TheXanthomonas campestris gumDGene Required for Synthesis of Xanthan Gum Is Involved in Normal Pigmentation and Virulence in Causing Black Rot

Chou, Fang-Li; Chou, Huei‐Chi; Lin, Yen-Shin; Yang, Bing; Lin, Ning; Weng, Shu-Fen; Tseng, Yi-Hsiung

doi:10.1006/bbrc.1997.6365

Cited by 71 publications

(40 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This organism is capable of producing large amounts of an exopolysaccharide and an array of extracellular enzymes including proteases, endoglucanases and pectinases. These extracellular products have long been considered important virulence determinants (Chan & Goodwin, 1999;Chang et al, 2001;Chou et al, 1997;Dow et al, 1987;Dums et al, 1991;Soby & Daniels, 1996;Yang & Tseng, 1988). Production of these determinants is regulated by the global transcription factor Clp (cAMP receptor protein-like protein) and the rpf (regulator of pathogenicity factors) gene cluster (Barber et al, 1997;de Crecy-Lagard et al, 1990;Dow et al, 2000;He et al, 2006He et al, , 2007Tang et al, 1991;Tseng et al, 1999;Wilson et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Hsiao

Zheng

et al. 2008

Microbiology

Self Cite

View full text Add to dashboard Cite

Exopolysaccharide and several extracellular enzymes of Xanthomonas campestris pv. campestris (Xcc), the causative agent of black rot in crucifers, are virulence factors. In this study, sequence and mutational analysis has demonstrated that Xcc pehA encodes the major polygalacturonase, a member of family 28 of the glycosyl hydrolases. Using the 59 RACE (rapid amplification of cDNA ends) method, the pehA transcription initiation site was mapped at 102 nt downstream of a Clp (cAMP receptor protein-like protein)-binding site. Transcriptional fusion assays showed that pehA transcription is greatly induced by polygalacturonic acid, positively regulated by Clp and RpfF (an enoyl-CoA hydratase homologue which is required for the synthesis of cis-11-methyl-2-dodecenoic acid, a low-molecular-mass diffusible signal factor), subjected to catabolite repression, which is independent of Clp or RpfF, and repressed under conditions of oxygen limitation or nitrogen starvation. Our findings extend previous work on Clp and RpfF regulation to show that they both influence the expression of pehA in Xcc.

show abstract

Section: Introductionmentioning

confidence: 99%

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Hsiao

Zheng

et al. 2008

Microbiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…The consequence of mutation in the Xcc mopB gene is pleiotropic, including formation of cell aggregates, reduction in xanthan production, adhesion and motility and increased sensitivity to stress conditions. Since we have previously shown that a mutation causing reduction in xanthan (about 95 % reduction) resulted in only a delayed appearance of the black rot symptoms and not a complete loss of pathogenicity (Chou et al, 1997), a 42 % reduction in xanthan production is unlikely to be the major reason for the loss of pathogenicity in XcMopB. In addition, as synthesis of extracellular enzymes was not altered in this mutant, the importance of such enzymes in the initial stages of pathogenesis may be limited.…”

Section: Discussionmentioning

confidence: 99%

“…Xcc is capable of producing large amounts of xanthan polysaccharide and an array of extracellular enzymes, which collectively have long been considered important virulence determinants (Chan & Goodwin, 1999;Chou et al, 1997;Dharmapuri & Sonti, 1999;Dow et al, 2003;Dums et al, 1991;Yang & Tseng, 1988). In the present study, we have shown that production of xanthan was impaired by mopB mutation but that synthesis of extracellular enzymes was not affected.…”

Section: Discussionmentioning

confidence: 99%

“…These results indicate that the ability to synthesize EPS was impaired by mutation of the mopB gene. Extracellular enzymes, in addition to EPS, have been implicated as virulence factors (Chan & Goodwin, 1999;Chou et al, 1997;Dharmapuri & Sonti, 1999;Dow et al, 2003;Katzen et al, 1998); hence, the hydrolytic activities of XcMopB were assayed on XOLN and LB agar plates containing skimmed milk, CM-cellulose, pectin, mannan or starch. No significant differences were found between the parental Xc17 and XcMopB.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity

