STEROID GLYCOSIDE LOCATION AND ULTRASTRUCTURE OF DIOSCOREA-DELTOIDEA CELLS IN CULTURE

The ultrastructure of cultured cells of Dioscorea deltoidea Wall., DM-0.5 strain, was studied. This strain is an overproducer of furostanolic steroid glycosides. Various fixation procedures providing the preservation of native cell structure and stabilization of cell glycosides were compared. It was found that the fine structures of DM-0.5 strain cells and terpenoid-producing cells were similar. An accumulation of electron dense substances was observed in the vacuoles, cell walls, and intercellular spaces. It agreed with the quantitative glycoside determination in cells and protoplasts of DM-0.5 strain. Essential reduction in electron dense material in cell walls and intercellular spaces was recorded after selective extraction of steroid compounds during the fixation procedures. We suggested that the electron dense substance that disappeared consisted of steroid glycosides.