engleski

Oxidative DNA damage induced by thallium(I) acetate in Lemna minor L.

Plants have been proven to be suitable model organisms for investigations of environmental mutagenesis, especially of heavy-metals toxicity. Although thallium is present in a very low concentration, it is widely distributed in the environment. Ecotoxicological importance of thallium is based on its high toxicity on living organisms, comparable to that of cadmium and lead known for being genotoxic even at low doses. In this study, Lemna minor plants were exposed to a range of thallium(I) acetate concentrations, the effect of which was monitored after 1, 4, 7 and 14 days of exposure. The plants were also exposed to potassium(I) acetate in order to role out the possible effect of acetate group. The results revealed a significant hydrogen peroxide accumulation, lipid peroxidation and oxidative damage to DNA molecule in the plants exposed to thallium. To determine the mechanism of thallium genotoxicity, cellular and acellular versions of comet assay were performed. Since only the cellular assay detected an increase in DNA damage, it follows that thallium genotoxicity is not related to thallium itself but to thallium-induced oxidative stress which indirectly leads to DNA strand breaks in time and dose dependent manner.

Lemna minor L.; thallium; oxidative stress; genotoxicity

nije evidentirano