CaCl2 (50 mM) and hemicellulase (0.5 U mg(-1)) increased the intracellular accumulation (60-250%), release (60-200%) and production (45-200%) of hyoscyamine and scopolamine in hairy roots of Brugmansia candida. Theophylline (0.25 mM), alone or in combination with hemicellulase, was ineffective in increasing hyoscyamine and scopolamine production.