An <i>Agrobacterium</i> catalase is a virulence factor involved in tumorigenesis

Xu, Xiaozheng; Pan, Shen Q.

doi:10.1046/j.1365-2958.2000.01709.x

Cited by 106 publications

(103 citation statements)

References 52 publications

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“…Furthermore, the H 2 O 2 signal appeared to be suppressed. At initiation of infection, the agrobacterial catalase (Xu and Pan, 2000) seems to degrade H 2 O 2 produced by the host plant. Later on, at 6 d postinoculation, transcription of several peroxidases and to GSTs might prevent H 2 O 2 accumulation (see Supplemental Figures 3C and 3D online).…”

Section: Auxin and Et Are Involved In The Initiation Of Infection Witmentioning

confidence: 99%

Agrobacterium tumefaciensPromotes Tumor Induction by Modulating Pathogen Defense inArabidopsis thaliana

et al. 2009

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Agrobacterium tumefaciens causes crown gall disease by transferring and integrating bacterial DNA (T-DNA) into the plant genome. To examine the physiological changes and adaptations during Agrobacterium-induced tumor development, we compared the profiles of salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and auxin (indole-3-acetic acid [IAA]) with changes in the Arabidopsis thaliana transcriptome. Our data indicate that host responses were much stronger toward the oncogenic strain C58 than to the disarmed strain GV3101 and that auxin acts as a key modulator of the ArabidopsisAgrobacterium interaction. At initiation of infection, elevated levels of IAA and ET were associated with the induction of host genes involved in IAA, but not ET signaling. After T-DNA integration, SA as well as IAA and ET accumulated, but JA did not. This did not correlate with SA-controlled pathogenesis-related gene expression in the host, although high SA levels in mutant plants prevented tumor development, while low levels promoted it. Our data are consistent with a scenario in which ET and later on SA control virulence of agrobacteria, whereas ET and auxin stimulate neovascularization during tumor formation. We suggest that crosstalk among IAA, ET, and SA balances pathogen defense launched by the host and tumor growth initiated by agrobacteria.

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Section: Auxin and Et Are Involved In The Initiation Of Infection Witmentioning

confidence: 99%

Agrobacterium tumefaciensPromotes Tumor Induction by Modulating Pathogen Defense inArabidopsis thaliana

et al. 2009

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“…Catalase is predicted to contribute to virulence as it may protect bacteria from active oxygen species produced by plants in response to microbial attack (Klotz and Hutcheson, 1992;Felix et al, 1999). The importance of catalase in the virulence of a plant pathogen has been demonstrated for Agrobacterium tumefaciens, in which tumour formation was significantly attenuated in a catalase mutant (Xu and Pan, 2000).…”

Section: Ipx Genes Known or Predicted To Be Involved In Virulencementioning

confidence: 99%

Identification of Pseudomonas syringae pv. tomato genes induced during infection of Arabidopsis thaliana

Boch

Joardar

Gao

et al. 2002

Molecular Microbiology

180

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SummaryPhytopathogenic bacteria possess a large number of genes that allow them to grow and cause disease on plants. Many of these genes should be induced when the bacteria come in contact with plant tissue. We used a modified in vivo expression technology (IVET) approach to identify genes from the plant pathogen Pseudomonas syringae pv. tomato that are induced upon infection of Arabidopsis thaliana and isolated over 500 in planta-expressed (ipx) promoter fusions. Sequence analysis of 79 fusions revealed several known and potential virulence genes, including hrp/hrc, avr and coronatine biosynthetic genes. In addition, we identified metabolic genes presumably important for adaptation to growth in plant tissue, as well as several genes with unknown function that may encode novel virulence factors. Many ipx fusions, including several corresponding to novel genes, are dependent on HrpL, an alternative RNA polymerase sigma factor that regulates the expression of virulence genes. Expression analysis indicated that several ipx fusions are strongly induced upon inoculation into plant tissue. Disruption of one ipx gene, conserved effector locus (CEL) orf1, encoding a putative lytic murein transglycosylase, resulted in decreased virulence of P. syringae. Our results demonstrate that this screen can be used successfully to isolate genes that are induced in planta, including many novel genes potentially involved in pathogenesis.

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“…Bifunctional catalase/peroxidases are haem co-factored enzymes that have been described in simple eukaryotes and prokaryotes, and are evolutionarily linked to plant peroxidases (Zamocky & Koller, 1999;Zamocky et al, 2000). This class of enzymes has been associated with virulence in various bacterial pathogens, including Legionella pneumophila and Agrobacterium tumefaciens (Bandyopadhyay & Steinman, 1998Bandyopadhyay et al, 2003;Xu & Pan, 2000).…”

Section: Introductionmentioning

confidence: 99%

A minor catalase/peroxidase from Burkholderia cenocepacia is required for normal aconitase activity

2005

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The opportunistic bacterium Burkholderia cenocepacia C5424 contains two catalase/peroxidase genes, katA and katB. To investigate the functions of these genes, katA and katB mutants were generated by targeted integration of suicide plasmids into the katA and katB genes. The catalase/peroxidase activity of the katA mutant was not affected as compared with that of the parental strain, while no catalase/peroxidase activity was detected in the katB mutant. However, the katA mutant displayed reduced resistance to hydrogen peroxide under iron limitation, while the katB mutant showed hypersensitivity to hydrogen peroxide, and reduced growth under all conditions tested. The katA mutant displayed reduced growth only in the presence of carbon sources that are metabolized through the tricarboxylic acid (TCA) cycle, as the growth defect was abrogated in cultures supplemented with glucose or glycerol. This phenotype was also correlated with a marked reduction in aconitase activity. In contrast, aconitase activity was not reduced in the katB mutant and parental strains. The authors conclude that the KatA protein is a specialized catalase/peroxidase that has a novel function by contributing to maintain the normal activity of the TCA cycle, while KatB is a classical catalase/peroxidase that plays a global role in cellular protection against oxidative stress.

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An Agrobacterium catalase is a virulence factor involved in tumorigenesis

Cited by 106 publications

References 52 publications

Agrobacterium tumefaciensPromotes Tumor Induction by Modulating Pathogen Defense inArabidopsis thaliana

Agrobacterium tumefaciensPromotes Tumor Induction by Modulating Pathogen Defense inArabidopsis thaliana

Identification of Pseudomonas syringae pv. tomato genes induced during infection of Arabidopsis thaliana

A minor catalase/peroxidase from Burkholderia cenocepacia is required for normal aconitase activity

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