6. these structural motifs are of interest both for their antibiotic effects and their biosynthesis. although the thienamycin gene cluster is the only active gene cluster publically available in this group, more comparative information is needed ...201424420617
lysine carboxylation: unveiling a spontaneous post-translational modification.the carboxylation of lysine residues is a post-translational modification (ptm) that plays a critical role in the catalytic mechanisms of several important enzymes. it occurs spontaneously under certain physicochemical conditions, but is difficult to detect experimentally. its full impact is unknown. in this work, the signature microenvironment of lysine-carboxylation sites has been characterized. in addition, a computational method called predictor of lysine carboxylation (prelyscar) for the de ...201324419378
lysine carboxylation: unveiling a spontaneous post-translational modification.the carboxylation of lysine residues is a post-translational modification (ptm) that plays a critical role in the catalytic mechanisms of several important enzymes. it occurs spontaneously under certain physicochemical conditions, but is difficult to detect experimentally. its full impact is unknown. in this work, the signature microenvironment of lysine-carboxylation sites has been characterized. in addition, a computational method called predictor of lysine carboxylation (prelyscar) for the de ...201324419378
functional characterization of the sucrose isomerase responsible for trehalulose production in plant-associated pectobacterium species.fifty-three plant-associated microorganisms were investigated for their ability to convert sucrose to its isomers. these microorganisms included one dickeya zeae isolate and 7 enterobacter, 3 pantoea, and 43 pectobacterium species. eleven out of the 53 strains (21%) showed the ability to transform sucrose to isomaltulose and trehalulose. among those, pectobacterium carotovorum kkh 3-1 showed the highest bioconversion yield (97.4%) from sucrose to its isomers. in this strain, the addition of up t ...201424411451
growth promotion-related mirnas in oncidium orchid roots colonized by the endophytic fungus piriformospora indica.piriformospora indica, an endophytic fungus of sebacinales, colonizes the roots of a wide range of host plants and establishes various benefits for the plants. in this work, we describe mirnas which are upregulated in oncidium orchid roots after colonization by the fungus. growth promotion and vigorous root development were observed in oncidium hybrid orchid, while seedlings were colonized by p. indica. we performed a genome-wide expression profiling of small rnas in oncidium orchid roots either ...201424409313
human pathogenic bacteria, fungi, and viruses in drosophila: disease modeling, lessons, and shortcomings.drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. many drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. we discuss studies of human pathogens in flies revealing not only ...201424398387
parallel histories of horizontal gene transfer facilitated extreme reduction of endosymbiont genomes in sap-feeding insects.bacteria confined to intracellular environments experience extensive genome reduction. in extreme cases, insect endosymbionts have evolved genomes that are so gene-poor that they blur the distinction between bacteria and endosymbiotically derived organelles such as mitochondria and plastids. to understand the host's role in this extreme gene loss, we analyzed gene content and expression in the nuclear genome of the psyllid pachypsylla venusta, a sap-feeding insect that harbors an ancient endosym ...201424398322
structure and expression of gsl1 and gsl2 genes encoding gibberellin stimulated-like proteins in diploid and highly heterozygous tetraploid potato reveals their highly conserved and essential status.gsl1 and gsl2, gibberellin stimulated-like proteins (also known as snakin-1 and snakin-2), are cysteine-rich peptides from potato (solanum tuberosum l.) with antimicrobial properties. similar peptides in other species have been implicated in diverse biological processes and are hypothesised to play a role in several aspects of plant development, plant responses to biotic or abiotic stress through their participation in hormone crosstalk, and redox homeostasis. to help resolve the biological role ...201424382166
host-microbe interactions in the gut of drosophila melanogaster.many insect species subsist on decaying and contaminated matter and are thus exposed to large quantities of microorganisms. to control beneficial commensals and combat infectious pathogens, insects must be armed with efficient systems for microbial recognition, signaling pathways, and effector molecules. the molecular mechanisms regulating these host-microbe interactions in insects have been largely clarified in drosophila melanogaster with its powerful genetic and genomic tools. here we review ...201324381562
intestinal inflammation and stem cell homeostasis in aging drosophila melanogaster.as a barrier epithelium, the intestinal epithelium has to coordinate physiological functions like digestion and nutrient resorption with the control of commensal bacteria and the prevention of pathogenic infections. it can therefore mount powerful innate immune and inflammatory responses, while, at the same time, maintaining tissue homeostasis through regenerative processes. how these different functions are coordinated remains unclear, and further insight is required to understand the age-relat ...201324380076
gsl2 over-expression confers resistance to pectobacterium atrosepticum in potato.over-expression of the potato gibberellin stimulated-like 2 ( gsl2 ) gene in transgenic potato confers resistance to blackleg disease incited by pectobacterium atrosepticum and confirms a role for gsl2 in plant defence. the gibberellin stimulated-like 2 (gsl2) gene (also known as snakin 2) encodes a cysteine-rich, low-molecular weight antimicrobial peptide produced in potato plants. this protein is thought to play important roles in the innate defence against invading microbes. over-expression o ...201424370960
