The J1 line of hairy roots of C. roseus used in this work was obtained by infection of plant roots with Agrobacterium rhizogenes strain 1855 pBI 121.1 {Ciau-Uitz, 1994 12709 /id}.
   Half gram of hairy root culture was initially inoculated into 100 mL of B5 medium half-strength {Gamborg, 1968 5176 /id} supplemented with 3% (w/v) sucrose contained in 250 mL Erlenmeyer flasks and subcultured every 21 days. Cultures were incubated in the dark on a rotate shaker at 100 rpm at 25 +/-2ºC for 15 d.