Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the free amino acid pool composition during growth of the culture of xanthomonas citri (hasse) dowson. | fourteen amino acids were found to constitute the intracellular amino compound pool of the developing culture of xanthomonas citri (hasse) dowson. these were serine, dl-alanine, beta-alanine, leucine/isoleucine, threonine, aspartic acid, glutamic acid, asparagine, glutamine, cystine, histidine, tyrosine, tryptophan, and proline. of these, beta-alanine, threonine, aspartic acid, glutamic acid, asparagine, and tyrosine could be traced as excretory amino acids in the bacterial culture filtrate, bei ... | 1979 | 120748 |
| application of the soft agar stab method for preservation of xanthomonas citri. | 1976 | 800975 | |
| an xanthomonas citri pathogenicity gene, ptha, pleiotropically encodes gratuitous avirulence on nonhosts. | the pathogenicity gene, ptha, of xanthomonas citri is required to elicit symptoms of asiatic citrus canker disease; introduction of ptha into xanthomonas strains that are mildly pathogenic or opportunistic on citrus confers the ability to induce cankers on citrus (s. swarup, r. de feyter, r. h. brlansky, and d. w. gabriel, phytopathology 81:802-809, 1991). the structure and the function of ptha in other xanthomonads and in x. citri were further investigated. when ptha was introduced into strains ... | 1992 | 1421509 |
| complete nucleotide sequence of filamentous phage cf1c from xanthomonas campestris pv. citri. | 1991 | 1840658 | |
| a simple method for maintaining xanthomonas campestris pv. citri. | a typical colony of each of strains xw17, xw45, xw47, xw82, xw86, xw118, and xw138 of xanthomonas campestris pv. citri was streaked onto nutrient agar, gy agar, minimal agar, and semi-enriched minimal agar plates, respectively. the agar plates, after incubated at 30 degrees c for 2-4 days, were inverted and stored at 4 degrees c in darkness. all of the x. campestris pv. citri strains retained their viability for at least 26 weeks on the semi-enriched minimal agar plates; whereas, cultures of the ... | 1990 | 2394191 |
| mechanism of action and selective toxicity of ascamycin, a nucleoside antibiotic. | an unidentified streptomyces sp. produces two nucleoside antibiotics, ascamycin and its dealanyl derivative. in contrast to the broad antibacterial activity of dealanylascamycin against various gram-negative and gram-positive bacteria, ascamycin showed selective toxicity against xanthomonas citri and x. oryzae. both ascamycin and dealanylascamycin inhibited the protein synthesis of x. citri, but only dealanylascamycin inhibited that of escherichia coli. in cell-free systems from e. coli and x. c ... | 1985 | 2580481 |
| identification and nucleotide sequence of attachment site of the cflt filamentous phage from xanthomonas campestris pv. citri. | it has been reported that the attachment site on the phage attp is located from 69.2 to 73.8 min on cflt rf dna. kpni and psti were used, which cut respectively at 67.2 and 72.6 min of cflt rf dna. a 0.54 kb fragment containing attp was obtained. for isolation of the right (attr) and left (attl) junctions of prophage and host chromosomal dna, lysogen dna was digested with hindiii and used to prepare a recombinant plasmid library. with cflt rf dna as a probe, three types of recombinant plasmids r ... | 1989 | 2605976 |
| efficient transformation of phytopathogenic strains of xanthomonas species. | efficient transformation and conjugation systems for use in phytopathogenic strains of xanthomonas species were developed with a dual-function plasmid vector, pbxc12, which was constructed from a newly isolated xanthomonas citri plasmid, pxcl6, and pbr328. by using this system, pbr328 could also transform the same strains of xanthomonas. the systems make useful cloning vectors for the study of genes involved in the plant pathogenesis of this species. | 1987 | 3040694 |
| characterization of a spontaneously segregating cf16-v1 lysogen of xanthomonas campestris pv. citri. | filamentous phage cf16 undergoes a unique neolysogenic infectious cycle in xanthomonas campestris pv. citri and generates stable lysogens. in contrast, we have isolated a distinctive unstable lysogen, designated lw. this new lysogen segregated spontaneously into three nonparental types, each with a unique combination of colony morphology, phage-producing capacity, and phage genome content. in a given population of lw lysogens the segregation frequency of these types varied randomly with drastic ... | 1988 | 3182235 |
| nucleotide sequences involved in the neolysogenic insertion of filamentous phage cf16-v1 into the xanthomonas campestris pv. citri chromosome. | following a protracted carrier state in the infected cell, filamentous bacteriophage cf16-v1 neolysogenizes xanthomonas campestris pv. citri by inserting the phage genome into the host chromosome. the integration region in the phage and the host chromosome, respectively, and the two junctions in the lysogen chromosome were isolated and their nucleotide sequence was determined. the phage and host attachment sites shared an identical 15-bp "core," 5'-tatacattatgcgaa-3'. located on either side of e ... | 1988 | 3201755 |
| differential stability of filamentous phage genomes in xanthomonas campestris pv citri. | stability of carrier state in filamentous phage-infected xanthomonas campestris pv citri varied drastically even for closely related phage types. the spontaneous curing frequency for cells infected with cf16-12, cf16, cf16-v1 and cf was 1, 5, 96 and 100%, respectively. the size of the phage replicative-form (rf) pool which built up rapidly at the onset of cf16 infection was critical to the maintenance of the carrier state and the eventual integration of the prophage. a correlation in stability b ... | 1988 | 3241573 |
| occurrence of an ascamycin dealanylating enzyme, xc-aminopeptidase, in mammalian cell membranes and susceptibility to ascamycin. | an ascamycin dealanylating enzyme (xc-aminopeptidase) has been isolated from xanthomonas citri and characterized as a proline iminopeptidase of molecular weight of 38,000 (h. osada & k. isono, biochem. j. 233: 459 approximately 463, 1986). immunological studies have shown that all the mammalian cells tested possess a closely-related enzyme(s) on their cell membranes. this enzyme is more active in transformed cells than in nontransformed cells. a decreased ratio of id50 (ascamycin/dealanylascamyc ... | 1986 | 3514563 |
