Publications

comparative analyses of xanthomonas and xylella complete genomes.	computational analyses of four bacterial genomes of the xanthomonadaceae family reveal new unique genes that may be involved in adaptation, pathogenicity, and host specificity. the xanthomonas genus presents 3636 unique genes distributed in 1470 families, while xylella genus presents 1026 unique genes distributed in 375 families. among xanthomonas-specific genes, we highlight a large number of cell wall degrading enzymes, proteases, and iron receptors, a set of energy metabolism genes, second co ...	2005	15805778
genetic analysis of citrus leafminer susceptibility.	damage caused by the citrus leafminer (clm), phyllocnistis citrella, is highly dependent on the citrus flushing pattern. chemical control is only required in young trees, both in nurseries and in newly established orchards. however, this situation is completely different in countries where the causal agent of citrus canker, the bacterium xanthomonas axonopodis pv. citri exists. clm infestation results in a higher incidence of citrus canker infection. among preventive control strategies that prov ...	2005	15834698
gene expression analysis of six gc-rich gram-negative phytopathogens.	predicted highly expressed (phx) genes are comparatively analyzed for six gc-rich gram-negative phytopathogens, i.e., ralstonia solanacearum, agrobacterium tumefaciens, xanthomonas campestris pv. campestris (xcc), xanthomonas axonopodis pv. citri (xac), pseudomonas syringae pv. tomato, and xylella fastidiosa. enzymes involved in energy metabolism, such as atp synthase, and genes involved in tca cycle, are phx in most bacteria except x. fastidiosa, which prefers an anaerobic environment. most pat ...	2005	15910748
phenylacetaldehyde o-methyloxime: a volatile compound produced by grapefruit leaves infected with the citrus canker pathogen, xanthomonas axonopodis pv. citri.	an aldehyde oxime o-methyl ether, phenylacetaldehyde o-methyloxime, was detected using solid-phase microextraction (spme) and gas chromatography-mass spectrometry (gc-ms) in the headspace above grapefruit leaves infected with xanthomonas axonopodis pv. citri, the causal agent of citrus bacterial canker disease (cbcd). this disease is a major phytosanitary concern, and an eradication campaign against it is currently underway in florida. phenylacetaldehyde o-methyloxime has been reported to be pro ...	2005	15969487
non-gamma-proteobacteria gene islands contribute to the xanthomonas genome.	horizontal gene transfer, a process through which genomes acquire sequences from distantly related organisms, is believed to be a major source of genetic diversity in bacteria. a central question concerning the impact of gene transfer on bacterial genome evolution is the proportion of horizontally transferred sequences within genomes. through blast search, we found that the genomes of two phytopathogens, xanthomonas campestris pv. campestris and xanthomonas axonopodis pv. citri, have close to 40 ...	2005	15969648
identification and characterization of a second lexa gene of xanthomonas axonopodis pathovar citri.	we previously identified and characterized a lexa gene from xanthomonas axonopodis pv. citri. for this study, we cloned and expressed a lexa homologue from x. axonopodis pv. citri. this gene was designated lexa2, and the previously identified lexa gene was renamed lexa1. the coding region of lexa2 is 606 bp long and shares 59% nucleotide sequence identity with lexa1. analyses of the deduced amino acid sequence revealed that lexa2 has structures that are characteristic of lexa proteins, including ...	2005	16000766
the f-plasmid trai protein contains three functional domains required for conjugative dna strand transfer.	the f-plasmid-encoded trai protein, also known as dna helicase i, is a bifunctional protein required for conjugative dna transfer. the enzyme catalyzes two distinct but functionally related reactions required for the dna processing events associated with conjugation: the site- and strand-specific transesterification (relaxase) reaction that provides the nick required to initiate strand transfer and a processive 5'-to-3' helicase reaction that provides the motive force for strand transfer. previo ...	2005	15629940
prokaryotic phylogenies inferred from protein structural domains.	the determination of the phylogenetic relationships among microorganisms has long relied primarily on gene sequence information. given that prokaryotic organisms often lack morphological characteristics amenable to phylogenetic analysis, prokaryotic phylogenies, in particular, are often based on sequence data. in this work, we explore a new source of phylogenetic information, the distribution of protein structural domains within fully sequenced prokaryotic genomes. the evolution of the structura ...	2005	15741510
site-directed gene replacement of the phytopathogen xanthomonas axonopodis pv. citri.	in this work we defined experimental conditions for site-directed gene replacement of the xanthomonas axonopodis pv. citri (xac), an economically relevant pathogen of citrus plants. the procedure involved, first, optimizing the electrotransformation conditions of the xac 306 strain and, second, constructing non-replicative suicide vectors carrying knockout copies of the target gene. using specific experimental conditions, transformation efficiencies of xac were at least 100 fold higher than thos ...	2006	16087261
amplification of dna of xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.	herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. xanthomonas axonopodis pv. citri (xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. the appearance of novel strains of the pathogen in florida and elsewhere make it increasingly important to understand the relationships among st ...	2006	16099061
expression, crystallization and preliminary crystallographic analysis of sufe (xac2355) from xanthomonas axonopodis pv. citri.	xanthomonas axonopodis pv. citri (xac) sufe (xac2355) is a member of a family of bacterial proteins that are conserved in several pathogens and phytopathogens. the escherichia coli suf operon is involved in iron-sulfur cluster biosynthesis under iron-limitation and stress conditions. it has recently been demonstrated that sufe and sufs form a novel two-component cysteine desulfarase in which sufs catalyses the conversion of l-cysteine to l-alanine, forming a protein-bound persulfide intermediate ...	2006	16511319
crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen xanthomonas axonopodis pv. citri.	xanthomonas axonopodis pv. citri moda protein is the abc periplasmic binding component responsible for the capture of molybdate. the protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of peg or sulfate. x-ray diffraction data were collected to a maximum resolution of 1.7 a using synchrotron radiation. the crystal belongs to the orthorhombic space group c222(1), with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 a. the crystal st ...	2006	16511325
identification of genomic islands in six plant pathogens.	genomic islands (gis) play important roles in microbial evolution, which are acquired by horizontal gene transfer. in this paper, the gis of six completely sequenced plant pathogens are identified using a windowless method based on z curve representation of dna sequences. consequently, four, eight, four, one, two and four gis are recognized with the length greater than 20-kb in plant pathogens agrobacterium tumefaciens str. c58, rolstonia solanacearum gmi1000, xanthomonas axonopodis pv. citri st ...	2006	16581205
