Influence of calcium and magnesium elimination on plant biomass and secondary metabolites of Stevia rebaudiana Bertoni.

This study reports the increment secondary metabolites in Stevia rebaudiana plant after exposure to the elimination of Ca and Mg from Murashige and Skoog culture medium. The effect of nutrient stress on regenerants of S. rebaudiana is measured, reveals significantly enhanced growth parameters, steviol glycosides (SGs) content, and non-enzymatic antioxidants; total phenolic content, total flavonoid content, total antioxidant capacity, total reducing power and DPPH-free radical scavenging activity as compared to control treatment. However, significantly highest amounts are obtained in a medium with only Ca deficiency. The amount of rebaudioside A (Reb A) and stevioside (ST) obtained in the case of Ca-deficient medium is 4.08 and 0.69%, respectively. It is followed by the results obtained from both Ca and Mg deprived medium [Reb A (3.23%) and ST (0.52%)] and the lowest values are obtained from medium lacking Mg only [Reb A (2.60%) and ST (0.40%)]. The most probable adaptation mechanism might be the production of reactive oxygen species by nutrients' stress which results in secondary metabolites production as defensive moieties to overcome stress situation. This effective protocol needs to be refined to apply on an industrial scale in bioreactors for increasing quantities of commercially important pharmaceutical compounds. This article is protected by copyright. All rights reserved.