| identification of legionella pneumophila with commercially available immunofluorescence test. | 1986 | 3522642 | |
| purification and characterization of ascamycin-hydrolysing aminopeptidase from xanthomonas citri. | a nucleoside antibiotic, ascamycin (9-beta-[5'-0-(n-l-alanyl) sulphamoyl-d-ribofuranosyl]-2-chloroadenine), has a selective antibacterial activity against xanthomonas species. when ascamycin was dealanylated, dealanylascamycin showed a broad antibacterial activity against various gram-negative and gram-positive bacteria. xanthomonas citri is susceptible to ascamycin by virtue of the ascamycin-dealanylating enzyme on the cell surface [osada & isono (1985) antimicrob. agents chemother. 27, 230-233 ... | 1986 | 3754135 |
| studies on terreic acid. | it was found that aspergillus sp. no. y-8980 which was isolated from a soil sample collected at yoron island in kagoshima prefecture belonged to aspergillus terreus group by morphological observation. the active substance produced by the strain was obtained with a high yield in sucrose-yeast extract medium and extracted by chloroform, ethyl acetate and n-butanol at ph 2.4 approximately 2.6 from the culture broth. the substance was crystallized from chloroform and ethyl acetate after charcoal tre ... | 1980 | 7190624 |
| enzymatic biosynthesis of cephalexin. | the reaction kinetics of the enzymatic synthesis of cephalexin from 7-aminodeacetoxy cephalosporanic acid and phenylglycine methylester was studied using the synthesizing enzyme obtained from xanthomonas citri. the activation energy, km values for 7-aminodeacetoxy cephalosporanic acid and phenylglycine methylester, and ki value for phenylglycine methylester were determined as 8.63 kcal/mol, 3.7mm, 14.5mm, and 70mm, respectively. the enzyme was found to be constitutive and susceptible to deactiva ... | 1980 | 7378557 |
| intragenic recombination of a single plant pathogen gene provides a mechanism for the evolution of new host specificities. | gene ptha is required for virulence of xanthomonas citri on citrus plants and has pleiotropic pathogenicity and avirulence functions when transferred to many different xanthomonads. dna sequencing revealed that ptha belongs to a family of xanthomonas avirulence/pathogenicity genes characterized by nearly identical 102-bp tandem repeats in the central region. by inserting an npti-sac cartridge into the tandemly repeated region of ptha as a selective marker, intragenic recombination among homologo ... | 1995 | 7665472 |
| characterization of an open reading frame involved in site-specific integration of filamentous phage cf1t from xanthomonas campestris pv. citri. | cf1t is a single-stranded dna filamentous phage; a 1.9-kb segment of dna from cf1t was found to be responsible for site-specific integration into xanthomonas campestris pv. citri (xw47), in the absence of any xanthomonas origin of replication. deletion analysis and introduction of amber stop codons into this fragment from cf1t revealed an open reading frame (orf344) which was involved in the integration function. the predicted amino-acid sequence of orf344 bears no homology with conserved sequen ... | 1995 | 7789813 |
| a long lytic cycle in filamentous phage cf1tv infecting xanthomonas campestris pv. citri. | in this study the lytic cycle of a filamentous phage is reported. under normal laboratory cultivation conditions a virulent form could spontaneously and easily arise from a temperate phage. the virulent one could superinfect cells containing cf1t lysogen. therefore, we have named it cf1tv. in a colony formation assay using cells from an infected culture, two types of colonies were observed, small and large. it could be proven that the formation of small colonies is the result of killing during c ... | 1994 | 7979966 |
| detection of xanthomonas campestris pv. citri by the polymerase chain reaction method. | pfl1 is a puc9 derivative that contains a 572-bp ecori insert cloned from plasmid dna of xanthomonas campestris pv. citri xc62. the nucleotide sequence of pfl1 was determined, and the sequence information was used to design primers for application of the polymerase chain reaction (pcr) to the detection of x. campestris pv. citri, the causal agent of citrus bacterial canker disease. seven 18-bp oligonucleotide primers were designed and tested with dna from x. campestris pv. citri strains and othe ... | 1993 | 8476288 |
| cell-associated glucans of burkholderia solanacearum and xanthomonas campestris pv. citri: a new family of periplasmic glucans. | the cell-associated glucans produced by burkholderia solanacearum and xanthomonas campestris pv. citri were isolated by trichloroacetic acid treatment and gel permeation chromatography. the compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry, and high-performance anion-exchange chromatography. b. solanacearum synthesizes only a neutral cyclic glucan containing 13 glucose residues, and x. campestris pv. citri synthesizes a ... | 1996 | 8636027 |
| isolation and characterization of the gene encoding an aminopeptidase involved in the selective toxicity of ascamycin toward xanthomonas campestris pv. citri. | an aminopeptidase gene named xap has been isolated from xanthomonas campestris pv. citri, a plant pathogenic bacterium. the bacterium is one of the rare micro-organisms susceptible to ascamycin, an aminoacyl nucleoside antibiotic that inhibits protein synthesis. sequence analysis reveals that the gene encodes a 311 amino acid protein with a calculated molecular mass of 35134 da and approx. 50% identity for amino acids to the proline iminopeptidase from neisseria gonorrhoeae. the xap gene product ... | 1996 | 8870654 |
| proline iminopeptidase gene from xanthomonas campestris pv. citri. | the pip gene coding for the proline iminopeptidase (pip) of xanthomonas campestris pv. citri was cloned in an escherichia coli leub strain using a selective medium containing the dipeptide d-ala-l-leu as the sole source of l-leucine. nucleotide sequencing of this gene revealed a 939 bp open reading frame encoding a 312 amino acid protein (35 126 da). the deduced amino acid sequence showed 47% identity with the pip from neisseria gonorrhoeae. a lacz-pip fusion gene was overexpressed in e. coli un ... | 1996 | 8885412 |
