Comparative study of frost tolerance and antioxidant activity in cereals

The aim of this study was to find a correlation between the frost tolerance of cereals and their antioxidant capacity. Frost-tolerant and frost-sensitive cereal species, including wheat, barley, rye, durum wheat and oat varieties and wheat chromosome substitution lines, were cold-hardened at low, gradually decreasing temperature for 7 weeks. Control, unhardened plants were grown at a constant temperature of 17/16 degreesC. Changes in the activity of antioxidant enzymes (catalase, ascorbate peroxidase, guaiacol peroxidase (GPx), glutathione-S-transferase and glutathione reductase (GR)) in the crown and leaves were determined in the control and in hardened plants. The glutathione-S-transferase in the crown and leaf, and the ascorbate peroxidase and GPx in the leaf were significantly higher in the hardened plants than in the controls. The catalase activity in the leaves was lower in the hardened plants. The highest correlation between the enzyme activity and frost tolerance was found in the case of GPx and ascorbate peroxidase from hardened leaves. Enzyme activities in the crown and in unhardened leaves showed no significant positive correlation. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.