B. Miranshahi - Department of Horticultural Sciences, College of Agriculture, Ilam University, Ilam, Islamic Republic of Iran.
M. Sayyari - Department of Horticultural Sciences, College of Agriculture, Bu-Ali Sina University, Hamedan, Islamic Republic of Iran.

Drought stress reduces growth and productivity of crops in arid and semiarid regions, such as Iran. Methyl Jasmonate (MeJA) is involved in regulating plants growth and their immune responses. The main purpose of this study was to evaluate the effects of MeJA on growth and some physiological responses of summer savory (Satureja hortensis) plant under drought stress condition. Treatments consisted of three levels of drought stress including stress free conditions, mild stress and severe stress, and four concentrations of MeJA (۰, ۷۵, ۱۵۰, and ۲۲۵ μM). The results showed that drought stress and MeJA application had a significant effect on morphological, physiological, and biochemical parameters. In drought conditions, some growth parameters, namely, relative water content and essential oil yield decreased and antioxidant activity, proline content, and essential oil percentage increased. The results suggest that MeJA application under drought stress can improve growth parameters as well as relative water content, proline content, antioxidant activity, and essential oil percentage and yield. The best protection appeared to be obtained from plants treated with MeJA at ۷۵ μM.

Antioxidant activity, Growth parameters, Proline content, Relative water content