ABSTRACT
For a long time, it was thought carbohydrates played only important roles as energy or structural components of plant cell wall. Recently, oligosaccharins have been known as biological signals for cells. Oligosaccharides, including chito-oligosaccharides, are cell molecular signals, which induce and regulate defensive, symbiotic, and developmental processes in plants (Darvill 1992, Cote and Hahn 1994, John et al. 1997).
