Sarinya BuranajitpakornAnong PiwkamNisanart CharoenlapPaiboon VattanaviboonSkorn MongkolsukChulabhorn Research InstituteChulabhorn Graduate InstituteCenter of Excellence on Environmental HealthMahidol University2018-05-032018-05-032011-04-01FEMS Microbiology Letters. Vol.317, No.1 (2011), 60-6615746968037810972-s2.0-79952128487https://repository.li.mahidol.ac.th/handle/123456789/11570Xanthomonas campestris pv. campestris, a soil-borne plant-pathogenic bacterium, is exposed to multiple stresses in the environment and during interaction with a host plant. The roles of hydrogen peroxide (H 2 O 2 )-protective genes (katA, katG, and ahpC) and a peroxide sensor/transcription regulator (oxyR) in the viability of X. campestris pv. campestris at an elevated temperature were evaluated. The single katA and katG mutants showed moderate decreased survival after the heat treatment, while the double katA-katG and oxyR mutants were the most vulnerable to the heat treatment compared with a wild-type strain. However, ahpC provided no protective function against the heat treatment. Flow cytometric analysis revealed an increased accumulation of peroxide in cells treated with heat. Altogether, the data revealed a crucial role of genes in the H 2 O 2 detoxification system for protection against lethal heat shock in X. campestris pv. campestris. © 2011 Federation of European Microbiological Societies.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyArticleSCOPUS10.1111/j.1574-6968.2011.02211.x