Salicylic Acid and UV-B/C Radiation Effects on Growth and Physiological Traits of <i>Satureja hortensis</i> L.

Higher UV irradiation may affect the structure of ecosystems directly or indirectly. In the present work, Satureja hortensis L. defence mechanisms against UV stress was studied with or without salicylic acid (SA). For this aim, a factorial based experimental was conducted on completely randomized design with three UV treatments (control, UV-B and UV-C) as first factor and two SA levels (0 and 1 mM) as second factor. The results showed UV-B and C decreased shoot dry weight, plant height (PH), node number (NN), inter-node distance (IND), root length (RL), leaf area index (LAI) and chlorophyll content, but increased stem diameter (SD), leaf thickness (LTh), total flavonoid content (TFC), total phenolic content (TFC) and antioxidant activity. Plants treated with SA (1 mM) showed higher growth factors than non-treated one. It seems that SA can be used as an alternative substance against UV stress