Evaluation of the elicitor properties of ergosterol obtained from residual brewing yeast

Sustainable agriculture requires solutions that combine cost-effectiveness and environmental safety. One of such approach is the use of biological pesticides for plant protection, which reduce dependence on synthetic chemicals, minimize environmental pollution, and preserve agroecosystems biodiversity. A key trend in the development of biological pesticides is the shift from the direct destruction of pathogens to the activation of the natural defense mechanisms of plants themselves. In this context, elicitors are of particular interest: exogenous substances of various types that can induce systemic acquired resistance (SAR) in plants. The most important naturally occurring elicitors are microorganism-associated molecular patterns (MAMPs). MAMPs are perceived by plant receptors and consequently trigger the plant’s own defense mechanisms against pests. Currently identified fungal MAMP molecules include chitin, chitosan, β-glucans, elicitins, and ergosterol. In this work, the natural elicitor ergosterol was obtained from residual brewing yeast and its protective properties were examined on the leaves of cucumber and pepper plants against the fungal phytopathogen Botrytis cinerea. It was found that it effectively inhibited B. cinerea infection with an efficiency of 95‒97%, which turned out to be at the level as the commercial synthetic elicitor tiadinil (90‒91%) and significantly exceeds the activity of another synthetic elicitor isotianil (56‒ 62%).