Indian Journal of Plant Physiology

Effects of two heavy metals (nickel and cadmium) with different phytotoxicity were examined on the activity of peroxidase (POX) and carotenoids content in pleurocarpous moss Thuidium cymbifolium (Doz and Molk.). Cd treatment for 3 days caused an increase in peroxidase activity only at 0.01 M concentration from 0.464 to 0.514 ΔA₄₇₀ min⁻¹ g⁻¹ fw, while for Ni, peroxidase activity was higher for all concentrations in comparison to control. However, carotenoids content after 3 days treatment increased upto 51% for Ni only and decreased upto 5–6% of control for Cd. POX activity after 15 days treatment decreased 74% for Ni and 90% for Cd. Contrastingly carotenoid declined upto 65% for Ni and only upto 26% of control for Cd. Results suggest that both POX and carotenoid content could be used as bio-indicators of metal pollution. Study suggests that Cd is more phytotoxic than Ni.