Membrane Fluidity and Compositional Changes in Response to High Temperature Stress in Wheat

Membranes are prime targets of high temperature stress in plants. Thus, cell membrane stability has been used as a measure of heat tolerance in wheat. Under optimal temperature conditions, membranes are lipid bilayers that are largely in fluid phase. High temperatures or dehydration can cause phase transitions of membranes to non-bilayer phases. In order to maintain optimal fluidity and stability of membranes under high temperature conditions, wheat plants alter lipid compositions and reduce unsaturation levels in the fatty acid chains. Besides altering the fatty acid chains synthesized, the composition of chloroplast and thylakoid membranes may be adjusted by adjusting the diacylglycerol species channeled from the endoplasmic reticulum to chloroplasts under heat stress conditions.