arabidopsis pectin methylesterases contribute to immunity against pseudomonas syringae.pectins, major components of dicot cell walls, are synthesized in a heavily methylesterified form in the golgi and are partially deesterified by pectin methylesterases (pmes) upon export to the cell wall. pme activity is important for the virulence of the necrotrophic fungal pathogen botrytis cinerea. here, the roles of arabidopsis pmes in pattern-triggered immunity and immune responses to the necrotrophic fungus alternaria brassicicola and the bacterial hemibiotroph pseudomonas syringae pv macu ...201324367018
arabidopsis pectin methylesterases contribute to immunity against pseudomonas syringae.pectins, major components of dicot cell walls, are synthesized in a heavily methylesterified form in the golgi and are partially deesterified by pectin methylesterases (pmes) upon export to the cell wall. pme activity is important for the virulence of the necrotrophic fungal pathogen botrytis cinerea. here, the roles of arabidopsis pmes in pattern-triggered immunity and immune responses to the necrotrophic fungus alternaria brassicicola and the bacterial hemibiotroph pseudomonas syringae pv macu ...201324367018
biochemical characterization of a novel l-asparaginase with low glutaminase activity from rhizomucor miehei and its application in food safety and leukemia treatment.a novel fungal gene encoding the rhizomucor miehei l-asparaginase (rmasnase) was cloned and expressed in escherichia coli. its deduced amino acid sequence shared only 57% identity with the amino acid sequences of other reported l-asparaginases. the purified l-asparaginase homodimer had a molecular mass of 133.7 kda, a high specific activity of 1,985 u/mg, and very low glutaminase activity. rmasnase was optimally active at ph 7.0 and 45°c and was stable at this temperature for 30 min. the final l ...201424362429
lignin: characterization of a multifaceted crop component.lignin is a plant component with important implications for various agricultural disciplines. it confers rigidity to cell walls, and is therefore associated with tolerance to abiotic and biotic stresses and the mechanical stability of plants. in animal nutrition, lignin is considered an antinutritive component of forages as it cannot be readily fermented by rumen microbes. in terms of energy yield from biomass, the role of lignin depends on the conversion process. it contains more gross energy t ...201324348159
knockdown of asparagine synthetase a renders trypanosoma brucei auxotrophic to asparagine.asparagine synthetase (as) catalyzes the atp-dependent conversion of aspartate into asparagine using ammonia or glutamine as nitrogen source. there are two distinct types of as, asparagine synthetase a (as-a), known as strictly ammonia-dependent, and asparagine synthetase b (as-b), which can use either ammonia or glutamine. the absence of as-a in humans, and its presence in trypanosomes, suggested as-a as a potential drug target that deserved further investigation. we report the presence of func ...201324340117
global analysis of cis-natural antisense transcripts and their heat-responsive nat-sirnas in brassica rapa.brassica rapa includes several important leaf vegetable crops whose production is often damaged by high temperature. cis-natural antisense transcripts (cis-nats) and cis-nats-derived small interfering rnas (nat-sirnas) play important roles in plant development and stress responses. however, genome-wide cis-nats in b. rapa are not known. the nats and nat-sirnas that respond to heat stress have never been well studied in b. rapa. here, we took advantage of rna-seq and small rna (srna) deep sequenc ...201324320882
genome sequence of enterobacter turicensis strain 610/05 (lmg 23731), isolated from fruit powder.we report the draft genome sequence of enterobacter turicensis strain 610/05 (lmg 23731), isolated from fruit powder. the draft genome has a size of 4,182,790 bp and a g+c% content of 58.0.201324309739
nitrogen assimilation in escherichia coli: putting molecular data into a systems perspective.we present a comprehensive overview of the hierarchical network of intracellular processes revolving around central nitrogen metabolism in escherichia coli. the hierarchy intertwines transport, metabolism, signaling leading to posttranslational modification, and transcription. the protein components of the network include an ammonium transporter (amtb), a glutamine transporter (glnhpq), two ammonium assimilation pathways (glutamine synthetase [gs]-glutamate synthase [glutamine 2-oxoglutarate ami ...201324296575
secretory pathway of cellulase: a mini-review.cellulase plays an important role in modern industry and holds great potential in biofuel production. many different types of organisms produce cellulase, which go through secretory pathways to reach the extracellular space, where enzymatic reactions take place. secretory pathways in various cells have been the focus of many research fields; however, there are few studies on secretory pathways of cellulases in the literature. it is therefore necessary and important to review the current knowledg ...201324295495
ralstonia solanacearum requires pops, an ancient avre-family effector, for virulence and to overcome salicylic acid-mediated defenses during tomato pathogenesis.during bacterial wilt of tomato, the plant pathogen ralstonia solanacearum upregulates expression of pops, which encodes a type iii-secreted effector in the avre family. pops is a core effector present in all sequenced strains in the r. solanacearum species complex. the phylogeny of pops mirrors that of the species complex as a whole, suggesting that this is an ancient, vertically inherited effector needed for association with plants. a pops mutant of r. solanacearum uw551 had reduced virulence ...201324281716
