Synergistic effects of biotic and abiotic elicitors on the production of tanshinones in Salvia miltiorrhiza hairy root culture

Objective: To investigate the synergistic effects of a biotic elicitor yeast extract and different abiotic elicitors (Ag+, Co2+ and α-amino isobutyric acid) on the production of lanshinones in Salvia miltiorrhiza hairy root. Method: Different elicitors and their combinations were added to S. miltiorrhiza hairy root culture and the contents of three major tanshinones (crypotanshinone, tanshinone I and tanshinone IIA) were analyzed by HPLC. Result: The combinations of yeast extract with different abiotic elicitors had notable synergistic effects on the tanshinone I and tanshinone IIA production but not on crypotanshinone. The combination of yeast extract and Ag+ (300 μmol·L-1) yielded the highest tanshinone I content, which was nearly 14-fold of the control, and the synergistic elicitation coefficient was 3.0. The combination of yeast extract and Co2+ (100 μmol·L-1) led to the highest tanshinone IIA content, which was about 14.5-fold of the control, and the synergistic elicitation coefficient was 2.1. Only yeast extract combined with α-amino isobutyric acid (200 μmol·L-1) increased the crypotanshinone content more effectively than single elicitors. The highest crypotanshinone content was 1.28 mg·g-1, about 30-fold of the control with a synergistic elicitation coefficient of 1.3. Conclusion: The elicitation by the combination of a biotic elicitor and an abiotic elicitor can generate a synergistic effect, which is more effective than single elicitors to promote secondary metabolite production in plant tissue cultures.