ELICITOR-INDUCED CHEMILUMINESCENCE IN CELL-SUSPENSION CULTURES OF TOMATO, SWEET-PEPPER AND TOBACCO PLANTS AND ITS INHIBITION BY SUPPRESSORS FROM PHYTOPHTHORA SPP

The hyphal wall components (HWC) from Phytophthora capsici, P. infestans and P. nicotianae var. nicotianae, which caused the hypersensitive cell death of suspension-cultured cells of sweet pepper (Capsicum frutescence L.), tomato (Lycopersicon esculentum Mill.) and tobacco (Nicotiana tabacum L.), enhanced the luminol-mediated chemiluminescence in suspension-cultured cells of each plant within several minutes after treatment with HWC in a species-nonspecific manner. HWC-induced chemiluminescence in suspension-cultured cells was enhanced by incubation with superoxide dismutase but was significantly inhibited by pretreatment with catalase or, the O2- scavenger, Tiron. Similarly, Tiron or water-soluble glucans (WSG) from respective species of Phytophthora suppressed both the HWC-induced chemiluminescence and hypersensitive cell death specific only to its own host. These results suggested that Phytophthora spp. may produce suppressor-glucans which inhibit the activation of O2- generation responsible for triggering hypersensitive cell death in the respective Solanaceous host plants and permit the establishment of a compatible interaction.