Počet záznamů: 1  

DNA damage induced by indirect and direct acting mutagens in catalase-deficient transgenic tobacco Cellular and acellular Comet assays

  1. 1. 0172311 - UEB-Q 20033036 RIV NL eng J - Článek v odborném periodiku
    Gichner, Tomáš
    DNA damage induced by indirect and direct acting mutagens in catalase-deficient transgenic tobacco Cellular and acellular Comet assays.
    Mutation Research - Genetic Toxicology and Environmental Mutagenesis. Roč. 535, - (2003), s. 187-193. ISSN 1383-5718
    Grant CEP: GA ČR GA521/02/0400
    Výzkumný záměr: CEZ:AV0Z5038910
    Klíčová slova: Hydrogen peroxide * Single-cell gel electrophoresis * Nicotiana tabacum
    Kód oboru RIV: EB - Genetika a molekulární biologie
    Impakt faktor: 1.748, rok: 2003

    We have measured the level of DNA damage induced by treating roots (cellular Comet assay) and isolated root nuclei (acellular Comet assay) of catalase-deficient (CAT1AS) and wild-type (SR1) tobacco with the promutagen o-phenylenediamine (o-PDA) and the direct acting genotoxic agents hydrogen peroxide and ethyl methanesulphonate (EMS). The roots of CAT1AS have about 60% less catalase activity compared to the roots of SR1. The promutagen o-PDA applied on tobacco roots induced significantly higher levels of DNA damage in the CAT1AS transgenic line than in SR1, while after application of o-PDA on isolated root nuclei, no DNA damage could be detected. In the catalase-deficient line CAT1AS about six-fold lower concentrations of H2O2 are sufficient to induce the same levels of DNA damage as in SR1. By contrast, after treatment of isolated root nuclei with H2O2 no difference in the induced levels of DNA damage was observed between CAT1AS and SR1. The DNA damaging effect of EMS was not affected by the presence of catalase in the tobacco roots and the levels of DNA damage measured by the cellular and acellular assay were similar. Comparing the effects of genotoxic agents in both the cellular and acellular Comet assays may help to elucidate their mechanism of action. Differences in both systems may reveal the participation of scavengers and of repair and metabolic enzymes on the activity of the genotoxic agent and the role of the cell wall in preventing the agent from reacting with nuclear DNA.
    Trvalý link: http://hdl.handle.net/11104/0069350