| single-stranded dna binding protein from bacteriophage cf: characterization, gene localization and protein-ssdna complex. | the single-stranded dna binding protein from the filamentous bacteriophage cf has been purified and characterized. the first 12 amino acids, resulting from the n-terminal amino acid sequencing analysis of the protein, agree with an open reading frame (orf) on the cf genome. the orf contains 294 bp and codes for a 98 a.a. protein of molecular weight 10.8 kda, consistent with the result from the denaturing protein gel analysis. the protein appears to be a homodimer as evident from the apparent mol ... | 1996 | 8950189 |
| crystallization and preliminary x-ray diffraction analysis of proline iminopeptidase from xanthomonas campestris pv. citri. | proline iminopeptidase from xanthomonas campestris pv. citri, displaying no significant sequence homology to any protein previously analyzed by x-ray crystallography, has been crystallized using the vapour diffusion method. two different orthorhombic crystal forms (space group c222 and i222) were obtained from a solution containing nacl or polyethylene glycol monomethyl ether (mw 5000) as precipitating agent for the native and lanthanum-derivatized protein, respectively. complete diffraction dat ... | 1997 | 9000519 |
| the a protein of the filamentous bacteriophage cf of xanthomonas campestris pv. citri. | filamentous bacteriophages have very strict host specificities. experiments were performed to investigate whether the a protein of the filamentous phage cf, which infects xanthomonas campestris pv. citri but not x. campestris pv. oryzae, is involved in determining cf's host specificity. the gene encoding the a protein of cf was cloned and expressed in x. campestris pv. citri. the genomic dna of another filamentous bacteriophage, xf, which infects x. campestris pv. oryzae but not x. campestris pv ... | 1997 | 9139897 |
| structure of proline iminopeptidase from xanthomonas campestris pv. citri: a prototype for the prolyl oligopeptidase family. | the proline iminopeptidase from xanthomonas campestris pv. citri is a serine peptidase that catalyses the removal of n-terminal proline residues from peptides with high specificity. we have solved its three-dimensional structure by multiple isomorphous replacement and refined it to a crystallographic r-factor of 19.2% using x-ray data to 2.7 a resolution. the protein is folded into two contiguous domains. the larger domain shows the general topology of the alpha/beta hydrolase fold, with a centr ... | 1998 | 9427736 |
| isolation of ethylene-insensitive soybean mutants that are altered in pathogen susceptibility and gene-for-gene disease resistance | plants commonly respond to pathogen infection by increasing ethylene production, but it is not clear if this ethylene does more to promote disease susceptibility or disease resistance. ethylene production and/or responsiveness can be altered by genetic manipulation. the present study used mutagenesis to identify soybean (glycine max l. merr.) lines with reduced sensitivity to ethylene. two new genetic loci were identified, etr1 and etr2. mutants were compared with isogenic wild-type parents for ... | 1999 | 10069832 |
| transcription of the genome of the filamentous bacteriophage cf from both plus and minus dna strands. | the filamentous bacteriophage cf infects the bacterium xanthomonas campestris pv. citri. northern blot analysis with probes derived from various restriction fragments of cf replicative form (rf) dna has revealed the presence of five major phage-specific transcripts in infected cells. four of these transcripts were shown to be derived from the region of the cf genome extending from gene ii to gene viii and are consistent with the cascade model of transcription proposed for ff coliphages. these tr ... | 1999 | 10191188 |
| the adsorption protein genes of xanthomonas campestris filamentous phages determining host specificity. | gene iii (giii) of philf, a filamentous phage specifically infecting xanthomonas campestris pv. campestris, was previously shown to encode a virion-associated protein (piii) required for phage adsorption. in this study, the transcription start site for the gene and the n-terminal sequence of the protein were determined, resulting in the revision of the translation initiation site from the one previously predicted for this gene. for comparative study, the giii of phixv, a filamentous phage specif ... | 1999 | 10198010 |
| a simple extraction procedure for efficient routine detection of pathogenic bacteria in plant material by polymerase chain reaction. | a simple and rapid method for extracting dna from plants based on the use of an extraction buffer and precipitation with isopropanol was assayed to see its usefulness in detecting pathogenic bacteria in plant material. the method was compared with a phenol-chloroform standard procedure obtaining higher sensitivity levels of detection. the protocol developed was efficient for detecting a gram-positive bacterium, clavibacter michiganensis subsp. sepedonicus and several gram-negative pathogenic bac ... | 1999 | 10395461 |
| identification of the promoter region of the xanthomonas campestris pv. citri reca gene responsible for induction by dna-damaging agents. | the abundance of the reca protein and of reca transcripts was markedly increased on exposure of xanthomonas campestris pathovar citri to various dna-damaging agents, including mitomycin c. the promoter sequence responsible for mediating the sensitivity of reca expression to dna damage was investigated by subcloning a 426-bp restriction fragment of the 5' untranslated and coding region of the gene into a promoterless vector containing the luxab genes of vibrio fischeri. xanthomonas campestris pv. ... | 1999 | 10418131 |
| a simplified subtractive hybridization protocol used to isolate dna sequences specific to xylella fastidiosa. | a simplified protocol of subtractive hybridization based on the technique of l. m. kunkel, a. p. monaco, w. middlesworth, h. d. ochs & s. a. latt (1985, proc natl acad sci usa, 82, 4778-4782) was used to obtain dna sequences specific to xylella fastidiosa isolated from diseased citrus plants. as a driver, dna extracted from bacteria showing different degrees of relatedness was used: xy. fastidiosa 788 isolated from another host (plum), xanthomonas campestris pv. campestris and burkholderia gladi ... | 1999 | 10463163 |
| the pila gene of xanthomonas campestris pv. citri is required for infection by the filamentous phage cf. | host factors that are important for infection of xanthomonas campestris pv. citri by the filamentous bacteriophage cf were investigated by transposon mutagenesis with tn5tac1. a mutant, xt501, that was resistant to cf infection was recovered, showing that the gene inactivated by the transposon is required for infection by the phage but not for cf replication or assembly. a 1.7-kb saci-apai dna fragment from xt501 containing the bacterial dna flanking one end of the transposon was cloned and show ... | 1999 | 10503532 |
