Crucial Role of the Ca 2+ /CN Signaling Pathway in the Antifungal Activity of Seselin against Botrytis cinerea .

Botrytis cinerea causes gray mold in many fruit and vegetable crops. We previously found that Seselin (SL) displayed antifungal activity against B. cinerea (EC 50 = 6.1 μg·mL -1 ), and this study investigated the effects of Ca 2+ and the Ca 2+ /CN signaling pathway on its antifungal activity against B. cinerea . The results indicated that exogenous Ca 2+ , Cyclosporine A, and Verapamil reduced the sensitivity of SL against B. cinerea ; SL significantly reduced the intracellular Ca 2+ concentration in the hyphae; the sensitivity of strains Δ bcCCH 1 and Δ bcMID 1 to SL were significantly increased; and the expressions of CCH 1, MID 1, CNA , PMC 1, and PMR 1 genes of the Ca 2+ /CN signaling pathway were significantly downregulated by SL treatment. Hence, SL is a potential compound for developing fungicides against B. cinerea . SL dramatically reduces intracellular Ca 2+ concentration and disturbs Ca 2+ homeostasis, leading to cell death. The Ca 2+ /CN signaling pathway plays an important role in the antifungal activity of SL against B. cinerea .