EN
Seven-day-old seedlings of cucumber (Cucumis sativus L.) cv. Wisconsin were treated with 0.01, 0.1 and 0.5 mM solutions of derivatives of cinnamic acid (ferulic and p-coumaric acids) and benzoic acid (p-hydroxybenzoic and vanillic acids) as stress factors. In cucumber roots phenolics (free and glucosylated), phenol β-glucosyltransferase (E.C. 2.4.1.35) activity as well as membrane permeability were examined. The most intensive glucosylation took place in the first hour of stress duration in roots treated with 0.01 mM ferulic and p-coumaric acids and with 0.01 and 0.1 mM p-hydroxybenzoic and vanillic acids. At these concentrations a high phenol β-glucosyltransferase activity was found. The deterioration of capacity for phenolic glucosylation as well as the decrease of the phenol β-glucosyltransferase was observed at the higher concentrations. It was associated with increased membrane permeability.