nmr assignment of the outer membrane lipoprotein (omla) from xanthomonas axonopodis pv citri.		2006	16596342
a study on the molecular mechanism of resistance to amicarthiazol in xanthomonas campestris pv. citri.	three amicarthiazol-resistant mutants (xuv10, xuv20 and xuv40) were obtained by uv induction and used in this study. minimal inhibition concentrations (mics) of amicarthiazol against the growth of mutants and wild-type isolate were 400 and 100 microg ml(-1) respectively. inhibition by amicarthiazol of succinate dehydrogenase (sdh) activities of xanthomonas campestris pv. citri (hasse) dye wild-type isolate (xcc) and three resistant mutants derived from this isolate were assayed using triphenylte ...	2006	16602085
crystallization and preliminary x-ray diffraction analysis of xac1151, a small heat-shock protein from xanthomonas axonopodis pv. citri belonging to the alpha-crystallin family.	the hspa gene (xac1151) from xanthomonas axonopodis pv. citri encodes a protein of 158 amino acids that belongs to the small heat-shock protein (shsp) family of proteins. these proteins function as molecular chaperones by preventing protein aggregation. the protein was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. x-ray diffraction data were collected to 1.65 angstroms resolution using a synchrotron-radiation source. the crystal belongs to the ...	2006	16682772
[study on a bacterial strain bt8 for biocontrol against citrus bacterial canker].	citrus bacterial canker is an important disease of citrus species in china. the disease severely occurs especially in the coastal area. integrated control system has been used for the control of the disease, in which chemotherapy plays an important role at present. the chemotherapy-dominant control system brought many problems to the environment, such as chemical residua in the products and induction of resistance to fungicide(s) by the pathogen. to solve these problems, an intensive study on bi ...	2006	16736594
the molybdate-binding protein (moda) of the plant pathogen xanthomonas axonopodis pv. citri.	the modabc operon of phytopathogen xanthomonas axonopodis pv. citri (x. citri) encodes a putative abc transporter involved in the uptake of the molybdate and tungstate anions. sequence analyses showed high similarity values of moda orthologs found in x. campestris pv. campestris (x. campestris) and escherichia coli. the x. citri moda gene was cloned in pet28a and the recombinant protein, expressed in the e. coli bl21 (de3) strain, purified by immobilized metal affinity chromatography. the purifi ...	2006	16879982
the hd-gyp domain of rpfg mediates a direct linkage between the rpf quorum-sensing pathway and a subset of diguanylate cyclase proteins in the phytopathogen xanthomonas axonopodis pv citri.	bacteria use extracellular levels of small diffusible autoinducers to estimate local cell-density (quorum-sensing) and to regulate complex physiological processes. the quorum-sensing signal transduction pathway of xanthomonas spp. phytopathogens has special features that distinguish it from that of other pathogens. this pathway consists of rpff, necessary for the production of the unique autoinducer 'diffusible signalling factor' (dsf), and rpfc and rpfg, a two-component system necessary for the ...	2006	17020586
rapid, specific and quantitative assays for the detection of the endophytic bacterium methylobacterium mesophilicum in plants.	xylella fastidiosa is a xylem-limited bacterium that causes citrus variegated chlorosis disease in sweet orange. there is evidence that x. fastidiosa interacts with endophytic bacteria present in the xylem of sweet orange, and that these interactions, particularly with methylobacterium mesophilicum, may affect disease progress. however, these interactions cannot be evaluated in detail until efficient methods for detection and enumeration of these bacteria in planta are developed. we have previou ...	2006	16266765
sensitive and specific detection of xanthomonas axonopodis pv. citri by pcr using pathovar specific primers based on hrpw gene sequences.	a sensitive and specific assay was developed to detect citrus bacterial canker caused by xanthomonas axonopodis pv. citri, in leaves and fruits of citrus. primers xacf and xacr from hrpw homologous to pectate lyase, modifying the structure of pectin in plants, were used to amplify a 561 bp dna fragment. pcr technique was applied to detect the pathogen in naturally or artificially infected leaves of citrus. the pcr product was only produced from x. axonopodis pv. citri among 26 isolates of xantho ...	2006	16427518
primers based on the rpf gene region provide improved detection of xanthomonas axonopodis pv. citri in naturally and artificially infected citrus plants.	to have a pcr-based detection method for xanthomonas axonopodis pv. citri (xac) using primers designed in a specific region of its genome.	2006	16430504
dwarf--a data warehouse system for analyzing protein families.	the emerging field of integrative bioinformatics provides the tools to organize and systematically analyze vast amounts of highly diverse biological data and thus allows to gain a novel understanding of complex biological systems. the data warehouse dwarf applies integrative bioinformatics approaches to the analysis of large protein families.	2006	17094801
baygo: bayesian analysis of ontology term enrichment in microarray data.	the search for enriched (aka over-represented or enhanced) ontology terms in a list of genes obtained from microarray experiments is becoming a standard procedure for a system-level analysis. this procedure tries to summarize the information focussing on classification designs such as gene ontology, kegg pathways, and so on, instead of focussing on individual genes. although it is well known in statistics that association and significance are distinct concepts, only the former approach has been ...	2006	16504085
[high efficient expression and bio-activity assay of recombinant antibody for citrus bacterial canker disease].	citrus bacterial canker disease caused by the gram negative bacterium xanthomonas axonopodis pv. citri (xac) is a severe bacterial disease of most commercial citrus species and cultivars around the world. single chain variable fragment (scfv) is artificial construction small molecular antibody produced by genetic engineering which may be used to identify target pathogens and prevent plant diseases including xac. to express scfv against xac and obtain functional scfv, single-chain antibody fragme ...	2007	18271265
structural model and ligand interactions of the xanthomonas axonopodis pv. citri oligopeptide-binding protein.	the oligopeptide-binding protein, oppa, ushers oligopeptide substrates to the membrane-associated oligopeptide permease (opp), a multi-component abc-type transporter involved in the uptake of oligopeptides by several bacterial species. in the present study, we report a structural model and an oligopeptide docking analysis of the oppa protein expressed by xanthomonas axonopodis pv. citri (x. citri), the etiological agent of citrus canker. the x. citri oppa structural model showed a conserved thre ...	2007	18273810
