Phospholipase A2 activity during cold acclimation of wheat

Authors: Skinner, Daniel

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2008
Publication Date: 1/28/2009
Citation: Skinner, D.Z. 2009. Phospholipase A2 activity during cold acclimation of wheat. Crop Sci. 49:323-328. DOI:10.2135/cropsci2008.06.0359

Interpretive Summary: Cold temperature is a significant stress factor impacting crop plant productivity. Understanding mechanisms involved in the response of plants to cold stress is essential to long-term crop improvement goals. In this research, the behavior of phospholipase A2, an enzyme that modifies components of plant cell membranes, was investigated in wheat plants undergoing cold acclimation and/or chilling stress. Activity of the enzyme increased earlier in the cold acclimation process in cold tolerant plants than in poorly cold tolerant plants. Enzyme activity also increased in partially acclimated, but not in fully acclimated plants, exposed to chilling stress. These results suggest that phospholipase A2 is an important component of the initial response mechanism to cold temperature in wheat plants, and differs significantly among plants with differing levels of cold tolerance, providing an avenue for plant improvement.

Technical Abstract: Phospholipase A2 (EC 3.1.1.4; PLA2) activity in wheat (Triticum aestivum L.) crown tissue from plants undergoing cold acclimation and/or chilling stress was investigated in a moderately cold tolerant winter wheat, a spring wheat, and a poorly cold tolerant winter wheat. Activity levels were investigated in plants that had been cold acclimated 0-4 weeks. In nonacclimated cold tolerant winter wheat, the level of PLA2 activity was significantly less than in the poorly cold tolerant winter wheat and the spring wheat, but then increased significantly during the first week of cold acclimation while remaining unchanged in the other two lines. All three wheat lines experienced increased levels of PLA2 activity during the second week of cold acclimation, but activity levels declined by the end of four weeks of acclimation. Chilling stress resulted in increased PLA2 activity levels in all wheat lines, but only in plants that had been acclimated for one week. Taken together, these data suggest PLA2 activity is involved in the initial response of plants to cold temperature, but not in responses to colder temperatures in acclimated plants.