Antioxidative enzymes in barley plants subjected to soil flooding

Effects of soil flooding on the activity of foliar antioxidative enzymes-superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR) of barley plants (Hordeum vulgare cv. Alfa) were studied. Seventy-two to 120 h of soil flooding decreased the activity of SOD and the decrease was mainly due to progressive reduction in the activity of Fe-containing SOD located in chloroplasts. The activity of POD significantly increased and 120 h after flooding it was two-fold higher than the control. The changes in the activity of CAT followed the same tendency as for POD activity. Soil flooding affected differently the activity of GR and APX. GR activity was insignificantly influenced over the course of treatment. Both total soluble and thylakoid-bound APX activity increased in all flooded plants. Regardless of the increased activity of hydrogen peroxide scavenging enzymes, flooding treatment caused a substantial rise in total endogenous peroxide concentration. It is suggested that root oxygen deficiency caused photoxidative damage to barley leaves via an increased generation of active oxygen species. (C) 2003 Elsevier B.V. All rights reserved.