Nonspecific elicitation of defense reaction in suspension tobacco cells by elicitors from Armillaria.

Ergosterol and chitin oligomers were detected in water extracts from Armillaria gallica, A. cepistipes, A. tabescens, A. ostoyae and A. mellea containing as active components elicitors able to trigger early events of defense reaction in suspension tobacco cells. More virulent strains of A. ostoyae and A. mellea had the same ability of elicitation as weak pathogens A. gallica, A. cepistipes, A. tabescens. The elicitation of the defense reaction early events by chitin oligomers was markedly enhanced by ergosterol probably due to the activation of several signal pathways.