| a tale of two sugars: trehalose 6-phosphate and sucrose. | trehalose 6-phosphate (tre6p), the intermediate of trehalose biosynthesis, is an essential signal metabolite in plants, linking growth and development to carbon status. the suc-tre6p nexus model postulates that tre6p is both a signal and negative feedback regulator of suc levels, forming part of a mechanism to maintain suc levels within an optimal range and functionally comparable to the insulin-glucagon system for regulating blood glc levels in animals. the target range and sensitivity of the t ... | 2016 | 27482078 |
| overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (hlb). | huanglongbing (hlb or citrus greening disease) caused by candidatus liberibacter asiaticus (las) is a great threat to the us citrus industry. there are no proven strategies to eliminate hlb disease and no cultivar has been identified with strong hlb resistance. citrus canker is also an economically important disease associated with a bacterial pathogen (xanthomonas citri). in this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. si ... | 2016 | 27499757 |
| comparison of droplet digital pcr and quantitative pcr assays for quantitative detection of xanthomonas citri subsp. citri. | droplet digital polymerase chain reaction (ddpcr) is a novel molecular biology technique providing absolute quantification of target nucleic acids without the need for an external calibrator. despite its emerging applications in medical diagnosis, there are few reports of its use for the detection of plant pathogens. this work was designed to assess the diagnosis potential of the ddpcr for absolute quantitative detection of xanthomonas citri subsp. citri, a quarantine plant pathogenic bacterium ... | 2016 | 27427975 |
| use of an improved matching algorithm to select scaffolds for enzyme design based on a complex active site model. | active site preorganization helps native enzymes electrostatically stabilize the transition state better than the ground state for their primary substrates and achieve significant rate enhancement. in this report, we hypothesize that a complex active site model for active site preorganization modeling should help to create preorganized active site design and afford higher starting activities towards target reactions. our matching algorithm prodamatch was improved by invoking effective pruning st ... | 2016 | 27243223 |
| genetic and molecular basis of kingella kingae encapsulation. | kingella kingae is a common cause of invasive disease in young children and was recently found to produce a polysaccharide capsule containing n-acetylgalactosamine (galnac) and β-3-deoxy-d-manno-octulosonic acid (βkdo). given the role of capsules as important virulence factors and effective vaccine antigens, we set out to determine the genetic determinants of k. kingae encapsulation. using a transposon library and a screen for nonencapsulated mutants, we identified the previously identified ctra ... | 2016 | 27045037 |
| correction: identification of an extracellular endoglucanase that is required for full virulence in xanthomonas citri subsp. citri. | [this corrects the article doi: 10.1371/journal.pone.0151017.]. | 2016 | 27214201 |
| a survey of fls2 genes from multiple citrus species identifies candidates for enhancing disease resistance to xanthomonas citri ssp. citri. | pathogen-associated molecular patterns (pamps)-triggered immunity (pti) is an important component of plant innate immunity. in a previous study, we showed that the pamp flg22 from xanthomonas citri ssp. citri (xflg22), the causal agent of citrus canker, induced pti in citrus, which correlated with the observed levels of canker resistance. here, we identified and sequenced two bacterial flagellin/flg22 receptors (fls2-1 and fls2-2) from 'duncan' grapefruit (citrus paradisi, cpfls2-1 and cpfls2-2) ... | 2016 | 27222722 |
| development of a microemulsion formulation for antimicrobial seca inhibitors. | in our previous study, we have identified five antimicrobial small molecules via structure based design, which inhibit seca of candidatus liberibacter asiaticus (las). seca is a critical protein translocase atpase subunit and is involved in pre-protein translocation across and integration into the cellular membrane in bacteria. in this study, eleven compounds were identified using similarity search method based on the five lead seca inhibitors identified previously. the identified seca inhibitor ... | 2016 | 26963811 |
| a protein expression system for tandem affinity purification in xanthomonas citri subsp. citri. | citrus canker, caused by the gram-negative bacterium xanthomonas citri subsp. citri (xac), is one of the most devastating diseases to affect citrus crops. there is no treatment for citrus canker; effective control against the spread of xac is usually achieved by the elimination of affected plants along with that of asymptomatic neighbors. an in depth understanding of the pathogen is the keystone for understanding of the disease; to this effect we are committed to the development of strategies to ... | 2016 | 26991273 |
| bioactive organocopper compound from pseudomonas aeruginosa inhibits the growth of xanthomonas citri subsp. citri. | citrus canker is a very destructive disease of citrus species. the challenge is to find new compounds that show strong antibiotic activity and low toxicity to plants and the environment. the objectives of the present study were (1) to extract, purify and evaluate the secondary metabolites with antibiotic activity produced by pseudomonas aeruginosa lv strain in vitro against xanthomonas citri subsp. citri (strain 306), (2) to determine the potential of semi-purified secondary metabolites in folia ... | 2016 | 26903992 |
| possible role of plant volatiles in tolerance against huanglongbing in citrus. | volatile organic compounds (voc) play an important role in protecting plants from insect and pathogen attack. in this study, we investigated the leaf volatile profiles of 14 citrus varieties. the voc in citrus leaves were extracted with n-hexane and analyzed using gas chromatography-mass spectrometry (gc-ms). overall, 4six volatile compounds were identified in the n-hexane extract from citrus leaves. most of the detected compounds belonged to 3 main groups (monoterpenes, sesquiterpenes, and alip ... | 2016 | 26829496 |
| citrus breeding, genetics and genomics in japan. | citrus is one of the most cultivated fruits in the world, and satsuma mandarin (citrus unshiu marc.) is a major cultivated citrus in japan. many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. the citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (mas) will overcome the obstacle and improve the efficiency of conventional breed ... | 2016 | 27069387 |
| crystal structure of the fad-containing ferredoxin-nadp+ reductase from the plant pathogen xanthomonas axonopodis pv. citri. | we have solved the structure of ferredoxin-nadp(h) reductase, fpr, from the plant pathogen xanthomonas axonopodis pv. citri, responsible for citrus canker, at a resolution of 1.5 å. this structure reveals differences in the mobility of specific loops when compared to other fprs, probably unrelated to the hydride transfer process, which contributes to explaining the structural and functional divergence between the subclass i fprs. interactions of the c-terminus of the enzyme with the phosphoadeno ... | 2013 | 23984418 |
| the signal peptide-like segment of hpaxm is required for its association to the cell wall in transgenic tobacco plants. | harpins, encoded by hrp (hypersensitive response and pathogenicity) genes of gram-negative plant pathogens, are elicitors of hypersensitive response (hr). hpaxm is a novel harpin-like protein described from cotton leaf blight bacteria, xanthomonas citri subsp. malvacearum-a synonym of x. campestris pv. malvacearum (smith 1901-1978). a putative signal peptide (1-mnslntqiganssfl-15) of hpaxm was predicted in the nitroxyl-terminal (n-terminal)by signalp (signalp 3.0 server). here, we explored the f ... | 2017 | 28141855 |
