Improvement of echinacoside and acteoside production by two-stage elicitation in cell suspension culture of Cistanche deserticola

At appropriate concentrations, polyamines promoted the callus growth and echinacoside content of Cistanche deserticola while Ag+ increased the content of echinacoside and acteoside. In a 20-day culture period, when putrescine (25 mu M) and Ag+ (10 mu M) were added on day 8 and day 16, respectively, the echinacoside production (1.7 g l(-1)) and acteoside production (0.4 g l(-1)) reached the maximum, which were 1.4-fold and 1.5-fold of those in single putrescine treatment, 1.6-fold and 1.4-fold of those in single Ag+ treatment, respectively. Exogenous putrescine enhanced cell viability and antioxidant enzyme activity markedly, so increased the final biomass. Ag+ addition increased H2O2 content and phenylalanine ammonia-lyase activity significantly which led to higher echinacoside and acteoside contents.