CUCURBITACINS PROTECT CUCUMBER TISSUE AGAINST INFECTION BY BOTRYTIS-CINEREA

Extracts of Ecballium elaterium or cucurbitacin I were applied to cucumber fruits or plants or to cabbage leaves, prior to inoculation with Botrytis cinerea. This treatment prevented infection of the tissue, the infecting fungus being restricted to the site of infection. Infection was always accompanied by localized lignification. The protective effect was not due to the induction of lignification. It is suggested that the ability of cucurbitacin I to inhibit induction of laccase formation by Botrytis is responsible for its protective effect. © 1990.