| antibacterial activity of cyclo(l-pro-l-tyr) and cyclo(d-pro-l-tyr) from streptomyces sp. strain 22-4 against phytopathogenic bacteria. | two bioactive cyclic dipeptides, cyclo(l-pro-l-tyr) and cyclo(d-pro-l-tyr), were isolated from the culture broth of streptomyces sp. strain 22-4 and tested against three economically important plant pathogens, xanthomonas axonopodis pv. citri, ralstonia solanacearum and clavibacter michiganensis. both cyclic dipeptides were active against x. axonopodis pv. citri and r. solanacearum with mic of 31.25 μg/ml. no activity could be observed against c. michiganensis. | 2016 | 26469746 |
| mechanistic and evolutionary insights from comparative enzymology of phosphomonoesterases and phosphodiesterases across the alkaline phosphatase superfamily. | naively one might have expected an early division between phosphate monoesterases and diesterases of the alkaline phosphatase (ap) superfamily. on the contrary, prior results and our structural and biochemical analyses of phosphate monoesterase pafa, from chryseobacterium meningosepticum, indicate similarities to a superfamily phosphate diesterase [xanthomonas citri nucleotide pyrophosphatase/phosphodiesterase (npp)] and distinct differences from the three metal ion ap superfamily monoesterase, ... | 2016 | 27670607 |
| pseudomonas protegens cs1 from the lemon phyllosphere as a candidate for citrus canker biocontrol agent. | citrus canker is a worldwide-distributed disease caused by xanthomonas citri subsp. citri. one of the most used strategies to control the disease is centred on copper-based compounds that cause environmental problems. therefore, it is of interest to develop new strategies to manage the disease. previously, we reported the ability of the siderophore pyochelin, produced by the opportunistic human pathogen pseudomonas aeruginosa, to inhibit in vitro several bacterial species, including x. citri sub ... | 2017 | 28194866 |
| characterization of three linalool synthase genes from citrus unshiu marc. and analysis of linalool-mediated resistance against xanthomonas citri subsp. citri and penicilium italicum in citrus leaves and fruits. | three cdna clones from satsuma mandarin (citrus unshiu marc.) were isolated and expressed in escherichia coli. custs3-1 and custs3-2 encode linalool synthases and custs4 encodes a nerolidol/linalool synthase. transcripts of custs3-1, custs3-2 and custs4 were abundant in young fruit at 60 days after flowering (daf), flowers and leaves, respectively. treatments with xanthomonas citri subsp. citri (xcc), the causal agent of citrus canker and penicillium italicum (pi), the cause of post-harvest frui ... | 2014 | 25443842 |
| characterisation of a novel endo-xyloglucanase (xcxgha) from xanthomonas that accommodates a xylosyl-substituted glucose at subsite -1. | a xyloglucan-specific endo-1,4β-glucanase (xcxgha) from xanthomonas citri pv. mangiferaeindicae has been cloned, expressed in escherichia coli, purified and characterised. the xcxgha enzyme belongs to cazy family gh74 and has catalytic site residues conserved with other xyloglucanases in this family. at its optimal reaction conditions, ph 7.0 and 40 °c, the enzyme has a k cat/k m value of 2.2 × 10(7) min(-1) m(-1) on a tamarind seed xyloglucan substrate. xcxgha is relatively stable within a broa ... | 2014 | 24898632 |
| phosphate regulated proteins of xanthomonas citri subsp. citri: a proteomic approach. | xanthomonas citri subsp. citri (x. citri) is the causative agent of the citrus canker, a disease that affects several citrus plants in brazil and across the world. although many studies have demonstrated the importance of genes for infection and pathogenesis in this bacterium, there are no data related to phosphate uptake and assimilation pathways. to identify the proteins that are involved in the phosphate response, we performed a proteomic analysis of x. citri extracts after growth in three cu ... | 2014 | 24846853 |
| chimeric proteins combining phosphatase and cellulose-binding activities: proof-of-concept and application in the hydrolysis of paraoxon. | phosphatases for organophosphate degradation and carbohydrate-binding domains (cbms) have potential biotechnological applications. as a proof-of-concept, a soluble chimeric protein that combines acid phosphatase (appa) from escherichia coli and a cbm from xanthomonas axonopodis pv. citri (appa-cbm) was produced in e.coli. appacbm adsorbed in microcrystalline cellulose avicel ph101 catalyzed the hydrolysis of p-nitrophenyl phosphate (pnpp). the binding to microcrystalline cellulose displayed satu ... | 2014 | 24555432 |
| xbmr, a new transcription factor involved in the regulation of chemotaxis, biofilm formation and virulence in xanthomonas citri subsp. citri. | xanthomonas citri subsp. citri (xcc) is the causal agent of citrus canker. biofilm formation on citrus leaves plays an important role in epiphytic survival of xcc. biofilm formation is affected by transposon insertion in xac3733, which encodes a transcriptional activator of the ntrc family, not linked to a gene encoding a sensor protein, thus could be considered as an 'orphan' regulator whose function is poorly understood in xanthomonas spp. here we show that mutation of xac3733 (named xbmr) res ... | 2015 | 25346091 |
| xanthomonas citri subsp. citri type iv pilus is required for twitching motility, biofilm development, and adherence. | bacterial type iv pili (t4p) are long, flexible surface filaments that consist of helical polymers of mostly pilin subunits. cycles of polymerization, attachment, and depolymerization mediate several pilus-dependent bacterial behaviors, including twitching motility, surface adhesion, pathogenicity, natural transformation, escape from immune system defense mechanisms, and biofilm formation. the xanthomonas citri subsp. citri strain 306 genome codes for a large set of genes involved in t4p biogene ... | 2014 | 25180689 |
| a csra/rsma translational regulator gene encoded in the replication region of a sinorhizobium meliloti cryptic plasmid complements pseudomonas fluorescens rsma/e mutants. | members of the csra/rsma family are global regulatory proteins that bind to mrnas, usually at the ribosome-binding site, to control mrna translation and stability. their activity is counteracted by small non-coding rnas (srnas), which offer several binding sites to compete with mrna binding. the csra/rsma genes are widespread in prokaryotic chromosomes, although certain phylogenetic groups such as alphaproteobacteria lack this type of global regulator. interestingly, a csra/rsma-like sequence wa ... | 2013 | 23175505 |
| the arabidopsis elongator complex is required for nonhost resistance against the bacterial pathogens xanthomonas citri subsp. citri and pseudomonas syringae pv. phaseolicola nps3121. | although in recent years nonhost resistance has attracted considerable attention for its broad spectrum and durability, the genetic and mechanistic components of nonhost resistance have not been fully understood. we used molecular and histochemical approaches including quantitative pcr, chromatin immunoprecipitation, and 3,3'-diaminobenzidine and aniline blue staining. the evolutionarily conserved histone acetyltransferase complex elongator was identified as a major component of nonhost resistan ... | 2017 | 28134437 |
| synthesis and antibacterial evaluation of new sulfone derivatives containing 2-aroxymethyl-1,3,4-oxadiazole/thiadiazole moiety. | sulfones are one of the most important classes of agricultural fungicides. to discover new lead compounds with high antibacterial activity, a series of new sulfone derivatives were designed and synthesized by introducing the aroxymethyl moiety into the scaffold of 1,3,4-oxadiazole/thiadiazole sulfones. antibacterial activities against three phytopathogens (xanthomonas oryzae pv. oryzae, ralstonia solanacearum, xanthomonas axonopodis pv. citri.) were assayed in vitro. as compared to the control o ... | 2016 | 28042864 |
