Glycinebetaine is an important compatible solute in response to salt,drought and other osmotic stresses in many organisms. It exists in cytoplasm as a non-toxic osmolyte and its concentration increases so as to maintain the osmotic balance of the cell when plants are stressed. At the same time,it acts as a low molecular weight chaperone to stabilize the structure of the protein and enzyme so that they can keep in functional conformation. Synthesis of glycinebetaine needs the catalysis of betaine ...