Impact of Drought Stress during Germination on Antioxidant Capacities and Antioxidant Enzymes Activities of Madura Local Maize (<i>Zea mays</i>) Seeds

Abstract

The effect of various polyethylene glycol (PEG) concentrations to induced drought stress on the antioxidant capacities and antioxidant enzyme activities was investigated on Madura local maize during germination. Seed samples were treated under 5%, 10%, and 15% of PEG for 6 days. The changes in the antioxidant capacities such as 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and hydroxyl radical scavenging; antioxidant enzyme activities including catalase (CAT) and ascorbate peroxidase (APX) and gene expression were observed during seeds germination. The result showed the antioxidants capacities and enzyme activities exhibited a significantly higher level in drought-treated. The most effective level of drought stress to elevate the capabilities and enzyme activity of antioxidant as well as it gene expression was observed at 15% PEG, whereas ABTS scavenging activity was increased 20% over the control, hydroxyl scavenging activity up to 14%, CAT and APX activity increased 4 - 5 times over the control. Along with the presence of antioxidant mechanisms, including the capacities and activities of different types of ABTS+, hydroxyl, CAT, and APX might play important roles during the germination phase and be able to manage reactive oxygen species to the normal level under stress condition.