| synthesis and antibacterial activity of pyridinium-tailored aromatic amphiphiles. | in this letter, the antibacterial activities of pyridinium-tailored aromatic amphiphiles were evaluated by turbidimeter tests in vitro. the bioassays revealed that most of the target compounds exhibit appreciable inhibition activities against the plant pathogenic bacteria xanthomonas oryzae pv. oryzae, ralstonia solanacearum, and xanthomonas axonopodis pv. citri. the half-maximal effective concentrations (ec50) of 2-np-10, 9-ap-10, and 9-ap-7 against these three bacteria were relatively high, wh ... | 2016 | 26832217 |
| synthesis and antibacterial activity of pyridinium-tailored 2,5-substituted-1,3,4-oxadiazole thioether/sulfoxide/sulfone derivatives. | by introducing the pyridinium group into 2,5-substituted-1,3,4-oxadiazole, a series of pyridinium-tailored 2,5-substituted-1,3,4-oxadiazole thioether/sulfoxide/sulfone derivatives were obtained, and their antibacterial activities were evaluated via turbidimeter test in vitro. the bioassays reveal that most of the target compounds exhibit better inhibition activities against pathogen xanthomonas oryzae pv. oryzae, ralstonia solanacearum, and xanthomonas axonopodis pv. citri than positive controls ... | 2016 | 26810264 |
| nanofilms of hyaluronan/chitosan assembled layer-by-layer: an antibacterial surface for xylella fastidiosa. | in this work, nanofilms of hyaluronan/chitosan (ha/chi) assembled layer by layer were synthesized; their application as a potential antimicrobial material was demonstrated for the phytopathogen xylella fastidiosa, a gram-negative bacterium, here used as a model. for the synthesis, the influence of ph and ionic strength of these natural polymer stem-solutions on final characteristics of the ha/chi nanofilms was studied in detail. the antibacterial effect was evaluated using widefield fluorescence ... | 2016 | 26572322 |
| analysis of three xanthomonas axonopodis pv. citri effector proteins in pathogenicity and their interactions with host plant proteins. | xanthomonas axonopodis pv. citri, the bacterium responsible for citrus canker, uses effector proteins secreted by a type iii protein secretion system to colonize its hosts. among the putative effector proteins identified for this bacterium, we focused on the analysis of the roles of avrxace1, avrxace2 and xac3090 in pathogenicity and their interactions with host plant proteins. bacterial deletion mutants in avrxace1, avrxace2 and xac3090 were constructed and evaluated in pathogenicity assays. th ... | 2012 | 22435635 |
| inducible expression of bs2 r gene from capsicum chacoense in sweet orange (citrus sinensis l. osbeck) confers enhanced resistance to citrus canker disease. | transgenic expression of the pepper bs2 gene confers resistance to xanthomonas campestris pv. vesicatoria (xcv) pathogenic strains which contain the avrbs2 avirulence gene in susceptible pepper and tomato varieties. the avrbs2 gene is highly conserved among members of the xanthomonas genus, and the avrbs2 of xcv shares 96% homology with the avrbs2 of xanthomonas citri subsp. citri (xcc), the causal agent of citrus canker disease. a previous study showed that the transient expression of pepper bs ... | 2017 | 28155188 |
| complete nucleotide sequence of a new filamentous phage, xf109, which integrates its genome into the chromosomal dna of xanthomonas oryzae. | unlike ff-like coliphages, certain filamentous inoviridae phages integrate their genomes into the host chromosome and enter a prophage state in their infectious cycle. this lysogenic life cycle was first reported for xanthomonas citri cf phage. however, except for the x. citri phages cf and xacf1, complete genome sequence information about lysogenic xanthomonas phages is not available to date. a proviral sequence of xf109 phage was identified in the genome of xanthomonas oryzae, the rice bacteri ... | 2017 | 27743252 |
| lactose consuming strains of xanthomonas citri subsp. citri (xcc) insight into the emergence of natural field resources for xanthan gum production. | xanthomonas genus possesses a low level of β-galactosidase gene expression and is therefore unable to produce xanthan gum in lactose-based media. in this study, we report the emergence of some natural field strains of xanthomonas citri subsp. citri (xcc) capable to use lactose as a sole carbon source to produce xanthan gum. from 210 xcc strains isolated from key lime (c. aurantifolia), 27 showed the capacity to grow on lactose containing medium. xcc lactose consuming strains demonstrated a good ... | 2014 | 24318518 |
| characterization of citrus sinensis transcription factors closely associated with the non-host response to xanthomonas campestris pv. vesicatoria. | plants, when exposed to certain pathogens, may display a form of genotype-independent resistance, known as non-host response. in this study, the response of citrus sinensis (sweet orange) leaves to xanthomonas campestris pv. vesicatoria (xcv), a pepper and tomato pathogenic bacterium, was analyzed through biochemical assays and cdna microarray hybridization and compared with asiatic citrus canker infection caused by xanthomonas citri subsp. citri. citrus leaves exposed to the non-host bacterium ... | 2013 | 23453188 |
| improved thermostability of aeh by combining b-fit analysis and structure-guided consensus method. | α-amino ester hydrolases (aeh, e.c. 3.1.1.43) catalyze the synthesis and hydrolysis of α-amino β-lactam antibiotics. the aeh enzymes have been shown to feature excellent synthetic capability but suffer from poor thermostability. aeh from xanthomonas campestris exhibits an optimal activity temperature of 25 °c, an observed half-life of 5 min at 30 °c, and a "t-50" value, the temperature at which the half-life is 30 min, of 27 °c. to improve the thermostability of aeh, a modified structure-guided ... | 2012 | 22426092 |
| engineering canker-resistant plants through crispr/cas9-targeted editing of the susceptibility gene cslob1 promoter in citrus. | citrus canker, caused by xanthomonas citri subsp. citri (xcc), is severely damaging to the global citrus industry. targeted editing of host disease-susceptibility genes represents an interesting and potentially durable alternative in plant breeding for resistance. here, we report improvement of citrus canker resistance through crispr/cas9-targeted modification of the susceptibility gene cslob1 promoter in citrus. wanjincheng orange (citrus sinensis osbeck) harbors at least three copies of the cs ... | 2017 | 28371200 |
| protein depletion using the arabinose promoter in xanthomonas citri subsp. citri. | xanthomonas citri subsp. citri (x. citri) is a plant pathogen and the etiological agent of citrus canker, a severe disease that affects all the commercially important citrus varieties, and has worldwide distribution. citrus canker cannot be healed, and the best method known to control the spread of x. citri in the orchards is the eradication of symptomatic and asymptomatic plants in the field. however, in the state of são paulo, brazil, the main orange producing area in the world, control is evo ... | 2017 | 28343961 |
| complete genome sequences of six copper-resistant xanthomonas citri pv. citri strains causing asiatic citrus canker, obtained using long-read technology. | the gammaproteobacterium xanthomonas citri pv. citri causes asiatic citrus canker. pathotype a strains have a broad host range, which includes most commercial citrus species, and they cause important economic losses worldwide. control often relies on frequent copper sprays. we present here the complete genomes of six x. citri pv. citri copper-resistant strains. | 2017 | 28336584 |
