Effect of lead and copper on enzyme activity in two bryophytes

Effect of lead and copper on nitrate reductase activity (NRA), peroxidase (POX) and superoxide dismutase (SOD) in mosses Rhodobryum roseum and Hypnum cupressiforme grown in different concentrations (control, 5, 10, 50 and 100 mM) for 7 and 15 days was studied. Level of NR activity significantly increased in comparison to control in 5 mM concentartion in 7 days treatment, which decreased if time period and concentration of metals (Pb and Cu) was increased, whereas, oxidative enzymes (i.e. POX and SOD) activity were observed to be significantly higher at all concentrations in 7 and 15 days of treatment period in both the mosses. The result suggests that Rhodobryum roseum is less sensitive to Pb and Cu in comparison to Hypnum cupressiforme.