Studies on the role of active oxygen in ozone injury to plant cells. II. Effect of antioxidants on rice protoplasts exposed to ozone

Abstract The effects of antioxidants, ascorbic acid, hydroquinone and mannitol, on ATPase activity in cellular membranes and on the formation of malondialdehyde in rice protoplasts treated with air or ozone in vitro, were examined. All three substances restrained the increase in malondialdehyde (MDA) during the treatment with both air and ozone, and ascorbic acid and hydroquinone were more effective on the protoplasts treated with ozone than those treate With regard to mannitol, however, no difference was noticed in the decrease in MDA between protoplasts treated with ozone and those treated with air. Only ascorbic acid was effective in maintaining ATPase activity in cellular membranes. The addition of ascorbic acid during ozone treatment restrained the decrease the ATPase activity by half compared with treatment without ascorbic acid.