Membrane stability of winter wheat plants exposed to subzero temperatures for variable lengths of time

Abstract

To survive the temperature variation that occurs during the winter months, winter wheat (Triticum aestivum L.) plants must tolerate episodes of freezing of varying intensity and duration. In this study, fully cold-acclimated plants of six lines of winter wheat were exposed to -12, -14, -16, or -18 °C, for 1-5 hours. Electrolyte leakage and plant survival were used to assess damage to the plants. Plants exposed to subzero temperatures for 4 hours experienced less electrolyte leakage and survived more frequently than plants exposed for 1-3, or 5 hours. This increased tolerance of freezing stress after longer exposure suggests a threshold effect that, once reached, results in activation of mechanisms that enable greater stability of the cell membranes and greater plant survival. Further elucidation of this mechanism and the genes involved may provide new avenues of approach to improve freezing tolerance of crop plants.

Keywords

• Triticum aestivum
• Winterhardiness
• Freezing
• Cold
• Tolerance