| numerical analysis of 295 phenotypic features of 266 xanthomonas strains and related strains and an improved taxonomy of the genus. | an extensive phenotypic description and an improved classification and nomenclature of the genus xanthomonas are presented. a total of 266 strains obtained from different geographical areas, including representative strains of all species of the genus xanthomonas and most pathovars of xanthomonas campestris, as well as strains which might be genetically related to the genus xanthomonas, were examined for 295 morphological, biochemical, and physiological features. similarities among the strains w ... | 1990 | 2275852 |
| preliminary characterization of an antibiotic produced by xanthomonas albilineans which inhibits dna synthesis in escherichia coli. | chlorosis-inducing isolates of xanthomonas albilineans, the sugarcane leaf scald pathogen, produced a mixture of antibacterial compounds in culture. the antibiotic mixture, which eluted as a single strongly retarded peak from sephadex lh-20 in methanol, was bactericidal to escherichia coli. inhibition of e. coli was not reversed by added nutrients, and affected cells were not lysed but many accumulated polyphosphate granules. the major antibacterial component, isolated in crystalline form after ... | 1985 | 2410547 |
| trna intergenic spacers reveal polymorphisms diagnostic for xanthomonas albilineans. | a pcr-based detection system was developed for xanthomonas albilineans, a pathogen of sugarcane, and other related xanthomonads, using the conserved sequence of two adjacent trna genes and the variable length and sequence of the spacer region between them. an appropriate region was identified as follows: trna genes with the same anticodon from a wide variety of bacteria were aligned and the most frequent base at each position was chosen to derive primers that would anneal to the gene in either o ... | 1995 | 8574414 |
| at least two separate gene clusters are involved in albicidin production by xanthomonas albilineans. | transposon mutagenesis was used to obtain mutations affecting production of the toxin albicidin in xanthomonas albilineans, which causes leaf scald disease of sugarcane and is also pathogenic to corn. transposon tn5-gusa inserted randomly into genomic dna of x. albilineans xa23r1 at a frequency of 10(-4) to 10(-5) per recipient after conjugal transfer from escherichia coli. fifty prototrophic mutants defective in albicidin production were isolated from 7,100 tn5-gusa insertional derivatives test ... | 1996 | 8755889 |
| random-amplified polymorphic dna (rapd) analysis shows intraspecies differences among xanthomonas albilineans strains. | five strains of xanthomonas albilineans, causal agent of leaf scald disease in sugarcane from various geographical regions, were compared using random amplification of polymorphic dna (rapd) to determine whether they could be differentiated at the dna level. cscl-purified genomic dna from these strains were amplified by the polymerase chain reaction (pcr) using arbitrary 10-mer primers according to standard rapd conditions and the amplification product profiles analysed by conventional agarose g ... | 1996 | 8987711 |
| comparison of 16s ribosomal dna sequences of all xanthomonas species. | the phylogenetic relationships of all validly described species of the genus xanthomonas and the type strain of stenotrophomonas maltophilia were analyzed by sequencing and comparing 16s ribosomal dnas (rdnas). the two genera exhibited a mean sequence similarity value of 96.6%, corresponding to differences at 50 nucleotide positions on average. the species of the genus xanthomonas exhibited relatively high levels of overall sequence similarity; the mean similarity value was 98.2%, which correspo ... | 1997 | 9103617 |
| mechanisms of biocontrol by pantoea dispersa of sugar cane leaf scald disease caused by xanthomonas albilineans. | albicidins, a family of phytotoxins and antibiotics produced by xanthomonas albilineans, are important in sugar cane leaf scald disease development. the albicidin detoxifying bacterium pantoea dispersa (syn. erwinia herbicola) sb1403 provides very effective biocontrol against leaf scald disease in highly susceptible sugar cane cultivars. the p. dispersa gene (albd) for enzymatic detoxification of albicidin has recently been cloned and sequenced. to test the role of albicidin detoxification in bi ... | 1997 | 9134719 |
| genes for albicidin biosynthesis and resistance span at least 69 kb in the genome of xanthomonas albilineans. | all tn5 insertion mutants of xanthomonas albilineans, the cause of leaf scald disease of sugar cane, which failed to produce albicidin antibiotics failed to cause chlorosis in inoculated sugar cane but remained resistant to albicidin. southern analysis revealed that mutants deficient in albicidin production carried the transposon on different chromosomal restriction fragments spanning at least 50 kb in the x. albilineans genome, which is larger than any reported cluster of genes involved in the ... | 1997 | 9134771 |
