EFFECTS OF GIBBERELLIC-ACID ON HAIRY ROOT CULTURES OF ARTEMISIA-ANNUA- GROWTH AND ARTEMISININ PRODUCTION

Artemisinin (AN), a potent antimalarial drug that has been used for ce nturies as a folk remedy in China, is an effective treatment against q uinine-resistant strains of Plasmodium. It can be produced through the in vitro culture of genetically transformed (hairy) roots. The effect of gibberellic acid (GA(3)) on the growth and secondary metabolite pr oduction of hairy roots of Artemisia annua was investigated. Six diffe rent concentrations of GA(3) were tested in shaker flasks to determine the optimum concentration. GA(3) levels of 0.01-0.001 mg/l (28.9-2.89 mu M) provided the most significant increase in biomass, and 0.01 mg/ l (28.9 mu M) produced the highest amount of AN. Investigation of grow th kinetics showed that the use of GA(3) at 0.01 mg/l (28.9 mu M) incr eased the growth rate of hairy roots of A. annua by 24.9%. Thus, the c ultures treated with GA(3) reached stationary phase faster than contro l cultures.