Cell Surfaces in Plant-Microorganism Interactions : IV. Fungal Glycopeptides Which Elicit the Synthesis of Ethylene in Plants

The production of ethylene by melon (Cucumis melo cv Cantaloup charentais) tissues is stimulated during incubation in the presence of fungal glycopeptides extracted from Colletotrichum lagenarium, a pathogen of melon. These glycopeptides, called elicitors of ethylene, are found in the mycelium, the cell wall, and the culture filtrate. Elicitation of ethylene is a relatively early phenomenon and lasts for several hours. Upon purification of the crude elicitor extract by gel filtration and ion exchange chromatography, three elicitors were isolated. The three elicitors contained amino acid, sugar, and phosphate residues, and they have a decreased activity after partial chemical degradation of their sugar moiety.

Elicitation of ethylene is not fungal species specific. Elicitors of phytoalexins, obtained from three Phytophtora species, enhanced ethylene biosynthesis in melon tissues.