Publication: Oxidant-inducible resistance to hydrogen peroxide killing in Agrobacterium tumefaciens requires the global peroxide sensor-regulator OxyR and KatA
Issued Date
2003-08-08
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ISSN
03781097
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2-s2.0-0142043298
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Mahidol University
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SCOPUS
Bibliographic Citation
FEMS Microbiology Letters. Vol.225, No.1 (2003), 167-172
Suggested Citation
Warawan Eiamphungporn, Kaewkanya Nakjarung, Benjaphorn Prapagdee, Paiboon Vattanaviboon, Skorn Mongkolsuk Oxidant-inducible resistance to hydrogen peroxide killing in Agrobacterium tumefaciens requires the global peroxide sensor-regulator OxyR and KatA. FEMS Microbiology Letters. Vol.225, No.1 (2003), 167-172. doi:10.1016/S0378-1097(03)00511-1 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/20701
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Title
Oxidant-inducible resistance to hydrogen peroxide killing in Agrobacterium tumefaciens requires the global peroxide sensor-regulator OxyR and KatA
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Abstract
Induced adaptive and cross-protective responses to peroxide stress are important strategies used by bacteria to survive stressful environments. We have shown that exposure to low levels of peroxide (adaptive) and superoxide anions (cross-protection) induced high levels of resistance to peroxide killing in Agrobacterium tumefaciens. The mechanisms and genes involved in these processes have not been identified. Here, the roles played by peroxide (oxyR) and superoxide (soxR) global regulators and a catalase gene (katA) during these responses were investigated. H2O2-induced adaptive protection was completely abolished in both the oxyR and katA mutants. Superoxide generator (menadione)-induced cross-protection to H2O2killing was observed in a soxR mutant, but not in either an oxyR or a katA mutant. In vivo analysis of the katA promoter, using a katA::lacZ transcriptional fusion, revealed that it could be induced by menadione in an oxyR-dependent manner. These results lead us to conclude that H2O2and superoxide anions directly or indirectly oxidize OxyR and it is the resulting activation of katA expression that is responsible for the induced protection against lethal concentrations of H2O2. © 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.