| requirement for phosphoglucose isomerase of xanthomonas campestris in pathogenesis of citrus canker. | a mutant (xt906) of xanthomonas campestris pv. citri, the causal agent of citrus canker, was induced by insertion of the transposon tn5tac1 and isolated. this mutant did not grow or elicit canker disease in citrus leaves but was still able to induce a hypersensitive response in a nonhost plant (the common bean). the mutant was also unable to grow on minimal medium containing fructose or glycerol as the sole carbon source. a 2.5-kb fragment of wild-type dna that complemented the mutant phenotype ... | 1999 | 10584018 |
| identification of a lexa gene in, and construction of a lexa mutant of, xanthomonas campestris pv. citri. | the lexa gene of xanthomonas campestris pathovar citri (x.c. pv. citri) was cloned and sequenced. the 639-bp open reading frame encodes a protein of 213 amino acids that shares substantial sequence homology with the products of previously characterized lexa genes, sharing 46% identity with the lexa protein of escherichia coli. amino acids required for autocatalytic cleavage of lexa are conserved in the x.c. pv. citri protein, whereas domains thought to mediate dna binding differ markedly from th ... | 2000 | 10688691 |
| virulence of the phytopathogen pseudomonas syringae pv. maculicola is rpon dependent. | we cloned the rpon (ntra and glnf) gene encoding sigma(54) from the phytopathogen pseudomonas syringae pv. maculicola strain es4326. the p. syringae es4326 rpon gene complemented pseudomonas aeruginosa, escherichia coli, and klebsiella aerogenes rpon mutants for a variety of rpon mutant phenotypes, including the inability to utilize nitrate as sole nitrogen source. dna sequence analysis of the p. syringae es4326 rpon gene revealed that the deduced amino acid sequence was most similar (86% identi ... | 2000 | 10852883 |
| cloning and molecular characterization of hrpx from xanthomonas axonopodis pv. citri. | the hrpx gene of plant pathogenic xanthomonas species is essential for pathogenicity on host plants and to cause hypersensitive reaction on non-host plants. we cloned and analyzed a hrpx homologue, designated hrpxct, of x. axonopodis pv. citri, a pathogen of citrus canker. the open reading frame of hrpxct has 1431 bp in nucleotides which has a coding capacity of 476 amino acid residues with a molecular mass of 52.4 kda. the predicted amino acid sequence of hrpxct has 90% identity to the arac fam ... | 2000 | 10902926 |
| the virulence factor avrxa7 of xanthomonas oryzae pv. oryzae is a type iii secretion pathway-dependent nuclear-localized double-stranded dna-binding protein. | avrxa7 is a member of the avrbs3 avirulence gene family, which encodes proteins targeted to plant cells by a type iii secretion apparatus. avrxa7, the product of avrxa7, is also a virulence factor in strain pxo86 of xanthomonas oryzae pv. oryzae. avirulence and virulence specificities are associated with the central repeat domain, which, in avrxa7, consists of 25.5 direct repeat units. mutations in three c-terminal nuclear localization signal motifs eliminated avirulence and virulence activities ... | 2000 | 10931960 |
| molecular evolution of virulence in natural field strains of xanthomonas campestris pv. vesicatoria. | the avrbs2 avirulence gene of the bacterial plant pathogen xanthomonas campestris pv. vesicatoria triggers disease resistance in pepper plants containing the bs2 resistance gene and contributes to bacterial virulence on susceptible host plants. we studied the effects of the pepper bs2 gene on the evolution of avrbs2 by characterizing the molecular basis for virulence of 20 x. campestris pv. vesicatoria field strains that were isolated from disease spots on previously resistant bs2 pepper plants. ... | 2000 | 11092868 |
| genetic snapshots of the rhizobium species ngr234 genome. | in nitrate-poor soils, many leguminous plants form nitrogen-fixing symbioses with members of the bacterial family rhizobiaceae. we selected rhizobium sp. ngr234 for its exceptionally broad host range, which includes more than i 12 genera of legumes. unlike the genome of bradyrhizobium japonicum, which is composed of a single 8.7 mb chromosome, that of ngr234 is partitioned into three replicons: a chromosome of about 3.5 mb, a megaplasmid of more than 2 mb (pngr234b) and pngr234a, a 536,165 bp pl ... | 2000 | 11178268 |
| molecular characterization and expression of the recx gene of xanthomonas campestris pv. citri. | two genes important in dna repair, reca and lexa, were recently identified in xanthomonas campestris pathovar citri (x.c. pv. citri). an open reading frame located immediately downstream of lexa and reca has now been isolated from this pathovar and characterized. this 486-bp open reading frame encodes a protein of 162 amino acids and shares substantial sequence similarity with recx of other bacterial species. the x.c. pv. citri recx protein was overexpressed in escherichia coli and purified; sds ... | 2001 | 11178726 |
| p(ii) signal transduction proteins, pivotal players in microbial nitrogen control. | the p(ii) family of signal transduction proteins are among the most widely distributed signal proteins in the bacterial world. first identified in 1969 as a component of the glutamine synthetase regulatory apparatus, p(ii) proteins have since been recognized as playing a pivotal role in control of prokaryotic nitrogen metabolism. more recently, members of the family have been found in higher plants, where they also potentially play a role in nitrogen control. the p(ii) proteins can function in t ... | 2001 | 11238986 |
| agricultural microbes genome 2: first glimpses into the genomes of plant-associated microbes. | 2001 | 11251088 | |
| quantitative pcr method for diagnosis of citrus bacterial canker. | for diagnosis of citrus bacterial canker by pcr, an internal standard is employed to ensure the quality of the dna extraction and that proper requisites exist for the amplification reaction. the ratio of pcr products from the internal standard and bacterial target is used to estimate the initial bacterial concentration in citrus tissues with lesions. | 2001 | 11375206 |