expression, purification, and characterization of an aminopeptidase (xac2987) with broad specificity from xanthomonas axonopodis pv. citri.	we report here, the cloning, expression, and purification of a broad specificity aminopeptidase from xanthomonas campestris pv. citri in fusion with a hexa-histidine tag at the n-terminal portion of the protein to facilitate purification. the protein was expressed in the soluble fraction and could be purified in one step by imac, yielding approximately 50mg pure protein per liter of cells. we show that the protein is folded and presents aminopeptidase activity against synthetic substrates. also, ...	2007	17110128
insight in to the phylogeny of polyhydroxyalkanoate biosynthesis: horizontal gene transfer.	polyhydroxyalkanoates (phas) are gaining more and more importance the world over due to their structural diversity and close analogy to plastics. their biodegradability makes them extremely desirable substitutes for synthetic plastics. phas are produced in organisms under certain stress conditions. here, we investigated 253 sequenced (completely and unfinished) genomes for the diversity and phylogenetics of the pha biosynthesis. discrepancies in the phylogenetic trees for phaa, phab and phac gen ...	2007	17113245
identification and characterization of two uvra genes of xanthomonas axonopodis pathovar citri.	two uvra-like genes, designated uvra1 and uvra2, that may be involved in nucleotide excision repair in xanthomonas axonopodis pv. citri (x. a. pv. citri) strain xw47 were characterized. the uvra1 gene was found to be 2,964 bp in length capable of encoding a protein of 987 amino acids. the uvra2 gene was determined to be 2,529 bp with a coding potential of 842 amino acids. these two proteins share 71 and 39% identity, respectively, in amino acid sequence with the uvra protein of escherichia coli. ...	2007	17146667
absence of classical heat shock response in the citrus pathogen xylella fastidiosa.	the fastidious bacterium xylella fastidiosa is associated with important crop diseases worldwide. we have recently shown that x. fastidiosa is a peculiar organism having unusually low values of gene codon bias throughout its genome and, unexpectedly, in the group of the most abundant proteins. here, we hypothesized that the lack of codon usage optimization in x. fastidiosa would incapacitate this organism to undergo quick and massive changes in protein expression as occurs in a classical stress ...	2007	17211542
in planta horizontal transfer of a major pathogenicity effector gene.	xanthomonas citri pv. citri is a clonal group of strains that causes citrus canker disease and appears to have originated in asia. a phylogenetically distinct clonal group that causes identical disease symptoms on susceptible citrus, x. citri pv. aurantifolii, arose more recently in south america. genomes of x. citri pv. aurantifolii strains carry two dna fragments that hybridize to ptha, an x. citri pv. citri gene which encodes a major type iii pathogenicity effector protein that is absolutely ...	2007	17220258
solution structure of apag from xanthomonas axonopodis pv. citri reveals a fibronectin-3 fold.	apag proteins are found in a wide variety of bacterial genomes but their function is as yet unknown. some eukaryotic proteins involved in protein-protein interactions, such as the human polymerase delta-interacting protein (pdip38) and the f box a (fba) proteins, contain apag homology domains. we have used nmr to determine the solution structure of apag protein from the plant pathogen xanthomonas axonopodis pv. citri (apag(xac)) with the aim to shed some light on its molecular function. apag(xac ...	2007	17256769
a ptha homolog from xanthomonas axonopodis pv. citri responsible for host-specific suppression of virulence.	strains of the plant-pathogenic bacterium xanthomonas axonopodis pv. citri are differentiated into two groups with respect to aggressiveness (normal and weak) on citrus grandis cultivars but not on other citrus species such as citrus sinensis. random mutagenesis using the transposon tn5 in x. axonopodis pv. citri strain kc21, which showed weak aggressiveness on a c. grandis cultivar, was used to isolate mutant kc21t46, which regained a normal level of aggressiveness on the cultivar. the gene ina ...	2007	17293422
cloning and characterization of three hypothetical secretion chaperone proteins from xanthomonas axonopodis pv. citri.	xanthomonas axonopodis pv. citri (xac) causes citrus canker in plantations around the world and is of particular significance in brazil where its incidence has risen exponentially over the past decade. approximately one third of the predicted xac open reading frames show no homology, or homology with very low score with that of known sequences. it is believed that xac utilizes secretion systems to transfer virulence proteins into susceptible eukaryotic cells. this process is assisted by secretio ...	2007	17350859
xanthan is not essential for pathogenicity in citrus canker but contributes to xanthomonas epiphytic survival.	xanthan-deficient mutants of xanthomonas axonopodis pv. citri, the bacterium responsible for citrus canker, were generated by deletion and marker exchange of the region encoding the carboxy-terminal end of the first glycosyltransferase, gumd. mutants of gumd did not produce xanthan and remained pathogenic in citrus plants to the same extent as wild-type bacteria. the kinetics of appearance of initial symptoms, areas of plant material affected, and growth of bacteria inside plant tissue throughou ...	2007	17356870
repeat domain diversity of avrbs3-like genes in ralstonia solanacearum strains and association with host preferences in the field.	genes homologous to avrbs3 of xanthomonas were detected in 309 strains of ralstonia solanacearum biovars 3, 4, and 5 but not biovar 1 or 2. a statistically significant association between the originating plant species and internal repeats of the gene was found. sequences of repeats and variation between nearly clonal strains revealed evidence of frequent recombination.	2007	17468277
identification of the flagellar chaperone flgn in the phytopathogen xanthomonas axonopodis pathovar citri by its interaction with hook-associated flgk.	genome annotation of the plant pathogen xanthomonas axonopodis pv. citri (xac), identified flagellar genes in a 15.7 kb gene cluster. however, flgn, a secretion chaperone for hook-associated proteins flgk and flgl, was not identified. we performed extensive screening of the x. axonopodis pv. citri genome with the yeast two-hybrid system to identify a protein with the characteristics of the flagellar chaperone flgn. we found a candidate (xac1990) encoded by an operon for components of the flagell ...	2007	17492271
characterization of the first angiotensin-converting like enzyme in bacteria: ancestor ace is already active.	angiotensin-converting enzyme (ace) is a metallopeptidase that converts angiotensin i into angiotensin ii. ace is crucial in the control of cardiovascular and renal homeostasis and fertility in mammals. in vertebrates, both transmembrane and soluble ace, containing one or two active sites, have been characterized. so far, only soluble, single domain aces from invertebrates have been cloned, and these have been implicated in reproduction in insects. furthermore, an ace-related carboxypeptidase wa ...	2007	17597310
