ABSTRACT
The plant cell may respond to the excess of heavy metals in its environment by various mechanisms, including enhanced biosynthesis of secondary metabolites. In this study, zinc (0 to 1500 µM) and cadmium ions (0 to 100 µM) were tested as potential elicitors of the production of coumarins in angelica cell suspension cultures. In addition, the toxicity of both metals was assessed by evaluating their effect on cell growth (characterized by fresh and dry biomass at the end of a two-week subculture). It has been found that fresh biomass was not influenced up to zinc concentrations of 150 and 300 µM in the dark-grown and light-grown cultures, resp. Then it declined with an increasing zinc level. Zinc at 1500 µM diminished it by 54% and 24% in the dark-grown and light-grown cultures, resp. Dry biomass was influenced in a similar way. Zinc at 1500 µM reduced dry cell weight by 30% and 20% in cultures in the dark and in the light, resp. Cadmium ions did not affect fresh and dry weights of cells up to concentrations of 10 µM and 50 µM in cultures in the dark and in the light, resp. Toxic concentrations of cadmium are by an order of magnitude lower than those of zinc. Cadmium at 50 µM reduced fresh and dry cell weights by 66% and 59%, resp., in the dark-grown cultures. Cadmium at 100 µM caused a decrease in fresh and dry biomass by 40% and 44%, resp., in the light-grown cultures. Neither zinc nor cadmium improved production of coumarins.
