Selenium biofortification of wheat grain via foliar application and its effect on plant metabolism

Selenium-biofortified wheat can substantially improve human nutrition, by reducing selenium deficiency in humans. In this study, field trials were conducted to investigate the biofortification of selenium (Se) in wheat and also to assess the influence of foliar application of Se (as sodium selenate) on the metabolism of carbohydrates, nitrogen contents, and on the antioxidant system of the plants. Selenium was applied via foliar sprays at the following doses: 0, 12, 21, 38, 68, and 120 g ha(-1). The dose of 120 g ha(-1) provided the highest concentrations of Se in the grains and the highest biomass production. The dose of 21 g ha(-1) of Se caused an increase of 48% in wheat productivity and 30% in biomass production, increasing also the net photosynthetic rate. Selenium positively affected also the activity of ascorbate peroxidase enzyme (APX) and carbohydrate contents. Moreover, treatments using 21 and 38 g ha(-1) of Se increased total nitrogen contents. Thus, wheat is indicated for agronomic biofortification with selenium since it accumulated Se in grains and was not negatively affected with respect to its vegetative growth. In addition, the contents of carbohydrates and total nitrogen as well as the activity of APX increased, favoring wheat production and biomass accumulation.