Morphophysiological and biochemical response of savory medicinal plant using silicon under salt stress

Salt stress is one of the most important factors limiting the growth and yield of plants around the world. However, silicon can reduce the harmful effects of salt stress on plants. For this purpose, an experiment was conducted in a factorial arrangement on randomized complete block design with three replications in a research greenhouse on the Satureja hortensis medicinal plant. Experimental treatments consisted of two salinity levels (control and 100 mM) and potassium silicate (Si) at three levels (0, 1, and 2 mM). The results showed that salinity reduced shoot dry weight, photosynthetic pigments and potassium content of shoot. However, sodium, proline, MDA, and H2O2 contents in shoot increased. The highest shoot dry weight, photosynthetic pigment content, proline, RWC, and the lowest content of MDA and H2O2 of the shoot were observed with Si application under salt stress and non-salt stress conditions. The highest yield of essential oil was also observed with Si application under salt stress and non-salt stress conditions. Therefore, the use of silicon in salt stress condition not only minimizes the harmful effects of salt stress by increasing the K+/Na+ ratio and improving the morphological and physiological traits of the Satureja hortensis medicinal plant but also improves the essential oil yield of this medicinal plant in salt stress and non-salt stress conditions.