A COMPARISON OF THE EFFECTS OF A FUNGAL ELICITOR AND ULTRAVIOLET-RADIATION ON ION-TRANSPORT AND HYDROGEN-PEROXIDE SYNTHESIS BY ROSE CELLS

An elicitor preparation from a Phytophthora sp. induced an efflux of K+ and a production of H2O2 by cell suspensions of Rosa damascena. The kinetics and amounts of K+ efflux and of H2O2 production and degradation were similar to those observed when the cells were treated with u.v. radiation (254 nm). The K+ efflux from both elicitor-treated and u.v.-treated rose cells was inhibited at 0-degrees-C. K+ efflux from elicitor-treated cells was stimulated by a pretreatment of the cells at 40-degrees-C; efflux from u.v.-treated cells was inhibited by the same pretreatment. Washed cells lost sensitivity to elicitor (but not u.v.) over a period of several hours. Like u.v.-treated cells, elicitor-treated cells lost sensitivity to a second treatment with u.v. given 15-18 hr later. The results are interpreted in terms of a common ion transport process stimulated by elicitor and u.v. through different receptors.