Abstract: Plant oligosaccharides were enzymatically extracted from wheat cell walls, After their bioactivity analyses, the oligosaccharides were proved to possess functions upon induction of both soybean and wheat phytoalexins and improvement of wheat defence at its metabolism, cell and plant levels, Bioactivity of wheat oligosaccharide was closely correlated with variety, purification and active unit of the hydrolytic enzymes useds strongly biofunctional oligosaccharides could be released by enzymes of high purification and active unit, Three kinds of oligosaccharides from different sources were compared in their biofunctions, while other factors were also discussed about their influence on oligosaccharide bioactivity, such as the physiological status of wheat cells and the conditions to preserve oligosaccharides.

Key words: Enzymatic method, Plant oligosaccharides, Wheat cell wall, Bioactivity