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 furostanoli c steroid glycosides. Various fixation procedures providing the preser vation of native cell structure and stabilization of cell glycosides w ere compared. It was found that the fine structures of DM-0.5 strain c ells and terpenoid-producing cells were similar. An accumulation of el ectron dense substances was observed in the vacuoles, cell walls, and intercellular spaces. It agreed with the quantitative glycoside determ ination 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 f ixation procedures. We suggested that the electron dense substance tha t disappeared consisted of steroid glycosides.