Methyl Jasmonate Mitigates Drought Stress Injuries and Affects Essential Oil of Summer Savory

Abstract

Drought stress reduces growth and productivity of c rops in arid and semiarid regions, such as Iran. Methyl Jasmonate (MeJA) is involved i n regulating plants growth and their immune responses. The main purpose of this study wa s to evaluate the effects of MeJA on growth and some physiological responses of summer s avory ( Satureja hortensis ) plant under drought stress condition. Treatments consiste d of three levels of drought stress including stress free conditions, mild stress and s evere stress, and four concentrations of MeJA (0, 75, 150, and 225 μ M). The results showed that drought stress and MeJA application had a significant effect on morphologic al, physiological, and biochemical parameters. In drought conditions, some growth para meters, namely, relative water content and essential oil yield decreased and antio xidant activity, proline content, and essential oil percentage increased. The results sug gest that MeJA application under drought stress can improve growth parameters as wel l as relative water content, proline content, antioxidant activity, and essential oil pe rcentage and yield. The best protection appeared to be obtained from plants treated with Me JA at 75 μ M. Keywords : Antioxidant activity, Growth parameters, Proline content, Relative water content.