| the gene for albicidin detoxification from pantoea dispersa encodes an esterase and attenuates pathogenicity of xanthomonas albilineans to sugarcane. | albicidin phytotoxins are pathogenicity factors in a devastating disease of sugarcane known as leaf scald, caused by xanthomonas albilineans. a gene (albd) from pantoea dispersa has been cloned and sequenced and been shown to code for a peptide of 235 amino acids that detoxifies albicidin. the gene shows no significant homology at the dna or protein level to any known sequence, but the gene product contains a gxsxg motif that is conserved in serine hydrolases. the albd protein, purified to homog ... | 1997 | 9275238 |
| factors affecting biosynthesis by xanthomonas albilineans of albicidin antibiotics and phytotoxins. | albicidins are important factors in systemic pathogenesis by xanthomonas albilineans, which causes the devastating leaf scald disease of sugar cane. they are also of substantial interest as antibiotics that selectively block prokaryote dna replication. albicidin biosynthesis is highly sensitive to medium composition. an optimized, chemically defined medium (smg3) yielded 30-fold more albicidin from half the accumulated biomass, relative to sucrose peptone (sp) medium. phosphate starvation stimul ... | 1998 | 9871323 |
| genetic polymorphism in xanthomonas albilineans strains originating from 11 geographical locations, revealed by two dna probes. | two dna fragments from xanthomonas albilineans were used as probes to study the molecular diversity among strains of this pathogen. two serologically distinct groups, serovars i and ii, could be differentiated by hybridization to the probes. these probes, designated 830 and 838, were cloned after subtractive dna hybridization of common sequences of xanthomonas campestris pv. vasculorum from a serovar i strain of x. albilineans. they did not hybridize to the dna of several other xanthomonads or t ... | 2000 | 10792648 |
| rapid amplification and cloning of tn5 flanking fragments by inverse pcr. | a simple approach is described to efficiently amplify dna sequences flanking transposon tn5 insertions. the method involves: (i) digestion with a restriction enzyme that cuts within tn5; (ii) self-ligation under conditions favouring the production of monomeric circles; (iii) four parallel pcr reactions using primers designed to amplify left or right flanking sequences, and to distinguish target amplicons from non-specific products. this reveals the number of tn5 insertions and the size of flanki ... | 2000 | 10972718 |
| analysis of the genes flanking xabb: a methyltransferase gene is involved in albicidin biosynthesis in xanthomonas albilineans. | transposon mutagenesis and complementation studies previously identified a gene (xabb) for a large (526kda) polyketide-peptide synthase required for biosynthesis of albicidin antibiotics and phytotoxins in the sugarcane leaf scald pathogen xanthomonas albilineans. a cistron immediately downstream from xabb encodes a polypeptide of 343aa containing three conserved motifs characteristic of a family of s-adenosyl-l-methionine (sam)-dependent o-methyltransferases. insertional mutagenesis and complem ... | 2000 | 11024293 |
| characterization of the acyl carrier protein gene and the fab gene locus in xanthomonas albilineans. | a genomic region containing the fatty acid biosynthetic (fab) genes was isolated from the sugarcane leaf-scald pathogen xanthomonas albilineans. the order and predicted products of fabg (beta-ketoacyl reductase), acpp (acyl carrier protein), fabf (ketoacyl synthase ii) and downstream genes in x. albilineans are very similar to those in escherichia coli, with one exception. sequence analysis, confirmed by insertional knockout and specific substrate feeding experiments, shows that the position occ ... | 2000 | 11094291 |
| albicidin antibiotic and phytotoxin biosynthesis in xanthomonas albilineans requires a phosphopantetheinyl transferase gene. | xanthomonas albilineans produces a family of highly potent antibiotics and phytotoxins called albicidins, which are key pathogenesis factors in the systemic development of leaf scald disease of sugarcane. a gene (xaba) required for albicidin biosynthesis encodes a peptide of 278 amino acids, including the signature sequence motifs for phosphopantetheinyl transferases (pptases) that activate polyketide and non-ribosomal peptide synthetases. the escherichia coli entd gene, which encodes a pptase i ... | 2000 | 11111057 |
