The pathogenicity gene, pthA, of Xanthomonas citri is required to elicit symptoms Asiatic citrus canker disease; introduction pthA into strains that are mildly pathogenic or opportunistic on confers the ability induce cankers (S. Swarup, R. De Feyter, H. Brlansky, and D. W. Gabriel, Phytopathology 81:802-809, 1991). structure function in other xanthomonads X. were further investigated. When was introduced phaseoli campestris pv. malvacearum (neither citrus), transconjugants remained...

'Candidatus Liberibacter asiaticus' is transmitted by psyllids and causes huanglongbing (HLB), a lethal disease of citrus. Most pathogenic 'Ca. L. strains carry two nearly identical prophages similar to SC1 SC2 in strain UF506. was observed replicate as moderately high-copy excision plasmid encoding reactive oxygen species-scavenging peroxidase (SC2_gp095), predicted lysogenic conversion factor. SC2_gp095 expressed at significantly higher levels periwinkle than citrus suppressed psyllids....

Six plasmid-borne avirulence (avr) genes were previously cloned from strain XcmH of the cotton pathogen, Xanthomonas campestris pv. malvacearum. We have now localized all six avr on fragments by subcloning and Tn5-gusA insertional mutagenesis. None these appeared to exhibit exclusively gene-for-gene patterns interactions with R genes, avrB4 was demonstrated confer gene-for-R (plural) X. c. malvacearum congenic lines carrying either two different resistance loci, B1 or B4. Furthermore, locus...

ABSTRACT Citrus bacterial canker disease has been introduced at least three times into Florida in the last 15 years and, despite federal and state quarantine eradication efforts, continues to spread Florida. Accurate, fast, reliable detection of causal agent is great importance. However, citrus caused by two groups phylogenetically distinct Xanthomonas citri strains, there host range variation within both groups. We developed a sensitive real-time polymerase chain reaction (PCR) assay using...

"Candidatus Liberibacter asiaticus" is an uncultured alphaproteobacterium that systemically colonizes its insect host both inter- and intracellularly also causes a severe, crop-destroying disease of citrus called huanglongbing, or "greening." In planta, "Ca. systemic but phloem limited. strain UF506 carries two predicted prophages, SC1 SC2. Bacteriophage particles have been observed in experimentally asiaticus"-infected periwinkle not any other host. Comparative gene expression analysis late...

Pathogens utilize a panoply of effectors to manipulate plant defense. However, despite their importance, relatively little is actually known about regulation these virulence factors. Here, we show that the effector Fol -Secreted Virulence-related Protein1 (FolSvp1), secreted from fungal pathogen Fusarium oxysporum f. sp. lycopersici ( ), directly binds and translocates tomato pathogenesis-related protein1, SlPR1, apoplast outside plasma membrane host nucleus via its nuclear localization...

Host acquisition of a new microbial species can readily perturb the dynamics preexisting associations. Molecular cross talk between associates may be necessary for efficient resource allocation and enhanced survival. Classic examples involve quorum sensing (QS), which detects population densities is both used coopted to control expression bacterial genes, including host adaptation factors. We report that 56-amino-acid repressor protein made by resident psyllid endosymbiont Wolbachia enter...

The oxidative (H2O2) burst is a seminal feature of the basal plant defense response to attempted pathogen invasions. In 'Candidatus Liberibacter asiaticus' UF506, expression SC2 prophage-encoded secreted peroxidase (F489_gp15) increases bacterial fitness and delays symptom progression in citrus. Two chromosomal 1-Cys peroxiredoxin genes, CLIBASIA_RS00940 (Lasprx5) CLIBASIA_RS00445 (Lasbcp), are conserved among all sequenced 'Ca. L. strains, including those lacking prophages. Both LasBCP...

Xanthomonas albilineans, which causes leaf scald disease of sugarcane, produces a highly potent pathotoxin called albicidin. We report here sequencing and homology analysis the major gene cluster, XALB1 (55,839 bp), second, smaller region, XALB2 (2,986 involved in albicidin biosynthesis. contains 20 open reading frames, including i) three large genes with modular architecture characteristic polyketide synthases (PKSs) nonribosomal peptide (NRPSs) ii) several putative modifying, regulatory,...

The random amplified polymorphic DNA method was used to distinguish strains of Xanthomonas campestris pv. pelargonii from 21 other species and/or pathovars. Among the 42 arbitrarily chosen primers evaluated, 3 were found reveal diagnostic polymorphisms when purified DNAs compared by PCR. three revealed amplification patterns which conserved among all 53 tested X. isolated various locations worldwide. distinctive compestris clearly different those obtained with any 46 tested. An 1.2-kb...

