Cold induced changes in antioxidant enzymes activity in roots and leaves of two maize cultivars

Chilling induced oxidative stress in plants has been a widely investigated object recently. In this study we focus on response of enzymatic antioxidants, superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase to low temperatures and to consequent re-exposure to optimal temperatures in maize. Samples from roots and leaves of two maize cultivars differing in chilling sensitivity (ULTRA and X0954D, obtained from Pioneer) cultivated in growth chamber in Hoagland nutrient solution were used for spectrophotometrical measurements of enzyme activities. The response of each analyzed antioxidant enzyme to chilling had different pattern. Differences were observed between the leaves and roots too. An induction of catalase and glutathione reductase activities in roots and SOD, APX and GR activities in leaves was observed during the chilling period. The results showed a rapid decline in SOD activity in roots and leaves during the early stages chilling period. Catalase and APX work in regulated co-operation in both tissues. Activities of SOD were coordinated with catalase, APX and GR in our experiments being induced uniformly after 5-day chilling treatment. Antioxidants response to chilling did not substantially correspond with chilling sensitivity of the two studied cultivars.