Effects of cold stress on alterations of physiochemical and chemical properties of rice polysaccharides

The purpose of this research was to physiochemically characterize the temporal expression profiles of polysaccharides from cold-stressed rice. Rice seedlings (at the three-leaf stage) were subjected to cold treatment, and polysaccharides were characterized by size-exclusion chromatography (SEC) and high-performance anion-exchange chromatography (HPAEC). In general, the molecular weight distribution of polysaccharides was similar during the 6-day exposure to cold stress. We observed that very-low-molecular-weight (<1 kDa) polysaccharides increased during extended cold stress. We determined correlations between sugar components in the polysaccharides and prolonged exposure to cold stress. Arabinose was the main sugar component among polysaccharides found in this study. A positive correlation was observed for the contents of glucose and fructose with prolonged cold stress. Negative correlations existed for the contents of fucose and arabinose with cold-stress duration. The present results indicate that changes in the chemical profile of rice polysaccharides were correlated with extended exposure to cold stress.