structure of xanthomonas axonopodis pv. citri yaeq reveals a new compact protein fold built around a variation of the pd-(d/e)xk nuclease motif.	the yaeq family of proteins are found in many gram-negative and a few gram-positive bacteria. we have determined the first structure of a member of the yaeq family by x-ray crystallography. comparisons with other structures indicate that yaeq represents a new compact protein fold built around a variation of the pd-(d/e)xk nuclease motif found in type ii endonucleases and enzymes involved in dna replication, repair, and recombination. we show that catalytically important residues in the pd-(d/e)x ...	2007	17623842
all five host-range variants of xanthomonas citri carry one ptha homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.	citrus canker disease is caused by five groups of xanthomonas citri strains that are distinguished primarily by host range: three from asia (a, a*, and a(w)) and two that form a phylogenetically distinct clade and originated in south america (b and c). every x. citri strain carries multiple dna fragments that hybridize with ptha, which is essential for the pathogenicity of wide-host-range x. citri group a strain 3213. dna fragments that hybridized with ptha were cloned from a representative stra ...	2007	17722697
biofilm formation, epiphytic fitness, and canker development in xanthomonas axonopodis pv. citri.	the phytopathogenic bacterium xanthomonas axonopodis pv. citri is responsible for the canker disease affecting citrus plants throughout the world. here, we have evaluated the role of bacterial attachment and biofilm formation in leaf colonization during canker development on lemon leaves. crystal violet staining and confocal laser scanning microscopy analysis of x. axonopodis pv. citri strains expressing the green fluorescent protein were used to evaluate attachment and biofilm formation on abio ...	2007	17918624
genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens.	citrus bacterial canker (cbc) caused by xanthomonas axonopodis pv. citri (xac) was first documented in india and java in the mid 19th century. since that time, the known distribution of the disease has steadily increased. concurrent with the dispersion of the pathogen, the diversity of described strains continues to increase, with novel strains appearing in saudi arabia, iran, and florida in the last decade. herbarium specimens of infected plants provide an historical record documenting both the ...	2007	17998540
diagnosis of xanthomonas axonopodis pv. citri, causal agent of citrus canker, in commercial fruits by isolation and pcr-based methods.	to show the results of the detection of an eu quarantine organism, xanthomonas axonopodis pv. citri (xac), in citrus fruits imported from countries where this bacterium is present, using an integrated approach that includes isolation, pathogenicity assays and molecular techniques.	2007	18045415
computational biology in brazil.		2007	17967046
production of the refolded oligopeptide-binding protein (oppa) encoded by the citrus pathogen xanthomonas axonopodis pv. citri.	the oligopeptide-binding protein, oppa, binds and ushers oligopeptide substrates to the membrane-associated oligopeptide permease (opp), a multi-component abc-type transporter involved in the uptake of oligopeptides expressed by several bacterial species. in the present study, we report the cloning, purification, refolding and conformational analysis of a recombinant oppa protein derived from xanthomonas axonopodis pv. citri (x. citri), the etiological agent of citrus canker. the oppa gene was e ...	2008	18273827
in vivo proteome analysis of xanthomonas campestris pv. campestris in the interaction with the host plant brassica oleracea.	the genus xanthomonas is composed of several species that cause severe crop losses around the world. in latin america, one of the most relevant species is xanthomonas campestris pv. campestris, which is responsible for black rot in cruciferous plants. this pathogen causes yield losses in several cultures, including cabbage, cauliflower and broccoli. although the complete structural genome of x. campestris pv. campestris has been elucidated, little is known about the protein expression of this pa ...	2008	18318710
laterally transferred genomic islands in xanthomonadales related to pathogenicity and primary metabolism.	lateral gene transfer (lgt) is considered as one of the drivers in bacterial genome evolution, usually associated with increased fitness and/or changes in behavior, especially if one considers pathogenic vs. non-pathogenic bacterial groups. the genomes of two phytopathogens, xanthomonas campestris pv. campestris and xanthomonas axonopodis pv. citri, were previously inspected for genome islands originating from lgt events, and, in this work, potentially early and late lgt events were identified a ...	2008	18318843
the type iii secretion system of xanthomonas fuscans subsp. fuscans is involved in the phyllosphere colonization process and in transmission to seeds of susceptible beans.	understanding the survival, multiplication, and transmission to seeds of plant pathogenic bacteria is central to study their pathogenesis. we hypothesized that the type iii secretion system (t3ss), encoded by hrp genes, could have a role in host colonization by plant pathogenic bacteria. the seed-borne pathogen xanthomonas fuscans subsp. fuscans causes common bacterial blight of bean (phaseolus vulgaris). directed mutagenesis in strain cfbp4834-r of x. fuscans subsp. fuscans and bacterial popula ...	2008	18326683
detection of mechanical and disease stresses in citrus plants by fluorescence spectroscopy.	we have investigated the detection of mechanical and disease stresses in citrus plants (citrus limonia [l.] osbeck) using laser-induced fluorescence spectroscopy. due to its economic importance we have chosen to investigate the citrus canker disease, which is caused by the xanthomonas axonopodis pv. citri bacteria. mechanical stress was also studied because it plays an important role in the plant's infection by such bacteria. a laser-induced fluorescence spectroscopy system, composed of a spectr ...	2008	18404192
analyses of binding sequences of the two lexa proteins of xanthomonas axonopodis pathovar citri.	xanthomonas axonopodis pv. citri (x. axonopodis pv. citri) possesses two lexa genes, designated lexa1 and lexa2. electrophoretic mobility shift data show that lexa1 binds to both lexa1 and lexa2 promoters, but lexa2 does not bind to the lexa1 promoter, suggesting that lexa1 and lexa2 play different roles in regulating the expression of sos genes. in this study, we have determined that lexa2 binds to a 14-bp dyad-spacer-dyad palindromic sequence, 5'-tgtacaaatgtaca-3', located at nucleotides -41 t ...	2008	18437426
genome sequence and rapid evolution of the rice pathogen xanthomonas oryzae pv. oryzae pxo99a.	xanthomonas oryzae pv. oryzae causes bacterial blight of rice (oryza sativa l.), a major disease that constrains production of this staple crop in many parts of the world. we report here on the complete genome sequence of strain pxo99a and its comparison to two previously sequenced strains, kacc10331 and maff311018, which are highly similar to one another.	2008	18452608
