EN
The present study investigated the potential role of selected antioxidant enzymes: superoxide dismutase (SOD) and peroxidase (POX) as biochemical markers of the impact of tropospheric ozone. Experiments were carried out in ambient air conditions with two tobacco cultivars: Bel W3 and Bel B, which are sensitive and resistant to ozone, respectively. In this study, the degree of leaf injury of the sensitive cultivar was used as an indicator of the ozone level in correlation to the enzyme activity of both tobacco cultivars. In spite of low levels of tropospheric ozone during experimental season, the increase of antioxidant enzyme (SOD and POX) activity concomitant with the increase of ozone concentration was noticed in the sensitive cultivar as well as in the resistant one. This observation is especially important for the resistant tobacco, which does not exhibit any visual effects of ozone influence. Our results could be extrapolated to other plant species (i.e. Poaceae, Fabaceae, Solanaceae, Betulaceae, Salicaceae, Pinaceae), which do not reveal visible lesions in response to ozone stress.