engleski

Stress related biomarkers in tobacco experimentally exposed to cadmium and zinc

Because of their persistence, heavy metals of either natural or anthropogenic origin are considered to be the most common environmental pollutants. Although the impacts of single metals on various levels of biological organisation are well known, the combined impact of several metals has not been sufficiently investigated up to this moment. The aim of this study was to explore the effect of environmentally relevant concentrations and interactions between zinc and cadmium on seedlings of tobacco, Nicotiana tabacum L. Seedlings were exposed for one month, under laboratory conditions, first to cadmium and zinc separately, and then to the combination of the two. The assessment of cadmium and zinc contents showed that both metals were present at high concentrations in tobacco seedlings, although the bioaccumulation pattern of the mixture did not display linear dose-response relationship. The results of this study confirm that oxidative stress caused by heavy metals damages DNA, lipids, and proteins. In addition, cadmium and zinc when applied separately, reduced the activity of superoxide dismutase and glutathione reductase, but the combination of both metals caused mainly the same changes in enzyme activities like individual cadmium treatment. In conclusion, although cadmium induced more pronounced oxidative stress than zinc, exposure to mixed heavy metals reflected a complexity of their interaction in tobacco seedlings.

oxidative stress; cadmium; zinc; toxicity

nije evidentirano