Journal of Plant Process and Function

  Water deficit can be considered as one of the most important abiotic factors limiting plant function, which has also adverse affects on growth and production of medicinal plants. In this research, in order to evaluate the effects of water deficit stress on of Artemisia dracunculus plant, a completely randomized design with three replications was performed in greenhouse conditions. The experimental treatments were different levels of irrigation based on control (90% of field capacity), T1: 60% of field capacity and T2: 40% of field capacity. Four weeks after treatment, physiological and biochemical indices were measured. Results showed that, water deficit stress had significant effects on measured traits and the average value of some traits such as: fresh and dry weight, leaf area, relative water content and shoot length were decreased under stress in both A. dracunculus collections in compare to control plants. The least average value of these traits was observed in T2 plants. Analysis of biochemical data also showed that, enzyme activity of peroxidase, proline and soluble sugars contents and the specific activity of peroxidase were increased in both A. dracunculus collections under water stress condition. However, enzyme activity of catalase, content of photosynthetic pigments (chl a, chl b and carotenoides), soluble protein content and the specific activity of catalase were decreased under stress. As a conclusion, Irrigation level at 40% of field capacity can be considered as stress level for this plant. Furthermore, A. dracunculus can respond to water deficit stress by increasing of the contents of proline and soluble sugars and the activity of peroxidase as one of antioxidant enzymes.