Crucial Role of the Ca2+/CN Signaling Pathway in the Antifungal Activity of Seselin against Botrytis cinerea

Botrytis cinerea causesgray moldin many fruit and vegetable crops. We previously found that Seselin(SL) displayed antifungal activity against B. cinerea (EC50 = 6.1 mu g center dot mL(-1)), andthis study investigated the effects of Ca2+ and the Ca2+/CN signaling pathway on its antifungal activity against B. cinerea. The results indicated that exogenousCa(2+), Cyclosporine A, and Verapamil reduced the sensitivityof SL against B. cinerea; SL significantlyreduced the intracellular Ca2+ concentration in the hyphae;the sensitivity of strains Delta bcCCH1 and Delta bcMID1 to SL were significantly increased; and the expressionsof CCH1, MID1, CNA, PMC1, and PMR1 genes of the Ca2+/CN signaling pathway were significantly downregulated bySL treatment. Hence, SL is a potential compound for developing fungicidesagainst B. cinerea. SL dramaticallyreduces intracellular Ca2+ concentration and disturbs Ca2+ homeostasis, leading to cell death. The Ca2+/CNsignaling pathway plays an important role in the antifungal activityof SL against B. cinerea.