| ecological and evolutionary insights into pathovar diversity of xanthomonas citri. | citrus canker, caused by xanthomonas citri pv. citri (xct), is a serious disease of citrus plants worldwide. earlier phylogenetic studies using housekeeping genes revealed that xct is related to many other pathovars, which can be collectively referred as xanthomonas citri pathovars (xcps). in the present study, we report the genome sequence of eighteen xcps compared with four xcps available in the public domain. in a tree based on phylogenomic marker genes, all the xcps form a monophyletic clust ... | 2017 | 28258140 |
| xanthomonas citri pv. citri pathotypes: lps structure and function as microbe-associated molecular patterns. | xanthomonas citri pv. citri is the pathogen responsible for asiatic citrus canker, one of the most serious citrus diseases worldwide. the lipopolysaccharide (lps) molecule has been demonstrated to be involved in x. citri pv. citri virulence. despite enormous progress in investigations of the molecular mechanisms for bacterial pathogenicity, determination of the detailed lps structure-activity relationship is limited, as the current knowledge is mainly based on structural determination of one x. ... | 2017 | 28186388 |
| selection of small synthetic antimicrobial peptides inhibiting xanthomonas citri subsp. citri causing citrus canker. | citrus canker disease decreases the fruit quality and yield significantly, furthermore, emerging of streptomycin-resistant pathogens threatens the citrus industry seriously because of a lack of proper control agents. small synthetic antimicrobial peptides (amps) could be a promising alternative. fourteen hexapeptides were selected by using positional scanning of synthetic peptide combinatorial libraries. each hexapeptide showed different antimicrobial spectrum against bacillus, pseudomonas, xant ... | 2017 | 28167892 |
| ectopic accumulation of linalool confers resistance to xanthomonas citri subsp. citri in transgenic sweet orange plants. | in order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by xanthomonas citri subsp. citri (xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'hamlin' sweet orange (citrus sinensis l. osbeck) plants over-expressing a linalool synthase gene (custs3-1) were generated. transgenic lines (lil) with the highest linalool content showed strong resistance to citru ... | 2017 | 28131994 |
| adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements. | copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. pathogens have adapted in response to this selective pressure. xanthomonas citri pv. citri, a major citrus pathogen causing asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in argentina. this phenotype was conferred by the coplab gene system. the emergence of resistant strains has since been reported in réunion and martinique. using microsatellite-based genotyping and co ... | 2017 | 28101896 |
| genome editing of the disease susceptibility gene cslob1 in citrus confers resistance to citrus canker. | citrus is a highly valued tree crop worldwide, while, at the same time, citrus production faces many biotic challenges, including bacterial canker and huanglongbing (hlb). breeding for disease-resistant varieties is the most efficient and sustainable approach to control plant diseases. traditional breeding of citrus varieties is challenging due to multiple limitations, including polyploidy, polyembryony, extended juvenility and long crossing cycles. targeted genome editing technology has the pot ... | 2016 | 27936512 |
| comparative proteomic analysis of xanthomonas citri ssp. citri periplasmic proteins reveals changes in cellular envelope metabolism during in vitro pathogenicity induction. | citrus canker is a plant disease caused by gram-negative bacteria from the genus xanthomonas. the most virulent species is xanthomonas citri ssp. citri (xac), which attacks a wide range of citrus hosts. differential proteomic analysis of the periplasm-enriched fraction was performed for xac cells grown in pathogenicity-inducing (xam-m) and pathogenicity-non-inducing (nutrient broth) media using two-dimensional electrophoresis combined with liquid chromatography-tandem mass spectrometry. amongst ... | 2016 | 27798950 |
| structural and functional characterization of the phosphoglucomutase from xanthomonas citri subsp. citri. | citrus canker, caused by bacteria xanthomonas citri subsp. citri, can affect all economically important varieties of citrus. studying xanthomonas genes related to the invasive capacity may improve the knowledge on how this works and ultimately use the information to avoid the disease. some annotated genes from xanthomonas citri subsp. citri published genome are addressed to an interesting class of genes named "pathogenicity, virulence and adaptation". one of them is xana, which encodes a predict ... | 2016 | 27567706 |
| differential expression of pectolytic enzyme genes in xanthomonas citri subsp. citri and demonstration that pectate lyase pel3 is required for the formation of citrus canker. | bacterial canker, caused by xanthomonas citri subsp. citri (xcc), is one of the most destructive diseases of citrus. the pectolytic enzymes produced by phytobacteria are important virulence factors involved in tissue maceration, electrolyte loss and cell death of host plants. in this study, the promoter activity of the pectolytic enzyme genes pel1, pel2, pel3, pgla, and peh-1 were investigated in xcc xw19 strain using the β-glucuronidase (gus) gene as a reporter. gus activity expressed under the ... | 2016 | 27664718 |
| deletion of pila, a minor pilin-like gene, from xanthomonas citri subsp. citri influences bacterial physiology and pathogenesis. | type iv pili (tfp) are widely distributed adhesins of bacterial surfaces. in plant pathogenic bacteria, tfp are involved in host colonization and pathogenesis. xanthomonas citri subsp. citri (xcc) is the phytopathogen responsible for citrus canker disease. in this work, three tfp structural genes, fima, fima1, and pila from xcc were studied. a pila mutant strain from xcc (xccδpila) was constructed and differences in physiological features, such as motilities, adhesion, and biofilm formation, wer ... | 2016 | 27664015 |
| resistance to citrus canker induced by a variant of xanthomonas citri ssp. citri is associated with a hypersensitive cell death response involving autophagy-associated vacuolar processes. | xanthomonas citri ssp. citri (x. citri) is the causal agent of asiatic citrus canker, a disease that seriously affects most commercially important citrus species worldwide. we have identified previously a natural variant, x. citri a(t) , that triggers a host-specific defence response in citrus limon. however, the mechanisms involved in this canker disease resistance are unknown. in this work, the defence response induced by x. citri a(t) was assessed by transcriptomic, physiological and ultrastr ... | 2016 | 27647752 |
| virb7 and virb9 interactions are required for the assembly and antibacterial activity of a type iv secretion system. | the type iv secretion system (t4ss) from the phytopathogen xanthomonas citri (xac) is a bactericidal nanomachine. the t4ss core complex is a ring composed of multiple copies of virb7-virb9-virb10 subunits. xac-virb7 contains a disordered n-terminal tail (virb7(nt)) that recognizes virb9, and a c-terminal domain (virb7(ct)) involved in virb7 self-association. here, we show that virb7(nt) forms a short β strand upon binding to virb9 and stabilizes it. a tight interaction between them is essential ... | 2016 | 27594685 |