Axenically cultured Liberibacter crescens (Lcr) is a closely related surrogate for uncultured plant pathogenic species of the genus Liberibacter, including ‘ Candidatus L. asiaticus’ (CLas) and Ca . solanacearum’ (CLso). All Liberibacters encode completely conserved gene repertoire both flagella Tad ( T ight Ad herence) pili all are missing genes critical nucleotide biosynthesis. Both flagellar swimming pilus-mediated twitching motility in Lcr were demonstrated first time. A role uptake...

Fusarium oxysporum f. sp. lycopersici (Fol) is the causal agent of wilt disease in tomato. Proteins secreted by this pathogen during initial host colonization largely determine outcome pathogen-host interactions. Lysine acetylation (Kac) plays a vital role functions many proteins, but little known about Kac Fol proteins. In study, we analyzed lysine entire secretome. Using high affinity enrichment peptides and LC-MS/MS analysis, 50 potentially proteins were identified sites determined....

The phytotoxin and polyketide antibiotic albicidin produced by Xanthomonas albilineans is a highly potent DNA gyrase inhibitor. Low yields of production have slowed studies its chemical structure. Heterologous expression biosynthetic genes in X. axonopodis pv. vesicatoria resulted sixfold increase production, offering promising strategies for engineering overproduction.

Xanthomonas albilineans, the causal agent of leaf scald disease sugarcane, produces a highly potent polyketide-peptide antibiotic and phytotoxin called albicidin. Previous studies established involvement large cluster genes in biosynthesis this toxin. We report here sub-cloning sequencing an additional gene outside main essential for albicidin biosynthesis. This encodes 634-amino-acid protein that shows high identity with Escherichia coli heat shock HtpG. Complementation X. albilineans Tox-...

Liberibacter crescens is a bacterium that closely related to plant pathogens have caused billions of dollars in crop losses recent years. Particularly devastating are citrus due greening disease, also known as Huanglongbing, which by “ Candidatus asiaticus” and carried the Asian psyllid. L. only close relative Ca . can currently be grown culture, it therefore serves an important model organism for growth, genetic manipulation, biological control pathogenic species. Here, we show one greatest...

The objective of this work was the transformation tobacco and 'Valencia' sweet orange with GUS gene driven by citrus phenylalanine ammonia-lyase (PAL) promoter (CsPP). Transformation accomplished co-cultivation 'Valência' explants Agrobacterium tumefaciens containing binary vector CsPP-GUS/2201. After plant regeneration, histochemical analyses using staining revealed that CsPP preferentially, but not exclusively, conferred expression in xylem tissues tobacco. Weaker also detected throughout...

Huanglongbing (HLB) disease, also known as citrus greening was first reported in the US 2005. Since then, disease has decimated industry Florida, resulting billions of dollars crop losses and destruction thousands acres groves. The causative agent is phloem limited pathogen Candidatus Liberibacter asiaticus. As it not been cultured, very little about structural biology organism. are part Rhizobiaceae family, which includes nitrogen-fixing symbionts legumes well Agrobacterium plant pathogens....

The lipopolysaccharides (LPS) of gram-negative bacteria trigger a nitrosative and oxidative burst in both animals plants during pathogen invasion. Liberibacter crescens strain BT-1 is surrogate for functional genomic studies the uncultured pathogenic 'Candidatus Liberibacter' spp. that are associated with severe diseases such as citrus greening potato zebra chip. Structural determination L. LPS revealed presence very long chain fatty acid modification. pretreatment suppressed growth...

Fusarium oxysporum is one of the most abundant and diverse fungal species found in soils includes nonpathogenic, endophytic, pathogenic strains affecting a broad range plant animal hosts. Conidiation major mode reproduction many filamentous fungi, but regulation this process largely unknown. Lysine acetylation (Kac) an evolutionarily conserved widespread posttranslational modification implicated multiple metabolic processes. A total 62 upregulated 49 downregulated Kac proteins were...

The complete genome sequences of three Xanthomonas citri strains isolated from lime trees in Texas were found to belong the Aw group. All carried nearly identical large plasmids with similarity those a citrus canker strain India and xanthomonads Africa Colombia. harbored unusual pthA homologs.

'Candidatus Liberibacter asiaticus' (CLas) is associated with the devastating citrus 'greening' disease. All attempts to achieve axenic growth and complete Koch's postulates CLas have failed date, at best yielding complex cocultures very low titers detectable only by PCR. Reductive genome evolution has rendered all pathogenic 'Ca. Liberibacter' spp. deficient in multiple key biosynthetic, metabolic structural pathways that are highly unlikely be rescued vitro media supplementation alone. By...

DNA adenine N 6 -methylation (6mA) plays a critical role in various biological functions, but its occurrence and functions filamentous plant pathogens are largely unexplored. Botrytis cinerea is an important pathogenic fungus worldwide. A systematic analysis of 6mA B. was performed this study, revealing that widely distributed the genome fungus. The 2 kb regions flanking many genes, particularly upstream promoter regions, were susceptible to methylation. BcMettl4, methyltransferase,...