plant growth-promoting bacteria: mechanisms and applications.the worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. it is therefore essential that agricultural productivity be significantly increased within the next few decades. to this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. this includes both the increasing use of transgenic plants and plant ...201224278762
implication of lateral genetic transfer in the emergence of aeromonas hydrophila isolates of epidemic outbreaks in channel catfish.to investigate the molecular basis of the emergence of aeromonas hydrophila responsible for an epidemic outbreak of motile aeromonad septicemia of catfish in the southeastern united states, we sequenced 11 a. hydrophila isolates that includes five reference and six recent epidemic isolates. comparative genomics revealed that recent epidemic a. hydrophila isolates are highly clonal, whereas reference isolates are greatly diverse. we identified 55 epidemic-associated genetic regions with 313 predi ...201324278351
the influence of antibody fragment format on phage display based affinity maturation of igg.today, most approved therapeutic antibodies are provided as immunoglobulin g (igg), whereas small recombinant antibody formats are required for in vitro antibody generation and engineering during drug development. particularly,single chain (sc) antibody fragments like scfv or scfab are well suited for phage display and bacterial expression, but some have been found to lose affinity during conversion into igg.in this study, we compared the influence of the antibody format on affinity maturation o ...201324262918
the influence of antibody fragment format on phage display based affinity maturation of igg.today, most approved therapeutic antibodies are provided as immunoglobulin g (igg), whereas small recombinant antibody formats are required for in vitro antibody generation and engineering during drug development. particularly,single chain (sc) antibody fragments like scfv or scfab are well suited for phage display and bacterial expression, but some have been found to lose affinity during conversion into igg.in this study, we compared the influence of the antibody format on affinity maturation o ...201324262918
structural and functional role of gly281 in l-asparaginase from erwinia carotovora.l-asparaginases (e.c.3.5.1.1, l- asnases) have been widely used in clinical practice as chemotherapeutic drugs of acute lymphoblastic leukaemia (all). in order to evaluate the structural and functional role of selected residues in asnases we report the screening of a library of l-asnase mutants aiming to find detrimental mutations that significantly affect catalysis and substrate specificity. the library of mutants was created using the staggered extension process (step) and the genes of l- asna ...201324261975
chromosomal targeting by crispr-cas systems can contribute to genome plasticity in bacteria.the clustered regularly interspaced short palindromic repeats (crispr) and their associated (cas) proteins form adaptive immune systems in bacteria to combat phage and other foreign genetic elements. typically, short spacer sequences are acquired from the invader dna and incorporated into crispr arrays in the bacterial genome. small rnas are generated that contain these spacer sequences and enable sequence-specific destruction of the foreign nucleic acids. occasionally, spacers are acquired from ...201324251073
toxin-antitoxin systems: biology, identification, and application.toxin-antitoxin (ta) systems are small genetic elements composed of a toxin gene and its cognate antitoxin. the toxins of all known ta systems are proteins while the antitoxins are either proteins or non-coding rnas. based on the molecular nature of the antitoxin and its mode of interaction with the toxin the ta modules are currently grouped into five classes. in general, the toxin is more stable than the antitoxin but the latter is expressed to a higher level. if supply of the antitoxin stops, ...201324251069
cloning, characterization and effect of tmpgrp-le gene silencing on survival of tenebrio molitor against listeria monocytogenes infection.peptidoglycan recognition proteins (pgrps) are a family of innate immune molecules that recognize bacterial peptidoglycan. pgrp-le, a member of the pgrp family, selectively binds to diaminopimelic acid (dap)-type peptidoglycan to activate both the immune deficiency (imd) and prophenoloxidase (propo) pathways in insects. a pgrp-le-dependent induction of autophagy to control listeria monocytogenes has also been reported. we identified and partially characterized a novel pgrp-le homologue, from ten ...201324240808
dynamic interplay between the periplasmic and transmembrane domains of gspl and gspm in the type ii secretion system.the type ii secretion system (t2ss) is a multiprotein nanomachine that transports folded proteins across the outer membrane of gram-negative bacteria. the molecular mechanisms that govern the secretion process remain poorly understood. the inner membrane components gspc, gspl and gspm possess a single transmembrane segment (tms) and a large periplasmic region and they are thought to form a platform of unknown function. here, using two-hybrid and pull-down assays we performed a systematic mapping ...201324223969
the ribonucleoprotein csr network.ribonucleoprotein complexes are essential regulatory components in bacteria. in this review, we focus on the carbon storage regulator (csr) network, which is well conserved in the bacterial world. this regulatory network is composed of the csra master regulator, its targets and regulators. csra binds to mrna targets and regulates translation either negatively or positively. binding to small non-coding rnas controls activity of this protein. expression of these regulators is tightly regulated at ...201324217225
