Salicylic acid improving physiological and phytochemical changes in Stevia rebaudiana under salt stress and estimating steviol glycoside by LC-MS/MS

Abstract

Almost every area of plant development is negatively impacted by stress. Salicylic acid (SA), when supplied exogenously, has been demonstrated to be a regulatory hormone that may mitigate the harmful effects of salt stress. Diabetics, hypertensive and health-conscious people substitute Stevia rebaudiana for sugar. Salinity is the global problem directly affecting the quality and quantity of stevia. Each group received 100 mM NaCl treatment for seven days followed by 0.1 mM, 0.2 mM and 0.05 mM SA treatment. Salt stress reduces the amount of chlorophyll (P<0.001) and the antioxidant capacity (P<0.001) which is restored by SA treatment. Salt stress increased proline (P<0.001), MDA (P<0.001) and other antioxidant enzymes (P<0.001), with the exception of catalase (P<0.05). Furthermore, salt stress has a negative impact on stevioside production which SA assisted in improving. Salt stress hampered the biology and phytochemistry of Stevia. SA restored antioxidants, chlorophyll, proline and phytochemicals. SA also helped to improve the steviol production in salt stress which is significantly lower in normal plants. Method developed to estimate steviol level can also be helpful to different industries involved in stevia products.