| rapid and accurate identification of xanthomonas citri subspecies citri by fluorescence in situ hybridization. | citrus canker is an economically important disease caused by the bacterial pathogen xanthomonas citri subsp. citri (xcc). this organism targets a wide range of citrus plants, including sweet orange, grapefruit, lemon and lime. as xcc is spread by environmental factors such as wind and rain, it is difficult to control its movement once the disease has established. in order to facilitate monitoring of citrus canker we sought to design a novel diagnostic protocol based on fluorescence in situ hybri ... | 2016 | 27492577 |
| an engineered promoter driving expression of a microbial avirulence gene confers recognition of tal effectors and reduces growth of diverse xanthomonas strains in citrus. | xanthomonas citri ssp. citri (x. citri), causal agent of citrus canker, uses transcription activator-like effectors (tales) as major pathogenicity factors. tales, which are delivered into plant cells through the type iii secretion system (t3ss), interact with effector binding elements (ebes) in host genomes to activate the expression of downstream susceptibility genes to promote disease. predictably, tales bind ebes in host promoters via known combinations of tale amino acids to dna bases, known ... | 2016 | 27362693 |
| gherf-iib3 regulates the accumulation of jasmonate and leads to enhanced cotton resistance to blight disease. | the phytohormone jasmonic acid (ja) and its derivatives, collectively referred to as jasmonates, regulate many developmental processes, but are also involved in the response to numerous abiotic/biotic stresses. thus far, powerful reverse genetic strategies employing perception, signalling or biosynthesis mutants have broadly contributed to our understanding of the role of ja in the plant stress response and development, as has the chemical gain-of-function approach based on exogenous application ... | 2016 | 27291786 |
| deuterium-labeled precursor feeding reveals a new paba-containing meroterpenoid from the mango pathogen xanthomonas citri pv. mangiferaeindicae. | a new para-aminobenzoic-acid-containing natural product from the mango pathogenic organism xanthomonas citri pv. mangiferaeindicae is described. by means of stable isotope precursor feeding combined with nontargeted lc-ms/ms, the generated spectra were clustered and visualized in a molecular network. this led to the identification of a new member of the meroterpenoids, termed xanthomonic acid, which is composed of an isoprenylated para-aminobenzoic acid. in vitro cytotoxicity assays demonstrated ... | 2016 | 27232656 |
| xanthomonas citri ssp. citri requires the outer membrane porin oprb for maximal virulence and biofilm formation. | xanthomonas citri ssp. citri (xcc) causes canker disease in citrus, and biofilm formation is critical for the disease cycle. oprb (outer membrane protein b) has been shown previously to be more abundant in xcc biofilms compared with the planktonic state. in this work, we showed that the loss of oprb in an oprb mutant abolishes bacterial biofilm formation and adherence to the host, and also compromises virulence and efficient epiphytic survival of the bacteria. moreover, the oprb mutant is impair ... | 2016 | 27226289 |
| xanthomonas citri subsp. citri surface proteome by 2d-dige: ferric enterobactin receptor and other outer membrane proteins potentially involved in citric host interaction. | xanthomonas citri subsp. citri (xac) is the causative agent of citrus canker, a disease of great economic impact around the world. understanding the role of proteins on xac cellular surface can provide new insights on pathogen-plant interaction. surface proteome was performed in xac grown in vivo (infectious) and in vitro (non-infectious) conditions, by labeling intact cells followed by cellular lysis and direct 2d-dige analysis. seventy-nine differential spots were analyzed by mass spectrometry ... | 2017 | 27180281 |
| mapping and validation of xanthomonas citri subsp citri genes regulated by putative plant-inducible promoter box (pip-box). | citrus canker, caused by the gram-negative bacterium xanthomonas citri subsp citri (xac), is a major disease affecting citriculture worldwide, because of the susceptibility of the host and the lack of efficient control methods. previous studies have reported that some genes of phytopathogenic bacteria possess a consensus nucleotide sequence (ttcgc...n15...ttcgc) designated the "plant-inducible-promoter box" (pip box) located in the promoter region, which is responsible for activating the express ... | 2016 | 27173329 |
| modification of the ptha4 effector binding elements in type i cslob1 promoter using cas9/sgrna to produce transgenic duncan grapefruit alleviating xccδptha4:dcslob1.3 infection. | citrus canker caused by xanthomonas citri subspecies citri (xcc) is a severe disease for most commercial citrus cultivars and responsible for significant economic losses worldwide. generating canker-resistant citrus varieties will provide an efficient and sustainable solution to control citrus canker. here, we report our progress in generating canker-resistant grapefruit by modifying the ptha4 effector binding elements (ebes) in the cslob1 promoter (ebeptha4 -cslobp) of the cslob1 (citrus sinens ... | 2016 | 27071672 |
| deciphering the regulon of a gntr family regulator via transcriptome and chip-exo analyses and its contribution to virulence in xanthomonas citri. | xanthomonas contains a large group of plant-associated species, many of which cause severe diseases on important crops worldwide. six gluconate-operon repressor (gntr) family transcriptional regulators are predicted in xanthomonas, one of which, belonging to the ytra subfamily, plays a prominent role in bacterial virulence. however, the direct targets and comprehensive regulatory profile of ytra remain unknown. here, we performed microarray and high-resolution chromatin immunoprecipitation-exonu ... | 2017 | 26972728 |
| bismerthiazol inhibits xanthomonas citri subsp. citri growth and induces differential expression of citrus defense-related genes. | citrus canker, caused by xanthomonas citri ssp. citri, is a serious disease that causes substantial economic losses to the citrus industry worldwide. the bactericide bismerthiazol has been used to control rice bacterial blight (x. oryzae pv. oryzae). in this paper, we demonstrate that bismerthiazol can effectively control citrus canker by both inhibiting the growth of x. citri ssp. citri and triggering the plant's host defense response through the expression of several pathogenesis-related genes ... | 2016 | 26882850 |
| temporal transcription profiling of sweet orange in response to ptha4-mediated xanthomonas citri subsp. citri infection. | citrus canker, caused by xanthomonas citri subsp. citri, is a devastating disease of most commercial citrus varieties. in our previous study, we analyzed the transcriptional response of 'valencia' sweet orange to x. citri subsp. citri wild-type and ptha4 mutant infection at 48 h postinoculation (hpi). using microarray analysis, two ptha4 targets, cslob1 and cssweet1, were identified. we have shown that ptha4 binds to the effector binding element (ebe) of cslob1 and activates gene expression of t ... | 2016 | 26780431 |
| xacfhab adhesin, an important xanthomonas citri ssp. citri virulence factor, is recognized as a pathogen-associated molecular pattern. | adhesion to host tissue is one of the key steps of the bacterial pathogenic process. xanthomonas citri ssp. citri possesses a non-fimbrial adhesin protein, xacfhab, required for bacterial attachment, which we have previously demonstrated to be an important virulence factor for the development of citrus canker. xacfhab is a 4753-residue-long protein with a predicted β-helical fold structure, involved in bacterial aggregation, biofilm formation and adhesion to the host. in this work, to further ch ... | 2016 | 26724481 |