| a multifunctional polyketide-peptide synthetase essential for albicidin biosynthesis in xanthomonas albilineans. | albicidins, a family of potent antibiotics and phytotoxins produced by the sugarcane leaf scald pathogen xanthomonas albilineans, inhibit dna replication in bacteria and plastids. a gene located by tn5-tagging was confirmed by complementation to participate in albicidin biosynthesis. the gene (xabb) encodes a large protein (predicted m:(r) 525695), with a modular architecture indicative of a multifunctional polyketide synthase (pks) linked to a non-ribosomal peptide synthetase (nrps). at 4801 am ... | 2001 | 11238970 |
| xanthomonas albilineans diversity and identification based on rep-pcr fingerprints. | pcr with box and eric primers was used to analyze dna of xanthomonas albilineans and other bacteria associated with sugarcane. generated fingerprints permitted clear separation of x. albilineans from other bacteria and revealed variation within the species. good agreement between fingerprint groups and geographic origin and serovars was observed. | 2001 | 11270647 |
| phylogenetic analysis of xanthomonas species based upon 16s-23s rdna intergenic spacer sequences. | phylogenetic relationships of 17 species of xanthomonas were assessed based on analysis of 16s-23s rdna intergenic spacer (its) sequences; a higher level of resolution was obtained than that revealed by 16s rdna analysis. its sequences varied in size from 492 to 578 nt within the genus and the similarity among sequences ranged from 63 to 99%. major differences were found for the hyacinthi group, which included xanthomonas albilineans, xanthomonas hyacinthi, xanthomonas sacchari, xanthomonas thei ... | 2002 | 11931143 |
| identification of xanthans isolated from sugarcane juices obtained from scalded plants infected by xanthomonas albilineans. | the exudate gum produced by xanthomonas albilineans, a specific sugarcane pathogen, has been isolated from juices of diseased sugarcane stalks, hydrolyzed with hydrochloric acid, and the hydrolysate analyzed by capillary electrophoresis. sucrose. cellobiose, mannose, glucose, glucose-1-p and glucuronic acid were identified as the major components of the polysaccharide isolated from diseased stalks. juices from healthy stalks contained maltose instead of cellobiose. the chemical nature of this po ... | 2002 | 12013236 |
| gluconacetobacter diazotrophicus, a sugar cane endosymbiont, produces a bacteriocin against xanthomonas albilineans, a sugar cane pathogen. | gluconacetobacter diazotrophicus in liquid culture secretes proteins into the medium. both medium containing gluconacetobacter protein and a solution of this protein after acetone precipitation appeared to inhibit the growth of xanthomonas albilineans in solid culture. this apparent inhibition of bacterial growth has, in fact, been revealed to be lysis of bacterial cells, as demonstrated by transmission electron microscopy. fractionation of the gluconacetobacter protein mixture in size-exclusion ... | 2002 | 12234008 |
| albicidin pathotoxin produced by xanthomonas albilineans is encoded by three large pks and nrps genes present in a gene cluster also containing several putative modifying, regulatory, and resistance genes. | xanthomonas albilineans, which causes leaf scald disease of sugarcane, produces a highly potent pathotoxin called albicidin. we report here sequencing and homology analysis of the major gene cluster, xalb1 (55,839 bp), and a second, smaller region, xalb2 (2,986 bp), involved in albicidin biosynthesis. xalb1 contains 20 open reading frames, including i) three large genes with a modular architecture characteristic of polyketide synthases (pkss) and nonribosomal peptide synthases (nrpss) and ii) se ... | 2004 | 15077674 |
| xanthomonas albilineans htpg is required for biosynthesis of the antibiotic and phytotoxin albicidin. | xanthomonas albilineans, the causal agent of leaf scald disease of sugarcane, produces a highly potent polyketide-peptide antibiotic and phytotoxin called albicidin. previous studies established the involvement of a large cluster of genes in the biosynthesis of this toxin. we report here the sub-cloning and sequencing of an additional gene outside of the main cluster and essential for albicidin biosynthesis. this gene encodes a 634-amino-acid protein that shows high identity with the escherichia ... | 2005 | 16102911 |
| antagonism of gluconacetobacter diazotrophicus (a sugarcane endosymbiont) against xanthomonas albilineans (pathogen) studied in alginate-immobilized sugarcane stalk tissues. | xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. xanthan production has been verified after experimental infection of stalk segments of healthy plants. moreover, gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with x. albilineans by impeding the production of the bacterial gum. the physiological basis of this antagonism ... | 2005 | 16233803 |
| a dha14 drug efflux gene from xanthomonas albilineans confers high-level albicidin antibiotic resistance in escherichia coli. | identification of a gene for self-protection from the antibiotic-producing plant pathogen xanthomonas albilineans, and functional testing by heterologous expression. | 2006 | 16834602 |
