Abstract
Cold acclimation (CA), the process of increasing in freezing tolerance, is an important survival mechanism for temperate plants. During CA, lipid and protein composition alters in the plasma membrane (PM) and the cryostability of the membrane increases. These changes are essential for plant survival under freezing conditions. Recently, the presence of sphingolipid/cholesterol-enriched microdomains in the plasma membrane has been proposed but little is known in plant system. To understand the role of microdomains in CA, we have determined their lipid composition. In microdomains, sterols increased and sphingolipids (glucocerebrosides) and phospholipids decreased. In contrast, PM showed no changes in sterols and phospholipids but a decrease in glucocerebrosides. These results indicate that microdomains respond to CA differently from the bulk plasma membrane, suggesting that the specific changes of microdomain lipids may have a specific role in maintaining some functions associated with microdomains at low temperatures, which minimizes freezing injury.