protection from oxidative stress relies mainly on derepression of oxyr-dependent katb and dps in shewanella oneidensis.shewanella thrives in redox-stratified environments where accumulation of h2o2 becomes inevitable because of the chemical oxidation of reduced metals, sulfur species, or organic molecules. as a research model, the representative species shewanella oneidensis has been extensively studied for its response to various stresses. however, little progress has been made toward an understanding of the physiological and genetic responses of this bacterium to oxidative stress, which is critically relevant ...201424214945
phylogenomic analysis identifies gene gains that define salmonella enterica subspecies i.comparative methods for analyzing whole genome sequence (wgs) data enable us to assess the genetic information available for reconstructing the evolutionary history of pathogens. we used the comparative approach to determine diagnostic genes for salmonella enterica subspecies i. s. enterica subsp. i strains are known to infect warm-blooded organisms regularly while its close relatives tend to infect only cold-blooded organisms. we found 71 genes gained by the common ancestor of salmonella enteri ...201324204679
filamentous phages of ralstonia solanacearum: double-edged swords for pathogenic bacteria.some phages from genus inovirus use host or bacteriophage-encoded site-specific integrases or recombinases establish a prophage state. during integration or excision, a superinfective form can be produced. the three states (free, prophage, and superinfective) of such phages exert different effects on host bacterial phenotypes. in ralstonia solanacearum, the causative agent of bacterial wilt disease of crops, the bacterial virulence can be positively or negatively affected by filamentous phages, ...201324204365
steroid hormone signaling is essential to regulate innate immune cells and fight bacterial infection in drosophila.coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. drosophila metamorphosis represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. however, nothing is known about the mechanisms that coordinate development and immune cell activity in the transition from larva to adult. here, we reveal that regulation of macrophage-like cells (hemocytes) by the steroi ...201324204269
distribution of epiphytic bacteria on olive leaves and the influence of leaf age and sampling time.mesophilic heterotrophic, aerobic or facultatively anaerobic bacteria that grow on yeast tryptone glucose extract agar were isolated from the surface of olive leaves of 3 or 4 different ages in january, april, july, and october from 1984 to 1989. unweighted average linkage cluster analysis on either the jaccard coefficient or the simple matching coefficient recovered 1,701 representative strains in 32 phena defined at the 70% and 80% similarity level, respectively. of these, 25 were identified t ...199124194200
evolution of resistance to quorum-sensing inhibitors.the major cause of mortality and morbidity in human beings is bacterial infection. bacteria have developed resistance to most of the antibiotics primarily due to large-scale and "indiscriminate" usage. the need is to develop novel mechanisms to treat bacterial infections. the expression of pathogenicity during bacterial infections is mediated by a cell density-dependent phenomenon known as quorum sensing (qs). a wide array of qs systems (qss) is operative in expressing the virulent behavior of b ...201324194099
evolution of resistance to quorum-sensing inhibitors.the major cause of mortality and morbidity in human beings is bacterial infection. bacteria have developed resistance to most of the antibiotics primarily due to large-scale and "indiscriminate" usage. the need is to develop novel mechanisms to treat bacterial infections. the expression of pathogenicity during bacterial infections is mediated by a cell density-dependent phenomenon known as quorum sensing (qs). a wide array of qs systems (qss) is operative in expressing the virulent behavior of b ...201324194099
stimulating crosstalk between commensal bacteria and intestinal stem cells. 201324193404
in silico identification and experimental characterization of regulatory elements controlling the expression of the salmonella csrb and csrc genes.the small rnas csrb and csrc of salmonella indirectly control the expression of numerous genes encoding widespread cellular functions, including virulence. the expression of csrb and csrc genes, which are located in different chromosomal regions, is coordinated by positive transcriptional control mediated by the two-component regulatory system bara/sira. here, we identified by computational analysis an 18-bp inverted repeat (ir) sequence located far upstream from the promoter of salmonella enter ...201424187088
gdsl lipase1 modulates plant immunity through feedback regulation of ethylene signaling.ethylene is a key signal in the regulation of plant defense responses. it is required for the expression and function of gdsl lipase1 (glip1) in arabidopsis (arabidopsis thaliana), which plays an important role in plant immunity. here, we explore molecular mechanisms underlying the relationship between glip1 and ethylene signaling by an epistatic analysis of ethylene response mutants and glip1-overexpressing (35s:glip1) plants. we show that glip1 expression is regulated by ethylene signaling com ...201324170202
two-way plant mediated interactions between root-associated microbes and insects: from ecology to mechanisms.plants are members of complex communities and function as a link between above- and below-ground organisms. associations between plants and soil-borne microbes commonly occur and have often been found beneficial for plant fitness. root-associated microbes may trigger physiological changes in the host plant that influence interactions between plants and aboveground insects at several trophic levels. aboveground, plants are under continuous attack by insect herbivores and mount multiple responses ...201324167508