| additive roles of pthas in bacterial growth and pathogenicity associated with nucleotide polymorphisms in effector-binding elements of citrus canker susceptibility genes. | citrus canker, caused by xanthomonas citri, affects most commercial citrus varieties. all x. citri strains possess at least one transcription activator-like effector of the ptha family that activates host disease susceptibility (s) genes. the x. citri strain 306 encodes four ptha effectors; nevertheless, only ptha4 is known to elicit cankers on citrus. as none of the pthas act as avirulence factors on citrus, we hypothesized that pthas 1-3 might also contribute to pathogenicity on certain hosts. ... | 2016 | 26709719 |
| reduced susceptibility to xanthomonas citri in transgenic citrus expressing the fls2 receptor from nicotiana benthamiana. | overexpression of plant pattern-recognition receptors by genetic engineering provides a novel approach to enhance plant immunity and broad-spectrum disease resistance. citrus canker disease associated with xanthomonas citri is one of the most important diseases damaging citrus production worldwide. in this study, we cloned the fls2 gene from nicotiana benthamiana cdna and inserted it into the binary vector pbinplus/ars to transform hamlin sweet orange and carrizo citrange. transgene presence was ... | 2016 | 26554734 |
| the efficacy and underlying mechanism of sulfone derivatives containing 1,3,4-oxadiazole on citrus canker. | the objectives of the current study were to isolate and identify the pathogen responsible for citrus canker and investigate the efficacy of sulfone derivatives containing 1,3,4-oxadiazole moiety on controlling citrus canker caused by xanthomonas citri subsp. citri (xcc) under in vitro and field conditions. in an in vitro study, we tested eight sulfone derivatives against xcc and the results demonstrated that compound 3 exhibited the best antibacterial activity against xcc, with a half-maximal ef ... | 2015 | 26247929 |
| accumulation of transcription factors and cell signaling-related proteins in the nucleus during citrus-xanthomonas interaction. | the nucleus is the maestro of the cell and is involved in the modulation of cell signaling during stress. we performed a comprehensive nuclear proteome analysis of citrus sinensis during interaction with host (xanthomonas citri pv. citri-xcc) and non-host (xanthomonas oryzae pv. oryzae-xoo) pathogens. the nuclear proteome was obtained using a sequential method of organelle enrichment and determined by nano-lc-ms/ms analysis. a total of 243 proteins accumulated differentially during citrus-xantho ... | 2015 | 26202445 |
| functional characterization of a lov-histidine kinase photoreceptor from xanthomonas citri subsp. citri. | the blue-light (bl) absorbing protein xcc-lov from xanthomonas citri subsp. citri is composed of a lov-domain, a histidine kinase (hk) and a response regulator. spectroscopic characterization of xcc-lov identified intermediates and kinetics of the protein's photocycle. measurements of steady state and time-resolved fluorescence allowed determination of quantum yields for triplet (φt = 0.68 ± 0.03) and photoproduct formation (φ390 = 0.46 ± 0.05). the lifetime for triplet decay was determined as ... | 2016 | 26172037 |
| identification of seven novel virulence genes from xanthomonas citri subsp. citri by tn5-based random mutagenesis. | to identify novel virulence genes, a mutant library of xanthomonas citri subsp. citri 29-1 was produced using ez-tn5 transposon and the mutants were inoculated into susceptible grapefruit. forty mutants with altered virulence phenotypes were identified. nine of the mutants showed a complete loss of citrus canker induction, and the other 31 mutants resulted in attenuated canker symptoms. southern blot analysis revealed that each of the mutants carried a single copy of tn5. the flanking sequence w ... | 2015 | 25935304 |
| bridgehead invasion of a monomorphic plant pathogenic bacterium: xanthomonas citri pv. citri, an emerging citrus pathogen in mali and burkina faso. | molecular epidemiology studies further our understanding of migrations of phytopathogenic bacteria, the major determining factor in their emergence. asiatic citrus canker, caused by xanthomonas citri pv. citri, was recently reported in mali and burkina faso, a region remote from other contaminated areas. to identify the origin and pathways of these emergences, we used two sets of markers, minisatellites and microsatellites, for investigating different evolutionary scales. minisatellite typing su ... | 2015 | 25866121 |
| bacterial killing via a type iv secretion system. | type iv secretion systems (t4sss) are multiprotein complexes that transport effector proteins and protein-dna complexes through bacterial membranes to the extracellular milieu or directly into the cytoplasm of other cells. many bacteria of the family xanthomonadaceae, which occupy diverse environmental niches, carry a t4ss with unknown function but with several characteristics that distinguishes it from other t4sss. here we show that the xanthomonas citri t4ss provides these cells the capacity t ... | 2015 | 25743609 |
| cooperative substrate binding by a diguanylate cyclase. | xac0610, from xanthomonas citri subsp. citri, is a large multi-domain protein containing one gaf (cgmp-specific phosphodiesterases, adenylyl cyclases and fhla) domain, four pas (per-arnt-sim) domains and one ggdef domain. this protein has a demonstrable in vivo and in vitro diguanylate cyclase (dgc) activity that leads to the production of cyclic di-gmp (c-di-gmp), a ubiquitous bacterial signaling molecule. analysis of a xacδ0610 knockout strain revealed that xac0610 plays a role in the regulati ... | 2015 | 25463434 |
| chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by xanthomonas citri. | the genome of xanthomonas citri subsp. citri strain 306 pathotype a (xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics xac and its host compatible have been developed, specially related to adaptive events that allow the survival of xac within the plant. proteomic analysis of xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with i ... | 2015 | 25403594 |
| a novel periplasmic protein, vrpa, contributes to efficient protein secretion by the type iii secretion system in xanthomonas spp. | efficient secretion of type iii effector proteins from the bacterial cytoplasm to host cell cytosol via a type iii secretion system (t3ss) is crucial for virulence of plant-pathogenic bacterium. our previous study revealed a conserved hypothetical protein, virulence-related periplasm protein a (vrpa), which was identified as a critical virulence factor for xanthomonas citri subsp. citri. in this study, we demonstrate that mutation of vrpa compromises x. citri subsp. citri virulence and hypersens ... | 2015 | 25338144 |
| responsiveness of different citrus genotypes to the xanthomonas citri ssp. citri-derived pathogen-associated molecular pattern (pamp) flg22 correlates with resistance to citrus canker. | the bacterial agent of citrus canker disease (xanthomonas citri ssp. citri, xcc) has caused tremendous economic losses to the citrus industry around the world. pathogen-associated molecular pattern (pamp)-triggered immunity (pti) is important to plant immunity. in this study, we compared the defence responses of citrus canker-resistant and citrus canker-susceptible genotypes to the xcc-derived pamp flg22 (xflg22) by analysing the expression of 20 citrus defence-associated genes. we showed that, ... | 2015 | 25231217 |
| xcc-facilitated agroinfiltration of citrus leaves: a tool for rapid functional analysis of transgenes in citrus leaves. | xanthomonas citri subsp. citri pretreatment before agroinfiltration could significantly promote transient expression in citrus leaves which were previously recalcitrant to agroinfiltration. transient expression via agroinfiltration is widely used in biotechnology but remains problematic in many economically important plants. xanthomonas citri subsp. citri (xcc)-facilitated agroinfiltration was employed to promote transient protein expression in valencia sweet orange leaves, which are recalcitran ... | 2014 | 25146436 |
