it has been suggested that pectic polysaccharides ( or oligosaccharides cleaved from them ) are liberated from the cell wall upon wounding of leaf tissue , and that they act as long-distance hormones evoking a defence response in neighbouring uninjured leaves ( p.d . bishop et al . 1981 , proc . natl . acad . sci . usa 78 , 3536-3540 , and cited literature ) .
C0032594
polysaccharides
C0028959
oligosaccharides