[detection system for xanthomonas axonopodis pv. citri using rolling circle amplification].	padlock probe was designed based on the sequence of the unique hypothetic protein gene in complete genome of xanthomonas axonopodis pv. citri (xac), and amplification primers ware designed according to the universal linking sequence of padlock probe. detection system of rolling circle amplification (rca) was established and optimized. results show that the system could detect xac and its dna specifically, while other plant pathogens and bacteria attached on the surface of citrus leaves could not ...	2008	18479066
morphological evidence for phages in xylella fastidiosa.	presumptive phage particles associated with xylella fastidiosa strain temecula-1 grown in pw broth were observed by transmission electron microscopy (tem) in ultrathin sections of bacterial cell-containing low speed centrifugation pellets and in partially purified preparations from cscl equilibrium centrifugation density gradients. ultrathin-sectioned cell pellets contained icosahedral particles of about 45 nm in diameter. samples collected from cscl density gradients revealed mostly non-tailed ...	2008	18538030
small non-coding rnas in streptomyces coelicolor.	in bacteria, small rnas (srnas) make important regulatory contributions to an ever increasing number of cellular processes. to expand the repertoire of known srnas, we sought to identify novel srnas in the differentiating, multicellular bacterium streptomyces coelicolor. we describe a combined bioinformatic and experimental approach that enabled the identification and characterization of nine novel srnas in s. coelicolor, including a cis-encoded antisense srna. we examined srna expression throug ...	2008	19008244
xanthomonas axonopodis pv. citri uses a plant natriuretic peptide-like protein to modify host homeostasis.	plant natriuretic peptides (pnps) are a class of extracellular, systemically mobile molecules that elicit a number of plant responses important in homeostasis and growth. the bacterial citrus pathogen, xanthomonas axonopodis pv. citri, also contains a gene encoding a pnp-like protein, xacpnp, that shares significant sequence similarity and identical domain organization with plant pnps but has no homologues in other bacteria. we have expressed and purified xacpnp and demonstrated that the bacteri ...	2008	19015524
transcriptional analysis of the sweet orange interaction with the citrus canker pathogens xanthomonas axonopodis pv. citri and xanthomonas axonopodis pv. aurantifolii.	xanthomonas axonopodis pv. citri (xac) and xanthomonas axonopodis pv. aurantifolii pathotype c (xaa) are responsible for citrus canker disease; however, while xac causes canker on all citrus varieties, xaa is restricted to mexican lime, and in sweet oranges it triggers a defence response. to gain insights into the differential pathogenicity exhibited by xac and xaa and to survey the early molecular events leading to canker development, a detailed transcriptional analysis of sweet orange plants i ...	2008	19018992
acquisition and evolution of plant pathogenesis-associated gene clusters and candidate determinants of tissue-specificity in xanthomonas.	xanthomonas is a large genus of plant-associated and plant-pathogenic bacteria. collectively, members cause diseases on over 392 plant species. individually, they exhibit marked host- and tissue-specificity. the determinants of this specificity are unknown.	2008	19043590
crystallographic structure and substrate-binding interactions of the molybdate-binding protein of the phytopathogen xanthomonas axonopodis pv. citri.	in xanthomonas axonopodis pv. citri (xac or x. citri), the moda gene codes for a periplasmic protein (moda) that is capable of binding molybdate and tungstate as part of the abc-type transporter required for the uptake of micronutrients. in this study, we report the crystallographic structure of the xac moda protein with bound molybdate. the xac moda structure is similar to orthologs with known three-dimensional structures and consists of two nearly symmetrical domains separated by a hinge regio ...	2008	18088604
the solution structure of the outer membrane lipoprotein omla from xanthomonas axonopodis pv. citri reveals a protein fold implicated in protein-protein interaction.	the outer membrane lipoprotein a (omla) belongs to a family of bacterial small lipoproteins widely distributed across the beta and gamma proteobacteria. although the role of numerous bacterial lipoproteins is known, the biological function of omla remains elusive. we found that in the citrus canker pathogen, xanthomonas axonopodis pv. citri (x. citri), omla is coregulated with the ferric uptake regulator (fur) and their expression is enhanced when x. citri is grown on citrus leaves, suggesting t ...	2008	18186471
the copper resistance operon copab from xanthomonas axonopodis pathovar citri: gene inactivation results in copper sensitivity.	xanthomonas axonopodis pv. citri (xac) causes citrus canker and the completion of the xac genome sequence has opened up the possibility of investigating basic cellular mechanisms at the genomic level. copper compounds have been extensively used in agriculture to control plant diseases. the copa and copb genes, identified by annotation of the xac genome, encode homologues of proteins involved in copper resistance. a gene expression assay by northern blotting revealed that copa and copb are expres ...	2008	18227244
complete sequence of p07-406, a 24,179-base-pair plasmid harboring the blavim-7 metallo-beta-lactamase gene in a pseudomonas aeruginosa isolate from the united states.	an outbreak involving a pseudomonas aeruginosa strain that was resistant to all tested antimicrobials except polymyxin b occurred in a hospital in houston, tx. previous studies on this strain showed that it possesses a novel mobile metallo-beta-lactamase (mbl) gene, designated bla(vim-7), located on a plasmid (p07-406). here, we report the complete sequence, annotation, and functional characterization of this plasmid. p07-406 is 24,179 bp in length, and 29 open reading frames were identified rel ...	2008	18591274
ligation-mediated pcr, a fast and reliable technique for insertion sequence-based typing of xanthomonas citri pv. citri.	asiatic citrus canker, caused by xanthomonas citri pv. citri, is a major disease threatening citrus crops throughout the world. the most common methods for strain differentiation of this pathogen are repetitive element sequence-based pcr (rep-pcr) and pulsed field gel electrophoresis (pfge), using rare-cutting restriction enzyme analysis. we developed a ligation-mediated pcr targeting three insertion sequences (is-lm-pcr) present as several copies in the genome of the fully sequenced strain 306 ...	2008	18771421
single-residue changes in the c-terminal disulfide-bonded loop of the pseudomonas aeruginosa type iv pilin influence pilus assembly and twitching motility.	pila, the major pilin subunit of pseudomonas aeruginosa type iv pili (t4p), is a principal structural component. pila has a conserved c-terminal disulfide-bonded loop (dsl) that has been implicated as the pilus adhesinotope. structural studies have suggested that dsl is involved in intersubunit interactions within the pilus fiber. pila mutants with single-residue substitutions, insertions, or deletions in the dsl were tested for pilin stability, pilus assembly, and t4p function. mutation of eith ...	2009	19717595