| cloning, sequence analysis, and expression in escherichia coli of the gene encoding an alpha-amino acid ester hydrolase from acetobacter turbidans. | the alpha-amino acid ester hydrolase from acetobacter turbidans atcc 9325 is capable of hydrolyzing and synthesizing beta-lactam antibiotics, such as cephalexin and ampicillin. n-terminal amino acid sequencing of the purified alpha-amino acid ester hydrolase allowed cloning and genetic characterization of the corresponding gene from an a. turbidans genomic library. the gene, designated aeha, encodes a polypeptide with a molecular weight of 72,000. comparison of the determined n-terminal sequence ... | 2002 | 11772629 |
| differentially expressed proteins in the interaction of xanthomonas axonopodis pv. citri with leaf extract of the host plant. | the present study reports the expression of proteins of xanthomonas axonopodis pv. citri in response to different growth conditions. the bacterium was cultured in the basal medium mm1 and in the presence of leaf extracts from a susceptible host plant (sweet orange) as well as a resistant (ponkan) and a nonhost plant (passion fruit). the protein profiles were analyzed by two-dimensional gel electrophoresis (2-de). twelve differential spots (induced, up- and down-regulated and repressed) were obse ... | 2001 | 11990505 |
| comparison of the genomes of two xanthomonas pathogens with differing host specificities. | the genus xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the proteobacteria. xanthomonas axonopodis pv. citri (xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. xanthomonas campestris pv. campestris (xcc) causes black rot, which affects crucifers such a ... | 2002 | 12024217 |
| comparative genomic analysis of plant-associated bacteria. | this review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. these are the genomes of agrobacterium tumefaciens, mesorhizobium loti, sinorhizobium meliloti, xanthomonas campestris pv campestris, xanthomonas axonopodis pv citri, xylella fastidiosa, and ralstonia solanacearum. genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. despite the recognized importance of the type iii secretion sy ... | 2002 | 12147758 |
| characterization of xanthomonas axonopodis pv. citri lexa: recognition of the lexa binding site. | levels of l exa transcripts are markedly increased upon exposure of xanthomonas axonopodis pathovar citri ( x. a. pv. citri) to the dna-damaging agent mitomycin c. preliminary electrophoretic mobility-shift data led us to propose that binding of lexa protein to the sequence upstream of the lexa coding region is responsible for low promoter activity in the uniduced state. we determined that the lexa protein binds to the region located between the transcription start site and the translation initi ... | 2002 | 12471445 |
| x-ray analysis of two antibiotic-synthesizing bacterial ester hydrolases: preliminary results. | alpha-amino-acid ester hydrolases are multimeric enzymes of potential use in antibiotic production. knowledge of their structure could help to engineer these enzymes into economically viable biocatalysts. the alpha-amino-acid ester hydrolases from xanthomonas citri and acetobacter turbidans have been crystallized. the x. citri enzyme crystallizes in a primitive monoclinic space group (unit-cell parameters a = 90.1, b = 125.8, c = 132.1 a, beta = 90.9 degrees ). the a. turbidans enzyme crystalliz ... | 2003 | 12499556 |
| hgt-db: a database of putative horizontally transferred genes in prokaryotic complete genomes. | the horizontal gene transfer database (hgt-db) is a genomic database that includes statistical parameters such as g+c content, codon and amino-acid usage, as well as information about which genes deviate in these parameters for prokaryotic complete genomes. under the hypothesis that genes from distantly related species have different nucleotide compositions, these deviated genes may have been acquired by horizontal gene transfer. the current version of the database contains 88 bacterial and arch ... | 2003 | 12519978 |
| contribution of pila to competitive colonization of the squid euprymna scolopes by vibrio fischeri. | vibrio fischeri colonizes the squid euprymna scolopes in a mutualistic symbiosis. hatchling squid lack these bacterial symbionts, and v. fischeri strains must compete to occupy this privileged niche. we cloned a v. fischeri gene, designated pila, that contributes to colonization competitiveness and encodes a protein similar to type iv-a pilins. unlike its closest known relatives, vibrio cholerae msha and vcfa, pila is monocistronic and not clustered with genes associated with pilin export or ass ... | 2003 | 12571000 |
| the sequence and crystal structure of the alpha-amino acid ester hydrolase from xanthomonas citri define a new family of beta-lactam antibiotic acylases. | alpha-amino acid ester hydrolases (aehs) catalyze the hydrolysis and synthesis of esters and amides with an alpha-amino group. as such, they can synthesize beta-lactam antibiotics from acyl compounds and beta-lactam nuclei obtained from the hydrolysis of natural antibiotics. this article describes the gene sequence and the 1.9-a resolution crystal structure of the aeh from xanthomonas citri. the enzyme consists of an alpha/beta-hydrolase fold domain, a helical cap domain, and a jellyroll beta-do ... | 2003 | 12684501 |
| the mosaic structure of the symbiotic plasmid of rhizobium etli cfn42 and its relation to other symbiotic genome compartments. | symbiotic bacteria known as rhizobia interact with the roots of legumes and induce the formation of nitrogen-fixing nodules. in rhizobia, essential genes for symbiosis are compartmentalized either in symbiotic plasmids or in chromosomal symbiotic islands. to understand the structure and evolution of the symbiotic genome compartments (sgcs), it is necessary to analyze their common genetic content and organization as well as to study their differences. to date, five sgcs belonging to distinct spec ... | 2003 | 12801410 |
| composition, acquisition, and distribution of the vi exopolysaccharide-encoding salmonella enterica pathogenicity island spi-7. | vi capsular polysaccharide production is encoded by the viab locus, which has a limited distribution in salmonella enterica serovars. in s. enterica serovar typhi, viab is encoded on a 134-kb pathogenicity island known as spi-7 that is located between partially duplicated trna(pheu) sites. functional and bioinformatic analysis suggests that spi-7 has a mosaic structure and may have evolved as a consequence of several independent insertion events. analysis of viab-associated dna in vi-positive s. ... | 2003 | 12923078 |