| expression of xylella fastidiosa rpff in citrus disrupts signaling in xanthomonas citri subsp. citri and thereby its virulence. | xylella fastidiosa and xanthomonas citri subsp. citri, that cause citrus variegated chlorosis (cvc) and citrus canker diseases, respectively, utilize diffusible signal factor (dsf) for quorum sensing. dsf, produced by rpff, are similar fatty acids in both organisms, although a different set of genes is regulated by dsf in each species. because of this similarity, xylella fastidiosa dsf might be recognized and affect the biology of xanthomonas citri. therefore, transgenic citrus sinensis and carr ... | 2014 | 25099341 |
| xanthan gum removal for 1h-nmr analysis of the intracellular metabolome of the bacteria xanthomonas axonopodis pv. citri 306. | xanthomonas is a genus of phytopathogenic bacteria, which produces a slimy, polysaccharide matrix known as xanthan gum, which involves, protects and helps the bacteria during host colonization. although broadly used as a stabilizer and thickener in the cosmetic and food industries, xanthan gum can be a troubling artifact in molecular investigations due to its rheological properties. in particular, a cross-reaction between reference compounds and the xanthan gum could compromise metabolic quantif ... | 2014 | 24957023 |
| the role as inoculum sources of xanthomonas citri pv. citri surviving on the infected satsuma mandarin fruits. | importing citrus fruits infected by asiatic citrus canker caused by xanthomonas citri pv. citri (xcc) can act as an inoculum source for the disease epidemic in citrus canker-free countries. in this study, the pathogenicity of the causal agent of asiatic citrus canker surviving on infected satsuma mandarin fruits was evaluated. the washing solution of infected satsuma mandarin fruits did not cause lesion formation on the citrus leaves. however, a typical citrus canker lesion was formed on the lea ... | 2014 | 24723102 |
| comparative proteomic analysis reveals that t3ss, tfp, and xanthan gum are key factors in initial stages of citrus sinensis infection by xanthomonas citri subsp. citri. | the bacteria xanthomonas citri subsp. citri (xac) is the causal agent of citrus canker. the disease symptoms are characterized by localized host cell hyperplasia followed by tissue necrosis at the infected area. an arsenal of bacterial pathogenicity- and virulence-related proteins is expressed to ensure a successful infection process. at the post-genomic stage of xac, we used a proteomic approach to analyze the proteins that are displayed differentially over time when the pathogen attacks the ho ... | 2014 | 24676796 |
| surface barriers of mandarin 'okitsu' leaves make a major contribution to canker disease resistance. | field evaluations have shown that satsuma mandarin (citrus unshiu) 'okitsu' is one of the mandarin cultivars that shows substantial resistance to xanthomonas citri subsp. citri (x. citri), the causal agent of citrus bacterial canker disease. however, the mechanisms underlying this resistance are not well understood. in this study, we have shown that 'okitsu' leaves are nevertheless susceptible to x. citri infection during a period of their development; however, this period is shorter than that s ... | 2014 | 24548213 |
| a potential disease susceptibility gene cslob of citrus is targeted by a major virulence effector ptha of xanthomonas citri subsp. citri. | | 2014 | 24398629 |
| the relationship between ptha expression and the pathogenicity of xanthomonas axonopodis pv. citri. | citrus canker disease, caused by xanthomonas axonopodis pv. citri, affects almost all citrus species and cultivars and hascaused severe damage to the citrus industry worldwide. ptha is considered the main pathogenesis effector of the pathogen. this research aimed to temporally and spatially analyze the expression of the ptha protein of the bactrium during its culture, and then try to understand the relationship between the ptha expression levels and the pathogenicity. the relationship between th ... | 2014 | 24385299 |
| highly polymorphic markers reveal the establishment of an invasive lineage of the citrus bacterial pathogen xanthomonas citri pv. citri in its area of origin. | investigating the population biology of plant pathogens in their native areas is essential to understand the factors that shape their population structure and favour their spread. monomorphic pathogens dispatch extremely low genetic diversity in invaded areas, and native areas constitute a major reservoir for future emerging strains. one of these, the gammaproteobacterium xanthomonas citri pv. citri, causes asiatic canker and is a considerable threat to citrus worldwide. we studied its populatio ... | 2014 | 24373118 |
| extracellular matrix-associated proteome changes during non-host resistance in citrus-xanthomonas interactions. | non-host resistance (nhr) is a most durable broad-spectrum resistance employed by the plants to restrict majority of pathogens. plant extracellular matrix (ecm) is a critical defense barrier. understanding ecm responses during interaction with non-host pathogen will provide insights into molecular events of nhr. in this study, the ecm-associated proteome was compared during interaction of citrus with pathogen xanthomonas axonopodis pv. citri (xac) and non-host pathogen xanthomonas oryzae pv. ory ... | 2014 | 24117905 |
| a specific interdomain interaction preserves the structural and binding properties of the moda protein from the phytopathogen xanthomonas citri domain interaction and transport in moda. | the periplasmic-binding proteins in atp-binding cassette systems (abc transporters) are responsible for the capture and delivery of ligands to their specific transporters, triggering a series of atp-driven conformational changes that leads to the transport of the ligand. structurally consisting of two lobes, the proteins change conformation after interaction with the ligand. the structure of the molybdate-binding protein (moda) from xanthomonas citri, bound to molybdate, was previously solved by ... | 2013 | 24035743 |
| foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by xanthomonas citri subsp. citri. | citrus canker caused by the bacterium xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. biofilm formation plays an important role in early infection of x. citri subsp. citri on host leaves. in this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce x. citri subsp. citri infection and enhance the control of citrus canker disease. d-leucine and 3-indolylacetonitrile (ian) were found to prevent biofilm formation by x. ci ... | 2014 | 23901828 |
| transgenic sweet orange plants expressing a dermaseptin coding sequence show reduced symptoms of citrus canker disease. | citrus canker provoked by xanthomonas axonopodis pv. citri is a bacterial disease causing severe losses in all citrus-producing areas around the world. xanthomonas infection is considered as an endemic disease in northeast and northwest argentina, affecting as much as 10% of commercial citrus plantations. there is not known natural resistance neither in orange varieties nor in rootstocks used for grafting of commercial cultivars. to introduce resistance to this disease, plants of pineapple sweet ... | 2013 | 23896218 |
| identification and characterization of biofilm formation-defective mutants of xanthomonas citri subsp. citri. | xanthomonas citri subsp. citri (xcc) develops a biofilm structure both in vitro and in vivo. despite all the progress achieved by studies regarding biofilm formation, many of its mechanisms remain poorly understood. this work focuses on the identification of new genes involved in biofilm formation and how they are related to motility, virulence and chemotaxis in xcc. a tn5 library of approximately 6000 xcc (strain 306) mutants was generated and screened to search for biofilm formation defective ... | 2013 | 23813675 |
