Selenium biofortification improves bioactive composition and antioxidant status in Plantago ovata Forsk., a medicinal plant

[Abstract] [Background] Selenium (Se) is an essential micronutrient for humans, but its deficiency as well as toxicity affects large number of people worldwide. Plantago ovata, a commercially important medicinal plant, is mainly cultivated in western regions of India, where elevated levels of Se have been found in soil. Thus, we evaluated the potential of Se biofortification in P. ovata via phytoremediation and its effect on the bioactive composition. [Results] The results showed a significant alteration in various morphological and physiological parameters in a dose-dependent manner. The 10 μM Se dose improved seedling height, biomass and total chlorophyll content. There was a gradual increase in total Se content, with highest accumulation of 457.65 μg/g FW at 500 μM Se treatment. Se positively affected the antioxidative metabolism which was measured from the change in total antioxidant capacity, radical scavenging activity and Metallothionein 2 expression. Increasing levels of Se also affected the PAL activity, total polyphenol and flavonoid content. Caffeic acid, Coumaric acid and Rutin were found to be the most abundant phenolic compounds. [Conclusions] Low levels of selenium (below 50 μM) can successfully improve Se accumulation and elicit production of various polyphenols without hampering plant growth. Thus, Se fortification of P. ovata seedlings via phytoremediation appears to be a feasible and efficient way to enhance its nutraceutical value in dietary products.