Arsenic accumulation in Canna: Effect on antioxidative defense system

Abstract

Three Canna cultivars namely Canna red dazzler (CR), Canna flaccida (CF) and Canna cala lillies (CL) were selected to examine the uptake of arsenic and antioxidative response at four different arsenic concentrations (10, 20, 30 and 50 mg kg¯1). The study consisted of three harvestings at an interval of 45 days each, and at each harvest arsenic uptake and antioxidant activity were examined. The arsenic uptake and antioxidant activity were more in roots as compared to shoots. The percentage uptake of arsenate by CL, CF and CR at 10, 20, 30 and 50 mg kg¯1 were 52, 43, 36, 35 for CL, 39, 40, 35, 34 for CF and 45, 41, 37, 33 for CR respectively. The antioxidant enzymatic activity was higher in CL and CR than CF cultivar. The overall enzymatic antioxidants had their activities increased from first to second harvesting and were significantly higher in the third harvesting in all the three varieties as compared to control. Results suggested that Canna cultivars can be a better option for rhizofiltration or phytostabilization rather than phytoextraction and as it has an effective antioxidative mechanism in reducing the arsenic stress.