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

Authors: Cuevas, Cecilia; Bellinger, Brian; Skinner, Daniel

Submitted to: Communications in Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2014
Publication Date: 11/21/2014
Citation: Cuevas, C., Bellinger, B.S., Skinner, D.Z. 2014. Membrane stability of winter wheat plants exposed to subzero temperatures for variable lengths of time. Communications in Plant Sciences. 5(1-2):9-14.

Interpretive Summary: Winter wheat plants must be able to tolerate episodes of below-freezing temperatures, sometimes lasting for hours. This study showed that winter wheat plants appear to activate a severe freezing tolerance mechanism if they are exposed to potentially damaging temperatures for at least four hours, but not if the exposure is for a shorter time. This mechanism appears to result in greater physical integrity of the cell membranes and greater plant survival. Further elucidation of this mechanism may provide new approaches to improve freezing tolerance and greater winter hardiness of the wheat crop.

Technical Abstract: The ability to survive episodes of subfreezing temperature is essential to winter wheat. Fully cold-acclimated plants of six lines of winter wheat were exposed to -12, -14, -16 or -18° C, four 1-5 hours. Electrolyte leakage and plant survival were used to assess damage to the plants. Plants exposed to subzero temperatures for four hours experienced less electrolyte leakage and survived more frequently than plants exposed to 1-3, or five hours. This increased tolerance of freezing stress after longer exposure suggests a threshold effect that, once crossed, results in activation of mechanisms that enable greater integrity 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 and winter hardiness of winter wheat.