Enhancement of Diosgenin Production in Plantlet and Cell Cultures of Dioscorea zingiberensis by Palmarumycin C13 from the Endophytic fungus, Berkleasmium sp Dzf12

Purpose: To study the effect of palmarumycin C-13, an elicitor from the endophytic fungus Berkleasmium sp. Dzf12, on growth and diosgenin production in plantlet or cell cultures of its host plant, Dioscorea zingiberensis. Methods: Palmarumycin C-13 was isolated from the ethyl acetate extract of the endophytic fungus Berkleasmium sp. Dzf12 using a combination of high-speed counter-current chromatography (HSCCC), Sephadex LH-20 chromatography and preparative high performance liquid chromatography (HPLC). The biomass of the plantlet and cell cultures of D. zingiberensis as well as their diosgenin content and yield were analyzed after treatment with palmarumycin C-13. Results: Optimal elicitation of diosgenin production by palmarumycin C-13 in D. zingiberensis plantlet and cell cultures was achieved when palmarumycin C-13 was added to the medium at a concentration of 60 mg/L (for plantlet culture) at the beginning of culturing or 10 mg/L (for cell culture) on day 25 after inoculation. By using these optimal concentrations, the diosgenin yield of the cultured plantlets reached its maximum of 6.44 mg/L, that is, > 1.4-fold increase, while diosgenin yield of the cultured cells reached a maximum of 10.73 mg/L, which is an > 8.0-fold increase. Conclusion: Addition of palmarumycin C-13 from the endophytic fungus, Berkleasmium sp. Dzf12, is a potentially effective strategy for enhancing diosgenin production in D. zingiberensis plantlet and cell cultures.