screening of high-affinity scfvs from a ribosome displayed library using biacore biosensor.	an experimental protocol was developed to screen high-affinity single-chain fv antibody fragments (scfvs) from a xanthomonas axonopodis pv. citri (xac) immunized ribosome display library using biacore biosensor. the screening methods involved immobilizing antigen [lipopolysaccharides (lps) of xac] on sensor chip hpa and then unpurified expression products of scfvs flowing over the immobilized sensor chip. the affinity-improved scfvs were selected based on dissociation rate constants (k (d)). thi ...	2009	18574567
from local surveys to global surveillance: three high-throughput genotyping methods for epidemiological monitoring of xanthomonas citri pv. citri pathotypes.	asiatic citrus canker is a major disease worldwide, and its causal agent, xanthomonas citri pv. citri, is listed as a quarantine organism in many countries. analysis of the molecular epidemiology of this bacterium is hindered by a lack of molecular typing techniques suitable for surveillance and outbreak investigation. we report a comparative evaluation of three typing techniques, amplified fragment length polymorphism (aflp) analysis, insertion sequence ligation-mediated pcr (is-lm-pcr) typing, ...	2009	19088309
populations of xanthomonas citri pv. mangiferaeindicae from asymptomatic mango leaves are primarily endophytic.	epiphytic survival of several xanthomonas pathovars has been reported, but most studies failed to determine whether such populations were resident epiphytes, resulting from latent infections, or casual epiphytes. this study aimed at understanding the nature of xanthomonas citri pv. mangiferaeindicae populations associated with asymptomatic leaves. when spray-inoculated on mango leaves cv. maison rouge, the pathogen multiplied markedly in association with juvenile leaves, but was most often detec ...	2009	19139953
new genes of xanthomonas citri subsp. citri involved in pathogenesis and adaptation revealed by a transposon-based mutant library.	citrus canker is a disease caused by the phytopathogens xanthomonas citri subsp. citri, xanthomonas fuscans subsp. aurantifolli and xanthomonas alfalfae subsp. citrumelonis. the first of the three species, which causes citrus bacterial canker type a, is the most widely spread and severe, attacking all citrus species. in brazil, this species is the most important, being found in practically all areas where citrus canker has been detected. like most phytobacterioses, there is no efficient way to c ...	2009	19149882
crystallization, data collection and data processing of maltose-binding protein (male) from the phytopathogen xanthomonas axonopodis pv. citri.	maltose-binding protein is the periplasmic component of the abc transporter responsible for the uptake of maltose/maltodextrins. the xanthomonas axonopodis pv. citri maltose-binding protein male has been crystallized at 293 k using the hanging-drop vapour-diffusion method. the crystal belonged to the primitive hexagonal space group p6(1)22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 a, and contained two molecules in the asymetric unit. it diffracted to 2.24 a resolution.	2009	19193996
a filamentous hemagglutinin-like protein of xanthomonas axonopodis pv. citri, the phytopathogen responsible for citrus canker, is involved in bacterial virulence.	xanthomonas axonopodis pv. citri, the phytopathogen responsible for citrus canker has a number of protein secretion systems and among them, at least one type v protein secretion system belonging to the two-partner secretion pathway. this system is mainly associated to the translocation of large proteins such as adhesins to the outer membrane of several pathogens. xanthomonas axonopodis pv. citri possess a filamentous hemagglutinin-like protein in close vicinity to its putative transporter protei ...	2009	19194503
phylogenetic structure of xanthomonas determined by comparison of gyrb sequences.	previously, we have produced a phylogeny of species type strains from the plant-pathogenic genus xanthomonas based on gyrb sequences. to evaluate this locus further for species and infraspecies identification, we sequenced an additional 203 strains comprising all the pathovar reference strains (which have defined plant hosts), 67 poorly characterized pathovars, currently classified as xanthomonas campestris, and 59 unidentified xanthomonads. the well-characterized pathovars grouped either in cla ...	2009	19196764
polyphasic characterization of xanthomonads pathogenic to members of the anacardiaceae and their relatedness to species of xanthomonas.	we have used amplified fragment length polymorphism (aflp), multilocus sequence analysis (mlsa) and dna-dna hybridization for genotypic classification of xanthomonas pathovars associated with the plant family anacardiaceae. aflp and mlsa results showed congruent phylogenetic relationships of the pathovar mangiferaeindicae (responsible for mango bacterial canker) with strains of xanthomonas axonopodis subgroup 9.5. this subgroup includes x. axonopodis pv. citri (synonym xanthomonas citri). simila ...	2009	19196770
identification of xanthomonas citri ssp. citri host specificity genes in a heterologous expression host.	we provide the first conclusive evidence that xanthomonas axonopodis pv. citri asiatic strain (xac-a) and, in particular, xac-a(w), a unique citrus canker a strain isolated from key lime in wellington, florida, induces a hypersensitive reaction (hr) in grapefruit leaves. using the heterologous tomato pathogen x. perforans, as a recipient of the xac-a(w) genomic library, we identified a 1599-bp open reading frame responsible for hr in grapefruit, but not key lime, and designated it avrgf1. xac-a( ...	2009	19236573
expression, crystallization and preliminary crystallographic analysis of pilz(xac1133) from xanthomonas axonopodis pv. citri.	proteins containing pilz domains are widespread in gram-negative bacteria and have recently been shown to be involved in the control of biofilm formation, adherence, aggregation, virulence-factor production and motility. furthermore, some pilz domains have recently been shown to bind the second messenger bis(3'-->5')cyclic digmp. here, the cloning, expression, purification and crystallization of pilz(xac1133), a protein consisting of a single pilz domain from xanthomonas axonopodis pv. citri, is ...	2009	19255490
characterization of citrus sinensis type 1 mitochondrial alternative oxidase and expression analysis in biotic stress.	the higher plant mitochondrial electron transport chain contains an alternative pathway that ends with the aox (alternative oxidase). the aox proteins are encoded by a small gene family composed of two discrete gene subfamilies. aox1 is present in both monocot and eudicot plants, whereas aox2 is only present in eudicot plants. we isolated a genomic clone from citrus sinensis containing the aox1a gene. the orange aox1a consists of four exons interrupted by three introns and its promoter harbours ...	2009	19257856
comparative ultrastructure of nonwounded mexican lime and yuzu leaves infected with the citrus canker bacterium xanthomonas citri pv. citri.	ultrastructural aspects of citrus canker development were investigated in nonwounded leaves of citrus species by transmission electron microscopy (tem). a susceptible species mexican lime and a resistant species yuzu were spray-inoculated with a virulent strain of xanthomonas citri pv. citri. initial symptoms occurred on mexican lime approximately 9 days after inoculation, whereas they appeared on yuzu mostly 11 days after inoculation. in mexican lime leaves, the bacterial invasion was usually a ...	2009	19291686
