Abstract
Increase in freezing tolerance of temperate plants during cold acclimation is associated with accumulation of compatible solutes. To understand the cryoprotective mechanisms of compatible solutes in cold acclimation process, we initiated to determine the subcellular localization of compatible solutes in wheat and its changes during cold acclimation after leaves were fractionated using a nonaqueous fractionation technique. The results revealed that (1) sugars are the most accumulated compatible solutes in all subcellular compartments both before and after cold acclimation, (2) the total amount of compatible solutes is greatest in cytosol after cold acclimation, and (3) all of mono- and disaccharides, proline and glycinebetaine are accumulated most in cytosol after cold acclimation. With the volume of each organelle determined using electron microscopy, these results will be discussed in terms of relationship between changes in freezing tolerance and subcellular compatible solute concentrations in each organelle. (This study is in part supported by BRAIN.)
