The effect of drought stress on antioxidant enzymes activity and artemisinin content in wormwood (Artemisia siberi)

Drought stress increases production of secondary metabolites in wide ranges of plants and accumulation of these components usually occurs under stress. Secondary metabolites are natural compounds produced by plants that play different physiological roles in plants. Artemisinin is a sesquiterpene lactone, produces by some of Artemisia species. This secondary metabolite is one of the most important antimalarial drugs. This study was conducted to investigate the effect of drought stress on antioxidant enzymes activity and artimisinin content in Artemisia siberi. The experiment was carried out in a completely randomized design in greenhouse with four treatments of irrigation regime (control, 70, 50 and 30 percent of field capacity. intermittent drought stress was performed for 8 weeks. Drought stress caused increased the antioxidant activity of ascorbate peroxidase, peroxidase, superoxide dismutase and catalase. Highest activity for these enzymes was observed at 30% of field capacity. The amount of artemisinin were not significantly different between drought treatments and control. The results showed that drought stress does not always increase secondary metabolites and medicinal compounds such as artemisinin.