Selenate fertilization of sorghum via foliar application and its effect on nutrient content and antioxidant metabolism

Abstract

Since sorghum is the staple food for millions of people, coinciding with areas where selenium (Se) deficiency occurs, biofortification with Se in sorghum can considerably improve Se intake in humans living in these areas. In this study, the objective was to evaluate the response of sorghum plants to Se biofortification and the effect of Se foliar application through sodium selenate on grain yield, antioxidant system, and mineral content. The experiment was carried out in a completely randomized design in a 4 × 8 factorial scheme, with four Se doses (control - without Se application; 0.125, 0.250, and 0.500 mg plant-1 of Se by sodium selenate) and eight cultivars (BM737, BRS310, Enforcer, K200, Nugrain320, Nugrain420, Nugrain430, and SHS410) and four replicates, totaling 128 experimental plots. The highest grain yield was observed in Nugrain420 and Nugrain430 with 0.250 mg plant-1 of Se. Selenium efficiency absorption in K200 was higher with 0.125 mg plant-1 of Se. Selenium improves the antioxidant metabolism and mineral content of the studied cultivars. The application of 0.125 mg plant-1 of Se caused lower H2O2 content in the K200, increased lipid peroxidation in BRS310 and provided the highest activity of ascorbate peroxidase in SHS410. The catalase activity was higher with 0.500 mg plant-1 of Se in BRS 310. Therefore, sorghum plants respond positively to the Se foliar application, and the ingestion of sorghum grains biofortified with Se can provide Se for humans and animals.