Effect of light and passage on cardiac glycoside production on cultured cell of Digitalis nervosa Steud & Hochst

Light is important for the production of metabolites by plant cell culture. It is therefore necessary to evaluate the light conditions with respect to exposure time. Both enhancement and inhibition have been observed depending on exposure time and species. Callus culture of D. nervosa was established and effect of light and passage on cardiac glycoside production was studied. In vitro cultures were successfully established from seedling using MS medium supplemented with K (0.5 mg/l), 2, 4-D (0.5 mg/l), NAA (1 mg/l) as plant growth regulators. These were then left under a twelve hourly light/dark cycle or 24 dark condition. The phytochemical studies were carried out using Thin Layer Chromatography (TLC) and UV spectrometry. Although we were able to establish the production of cardiac glycosides in D. nerveso cultures, the yield was very low, and moreover, during successive transfers of the cultured cells the amount of cardenolides decreased. Culture passage had a significant effect on the yield of cardenolide. The production of cardiac glycosides did not differ depending on the light exposure time during the in vitro culture. No significance differences in cardenolide production by D. nerveso cells kept in the dark compared to that cells exposed to intervals of light were observed. It seems the effect of light and passage on cardiac glycoside production depend on plant species.