| purification and properties of an unusual udp-glucose dehydrogenase, nadph-dependent, from xanthomonas albilineans. | xanthomonas albilineans produces a udp-glucose dehydrogenase growing on sucrose. the enzyme oxidizes udp-glucose to udp-glucuronic acid by using molecular oxygen and nadph. kinetics of enzymatic oxydation of nadph is linearly dependent on the amount of oxygen supplied. the enzyme has been purified at homogeneity. the value of pi of the purified enzyme is 8.98 and its molecular mass has been estimated as about 14 kda. the enzyme shows a michaelian kinetics for udp-glucose concentrations. the valu ... | 2008 | 17010583 |
| associations between dna markers and resistance to diseases in sugarcane and effects of population substructure. | association between markers and sugarcane diseases were investigated in a collection of 154 sugarcane clones, consisting of important ancestors or parents, and cultivars. 1,068 polymorphic aflp and 141 srr markers were scored across all clones. data on the four most important diseases in the australian sugarcane industry were obtained; these diseases being pachymetra root rot (pachymetra chaunorhiza b.j. croft & m.w. dick), leaf scald (xanthomonas albilineans dowson), fiji leaf gall (fiji diseas ... | 2006 | 17047910 |
| the phytotoxin albicidin is a novel inhibitor of dna gyrase. | xanthomonas albilineans produces a family of polyketide-peptide compounds called albicidins which are highly potent antibiotics and phytotoxins as a result of their inhibition of prokaryotic dna replication. here we show that albicidin is a potent inhibitor of the supercoiling activity of bacterial and plant dna gyrases, with 50% inhibitory concentrations (40 to 50 nm) less than those of most coumarins and quinolones. albicidin blocks the religation of the cleaved dna intermediate during the gyr ... | 2007 | 17074789 |
| heterologous production of albicidin: a promising approach to overproducing and characterizing this potent inhibitor of dna gyrase. | the phytotoxin and polyketide antibiotic albicidin produced by xanthomonas albilineans is a highly potent dna gyrase inhibitor. low yields of albicidin production have slowed studies of its chemical structure. heterologous expression of albicidin biosynthetic genes in x. axonopodis pv. vesicatoria resulted in a sixfold increase in albicidin production, offering promising strategies for engineering overproduction. | 2007 | 17220426 |
| substrate specificity-conferring regions of the nonribosomal peptide synthetase adenylation domains involved in albicidin pathotoxin biosynthesis are highly conserved within the species xanthomonas albilineans. | albicidin is a pathotoxin produced by xanthomonas albilineans, a xylem-invading pathogen that causes leaf scald disease of sugarcane. albicidin is synthesized by a nonribosomal pathway via modular polyketide synthase and nonribosomal peptide synthetase (nrps) megasynthases, and nrps adenylation (a) domains are responsible for the recognition and activation of specific amino acid substrates. dna fragments (0.5 kb) encoding the regions responsible for the substrate specificities of six albicidin n ... | 2007 | 17630307 |
| xanthan production by xanthomonas albilineans infecting sugarcane stalks. | xanthomonas albilineans is the causal organism of leaf scald, a bacterial vascular disease of sugarcane. xanthomonas may invade the parenchyma between the bundles and cause reddened pockets of gum, identified as a xanthan-like polysaccharide. since xanthan contains glucuronic acid, the ability of xanthomonas to produce an active udp glucose dehydrogenase is often seen as a virulence factor. x. albilineans axenically cultured did not secrete xanthans to willbrink liquid media, but the use of inoc ... | 2008 | 17646030 |
| dna gyrase from the albicidin producer xanthomonas albilineans has multiple-antibiotic-resistance and unusual enzymatic properties. | the sugarcane pathogen xanthomonas albilineans produces a family of antibiotics and phytotoxins termed albicidins, which inhibit plant and bacterial dna gyrase supercoiling activity, with a 50% inhibitory concentration (50 nm) comparable to those of coumarins and quinolones. here we show that x. albilineans has an unusual, antibiotic-resistant dna gyrase. the x. albilineans gyra and gyrb genes are not clustered with previously described albicidin biosynthesis and self-protection genes. the gyra ... | 2008 | 18268084 |
| amplified fragment length polymorphisms reveal genetic differentiation among strains of xanthomonas albilineans. | xanthomonas albilineans, the causative agent of leaf scald disease (lsd), colonizes the vascular system of sugarcane (saccharum spp. hybrids). in this study x. albilineans strains from 28 countries were differentiated by using two methods of amplified fragment length polymorphism (aflp). in the manual procedure, aflp reactions were performed on 57 x. albilineans strains and after selective amplification using radiolabelled primers, the resulting products were separated using polyacrylamide gel e ... | 2009 | 18834907 |