xanthomonas axonopodis pv. citri enters the vbnc state after copper treatment and retains its virulence.	the most severe form of citrus canker disease is caused by xanthomonas axonopodis pv. citri (xac) and affects all types of important citrus crops, reducing fruit yield and quality. copper-based products are routinely used as a standard control measure for citrus canker. in this work we demonstrate that copper treatment induces the viable but nonculturable (vbnc) state in xac but does not prevent the development of symptoms in susceptible plants. short-term exposures to different concentrations o ...	2009	19624747
cyclic di-gmp allosterically inhibits the crp-like protein (clp) of xanthomonas axonopodis pv. citri.	the protein clp from xanthomonas axonopodis pv. citri regulates pathogenesis and is a member of the crp (cyclic amp receptor protein) superfamily. we show that unlike the dna-binding activity of other members of this family, the dna-binding activity of clp is allosterically inhibited by its effector and that cyclic di-gmp serves as that effector at physiological concentrations.	2009	19633082
pilz protein structure and interactions with pilb and the fimx eal domain: implications for control of type iv pilus biogenesis.	the pilz protein was originally identified as necessary for type iv pilus (t4p) biogenesis. since then, a large and diverse family of bacterial pilz homology domains have been identified, some of which have been implicated in signaling pathways that control important processes, including motility, virulence and biofilm formation. furthermore, many pilz homology domains, though not pilz itself, have been shown to bind the important bacterial second messenger bis(3'-->5')cyclic digmp (c-digmp). th ...	2009	19646999
development of 14 minisatellite markers for the citrus canker bacterium, xanthomonas citri pv. citri.	we screened the genome of xanthomonas citri pv. citri strain 306 for tandem repeats. a multiplex polymerase chain reaction protocol was used to assess the genetic diversity of 239 strains of x. citri pv. citri from asia. the total number of alleles per locus ranged from three to 20. using pooled data sets, 223 different haplotypes were identified. successful amplifications were obtained at most loci for seven other x. citri pathovars. this typing scheme is expected to be useful at different spat ...	2009	21564579
modulating host homeostasis as a strategy in the plant-pathogen arms race.	in plant-pathogen interactions, pathogens aim to overcome host defense responses while plants employ a battery of responses to limit pathogen growth and thus disease. in this "arms race" between hosts and pathogens, horizontal gene transfer is a potent source of 'pathogenic innovation' for viruses and bacteria. however, bacteria rarely acquire 'eukaryotic-like' genes from their hosts, and where they appear to, evidence for a role of the acquired genes remains outstanding. we have recently report ...	2009	19704897
optimal strategies for the eradication of asiatic citrus canker in heterogeneous host landscapes.	abstract the eradication of nonnative plant pathogens is a key challenge in plant disease epidemiology. asiatic citrus canker is an economically significant disease of citrus caused by the bacterial plant pathogen xanthomonas citri subsp. citri. the pathogen is a major exotic disease problem in many citrus producing areas of the world including the united states, brazil, and australia. various eradication attempts have been made on the disease but have been associated with significant social and ...	2009	19900003
a new member of the ribbon-helix-helix transcription factor superfamily from the plant pathogen xanthomonas axonopodis pv.citri.	xacb0070 is an uncharacterized protein coded by the two large plasmids isolated from xanthomonas axonopodis pv. citri, the agent of citrus canker and responsible for important economical losses in citrus world production. xacb0070 presents sequence homology only with other hypothetical proteins belonging to plant pathogens, none of which have their structure determined. the nmr-derived solution structure reveals this protein is a homodimer in which each monomer presents two domains with differen ...	2010	20060909
proteome of the phytopathogen xanthomonas citri subsp. citri: a global expression profile.	abstract:	2010	21062441
requirement of the galu gene for polysaccharide production by and pathogenicity and growth in planta of xanthomonas citri subsp. citri.	xanthomonas citri subsp. citri is the causal agent of citrus canker, which has a significant impact on citrus production. in this study, we characterized the galu gene of x. citri subsp. citri. two galu mutants (f6 and d12) were identified in an x. citri subsp. citri ez-tn5 <r6kgammaori/kan-2> tnp transposon library. rescue cloning, sequence analysis, and southern blot analysis indicated that both of these mutants had a single copy of the ez-tn5 transposon inserted in galu in the chromosome. fur ...	2010	20118360
optical fiber laser induced fluorescence spectroscopy as a citrus canker diagnostic.	citrus canker is a serious disease caused by xanthomonas citri subsp. citri bacteria, which infects citrus plants (citrus spp.) leading to large economic losses in citrus production worldwide. in this work, laser induced fluorescence spectroscopy (lif) was investigated as a diagnostic technique for citrus canker disease in citrus trees at an orchard using a portable optical fiber based spectrometer. for comparison we have applied lif to leaves contaminated with citrus canker, citrus scab, citrus ...	2010	20119016
a eukaryotic-acquired gene by a biotrophic phytopathogen allows prolonged survival on the host by counteracting the shut-down of plant photosynthesis.	xanthomonas citri pv. citri, the bacteria responsible for citrus canker posses a biological active plant natriuretic peptide (pnp)-like protein, not present in any other bacteria. pnps are a class of extracellular, systemically mobile peptides that elicit a number of plant responses important in homeostasis and growth. previously, we showed that a xanthomonas citri pv. citri mutant lacking the pnp-like protein xacpnp produced more necrotic lesions in citrus leaves than wild type infections and s ...	2010	20126632
hpaxm from xanthomonas citri subsp. malvacearum is a novel harpin with two heptads for hypersensitive response.	a novel harpin-like protein, hpaxm, was described from cotton leaf blight bacteria, xanthomonas. citri subsp. malvacearum. the hpaxm was found to be localized between hrp2 and hrcc. a phylogenetic analysis of the complete amino acid sequence or solely the 13 highly conserved residues h2n-sekqldqlltqli-cooh in the n-terminal alpha-helix indicates that hpaxm is evolutionarily closer to hpagxag and hpaxac than to hpa1xoo and hpa1xoc. a synthesized peptide containing two heptads, 39-ldqlltq-limallq- ...	2010	20134233
phylogenomics reveals a diverse rickettsiales type iv secretion system.	with an obligate intracellular lifestyle, alphaproteobacteria of the order rickettsiales have inextricably coevolved with their various eukaryotic hosts, resulting in small, reductive genomes and strict dependency on host resources. unsurprisingly, large portions of rickettsiales genomes encode proteins involved in transport and secretion. one particular transporter that has garnered recent attention from researchers is the type iv secretion system (t4ss). homologous to the well-studied archetyp ...	2010	20176788
