An antifungal compound involved in symbiotic germination of Cypripedium macranthos var. rebunense (Orchidaceae)

Germination of orchid seeds fully depends on a symbiotic association with soil-borne fungi. In contrast to the peaceful symbiotic associations between other plants and mycorrhizal fungi, this association is a life-and-death struggle. Germinating seeds of an orchid (Cypripedium macranthos var. rebunense) produce lusianthrin to regulate the growth of fungi and prevail in this struggle.