| high variation in pathogenicity of genetically closely related strains of xanthomonas albilineans, the sugarcane leaf scald pathogen, in guadeloupe. | abstract pathogenicity of 75 strains of xanthomonas albilineans from guadeloupe was assessed by inoculation of sugarcane cv. b69566, which is susceptible to leaf scald, and 19 of the strains were selected as representative of the variation in pathogenicity observed based on stalk colonization. in vitro production of albicidin varied among these 19 strains, but the restriction fragment length polymorphism pattern of their albicidin biosynthesis genes was identical. similarly, no genomic variation ... | 2006 | 18943496 |
| variation in albicidin biosynthesis genes and in pathogenicity of xanthomonas albilineans, the sugarcane leaf scald pathogen. | abstract total genomic dna from 137 strains of xanthomonas albilineans from worldwide locations was hybridized with two dna probes that together harbor the entire 49-kb albicidin biosynthesis gene cluster and two additional 3-kb genomic regions required for albicidin production. fourteen haplotypes and two major genetic groups (albicidin [alb]-restriction fragment length polymorphism [rflp] a and alb-rflp b) were identified, and strains that were isolated after recent outbreaks of leaf scald dis ... | 2006 | 18944203 |
| resistance to leaf scald disease is associated with limited colonization of sugarcane and wild relatives by xanthomonas albilineans. | abstract a streptomycin- and rifampicin-resistant mutant of xanthomonas al-bilineans was used to study symptom expression of leaf scald disease (lsd) and colonization of sugarcane (saccharum spp.) and its wild relatives by this bacterial pathogen. a total of 40 sugarcane cultivars and 15 clones from the saccharum complex that differed in resistance to lsd were inoculated by a decapitation technique in both field and greenhouse experiments. in the plant crop, disease severity varied between 0 for ... | 1997 | 18945019 |
| intraspecific genomic variation within xanthomonas albilineans, the sugarcane leaf scald pathogen. | abstract to better understand the nature of recent outbreaks of leaf scald disease of sugarcane in a number of sugarcane production regions of the world including florida, guadeloupe, louisiana, mauritius, taiwan, and texas, a study of the worldwide genetic variation of the pathogen was undertaken. a total of 218 strains from 31 geographic locations were examined. genomic dna of each strain was digested with the rare cutting restriction enzyme spei, and the fragments were separated by pulsed-fie ... | 1997 | 18945175 |
| gluconacetobacter diazotrophicus elicits a sugarcane defense response against a pathogenic bacteria xanthomonas albilineans. | a new role for the plant growth-promoting nitrogen-fixing endophytic bacteria gluconacetobacter diazotrophicus has been identified and characterized while it is involved in the sugarcane-xanthomonas albilineans pathogenic interactions. living g.diazotrophicus possess and/or produce elicitor molecules which activate the sugarcane defense response resulting in the plant resistance to x. albilineans, in this particular case controlling the pathogen transmission to emerging agamic shoots. a total of ... | 2006 | 19516988 |
| the complete genome sequence of xanthomonas albilineans provides new insights into the reductive genome evolution of the xylem-limited xanthomonadaceae. | the xanthomonadaceae family contains two xylem-limited plant pathogenic bacterial species, xanthomonas albilineans and xylella fastidiosa. x. fastidiosa was the first completely sequenced plant pathogen. it is insect-vectored, has a reduced genome and does not possess hrp genes which encode a type iii secretion system found in most plant pathogenic bacteria. x. fastidiosa was excluded from the xanthomonas group based on phylogenetic analyses with rrna sequences. | 2009 | 20017926 |
| functional analysis of genes for benzoate metabolism in the albicidin biosynthetic region of xanthomonas albilineans. | albicidins are potent dna-gyrase-inhibiting antibiotics and phytotoxins synthesised by xanthomonas albilineans. functions have been deduced for some clustered biosynthetic genes, including a pks-nrps megasynthase, methyltransferases and regulatory genes, and resistance genes including a transporter and a gyrase-binding protein. more puzzling is the presence in this cluster of apparent aromatic metabolism genes. here, we describe functional analysis of several such genes and propose a model for t ... | 2010 | 20437231 |