[expression of cecropin p1 gene increases resistance of camelina sativa (l.) plants to microbial phytopathogenes].transgenic plants of camelina (camelina sativa (l.) crantz) with the synthetic gene of antimicrobial peptide cecropin p1 (cecp1) were obtained. agrobacterium-mediated transformation is performed using the binary vector pga482::cecp1 by vacuum infiltration of flower buds. the presence of the cecp1 gene in the genome of plants was confirmed by pcr. cecp1 gene expression in transgenic plants was shown by western blot analysis and by antimicrobial activity of plant extracts against the bacterial phy ...201324159802
quorum sensing activity of enterobacter asburiae isolated from lettuce leaves.bacterial communication or quorum sensing (qs) is achieved via sensing of qs signaling molecules consisting of oligopeptides in gram-positive bacteria and n-acyl homoserine lactones (ahl) in most gram-negative bacteria. in this study, enterobacteriaceae isolates from batavia lettuce were screened for ahl production. enterobacter asburiae, identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (maldi-tof-ms) was found to produce short chain ahls. high resolutio ...201324152877
diversity and antimicrobial properties of lactic acid bacteria isolated from rhizosphere of olive trees and desert truffles of tunisia.a total of 119 lactic acid bacteria (lab) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. using the variability of the intergenic spacer 16s-23s and 16s rrna gene sequences, the isolates were identified as the genera lactococcus, pediococcus, lactobacillus, weissella, and enterococcus. all the strains showed proteolytic activity with variable rates 42% were eps producers, while only 1 ...201324151598
extensive differences in antifungal immune response in two drosophila species revealed by comparative transcriptome analysis.the innate immune system of drosophila is activated by ingestion of microorganisms. d. melanogaster breeds on fruits fermented by saccharomyces cerevisiae, whereas d. virilis breeds on slime flux and decaying bark of tree housing a variety of bacteria, yeasts, and molds. in this study, it is shown that d. virilis has a higher resistance to oral infection of a species of filamentous fungi belonging to the genus penicillium compared to d. melanogaster. in response to the fungal infection, a transc ...201324151578
interaction of microbes with mucus and mucins: recent developments.due to the recent rapid expansion in our understanding of the composition of the gut microflora and the consequences of altering that composition the question of how bacteria colonise mucus layers and interact with components of mucus, such as mucin, is now receiving widespread attention. using a combination of mucus secreting cells, and a novel mucin microarray platform containing purified native mucins from different sources we recently demonstrated that two gastrointestinal pathogens, helicob ...201324149677
interaction of microbes with mucus and mucins: recent developments.due to the recent rapid expansion in our understanding of the composition of the gut microflora and the consequences of altering that composition the question of how bacteria colonise mucus layers and interact with components of mucus, such as mucin, is now receiving widespread attention. using a combination of mucus secreting cells, and a novel mucin microarray platform containing purified native mucins from different sources we recently demonstrated that two gastrointestinal pathogens, helicob ...201324149677
expression of an engineered heterologous antimicrobial peptide in potato alters plant development and mitigates normal abiotic and biotic responses.antimicrobial cationic peptides (amps) are ubiquitous small proteins used by living cells to defend against a wide spectrum of pathogens. their amphipathic property helps their interaction with negatively charged cellular membrane of the pathogen causing cell lysis and death. amps also modulate signaling pathway(s) and cellular processes in animal models; however, little is known of cellular processes other than the pathogen-lysis phenomenon modulated by amps in plants. an engineered heterologou ...201324147012
pandoraea sp. rb-44, a novel quorum sensing soil bacterium.proteobacteria are known to communicate via signaling molecules and this process is known as quorum sensing. the most commonly studied quorum sensing molecules are n-acylhomoserine lactones (ahls) that consists of a homoserine lactone moiety and an n-acyl side chain with various chain lengths and degrees of saturation at the c-3 position. we have isolated a bacterium, rb-44, from a site which was formally a landfill dumping ground. using matrix-assisted laser desorption ionization time-of-flight ...201324145919
bacterial secretins form constitutively open pores akin to general porins.proteins called secretins form large multimeric complexes that are essential for macromolecular transit across the outer membrane of gram-negative bacteria. evidence suggests that the channels formed by some secretin complexes are not tightly closed, but their permeability properties have not been well characterized. here, we used cell-free synthesis coupled with spontaneous insertion into liposomes to investigate the permeability of the secretin puld. leakage assays using preloaded liposomes in ...201424142256
symbiotic lactobacilli stimulate gut epithelial proliferation via nox-mediated generation of reactive oxygen species.the resident prokaryotic microbiota of the metazoan gut elicits profound effects on the growth and development of the intestine. however, the molecular mechanisms of symbiotic prokaryotic-eukaryotic cross-talk in the gut are largely unknown. it is increasingly recognized that physiologically generated reactive oxygen species (ros) function as signalling secondary messengers that influence cellular proliferation and differentiation in a variety of biological systems. here, we report that commensa ...201324141879
