Sodium chloride and cadmium induced oxidative stress and antioxidant response in Calamus tenuis leaves

The effects of NaCl (0–300 mM), CdCl₂ (0–10 mM) and NaCl (300 mM) + CdCl₂ (10 mM) induced oxidative stress in Calamus tenuis Roxb. leaves were studied. Alterations in the activated oxygen metabolism was detected as evidenced by the increased peroxide content and lipid peroxidation due to the accumulation of thiobarbituric acid reactive substances (TBARS) with the increasing NaCl and Cd concentrations. Superoxide dismutase (SOD) and peroxidase (POX) decreased, while catalase (CAT) and glutathione reductase (GR) activities increased during NaCl treatments. Cd treatment decreased SOD and CAT activities, while POX and GR activities increased. NaCl + Cd treatment decreased all enzyme activities except GR. Ascorbate and glutathione content increased in response to NaCl and Cd treatments, whereas, NaCl + Cd treatment decreased ascorbate and increased glutathione content. The cadmium uptake increased up to 10 times in 10 mM treatment as compared to lower concentrations. Enhanced levels in some of the antioxidants observed in the investigation suggest that a better antioxidant defense is required for higher NaCl and cadmium tolerance.