Effects of excess water on the specific activities of antioxidative enzymes in Zea mays

Abstract

Plants can produce a number of antioxidants to protect itself against environmental stress that effect their growth and productivity. The antioxidants that have been produced include enzymatic antioxidants and non enzymatic antioxidants. The effects of different volumes of water (excess water) on the ascorbate peroxidase (APx), catalase (CAT), and guaiacol peroxidase (POD) specific activities were studied in Zea mays. Zea mays were treated with 100, 120, 140, 160, 180 and 200ml of water for 7 days. The specific activities of these anti oxidative enzymes were detected every 0, 1, 2, 3, 5 and 7 days of treatment period. Water treatment significantly induced the APx and POD specific activities especially at later stages of treatment period. Increases the volume of water led to great increased of APx and POD specific activity. However, CAT specific activities were not affected at earlier stage of treatment while reduced at the later stages. These results suggest that the treatment of excess water stimulates oxidative stress in Zea mays by inducing the APx and POD antioxidative specific activities and reduced in CAT specific activities. As a C4 plant or plant that uses C4 photosynthesis, maize is a considerably more water-efficient crop than C3 plants. The antioxidant metabolism has been shown to be important in determining the ability of Zea mays to survive under conditions of excess water stress and the up regulation of these enzymes would help to reduce the build up of reactive oxygen species.