Chen

Lin

et al. 2010

Microbiology

Self Cite

View full text Add to dashboard Cite

Xanthomonas cam pestris pv. campestris (Xcc) is the phytopathogen that causes black rot in crucifers. The xanthan polysaccharide and extracellular enzymes produced by this organism are virulence factors, the expression of which is upregulated by Clp (CRP-like protein) and DSF (diffusible signal factor), which is synthesized by RpfF. It is also known that biofilm formation/dispersal, regulated by the effect of controlled synthesis of DSF on cell-cell signalling, is required for virulence. Furthermore, a deficiency in DSF causes cell aggregation with concomitant production of a gum-like substance that can be dispersed by addition of DSF or digested by exogenous endo-beta-1,4-mannanase expressed by Xcc. In this study, Western blotting of proteins from a mopB mutant (XcMopB) showed Xcc MopB to be the major outer-membrane protein (OMP); Xcc MopB shared over 97% identity with homologues from other members of Xanthomonas. Similarly to the rpfF mutant, XcMopB formed aggregates with simultaneous production of a gummy substance, but these aggregates could not be dispersed by DSF or endo-beta-1,4-mannanase, indicating that different mechanisms were involved in aggregation. In addition, XcMopB showed surface deformation, altered OMP composition, impaired xanthan production, increased sensitivity to stressful conditions including SDS, elevated temperature and changes in pH, reduced adhesion and motility and defects in pathogenesis. The finding that the major OMP is required for pathogenicity is unprecedented in phytopathogenic bacteria

show abstract

“…This gene belongs to a group of 14 genes involved in the synthesis of xanthan gum, an extracellular polysaccharide (EPS) related to induced watersoaking and hyperplasia phenotype during host tissue colonization by Xanthomonas [49]. Xanthan gum is a virulence factor, since EPS-deficient mutants are usually avirulent [50] [51] [52].…”

Section: Mutants Leading To a Partial Reduction In Necrosis And Total Inmentioning

confidence: 99%

Identification of New Genes Related to Virulence of <i>Xanthomonas axonopodis</i> Pv. <i>Citri</i> during Citrus Host Interactions

Ferreira¹,

Moreira²,

Brigati³

et al. 2017

AiM

View full text Add to dashboard Cite

A mutant library of the bacterium Xanthomonas citri subsp. citri strain 306 pathotype A (Xac), the causative agent of most aggressive Asiatic type A citrus canker, was screened regarding altered canker symptoms after inoculations into Citrus sinensis and Citrus limonia host leaves. Twenty-six mutants have shown phenotypic virulence changes and have respectively knocked out gene identified by sequencing. In vivo growth curves were obtained for nine mutants to quantify how the mutations could affect pathogen's adaptability to growth inside and attack host plant infected tissue. Among identified genes in mutated strains, we could find those that until now had not been reported as being involved in Xac adaptation and/or virulence, such as predicted to encode for xylose repressor-like protein (XAC∆xylR), Fe-S oxidoredutase (XAC∆aslB), helicase IV (XAC∆helD), ubiquinol cytochrome c oxidoreductase iron-sulfur subunit (XAC∆petA), chromosome partitioning protein (XAC∆parB) and cell division protein FtsB (XAC∆ftsB), in addition to genes predicted to encode for hypothetical proteins. The new genes found in this study as being relevant to adaptation and virulence, improve the understanding of Xac fitness during citrus plant attack and canker symptoms development.

show abstract

TheXanthomonas campestris gumDGene Required for Synthesis of Xanthan Gum Is Involved in Normal Pigmentation and Virulence in Causing Black Rot

Cited by 71 publications

References 36 publications

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity

Identification of New Genes Related to Virulence of <i>Xanthomonas axonopodis</i> Pv. <i>Citri</i> during Citrus Host Interactions

Contact Info

Product

Resources

About

TheXanthomonas campestris gumDGene Required for Synthesis of Xanthan Gum Is Involved in Normal Pigmentation and Virulence in Causing Black Rot

Cited by 71 publications

References 36 publications

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF

Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity

Identification of New Genes Related to Virulence of &lt;i&gt;Xanthomonas axonopodis&lt;/i&gt; Pv. &lt;i&gt;Citri&lt;/i&gt; during Citrus Host Interactions

Contact Info

Product

Resources

About

Identification of New Genes Related to Virulence of <i>Xanthomonas axonopodis</i> Pv. <i>Citri</i> during Citrus Host Interactions