ABSTRACT
There is mounting evidence to suggest that plasma membranes play a central role in freezing injury of plant cells. Therefore, it is quite natural to assume that plasma membranes undergo chemical alterations during cold acclimation so as to adjust their properties against freezing stress. The lipid compositions of plant plasma membranes and tonoplasts isolated from etiolated mung bean hypocotyls, it was found that ceramide monohexoside (cerebroside) is one of the major lipid components in these membranes, especially in the tonoplasts which comprised about 17 mol% of the total tonoplast lipids. Plasma membrans have important physiological functions such as cell wall biosynthesis, active ion transports, hormone action, phytochrome responses, disease resistance, and stress responses, etc. Therefore, the membranes contained several types of proteins enrolled in these functions as well as structural proteins conferring to the membrane integrity.