oligopeptide m13 phage display in pathogen research.phage display has become an established, widely used method for selection of peptides, antibodies or alternative scaffolds. the use of phage display for the selection of antigens from genomic or cdna libraries of pathogens which is an alternative to the classical way of identifying immunogenic proteins is not well-known. in recent years several new applications for oligopeptide phage display in disease related fields have been developed which has led to the identification of various new antigens ...201324136040
elicitation of induced resistance against pectobacterium carotovorum and pseudomonas syringae by specific individual compounds derived from native korean plant species.plants have developed general and specific defense mechanisms for protection against various enemies. among the general defenses, induced resistance has distinct characteristics, such as broad-spectrum resistance and long-lasting effectiveness. this study evaluated over 500 specific chemical compounds derived from native korean plant species to determine whether they triggered induced resistance against pectobacterium carotovorum supsp. carotovorum (pcc) in tobacco (nicotiana tabacum) and pseudo ...201324135942
volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.volatile organic compounds (vocs) released by soil microorganisms influence plant growth and pathogen resistance. yet, very little is known about their influence on herbivores and higher trophic levels. we studied the origin and role of a major bacterial voc, 2,3-butanediol (2,3-bd), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. one of the major contributors to 2,3-bd in the headspace of soil-grown maize seedlings was identified as enterobact ...201324127750
volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.volatile organic compounds (vocs) released by soil microorganisms influence plant growth and pathogen resistance. yet, very little is known about their influence on herbivores and higher trophic levels. we studied the origin and role of a major bacterial voc, 2,3-butanediol (2,3-bd), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. one of the major contributors to 2,3-bd in the headspace of soil-grown maize seedlings was identified as enterobact ...201324127750
characterization of the small rna transcriptome in plant-microbe (brassica/erwinia) interactions by high-throughput sequencing.non-coding, small rnas (srnas) have been identified in a wide spectrum of organisms ranging from bacteria to humans; however, the role and mechanisms of these srna in plant immunity is largely unknown. to determine possible roles of srna in plant-pathogen interaction, we carried out a high-throughput srna sequencing of brassica campestris using non-infected plants and plants infected with erwinia carotovora. consistent with our hypothesis that distinct classes of host srnas alerts their expressi ...201424126536
understanding specificity of the mycosin proteases in esx/type vii secretion by structural and functional analysis.mycobacteria use specialized esx secretion systems to transport proteins across their cell membranes in order to manipulate their environment. in pathogenic mycobacterium tuberculosis there are five paralogous esx secretion systems, named esx-1 through esx-5. each system includes a subtilisin-like protease (mycosin or mycp) as a core component essential for secretion. here we report crystal structures of mycp1 and mycp3, the mycosins expressed by the esx-1 and esx-3 systems, respectively. in bot ...201324113528
screening and characterization of extracelluar l-asparaginase producing bacillus subtilis strain hswx88, isolated from taptapani hotspring of odisha, india.to screen and isolate an eco-friendly, a thermophilic and potent l-asparaginase producing bacterium, with novel immunological properties that may obviates hypersensitivity reactions.201324093783
plant antimicrobial peptides.plant antimicrobial peptides (amps) are a component of barrier defense system of plants. they have been isolated from roots, seeds, flowers, stems, and leaves of a wide variety of species and have activities towards phytopathogens, as well as against bacteria pathogenic to humans. thus, plant amps are considered as promising antibiotic compounds with important biotechnological applications. plant amps are grouped into several families and share general features such as positive charge, the prese ...201324092498
plant antimicrobial peptides.plant antimicrobial peptides (amps) are a component of barrier defense system of plants. they have been isolated from roots, seeds, flowers, stems, and leaves of a wide variety of species and have activities towards phytopathogens, as well as against bacteria pathogenic to humans. thus, plant amps are considered as promising antibiotic compounds with important biotechnological applications. plant amps are grouped into several families and share general features such as positive charge, the prese ...201324092498
host adaptation is contingent upon the infection route taken by pathogens.evolution of pathogen virulence is affected by the route of infection. also, alternate infection routes trigger different physiological responses on hosts, impinging on host adaptation and on its interaction with pathogens. yet, how route of infection may shape adaptation to pathogens has not received much attention at the experimental level. we addressed this question through the experimental evolution of an outbred drosophila melanogaster population infected by two different routes (oral and s ...201324086131
short chain n-acyl homoserine lactone production by soil isolate burkholderia sp. strain a9.in the bacteria kingdom, quorum sensing (qs) is a cell-to-cell communication that relies on the production of and response to specific signaling molecules. in proteobacteria, n-acylhomoserine lactones (ahls) are the well-studied signaling molecules. the present study aimed to characterize the production of ahl of a bacterial strain a9 isolated from a malaysian tropical soil. strain a9 was identified as burkholderia sp. using matrix-assisted laser desorption ionization-time-of-flight mass spectro ...201324084115
