Effects of Salicylic Acid on Photosynthetic Pigments, Osmolytes, and Antioxidant Enzyme Activities in White Savory (Satureja mutica Fisch.) Exposed to Various Salt Levels

White savory (Satureja mutica Fisch.) is an oil-bearing plant with applications in traditional medicine, pharmaceutical industries, and food additives in homemade dishes. The current research comprised a greenhouse experiment in a factorial arrangement based on a completely randomized design (CRD). It included four salinity levels (۰, ۵۰, ۱۰۰, and ۱۵۰ mM NaCl), two salicylic acid (SA) levels (۰ and ۲ mM), and three replicates. By increasing the NaCl concentration, the content of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid significantly declined. Increasing NaCl up to ۱۰۰ mM caused a significant increase in proline and soluble protein content. The amount of proline at ۱۵۰ mM NaCl showed no significant change compared to ۱۰۰ mM NaCl, but the soluble protein sharply decreased at ۱۵۰ mM NaCl. The enzymatic activities of superoxide dismutase, catalase, and peroxidase significantly increased in response to higher NaCl concentrations. Saturated water deficiency increased significantly, and leaf fresh and dry weights decreased substantially at ۱۰۰ and ۱۵۰ mM NaCl. SA enhanced chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, and leaf fresh and dry weight, depending on the NaCl treatments. SA applications considerably boosted peroxidase and catalase activities despite the presence of NaCl at any concentration. Also, SA significantly improved superoxide dismutase activity at ۵۰ and ۱۰۰ mM NaCl but could not counter its decrease when the NaCl level was ۱۵۰ mM. SA significantly reduced saturated water deficiency and proline content despite any of the NaCl treatments. SA mitigated the adverse effects of NaCl on S. mutica by improving antioxidant activity, photosynthetic pigments, and physiological characteristics.

کلیدواژه ها:

Antioxidant activity ، Chlorophyll ، proline ، salt stress ، Savory