Benzothiadiazole enhances the elicitation of rosmarinic acid production ina suspension culture of Agastache rugosa O. Kuntze

Callus and suspension cultures were established from the leaves of Agastach e rugosa. The suspension cell growth was maximum at 15 days after inoculati on. The cellular content of rosmarinic acid increased slowly and reached ma ximum (0.42 mg g(-1) dry wt) during the stationary phase of culture, after 18 days of inoculation. The addition of yeast extract preparation (MW < 10 000) at 50 mug ml(-1) elevated the rosmarinic acid content up to 5.7-fold o f that found in non-elicited suspension cells. The elicitation of yeast ext ract preparation was further 2-fold enhanced by the presence of benzothiadi azole, a synthetic activator of plant systemic acquired resistance, as comp ared to yeast extract alone. These results showed that benzothiadiazole can be used as a tool for enhancing secondary metabolite accumulation in cell cultures.