Antioxidative defense mechanism of the ruderal Verbascum olympicum Boiss. against copper (Cu)-induced stress

Abstract

The endemic Verbascum olympicum has characteristics that allows it to live in degraded areas of Uludag Mountain, Turkey and therefore known as a ruderal species. In this study, V. olympicum seeds collected from Uludag Mountain were grown in the Hoagland nutrient solution, under hydroponic conditions. The activity of antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX) were examined to demonstrate the role of antioxidative mechanism in the seedlings exposed to different Cu concentrations (0, 50, 250, 500 mu M) for seven days. Also, certain growth parameters (such as the water content, biomass production, soluble protein), the level of lipid peroxidation, cell membrane injury and permeability were investigated. As a result, some toxic effects are observed following the application of 500 mu M Cu, after the seedlings growing in 50 and 250 mM Cu concentrations showed high resistance and survived in hydroponic conditions. Our findings provide information about the resistance of V. olympicum seedlings to oxidative stress caused by excessive Cu concentrations.