| xanthomonas albilineans and the antipathogenesis approach to disease control. | summary molecular studies into sugarcane leaf scald disease, caused by x. albilineans, revealed an unusual pathogenesis strategy, a new family of antibiotics, an extraordinary biosynthetic apparatus, and a new approach to disease control in plants and animals. taxonomy: bacteria; proteobacteria; gamma subdivision; xanthomonadales; xanthomonas group; x. albilineans (ashby 1929) dowson 1943. microbiological properties: gram-negative, slender rod-shaped, nonsporing, aerobic, motile by a single pola ... | 2001 | 20572987 |
| genomic and evolutionary features of the spi-1 type iii secretion system that is present in xanthomonas albilineans but is not essential for xylem colonization and symptom development of sugarcane leaf scald. | xanthomonas albilineans is the causal agent of sugarcane leaf scald. interestingly, this bacterium, which is not known to be insect or animal associated, possesses a type iii secretion system (t3ss) belonging to the injectisome family salmonella pathogenicity island 1 (spi-1). the t3ss spi-1 of x. albilineans shares only low similarity with other available t3ss spi-1 sequences. screening of a collection of 128 plant-pathogenic bacteria revealed that this t3ss spi-1 is present in only two species ... | 2011 | 20955079 |
| identification of new candidate pathogenicity factors in the xylem-invading pathogen xanthomonas albilineans by transposon mutagenesis. | xanthomonas albilineans is a xylem-invading pathogen that produces the toxin albicidin that blocks chloroplast differentiation, resulting in disease symptoms of sugarcane leaf scald. in contrast to other xanthomonads, x. albilineans does not possess a hypersensitive response and pathogenicity type iii secretion system and does not produce xanthan gum. albicidin is the only previously known pathogenicity factor in x. albilineans, yet albicidin-deficient mutant strains are still able to efficientl ... | 2011 | 21190440 |
| pentapeptide-repeat proteins that act as topoisomerase poison resistance factors have a common dimer interface. | the protein albg is a self-resistance factor against albicidin, a nonribosomally encoded hybrid polyketide-peptide with antibiotic and phytotoxic properties produced by xanthomonas albilineans. primary-sequence analysis indicates that albg is a member of the pentapeptide-repeat family of proteins (prp). the structure of albg from x. albilineans was determined at 2.0ôçà+à resolution by sad phasing using data collected from a single trimethyllead acetate derivative on a home source. albg folds int ... | 2011 | 21393830 |
| sugarcane glycoproteins may act as signals for the production of xanthan in the plant-associated bacterium xanthomonas albilineans. | visual symptoms of leaf scald necrosis in sugarcane (saccharum officinarum) leaves develop in parallel to the accumulation of a fibrous material invading exocellular spaces and both xylem and phloem. these fibers are produced and secreted by the plant-associated bacterium xanthomonas albilineans. electron microscopy and specific staining methods for polysaccharides reveal the polysaccharidic nature of this material. these polysaccharides are not present in healthy leaves or in those from disease ... | 2011 | 21791980 |
| Phylogenetic analysis of Xanthomonas based on partial rpoB gene sequences and species differentiation by PCR-RFLP. | The rpoB gene was evaluated as an alternative molecular marker for the differentiation of Xanthomonas species and to better understand of the phylogenetic relationship within the genus. PCR-RFLP experiments using Hae III allowed differentiating Xanthomonas species, mainly those that affect the same plant host such as X. albilineans and X. sacchari, pathogenic to sugarcane; X. cucurbitae and X. melonis, which cause disease in melon; and X. gardneri, X. vesicatoria and X. euvesicatoria/X. perforan ... | 2011 | 21984675 |
| genomic insights into strategies used by xanthomonas albilineans with its reduced artillery to spread within sugarcane xylem vessels. | xanthomonas albilineans causes leaf scald, a lethal disease of sugarcane. x. albilineans exhibits distinctive pathogenic mechanisms, ecology and taxonomy compared to other species of xanthomonas. for example, this species produces a potent dna gyrase inhibitor called albicidin that is largely responsible for inducing disease symptoms; its habitat is limited to xylem; and the species exhibits large variability. a first manuscript on the complete genome sequence of the highly pathogenic x. albilin ... | 2012 | 23171051 |
| genome mining reveals the genus xanthomonas to be a promising reservoir for new bioactive non-ribosomally synthesized peptides. | various bacteria can use non-ribosomal peptide synthesis (nrps) to produce peptides or other small molecules. conserved features within the nrps machinery allow the type, and sometimes even the structure, of the synthesized polypeptide to be predicted. thus, bacterial genome mining via in silico analyses of nrps genes offers an attractive opportunity to uncover new bioactive non-ribosomally synthesized peptides. xanthomonas is a large genus of gram-negative bacteria that cause disease in hundred ... | 2013 | 24069909 |