bacterial mg2+ homeostasis, transport, and virulence.organisms must maintain physiological levels of mg(2+) because this divalent cation is critical for the stabilization of membranes and ribosomes, for the neutralization of nucleic acids, and as a cofactor in a variety of enzymatic reactions. in this review, we describe the mechanisms that bacteria utilize to sense the levels of mg(2+) both outside and inside the cytoplasm. we examine how bacteria achieve mg(2+) homeostasis by adjusting the expression and activity of mg(2+) transporters and by ch ...201324079267
molecular basis of active copper resistance mechanisms in gram-negative bacteria.copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. the dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. this challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. such mechanisms have been found in both eukaryotic and prokary ...201324072389
degradation of bacterial quorum sensing signaling molecules by the microscopic yeast trichosporon loubieri isolated from tropical wetland waters.proteobacteria produce n-acylhomoserine lactones as signaling molecules, which will bind to their cognate receptor and activate quorum sensing-mediated phenotypes in a population-dependent manner. although quorum sensing signaling molecules can be degraded by bacteria or fungi, there is no reported work on the degradation of such molecules by basidiomycetous yeast. by using a minimal growth medium containing n-3-oxohexanoylhomoserine lactone as the sole source of carbon, a wetland water sample f ...201324072030
the drosophila jak-stat pathway in blood cell formation and immunity.genetic alterations affecting the jak-stat signaling pathway are linked to several malignancies and hematological disorders in humans. despite being one of the most extensively studied pathways, there remain many gaps to fill. jak-stat components are widely conserved during evolution. here, we review the known roles of the jak-stat pathway in drosophila immunity: controlling the different steps of hematopoiesis, both under physiological conditions and in response to immune challenge, and contrib ...201324069567
an atypical kinase under balancing selection confers broad-spectrum disease resistance in arabidopsis.the failure of gene-for-gene resistance traits to provide durable and broad-spectrum resistance in an agricultural context has led to the search for genes underlying quantitative resistance in plants. such genes have been identified in only a few cases, all for fungal or nematode resistance, and encode diverse molecular functions. however, an understanding of the molecular mechanisms of quantitative resistance variation to other enemies and the associated evolutionary forces shaping this variati ...201324068949
quorum quenching enzymes and their application in degrading signal molecules to block quorum sensing-dependent infection.with the emergence of antibiotic-resistant strains of bacteria, the available options for treating bacterial infections have become very limited, and the search for a novel general antibacterial therapy has received much greater attention. quorum quenching can be used to control disease in a quorum sensing system by triggering the pathogenic phenotype. the interference with the quorum sensing system by the quorum quenching enzyme is a potential strategy for replacing traditional antibiotics beca ...201324065091
early and late trisporoids differentially regulate β-carotene production and gene transcript levels in the mucoralean fungi blakeslea trispora and mucor mucedo.the multistep cleavage of carotenoids in mucorales during the sexual phase results in a cocktail of trisporic acid (c18) sex pheromones. we hypothesized that the c18 trisporoid intermediates have a specific regulatory function for sex pheromone production and carotenogenesis that varies with genus/species and vegetative and sexual phases of their life cycles. real-time quantitative pcr kinetics determined for blakeslea trispora displayed a very high transcript turnover in the gene for carotenoid ...201324056470
growth of arabidopsis seedlings on high fungal doses of piriformospora indica has little effect on plant performance, stress, and defense gene expression in spite of elevated jasmonic acid and jasmonic acid-isoleucine levels in the roots.the endophytic fungus piriformospora indica colonizes the roots of many plant species including arabidopsis and promotes their performance, biomass, and seed production as well as resistance against biotic and abiotic stress. imbalances in the symbiotic interaction such as uncontrolled fungal growth result in the loss of benefits for the plants and activation of defense responses against the microbe. we exposed arabidopsis seedlings to a dense hyphal lawn of p. indica. the seedlings continue to ...201324047645
role and regulation of the flp/tad pilus in the virulence of pectobacterium atrosepticum scri1043 and pectobacterium wasabiae scc3193.in this study, we characterized a putative flp/tad pilus-encoding gene cluster, and we examined its regulation at the transcriptional level and its role in the virulence of potato pathogenic enterobacteria of the genus pectobacterium. the flp/tad pilus-encoding gene clusters in pectobacterium atrosepticum, pectobacterium wasabiae and pectobacterium aroidearum were compared to previously characterized flp/tad gene clusters, including that of the well-studied flp/tad pilus model organism aggregati ...201324040039
glucose(xylose) isomerase production by streptomyces sp. ch7 grown on agricultural residues.streptomyces sp. ch7 was found to efficiently produce glucose(xylose) isomerase when grown on either xylan or agricultural residues. this strain produced a glucose(xylose) isomerase activity of roughly 1.8 u/mg of protein when it was grown in medium containing 1% xylose as a carbon source. maximal enzymatic activities of about 5 and 3 u/mg were obtained when 1% xylan and 2.5% corn husks were used, respectively. the enzyme was purified from a mycelial extract to 16-fold purity with only two conse ...201224031932