| high-throughput screening of structural proteomics targets using nmr. | we applied a high-throughput strategy for the screening of targets for structural proteomics of xanthomonas axonopodis pv citri. this strategy is based on the rapid (1)h-(15)n hsqc nmr analysis of bacterial lysates containing selectively (15)n-labelled heterologous proteins. our analysis permitted us to classify the 19 soluble candidates in terms of 'foldedness', that is, the extent to which they present a well-folded solution structure, as reflected by the quality of their nmr spectra. this cla ... | 2003 | 14527688 |
| phya, a secreted protein of xanthomonas oryzae pv. oryzae, is required for optimum virulence and growth on phytic acid as a sole phosphate source. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. we have identified a novel virulence deficient mutant (bxo1691) of x. oryzae pv. oryzae that has a tn5 insertion in an open reading frame (phya; putative phytase a) encoding a 373-amino acid (aa) protein containing a 28-aa predicted signal peptide. extracellular protein profiles revealed that a 38-kda band is absent in phya mutants as compared with phya+ strains. a blast search with phya and its deduced polype ... | 2003 | 14601665 |
| a simple method for in vivo expression studies of xanthomonas axonopodis pv. citri. | a major problem in studying bacterial plant pathogens is obtaining the microorganism directly from the plant tissue to perform in vivo expression (protein or mrna) analyses. here we report an easy and fast protocol to isolate xanthomonas axonopodis pv. citri directly from the host plant, in sufficient amounts to perform protein fingerprinting by 2-d gel electrophoresis as well as rna expression assays. the protein profile obtained was very similar to that of x. axonopodis pv. citri grown in the ... | 2003 | 14669917 |
| are protein-protein interfaces more conserved in sequence than the rest of the protein surface? | protein interfaces are thought to be distinguishable from the rest of the protein surface by their greater degree of residue conservation. we test the validity of this approach on an expanded set of 64 protein-protein interfaces using conservation scores derived from two multiple sequence alignment types, one of close homologs/orthologs and one of diverse homologs/paralogs. overall, we find that the interface is slightly more conserved than the rest of the protein surface when using either align ... | 2004 | 14691234 |
| differential expression of two paralogous genes of bacillus subtilis encoding single-stranded dna binding protein. | the bacillus subtilis genome comprises two paralogous single-stranded dna binding protein (ssb) genes, ssb and ywph, which show distinct expression patterns. the main ssb gene is strongly expressed during exponential growth and is coregulated with genes encoding the ribosomal proteins s6 and s18. the gene organization rpsf-ssb-rpsr as observed in b. subtilis is found in many gram-positive as well as some gram-negative bacteria, but not in escherichia coli. the ssb gene is essential for cell viab ... | 2004 | 14762004 |
| transcriptional profiling of caulobacter crescentus during growth on complex and minimal media. | microarray analysis was used to examine gene expression in the freshwater oligotrophic bacterium caulobacter crescentus during growth on three standard laboratory media, including peptone-yeast extract medium (pye) and minimal salts medium with glucose or xylose as the carbon source. nearly 400 genes (approximately 10% of the genome) varied significantly in expression between at least two of these media. the differentially expressed genes included many encoding transport systems, most notably di ... | 2004 | 14973021 |
| the leucine-responsive regulatory protein (lrp) gene for characterization of the relationship among xanthomonas species. | characterization of strains of xanthomonas axonopodis pv. citri by using dna fingerprints that were generated from primers for enterobacterial repetitive intergenic consensus (eric) elements led to the discovery of differential sequences for a leucine-responsive regulatory protein (lrp) gene in two subgroups of strains with different host ranges on citrus spp. dna hybridization and pcr-based assays that used different sets of primers were designed to detect the core sequence, as well as to obtai ... | 2004 | 15023955 |
| pilr enhances the sensitivity of xanthomonas axonopodis pv. citri to the infection of filamentous bacteriophage cf. | the pila gene, which encodes the major structure of pili, is required for infection of xanthomonas axonopodis pv. citri ( x. a. pv. citri) by the filamentous bacteriophage cf. two open reading frames (orfs) located downstream of pila were cloned and characterized. one 1392-bp orf encodes a protein of 464 amino acids which shares substantial similarity with pilr of other bacterial species; the second orf ( orf618), of 1854-bp, shares sequence similarity with pils. the existence of the pilr-like a ... | 2004 | 15057449 |
| the oligopeptide permease (opp) of the plant pathogen xanthomonas axonopodis pv. citri. | the oligopeptide permease (opp), a protein-dependent abc transporter, has been found in the genome of xanthomonas axonopodis pv. citri ( xac), but not in xanthomonas campestris pv. campestris ( xcc). sequence analysis indicated that 4 opp genes ( oppa, oppb, oppc, oppd/f), located in a 33.8-kbp dna fragment present only in the xac genome, are arranged in an operon-like structure and share highest sequence similarities with streptomyces roseofulvus orthologs. nonetheless, analyses of the gc conte ... | 2004 | 15060731 |
| [cloning the gene fragment coding the putative integrase-like protein from x maltophilia]. | to amplify the nucleotide sequence of cg-like receptor from x anthomonas maltophilia(x maltophilia). | 2004 | 15071903 |
| horizontal transfer of cs1 pilin genes of enterotoxigenic escherichia coli. | cs1 is one of a limited number of serologically distinct pili found in enterotoxigenic escherichia coli (etec) strains associated with disease in people. the genes for the cs1 pilus are on a large plasmid, pcoo. we show that pcoo is not self-transmissible, although our sequence determination for part of pcoo shows regions almost identical to those in the conjugative drug resistance plasmid r64. when we introduced r64 into a strain containing pcoo, we found that pcoo was transferred to a recipien ... | 2004 | 15126486 |
