The role of Ca 2 + ‐calcineurin signaling pathway on the antifungal activity of Murrayone against Botrytis cinerea

Abstract BACKGROUND Botrytis cinerea causes serious gray mold disease in a wide range of crops, resulting in significant economic losses annually. Our preliminary studies demonstrated that Murrayone exhibited antifungal activity against various plant pathogens, including B. cinerea . However, its antifungal mechanism against B. cinerea remains unclear. This study aimed to investigate the role of the Ca 2+ ‐calcineurin signaling pathway in the antifungal activity of Murrayone against B. cinerea . RESULTS Murrayone exhibited efficacy against B. cinerea in both in vitro and in vivo assays. It markedly reduced intracellular Ca 2+ concentrations in the mycelia. The antifungal activity of Murrayone was influenced by CaCl 2 , the calcium channel blocker verapamil, and the calcineurin inhibitor cyclosporin A. Murrayone treatment significantly downregulated the expression of key genes ( Bccch1, Bcmid1, BccnA, Bcpmc1 , and Bcpmr1 ) in the Ca 2+ ‐calcineurin signaling pathway. Patch‐clamp analysis suggested that Murrayone acted as a potential Ca 2+ channel blocker. CONCLUSION Murrayone significantly decreases the cytosolic Ca 2+ concentration and disrupts Ca 2+ homeostasis in B. cinerea . Its antifungal mechanism is linked to the Ca 2+ ‐calcineurin signaling pathway, potentially through acting as a calcium channel blocker. This work provides a theoretical foundation for developing Murrayone as a promising antifungal candidate and promotes its further application. © 2026 Society of Chemical Industry.