production, purification and characterization of l-asparaginase from streptomyces gulbargensis.l-asparaginase is an anti-neoplastic agent used in the lymphoblastic leukaemia chemotherapy. in the present study a novel strain, streptomyces gulbargensis was explored for the production of extra-cellular l-asparaginase using groundnut cake extract. the optimum ph, temperature, inoculum size and agitation speed for enzyme production were ph 8.5, 40°c, 1x10(8)spores/ml and 200 rev/min respectively. maltose (0.5%) and l-asparagine (0.5%) proved to be the best carbon and nitrogen sources respectiv ...201024031478
control of colletotrichum gloeosporioides (penz.) sacc. in yellow passion fruit using cymbopogon citratus essential oil.the use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. on the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. the aim of this study was to determine the activity of 28 essential oils fro ...201024031465
molecular analysis of endophytic bacteria from the genus bacillus isolated from tropical maize (zea mays l.).endophytic bacteria play an important role in agriculture by improving plant performance and adaptation against biotic and abiotic stresses. in the present study molecular methods were used for identifying bacillus endophytic bacteria isolated from brazilian sweet corn. sds-page of whole-cell protein extract of forty-two isolates revealed a high number of scrutinable bands. twenty-four isolates were identified in nine different groups of duplicated bacteria and eighteen were identified as unique ...200924031395
genetic diversity of siderophore-producing bacteria of tobacco rhizosphere.the genetic diversity of siderophore-producing bacteria of tobacco rhizosphere was studied by amplified ribosomal dna restriction analysis (ardra), 16s rrna sequence homology and phylogenetics analysis methods. studies demonstrated that 85% of the total 354 isolates produced siderophores in iron limited liquid medium. a total of 28 ardra patterns were identified among the 299 siderophore-producing bacterial isolates. the 28 ardra patterns represented bacteria of 14 different genera belonging to ...200924031358
paraoxonases as protective agents against n-acyl homoserine lactone - producing pathogenic microorganisms.paraoxonases are a group of enzymes with a high "substrate-promiscuity", being able to act on many structurally different compounds. to date, there is no consensus regarding the physiological substrate(s) of these enzymes. recent data suggest that the n-acyl homoserine lactones (ahls) produced by different gram-negative bacteria, including the opportunistic pseudomonas aeruginosa, could be such substrates. due to the ability of paraoxonases to hydrolyze ahls, they represent an alternative mechan ...201324023599
suberin-associated fatty alcohols in arabidopsis: distributions in roots and contributions to seed coat barrier properties.suberin is found in a variety of tissues, such as root endoderms and periderms, storage tuber periderms, tree cork layer, and seed coats. it acts as a hydrophobic barrier to control the movement of water, gases, and solutes as well as an antimicrobial barrier. suberin consists of polymerized phenolics, glycerol, and a variety of fatty acid derivatives, including primary fatty alcohols. we have conducted an in-depth analysis of the distribution of the c18:0 to c22:0 fatty alcohols in arabidopsis ...201324019425
populations of fungi and bacteria associated with samples of stored rice in korea.stored rice was collected from rice processing complexes of national agricultural cooperative federation of 11 regions in korea to evaluate the occurrence of fungi and bacteria and to identify the predominant fungi and bacteria to the genus levels. most rice samples generally produced the higher levels of fungi and bacteria than white rice. the occurrence of fungi and bacteria varied in various locations of korea. among fungi observed, aspergillus spp. and penicillium spp. were dominant in the s ...200724015066
d-alanine modification of a protease-susceptible outer membrane component by the bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing.bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. despite very high vaccine coverage, pertussis has reemerged as a serious threat in the united states and many developing countries. thus, it is important to pursue research to discover unknown pathogenic mechanisms of b. pertussis. we have investigated a previously uncharacterized locus in b. pertussis, the dra locus, which is homologous to the dlt operons of gram-positive bacter ...201324013634
alternating electric fields combined with activated carbon for disinfection of gram negative and gram positive bacteria in fluidized bed electrode system.strong electric fields for disinfection of wastewaters have been employed already for several decades. an innovative approach combining low strength (7 v/cm) alternating electric fields with a granular activated carbon fluidized bed electrode (fbe) for disinfection was presented recently. for disinfection performance of fbe several pure microbial cultures were tested: bacillus subtilis, bacillus subtilis subsp. subtilis, enterococcus faecalis as representatives from gram positive bacteria and er ...201324012021
essential oil prepared from cymbopogon citrates exerted an antimicrobial activity against plant pathogenic and medical microorganisms.essential oils are mixtures of volatile, lipophilic compounds originating from plants. some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. in this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, cymbopogon citrates, against three important plant pathogenic and medical microorganisms, pectobacterium carotovorum, colletotrichum gloeosporioides, and aspergillus nig ...200923983507
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