Selenium Effects on Some Morphological and Biochemical Properties and Secondary Metabolites accumulation in Moldavian balm under Salt Stress

Salt stress is one of the vital reasons that adversely affect the productivity of crops, hence suitable approaches are needed to mitigate its negative effects on plants. Selenium (Se) is playing important roles in plant growth, secondary metabolite accumulation, stress responses and adaptation. Moreover, the dual response of Se on plant growth (beneficial or toxic) depends on its concentration. The mechanism of selenium-mediated salt tolerance has not been fully clarified. This study investigated the possible role of Se in regulating moldavian balm (Dracocephalum moldavica L.) salt tolerance. A pot experiment was conducted to investigate the role of Se (۰, ۵ and ۱۰ μM, Na۲SeO۴) in growth, development, biochemical properties and secondary metabolite accumulation in moldavian balm plants grown at different levels of salt (۰, ۲۵, ۵۰ and ۷۵ mM, NaCl). As a result of the study it was demonstrated that all of the investigated parameters were affected by the applications of salt and Se. An increase in salinity led to reduction in fresh and dry weights of aerial parts and essential oil (EO) content while antioxidant enzyme activities, total phenol, flavonoids and anthocyanin contents increased depending on rising of the salt concentrations. Foliar application of selenium especially in the low concentration increased all the mentioned traits in stress conditions. In contrast, high level of selenium magnified the negative effect of salinity, so that the lowest value of growth parameters and EO obtained by ۱۰ μM selenium under ۷۵ mM NaCl. This study indicates that selenium at low concentration (۵μM) plays a significant role in alleviating the harmful effects of salinity through increasing of antioxidant enzymes activities and total phenolic contents and consequently improved the function in Moldavian balm plants growing and EO content under salt stress.

کلیدواژه ها:

Anthocyanin ، Oxidative Enzymes ، Essential Oil ، Flavonoid ، Total Phenol