Abstract
Chitin- and chitosan-like substances were isolated from mycelia and conidia of Mycospharella (M.) pinodes, a plant pathogen of peas causing brown spots. The elicitor activities of these substances were compared with those of commercially available crustacean chitin and chitosan or several neutral polysaccharides. Only low activities were detected in the chitin-like substnaces of this microbe and in the authentic chitin commercially obtained. Although the activity was not detectable in chitosan oligomers whose degree of polymerization was less than 6, the acivity which appeared in the chitosan hexamer and the octamer had almost the same activity as the commercially available chitosan. All of the authentic neutral linear polysaccharides tested were inactive. After having applied M. pinode suspension on pea leaves, activities of both chitinase and chitosanase increased quickly. Fluorescein isothiocyanate (FITC)-labelled chitosan was treated with a crude extract of pea leaves, and FITC-oligomers were obtained.
