Myriophyllum alterniflorum biochemical changes during in vitro Cu/Cd metal stress: Focusing on cell detoxifying enzymes

In this study, Myriophyllum alterniflorum (or alternate watermilfoil) enzyme activities (ascorbate peroxidase, catalase, glutathione peroxidase and superoxide dismutase) from in vitro cultures was measured over 27 days in response to copper (Cu) or cadmium (Cd) stress. These enzymes are unique to reactive oxygen species (ROS) scavenging (mainly hydrogen peroxide H2O2 and superoxide anion O2•−) and moreover showed specific or unspecific activity profiles, depending on the metal concentrations used. Our results suggest a higher-priority protection of chloroplasts during the initial days of exposure to both metals. At the same time, the increased catalase activity could indicate an H2O2 diffusion in peroxisome in order to protect other organelles from ROS accumulation. However, as opposed to the Cd effects, high Cu concentrations appear to induce a “limited oxidative threshold” for some antioxidant enzymes, which could suggest an ion absorption competition between Cu2+ and Fe2+. In spite of an overall analysis conducted of the scavenging processes occurring in plant cells, biochemical analyses still yielded relevant indications regarding the watermilfoil strategies used for ROS management.Graphical abstract
Source: Aquatic Toxicology - Category: Toxicology Source Type: research