Effect of Drought Stress on Antioxidant Activity, Phenolic and Flavonoid Content of Artemisia Sieberi

Background and aim: drought stress increases the contents of secondary metabolites in a wide variety of plant species. the present research aimed to study the effect of drought stress as an oxidative stress on artemisia sieberi.methods: drought stress was applied at three levels (30, 50 and 70% of field capacity) in the greenhouse for 8 weeks. the control plants received full irrigation. the traits of leaf relative water content, total phenol content, total flavonoid content and antioxidant capacity, antioxidant activities of catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase were measured.results: drought stress had a significant effect on relative water content, total phenolic content, total flavonoid content and antioxidant capacity at the 5% significance level. also, drought stress increased antioxidant activities of catalase, peroxidase, ascorbate peroxidase and superoxide dismutase. the highest total phenol content, antioxidant capacities and activities of ascorbate peroxidase, peroxidase, superoxide dismutase and catalase were observed in the severe drought stress treatment. the highest total flavonoid content was recorded under moderate drought stress. comparison of mean antioxidant capacities of the treatments revealed that drought stress increased inhibition of the dpph free radical. the highest percentage of dpph radical scavenging activity belonged to the level of drought at the 30% fc treatmentconclusion: applying moderate and severe periodic drought stress increased total phenolic content and total flavonoid content and antioxidant activities in artemisia sieberi in this study. end-season drought stress prior to harvest and/or periodic drought stress can increase the contents of sms in some medicinal plants. the effect of accurately applying different levels of drought stress was assessed in artemisia sieberi in this study.