| recognition of ferric catecholates by fepa. | escherichia coli fepa transports certain catecholate ferric siderophores, but not others, nor any noncatecholate compounds. direct binding and competition experiments demonstrated that this selectivity originates during the adsorption stage. the synthetic tricatecholate fe-trencam bound to fepa with 50- to 100-fold-lower affinity than fe-enterobactin (feent), despite an identical metal center, and fe-corynebactin only bound at much higher concentrations. neither fe-agrobactin nor ferrichrome bou ... | 2004 | 15150246 |
| bacterial genomes as new gene homes: the genealogy of orfans in e. coli. | differences in gene repertoire among bacterial genomes are usually ascribed to gene loss or to lateral gene transfer from unrelated cellular organisms. however, most bacteria contain large numbers of orfans, that is, annotated genes that are restricted to a particular genome and that possess no known homologs. the uniqueness of orfans within a genome has precluded the use of a comparative approach to examine their function and evolution. however, by identifying sequences unique to monophyletic g ... | 2004 | 15173110 |
| 1h, 15n and 13c resonance assignments of the apag protein of the phytopathogen xanthomonas axonopodis pv. citri. | 2004 | 15213450 | |
| comparative genomics analyses of citrus-associated bacteria. | xylella fastidiosa 9a5c (xf-9a5c) and xanthomonas axonopodis pv. citri (xac) are bacteria that infect citrus plants. sequencing of the genomes of these strains is complete and comparative analyses are now under way with the genomes of other bacteria of the same genera. in this review, we present an overview of this comparative genomic work. we also present a detailed genomic comparison between xf-9a5a and xac. based on this analysis, genes and operons were identified that might be relevant for a ... | 2004 | 15283664 |
| identification and functional analysis of dtdp-glucose-4,6-dehydratase gene and its linked gene cluster in an aminoglycoside antibiotics producer of streptomyces tenebrarius h6. | streptomyces tenebrarius h6 produces a variety of aminoglycoside antibiotics, such as apramycin, tobramycin, and kanamycin b. primers were designed according to the highly conserved sequences of the dtdp-glucose-4,6-dehydratase genes, and a 0.6-kb pcr product was obtained from s. tenebrarius h6 genomic dna. with the 0.6-kb pcr product as a probe, a bamhi 7.0-kb fragment was isolated. dna sequence analysis of the 7.0-kb fragment revealed four orfs and an incomplete orf. in search of databases, th ... | 2004 | 15297914 |
| new protein-protein interactions identified for the regulatory and structural components and substrates of the type iii secretion system of the phytopathogen xanthomonas axonopodis pathovar citri. | we have initiated a project to identify protein-protein interactions involved in the pathogenicity of the bacterial plant pathogen xanthomonas axonopodis pv. citri. using a yeast two-hybrid system based on gal4 dna-binding and activation domains, we have focused on identifying interactions involving subunits, regulators, and substrates of the type iii secretion system coded by the hrp (for hypersensitive response and pathogenicity), hrc (for hrp conserved), and hpa (for hrp associated) genes. we ... | 2004 | 15342589 |
| variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps) biosynthetic locus in xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice. | in animal pathogenic bacteria, horizontal gene transfer events (hgt) have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (lps). as a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. since lps is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. although lps has been suggested as a ... | 2004 | 15473911 |
| antibiotic multiresistance plasmid prsb101 isolated from a wastewater treatment plant is related to plasmids residing in phytopathogenic bacteria and carries eight different resistance determinants including a multidrug transport system. | ten different antibiotic resistance plasmids conferring high-level erythromycin resistance were isolated from an activated sludge bacterial community of a wastewater treatment plant by applying a transformation-based approach. one of these plasmids, designated prsb101, mediates resistance to tetracycline, erythromycin, roxythromycin, sulfonamides, cephalosporins, spectinomycin, streptomycin, trimethoprim, nalidixic acid and low concentrations of norfloxacin. plasmid prsb101 was completely sequen ... | 2004 | 15528650 |
| 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 |
| in silico analysis of nonribosomal peptide synthetases of xanthomonas axonopodis pv. citri: identification of putative siderophore and lipopeptide biosynthetic genes. | the genomes of the plant pathogens xanthomonas axonopodis (xac) and xanthomonas campestris (xcc) were analysed with the aim of deducing their ability to produce nonribosomal peptides. nonribosomal peptide synthetase (nrps) genes were identified in two separate loci of xac. while the genes of locus 1 are common to both strains, locus 2 was only found in xac. dissection and phylogenetic analysis of the condensation and thioesterase domains of the nrpss of loci 1 and 2 of xac revealed homology, res ... | 2004 | 15646388 |
| expression profiling of virulence and pathogenicity genes of xanthomonas axonopodis pv. citri. | dna macroarrays of 279 genes of xanthomonas axonopodis pv. citri potentially associated with pathogenicity and virulence were used to compare the transcriptional alterations of this bacterium in response to two synthetic media. data analysis indicated that 31 genes were up-regulated by synthetic medium xvm2, while only 7 genes were repressed. the results suggest that xvm2 could be used as an in vitro system to identify candidate genes involved in pathogenesis of x. axonopodis pv. citri. | 2005 | 15659697 |
| mapping transposon insertion sites by touchdown pcr and hybrid degenerate primers. | a novel mapping method based on touchdown pcr was developed for identifying a transposon insertion site in genomic dna using a hybrid consensus-degenerate primer in combination with a specific primer that anneals to the transposon. the method was tested using xanthomonas citri transposon mutants. pcr products contained adjacent dna regions that belonged to both x. citri genomic dna and the transposon. products were directly sequenced from pcrs using only the specific primer. different pcr condit ... | 2005 | 15727129 |