| draft genome sequences of xanthomonas sacchari and two banana-associated xanthomonads reveal insights into the xanthomonas group 1 clade. | we present draft genome sequences for three strains of xanthomonas species, each of which was associated with banana plants (musa species) but is not closely related to the previously sequenced banana-pathogen xanthomonas campestris pathovar musacearum. strain ncppb4393 had been deposited as xanthomonas campestris pathovar musacearum but in fact falls within the species xanthomonas sacchari. strain ncppb1132 is more distantly related to xanthomonas sacchari whilst strain ncppb 1131 grouped in a ... | 2011 | 24710305 |
| genomes-based phylogeny of the genus xanthomonas. | the genus xanthomonas comprises several plant pathogenic bacteria affecting a wide range of hosts. despite the economic, industrial and biological importance of xanthomonas, the classification and phylogenetic relationships within the genus are still under active debate. some of the relationships between pathovars and species have not been thoroughly clarified, with old pathovars becoming new species. a change in the genus name has been recently suggested for xanthomonas albilineans, an early br ... | 2012 | 22443110 |
| full genome sequence analysis of two isolates reveals a novel xanthomonas species close to the sugarcane pathogen xanthomonas albilineans. | xanthomonas albilineans is the bacterium responsible for leaf scald, a lethal disease of sugarcane. within the xanthomonas genus, x. albilineans exhibits distinctive genomic characteristics including the presence of significant genome erosion, a non-ribosomal peptide synthesis (nrps) locus involved in albicidin biosynthesis, and a type 3 secretion system (t3ss) of the salmonella pathogenicity island-1 (spi-1) family. we sequenced two x. albilineans-like strains isolated from unusual environments ... | 2015 | 26213974 |
| what makes xanthomonas albilineans unique amongst xanthomonads? | xanthomonas albilineans causes leaf scald, a lethal disease of sugarcane. compared to other species of xanthomonas, x. albilineans exhibits distinctive pathogenic mechanisms, ecology and taxonomy. its genome, which has experienced significant erosion, has unique genomic features. it lacks two loci required for pathogenicity in other plant pathogenic species of xanthomonas: the xanthan gum biosynthesis and the hrp-t3ss (hypersensitive response and pathogenicity-type three secretion system) gene c ... | 2015 | 25964795 |
| the o-carbamoyl-transferase alb15 is responsible for the modification of albicidin. | albicidin is a potent antibiotic and phytotoxin produced by xanthomonas albilineans which targets the plant and bacterial dna gyrase. we now report on a new albicidin derivative which is carbamoylated at the n-terminal coumaric acid by the action of the atp-dependent o-carbamoyltransferase alb15, present in the albicidin (alb) gene cluster. carbamoyl-albicidin was characterized by tandem mass spectrometry from cultures of a xanthomonas overproducer strain and the gene function confirmed by gene ... | 2016 | 26886160 |
| the albicidin resistance factor albd is a serine endopeptidase that hydrolyzes unusual oligoaromatic-type peptides. | the para-aminobenzoic acid-containing peptide albicidin is a pathogenicity factor synthesized by xanthomonas albilineans in infections of sugar cane. albicidin is a nanomolar inhibitor of the bacterial dna gyrase with a strong activity against various gram-negative bacteria. the bacterium pantoea dispersa expresses the hydrolase albd, conferring natural resistance against albicidin. we show that albd is a novel type of endopeptidase that catalyzes the cleavage of albicidin at a peptide backbone ... | 2015 | 26057615 |
| enzymatic characterization and gene identification of aconitate isomerase, an enzyme involved in assimilation of trans-aconitic acid, from pseudomonas sp. wu-0701. | trans-aconitic acid is an unsaturated organic acid that is present in some plants such as soybean and wheat; however, it remains unclear how trans-aconitic acid is degraded and/or assimilated by living cells in nature. from soil, we isolated pseudomonas sp. wu-0701 assimilating trans-aconitic acid as a sole carbon source. in the cell-free extract of pseudomonas sp. wu-0701, aconitate isomerase (ai; ec 5.3.3.7) activity was detected. therefore, it seems likely that strain pseudomonas sp. wu-0701 ... | 2015 | 26293748 |