a plant natriuretic peptide-like molecule of the pathogen xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host.	plant natriuretic peptides (pnps) belong to a novel class of peptidic signaling molecules that share some structural similarity to the n-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. the citrus pathogen xanthomonas axonopodis pv. citri possesses a pnp-like peptide (xacpnp) uniquely present in this bacteria. previously we observed that the expression of xacpnp is induced upon infection and that lesions produced in l ...	2010	20302677
novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of xanthomonas fuscans subsp. aurantifolii.	citrus canker is a disease that has severe economic impact on the citrus industry worldwide. there are three types of canker, called a, b, and c. the three types have different phenotypes and affect different citrus species. the causative agent for type a is xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. xanthomonas fuscans subsp. aurantifolii strain b causes canker b and xanthomonas fuscans subsp. aurantifolii strain c causes canker c.	2010	20388224
bacteria causing important diseases of citrus utilise distinct modes of pathogenesis to attack a common host.	in this review, we summarise the current knowledge on three pathogens that exhibit distinct tissue specificity and modes of pathogenesis in citrus plants. xanthomonas axonopodis pv. citri causes canker disease and invades the host leaf mesophyll tissue through natural openings and can also survive as an epiphyte. xylella fastidiosa and candidatus liberibacter are vectored by insects and proliferate in the vascular system of the host, either in the phloem (candidatus liberibacter) or xylem (x. fa ...	2010	20449739
the monofunctional catalase kate of xanthomonas axonopodis pv. citri is required for full virulence in citrus plants.	xanthomonas axonopodis pv. citri (xac) is an obligate aerobic phytopathogen constantly exposed to hydrogen peroxide produced by normal aerobic respiration and by the plant defense response during plant-pathogen interactions. four putative catalase genes have been identified in silico in the xac genome, designated as kate, catb, srpa (monofunctional catalases) and katg (bifunctional catalase).	2010	20520822
genomes of three tomato pathogens within the ralstonia solanacearum species complex reveal significant evolutionary divergence.	the ralstonia solanacearum species complex includes thousands of strains pathogenic to an unusually wide range of plant species. these globally dispersed and heterogeneous strains cause bacterial wilt diseases, which have major socio-economic impacts. pathogenicity is an ancestral trait in r. solanacearum and strains with high genetic variation can be subdivided into four phylotypes, correlating to isolates from asia (phylotype i), the americas (phylotype iia and iib), africa (phylotype iii) and ...	2010	20550686
transformation of sweet orange [citrus sinensis (l.) osbeck] with ptha-nls for acquiring resistance to citrus canker disease.	the cooh terminal of ptha encoding three nuclear localizing signals (nls) was amplified by polymerase chain reaction (pcr) from the plasmid of xanthomonas axonopodis pv. citri, the pathogen of citrus canker disease. then the sense and antisense strands of the nls were cloned into pbi121 vector. ptha-nls driven by the camv35 s promoter was transferred into sweet orange via agrobacterium -mediated transformation. successful integration was confirmed by pcr and southern blotting, and 12 sense-nls ( ...	2010	20972821
development of an efficient real-time quantitative pcr protocol for detection of xanthomonas arboricola pv. pruni in prunus species.	xanthomonas arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruit, is considered a quarantine organism by the european union and the european and mediterranean plant protection organization (eppo). the bacterium can undergo an epiphytic phase and/or be latent and can be transmitted by plant material, but currently, only visual inspections are used to certify plants as being x. arboricola pv. pruni free. a novel and highly sensitive real-time taqman pcr detection protoco ...	2010	21037298
development of an efficient real-time quantitative pcr protocol for detection of xanthomonas arboricola pv. pruni in prunus species.	xanthomonas arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruit, is considered a quarantine organism by the european union and the european and mediterranean plant protection organization (eppo). the bacterium can undergo an epiphytic phase and/or be latent and can be transmitted by plant material, but currently, only visual inspections are used to certify plants as being x. arboricola pv. pruni free. a novel and highly sensitive real-time taqman pcr detection protoco ...	2010	21037298
the usage of codons which are similar to stop codons in the genomes of xylella fastidiosa and xanthomonas citri.	during the evolution of living organisms, a natural selection event occurs toward the optimization of their genomes regarding the usage of codons. during this process which is known as codon bias, a set of preferred codons is naturally defined in the genome of a given organism, since there are 61 possible codons (plus 3 stop codons) to 20 amino acids. such event leads to optimization of metabolic cellular processes such as translational efficiency, rna stability and energy saving. although we kn ...	2010	21046398
the xanthomonas axonopodis pv. citri flagellum is required for mature biofilm and canker development.	xanthomonas axonopodis pv. citri (xac) is the causative agent of citrus canker. this bacterium develops a characteristic biofilm on both biotic and abiotic surfaces. to evaluate the participation of the single flagellum of xac in biofilm formation, mutants in the flic (flagellin) and the flge (hook) genes were generated. swimming motility, assessed on 0.25 % agar plates, was markedly reduced in flic and flge mutants. however, the flic and flge mutants exhibited a flagellar-independent surface tr ...	2010	21109564
differential expression of pathogenicity- and virulence-related genes of xanthomonas axonopodis pv. citri under copper stress.	in this study, we used real-time quantitative pcr (rt-qpcr) to evaluate the expression of 32 genes of xanthomonas axonopodis pv. citri related to pathogenicity and virulence that are also involved in copper detoxification. nearly all of the genes were up-regulated, including copa and copb. two genes homologous to members of the type ii secretion system (xcsh and xcsc) and two involved in the degradation of plant cell wall components (pgla and pel) were the most expressed in response to an elevat ...	2010	21637493
mutation in the xpsd gene of xanthomonas axonopodis pv. citri affects cellulose degradation and virulence.	the gram-negative bacterium xanthomonas axonopodis pv. citri, the causal agent of citrus canker, is a major threat to the citrus industry worldwide. although this is a leaf spot pathogen, it bears genes highly related to degradation of plant cell walls, which are typically found in plant pathogens that cause symptoms of tissue maceration. little is known on xac capacity to cause disease and hydrolyze cellulose. we investigated the contribution of various open reading frames on degradation of a c ...	2010	21637619