Changes in growth and superoxide dismutase activity in Hydrilla verticillata L. under abiotic stress

a study was made of the role of various heavy metals (chromium, zinc, copper and cadmium) together with the effects of nacl-salinity, peg-mediated water stress and temperature on growth and superoxide dismutase (sod) activity in hydrilla (hydrilla verticillata l.). almost all metals studied reduced growth but presented a modulatory effect at lower concentrations. nacl-salinity, water stress and temperature treatments also reduced growth. sod activity was inhibited by both chromium and zinc but increased by copper and cadmium. nacl-salinity increased sod activity while water stress decreased it. sod showed thermostability with a higher activity being recorded at 45oc.