Antifungal and Laccase-Suppressing Activity of Phenolic Compounds and Their Oxidation Products on Grey Mold-Fungus Botrytis cinerea

Abstract

Botrytis cinerea causes grey mold that results in severe problems for wine makers worldwide. Infected grapes lead to quality deterioration including formation of off-flavors or browning. The latter is caused by the enzyme laccase which is capable of oxidizing a wide range of phenolic compounds. Since the use of conventional pesticides is associated with many concerns of consumers and authorities regarding environmental and health related issues and may result in fungicide resistance, the development of green alternatives is gaining more attention. Phenolic compounds like ferulic acid or stilbens which serve as phytoalexins have shown promising results in terms of growth-inhibitory effects against B. cinerea. The present study focuses on further investigations of the antifungal and laccase-suppressing effects of these phenols and especially their laccase-derived oxidation products using the syringaldazine-assay for determination of the laccase activity. The results revealed that they can be considered as a sustainable alternative to synthetic fungicides for Botrytis cinerea management.