| 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 |
| identification of new protein-protein interactions involving the products of the chromosome- and plasmid-encoded type iv secretion loci of the phytopathogen xanthomonas axonopodis pv. citri. | the recently sequenced genome of the bacterial plant pathogen xanthomonas axonopodis pv. citri contains two virb gene clusters, one on the chromosome and one on a 64-kb plasmid, each of which codes for a previously uncharacterized type iv secretion system (t4ss). here we used a yeast two-hybrid assay to identify protein-protein interactions in these two systems. our results revealed interactions between known t4ss components as well as previously uncharacterized interactions involving hypothetic ... | 2005 | 15774874 |
| 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 |
| 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 |
| reclassification of xanthomonas campestris pv. citri (ex hasse 1915) dye 1978 forms a, b/c/d, and e as x. smithii subsp. citri (ex hasse) sp. nov. nom. rev. comb. nov., x. fuscans subsp. aurantifolii (ex gabriel 1989) sp. nov. nom. rev. comb. nov., and x. alfalfae subsp. citrumelo (ex riker and jones) gabriel et al., 1989 sp. nov. nom. rev. comb. nov.; x. campestris pv malvacearum (ex smith 1901) dye 1978 as x. smithii subsp. smithii nov. comb. nov. nom. nov.; x. campestris pv. alfalfae (ex riker and jones, 1935) dye 1978 as x. alfalfae subsp. alfalfae (ex riker et al., 1935) sp. nov. nom. rev.; and "var. fuscans" of x. campestris pv. phaseoli (ex smith, 1987) dye 1978 as x. fuscans subsp. fuscans sp. nov. | bacterial canker of citrus is a serious disease of citrus worldwide. five forms of the disease have been described, cankers "a", "b", "c", "d", and "e". although considerable genetic diversity has been described among the causal agents of the five forms of citrus canker and supports multiple taxons, the causal agents currently are classified as pathovars citri ("a"), aurantifolii ("b/c/d") and citrumelo ("e") of a single species, xanthomonas campestris pv. citri (or x. axonopodis pv. citri). to ... | 2005 | 16104350 |
| purification and in vitro characterization of the maltose-binding protein of the plant pathogen xanthomonas citri. | the uptake of maltose and maltodextrins in gram-negative bacteria is mediated by an atp-dependent transport complex composed of a periplasmic maltose-binding protein (mbp) and membrane-associated proteins responsible for the formation of a membrane pore and generation of energy to drive the translocation process. in this work, we report the purification and in vitro functional analysis of mbp, encoded by the male gene, of the plant pathogen xanthomonas citri, responsible for the canker disease a ... | 2005 | 16139753 |
| the pcoo plasmid of enterotoxigenic escherichia coli is a mosaic cointegrate. | cs1 is the prototype of a class of pili of enterotoxigenic escherichia coli (etec) associated with diarrheal disease in humans. the genes encoding this pilus are carried on a large plasmid, pcoo. we report the sequence of the complete 98,396-bp plasmid. like many other virulence plasmids, pcoo is a mosaic consisting of regions derived from multiple sources. complete and fragmented insertion sequences (is) make up 24% of the total dna and are scattered throughout the plasmid. the pcoo dna between ... | 2005 | 16159784 |
| the alpha-(1-->6) glycosidic linkage as a novel conformational entropic regulator in osmoregulated periplasmic alpha-cyclosophorohexadecaose. | molecular dynamics simulations were performed to explain the conformational effect of an alpha-(1-->6)-glycosidic linkage upon the cyclic osmoregulated periplasmic glucan (opg) produced by xanthomonas campestris pv. citri. we suggest that a single alpha-(1-->6)-glycosidic linkage in cyclic opg functions as a novel entropic regulator, which reduces the conformational entropy of cyclic opg and increases the motional entropy of solvent water molecules. | 2005 | 16169537 |
| virulence deficiency caused by a transposon insertion in the purh gene of xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. we have identified a tn5-induced virulence-deficient mutant (bxo1704) of x. oryzae pv. oryzae. the bxo1704 mutant exhibited growth deficiency in minimal medium but was proficient in inducing a hypersensitive response in a non-host tomato plant. sequence analysis of the chromosomal dna flanking the tn5 insertion indicated that the tn5 insertion is in the purh gene, which is highly homologous to purh genes of ot ... | 2005 | 16175206 |
| insights into genome plasticity and pathogenicity of the plant pathogenic bacterium xanthomonas campestris pv. vesicatoria revealed by the complete genome sequence. | the gram-negative plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria is the causative agent of bacterial spot disease in pepper and tomato plants, which leads to economically important yield losses. this pathosystem has become a well-established model for studying bacterial infection strategies. here, we present the whole-genome sequence of the pepper-pathogenic xanthomonas campestris pv. vesicatoria strain 85-10, which comprises a 5.17-mb circular chromosome and four plasmids. th ... | 2005 | 16237009 |
| 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 |
| use of immunogold labelling with scanning electron microscopy to identify phytopathogenic bacteria on leaf surfaces. | scanning electron microscopy coupled with high-resolution back-scattered electron imaging was used to detect gold-labelled specific immunoglobulins attached to epiphytic bacteria. strains of xanthomonas citri and x. campestris pv. citrumelo were specifically identified on grapefruit leaf surfaces when labelled with homologous gold-labelled immunoglobulins. | 1991 | 16348573 |
| evaluation of the biolog substrate utilization system to identify and assess metabolic variation among strains of xanthomonas campestris pv. citri. | metabolic fingerprints of 148 strains of xanthomonas campestris pv. citri originating from 24 countries and associated with various forms of citrus bacterial canker disease (cbcd) were obtained by using the biolog substrate utilization system. metabolic profiles were used to attempt strain identification. only 6.8% of the studied strains were correctly identified when the commercial microlog 2n data base was used alone. when the data base was supplemented with data from 54 strains of x. campestr ... | 1993 | 16348849 |
| 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 |