| synthesis of albicidin derivatives: assessing the role of n-terminal acylation on the antibacterial activity. | the peptide antibiotic albicidin, which is synthesized by the plant pathogenic bacterium, xanthomonas albilineans, represents the most prominent member of a new class of antibacterial gyrase inhibitors. it shows remarkable antibacterial activities against gram-positive and gram-negative microorganisms. its unique structure potentially represents a new lead structure for the development of an antibacterial drug. here we report the synthesis of 14 albicidin derivatives with structural variations a ... | 2016 | 27439374 |
| surface polysaccharides and quorum sensing are involved in the attachment and survival of xanthomonas albilineans on sugarcane leaves. | xanthomonas albilineans, the causal agent of sugarcane leaf scald, is a bacterial plant pathogen that is mainly spread by infected cuttings and contaminated harvesting tools. however, some strains of this pathogen are known to be spread by aerial means and are able to colonize the phyllosphere of sugarcane before entering the host plant and causing disease. the objective of this study was to identify the molecular factors involved in the survival or growth of x. albilineans on sugarcane leaves. ... | 2016 | 25962850 |
| the gyrase inhibitor albicidin consists of p-aminobenzoic acids and cyanoalanine. | albicidin is a potent dna gyrase inhibitor produced by the sugarcane pathogenic bacterium xanthomonas albilineans. here we report the elucidation of the hitherto unknown structure of albicidin, revealing a unique polyaromatic oligopeptide mainly composed of p-aminobenzoic acids. in vitro studies provide further insights into the biosynthetic machinery of albicidin. these findings will enable structural investigations on the inhibition mechanism of albicidin and its assessment as a highly effecti ... | 2015 | 25599532 |
| total synthesis of albicidin: a lead structure from xanthomonas albilineans for potent antibacterial gyrase inhibitors. | the peptide antibiotic albicidin, which is synthesized by the plant pathogenic bacterium xanthomonas albilineans, displays remarkable antibacterial activity against various gram-positive and gram-negative microorganisms. the low amounts of albicidin obtainable from the producing organism or through heterologous expression are limiting factors in providing sufficient material for bioactivity profiling and structure-activity studies. therefore, we developed a convergent total synthesis route towar ... | 2015 | 25504839 |
| breaking dogmas: the plant vascular pathogen xanthomonas albilineans is able to invade non-vascular tissues despite its reduced genome. | xanthomonas albilineans, the causal agent of sugarcane leaf scald, is missing the hrp type iii secretion system that is used by many gram-negative bacteria to colonize their host. until now, this pathogen was considered as strictly limited to the xylem of sugarcane. we used confocal laser scanning microscopy, immunocytochemistry and transmission electron microscopy (tem) to investigate the localization of x. albilineans in diseased sugarcane. sugarcane plants were inoculated with strains of the ... | 2014 | 24522883 |
| xanthomonas albilineans ompa1 appears to be functionally modular and both the omc and c-like domains are necessary for leaf scald disease of sugarcane. | several ez-tn5 insertions in gene locus xalc_0557 (ompa1) of the sugarcane leaf scald pathogen xanthomonas albilineans xafl07-1 were previously found to strongly affect pathogenicity and endophytic stalk colonization. xalc_0557 has a predicted ompa n-terminal outer membrane channel (omc) domain and an ompa c-like domain. further analysis of mutant m468, with an ez-tn5 insertion in the upstream omc domain coding region, revealed impaired epiphytic and endophytic leaf survival, impaired resistance ... | 2013 | 23758144 |
| the rpfcg two-component system negatively regulates the colonization of sugar cane stalks by xanthomonas albilineans. | the genome of xanthomonas albilineans, the causal agent of sugar cane leaf scald, carries a gene cluster encoding a predicted quorum sensing system that is highly related to the diffusible signalling factor (dsf) systems of the plant pathogens xylella fastidiosa and xanthomonas campestris. in these latter pathogens, a cluster of regulation of pathogenicity factors (rpf) genes encodes the dsf system and is involved in control of various cellular processes. mutation of xanthomonas albilineans rpff ... | 2013 | 23538716 |
| structural and dynamic insights into the role of conformational switching in the nuclease activity of the xanthomonas albilineans cas2 in crispr-mediated adaptive immunity. | clustered regularly interspaced short palindromic repeats (crisprs) and crispr-associated (cas) proteins constitute a microbial, adaptive immune system countering invading nucleic acids. cas2 is a universal cas protein found in all types of crispr-cas systems, and its role is implicated in new spacer acquisition into crispr loci. in subtype i-c crispr-cas systems, cas2 proteins are metal-dependent double-stranded dna (dsdna) nucleases, and a ph-dependent conformational transition has been propos ... | 2017 | 28612041 |