A lipophilic cation protects crops against fungal pathogens by multiple modes of action
Gero Steinberg, Martin Schuster, Sarah J. Gurr, Tina A. Schrader, Michael Schrader, Mark E. Wood, Andy Early, Sreedhar Kilaru
Abstract
Abstract The emerging resistance of crop pathogens to fungicides poses a challenge to food security and compels discovery of new antifungal compounds. Here, we show that mono-alkyl lipophilic cations (MALCs) inhibit oxidative phosphorylation by affecting NADH oxidation in the plant pathogens Zymoseptoria tritici , Ustilago maydis and Magnaporthe oryzae . One of these MALCs, consisting of a dimethylsulfonium moiety and a long alkyl chain (C 18 -SMe 2 + ), also induces production of reactive oxygen species at the level of respiratory complex I, thus triggering fungal apoptosis. In addition, C 18 -SMe 2 + activates innate plant defense. This multiple activity effectively protects cereals against Septoria tritici blotch and rice blast disease. C 18 -SMe 2 + has low toxicity in Daphnia magna , and is not mutagenic or phytotoxic. Thus, MALCs hold potential as effective and non-toxic crop fungicides.