Enhancing Wheat Resilience to Water Deficit through Selenium Biofortification: Perspectives on Physiological, Biochemical and Nutritional Responses

The present study aimed to evaluate the effects of soil Se application in wheat (Triticum aestivum L.) plants grown under a water deficit imposed during the flowering phase. The experiment was conducted under greenhouse conditions at the Federal University of Lavras in the State of Minas Gerais, Brazil. The statistical design was randomized blocks with four replicates in a 5 × 2 factorial scheme: five Se doses (0.00, 0.25, 0.50, 1.00, and 2.00 mg dm⁻³) and two irrigation conditions (with and without water deficit). The application of 1.00 mg dm⁻³ of Se in plants grown under water deficit increased the water use efficiency (WUE) and the activity of superoxide dismutase (SOD) when compared with control plants. Under water deficit, the presence of Se decreased hydrogen peroxide (H₂O₂) and malonaldehyde (MDA) concentrations, which resulted in lower grain yield losses. However, there was no difference between the control treatment and treatments where Se was applied regarding grain yield under full irrigation. Applying sodium selenate (Na₂SeO₄) via soil increased Se concentrations in wheat grains, and the concentrations of sulfur and Se in shoots were also enriched. In conclusion, soil Se application at 1.00 mg dm⁻³ is efficient for the biofortification of wheat grains, protecting wheat plants from water deficit imposed during the flowering stage and reducing the harmful effects of oxidative stress.