Role of antioxidant enzymes and plant performances towards heavy metal stress in ornamental sunflower by vermicompost implementation

Abstract

Almost hyperaccumulators have a short growth period and some are edible crops with low-biomass. So, in this study, the potential of ornamental sunflower to remedy contaminated soil was evaluated. The experiment was set in as factorial arrangements in a completely randomized design where the treatments were 3 concentrations vermicompost (0, 15, 30 kg m-2), 3 Pb concentrations (0, 400, 600 ppm) and 4 Cd concentrations (0, 5, 10, 15 ppm). The oxidative enzyme activities were greatly influenced by the presence of vermicompost and various contaminant levels. Treatment of Pb and Cd without vermicompost application, increased superoxide dismutase and cat- alase activity 27- and 12-folds, respectively, in comparison with control, but in the presence of both metal treatments accompany with 30 kg m-2 vermicompost, enzyme activity was increased 15 times in superoxide dismutase and 9 times in catalase more than the control. The addition of vermicompost amendments has been shown to increase soil microbial activity. The results show that the translocation factor was not greater than 1 in ornamental sunflower at none of the studied treatments, but the biological concentration factor was more than 1. Our results indicated that ornamental sunflower showed tolerance to Pb and Cd contamination and Helianthus annuus 'Sungold' was more favorable for Pb uptake compared to Cd.