| increased resistance against citrus canker mediated by a citrus mitogen-activated protein kinase. | mitogen-activated protein kinases (mapk) play crucial roles in plant immunity. we previously identified a citrus mapk (csmapk1) as a differentially expressed protein in response to infection by xanthomonas aurantifolii, a bacterium that causes citrus canker in mexican lime but a hypersensitive reaction in sweet oranges. here, we confirm that, in sweet orange, csmapk1 is rapidly and preferentially induced by x. aurantifolii relative to xanthomonas citri. to investigate the role of csmapk1 in citr ... | 2013 | 23777433 |
| glutamate transport and xanthan gum production in the plant pathogen xanthomonas axonopodis pv. citri. | l-glutamate plays a central role in nitrogen metabolism in all living organisms. in the genus xanthomonas, the nitrogen nutrition is an important factor involved in the xanthan gum production, an important exopolysaccharide with various industrial and biotechnological applications. in this report, we demonstrate that the use of l-glutamate by the phytopathogen xanthomonas axonopodis pv. citri as a nitrogen source in defined medium significantly increases the production of xanthan gum. this incre ... | 2013 | 23719672 |
| structure of the pilz-fimxeal-c-di-gmp complex responsible for the regulation of bacterial type iv pilus biogenesis. | signal transduction pathways mediated by cyclic-bis(3'→5')-dimeric gmp (c-di-gmp) control many important and complex behaviors in bacteria. c-di-gmp is synthesized through the action of ggdef domains that possess diguanylate cyclase activity and is degraded by eal or hd-gyp domains with phosphodiesterase activity. there is mounting evidence that some important c-di-gmp-mediated pathways require protein-protein interactions between members of the ggdef, eal, hd-gyp and pilz protein domain familie ... | 2013 | 23507310 |
| variations in type iii effector repertoires, pathological phenotypes and host range of xanthomonas citri pv. citri pathotypes. | the mechanisms determining the host range of xanthomonas are still undeciphered, despite much interest in their potential roles in the evolution and emergence of plant pathogenic bacteria. xanthomonas citri pv. citri (xci) is an interesting model of host specialization because of its pathogenic variants: pathotype a strains infect a wide range of rutaceous species, whereas pathotype a*/a(w) strains have a host range restricted to mexican lime (citrus aurantifolia) and alemow (citrus macrophylla) ... | 2013 | 23437976 |
| characterization of a variant of xanthomonas citri subsp. citri that triggers a host-specific defense response. | citrus is an economically important fruit crop that is severely afflicted by asiatic citrus bacterial canker (cbc), a disease caused by the phytopathogen xanthomonas citri subsp. citri (x. citri). to gain insight into the molecular epidemiology of cbc, 42 xanthomonas isolates were collected from a range of citrus spp. across 17 different orchards in tucumán, argentina and subjected to molecular, biochemical, and pathogenicity tests. analysis of genome-specific x. citri markers and dna polymorphi ... | 2013 | 23268580 |
| evidence for acquisition of copper resistance genes from different sources in citrus-associated xanthomonads. | abstract we determined that multiple and independent introductions of copper resistance genes have taken place for strains of xanthomonas citri subsp. citri from argentina and strains of x. alfalfae subsp. citrumelonis from florida. this study compared the partial nucleotide sequences of principal copper resistance genes copl, copa, and copb from x. citri subsp. citri and x. alfalfae subsp. citrumelonis to strains of other xanthomonas spp. resistant to copper that were isolated from 12 different ... | 2013 | 23252970 |
| recombinant expression and characterization of a cysteine peptidase from xanthomonas citri subsp citri. | xanthomonas citri subsp citri (xac) is the bacterium responsible for citrus canker disease in citrus plants. the aim of this study was to describe the recombinant expression, purification, and characterization of a cysteine peptidase from xac strain 306, which is a candidate for involvement in the pathogenicity of this bacterium. the gene was cloned and expressed in pichia pastoris, and the cysteine peptidase was successfully expressed, secreted, and purified using affinity chromatography with a ... | 2012 | 23212341 |
| pathogen-induced accumulation of an ellagitannin elicits plant defense response. | in an incompatible interaction between colletotrichum fragariae and strawberry plants, the accumulation of phenolic compounds in plant leaves was observed. a particularly abundant penta-esterified ellagitannin that accumulated in response to pathogen attack was identified as 1-0-galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-β-d-glucopyranose (het) by mass spectroscopy and nuclear magnetic resonance. foliar application of purified het prior to inoculation with a virulent pathogen was shown to increase ... | 2012 | 22934564 |
| contribution of a harpin protein from xanthomonas axonopodis pv. citri to pathogen virulence. | xanthomonas axonopodis pv. citri (xac), the bacterium that causes citrus canker, contains a gene in the hrp [for hypersensitive response (hr) and pathogenicity] cluster that encodes a harpin protein called hpa1. hpa1 produced hr in the nonhost plants tobacco, pepper and arabidopsis, whereas, in the host plant citrus, it elicited a weak defence response with no visible phenotype. co-infiltrations of xac with or without the recombinant hpa1 protein in citrus leaves produced a larger number of cank ... | 2012 | 22788999 |
| the structure of a xanthomonas general stress protein involved in citrus canker reveals its flavin-binding property. | xanthomonas citri pv. citri (xac) causes citrus canker and affects citrus agriculture worldwide. functional genetic analysis has indicated that a putative general stress protein (xacgsp) encoded by the xac2369 gene is involved in the bacterial infection. in this report, the crystal structure of xacgsp was determined to 2.5 å resolution. there are four xacgsp molecules in the crystal asymmetric unit. each xacgsp monomer folds into a six-stranded antiparallel β-barrel flanked by five α-helices. a ... | 2012 | 22751670 |
| hrpm is involved in glucan biosynthesis, biofilm formation and pathogenicity in xanthomonas citri ssp. citri. | xanthomonas citri ssp. citri (xcc) is the causal agent of citrus canker. this bacterium develops a characteristic biofilm on both biotic and abiotic surfaces. a biofilm-deficient mutant was identified in a screening of a transposon mutagenesis library of the xcc 306 strain constructed using the commercial tn5 transposon ez-tn5 <kan-2> tnp transposome (epicentre). sequence analysis of a mutant obtained in the screening revealed that a single copy of the ez-tn5 was inserted at position 446 of hrpm ... | 2012 | 22738424 |
| construction of egfp-labeling system for visualizing the infection process of xanthomonas axonopodis pv. citri in planta. | xanthomonas axonopodis pv. citri (xac) is the causal agent of citrus bacterial canker, an economically important disease to world citrus industry. to monitor the infection process of xac in different citrus plants, the enhanced green florescent protein (egfp) visualizing system was constructed to visualize the propagation and localization in planta. first, the wild-type xac was isolated from the diseased leaves of susceptible 'bingtang' sweet orange, and then the isolated xac was labeled with eg ... | 2012 | 22674174 |