Effect of different levels of nano-selenium on growth performance, physiological responses and antioxidative capacity of barley seedlings

Improving crop quality through the enhancement of plant health is a challenging task. Nanomaterials are emerging materials with great potential in promoting plant growth and improving crop stress resistance. This study addresses the limited understanding of nano-Se’s role in barley physiology by investigating its effects on growth, photosynthesis, nutrient absorption, and antioxidant capacity. The research highlights the essential roles of nano-Se in enhancing plant growth and development in trace amounts. Hydroponic experiments were conducted on barley seedlings grown under conditions of control and nano-Se treatment (2–10 μmol/L) applied on the 5th day after transplanting. Nano-Se has been synthesized through the green route using ascorbic acid and chitosan. The results showed that nano-Se (2–5 μmol/L nano-Se) improved plant health performance and increased plant biomass. The barley growth indecies of root FW, shoot FW, and root DW under Nano-Se2 were improved by 11.5 %, 5.0 %, and 15.0 %, respectively, over untreated controls. Moreover, Nano-Se2 enhanced chlorophyll content, improved photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and nutrient contents, raised amino acid, soluble protein, soluble sugar and sucrose levels, as well as the antioxidant capacity. Additionally, Nano-Se10 significantly inhibited the growth of barley seedlings. This study revealed that the use of nano-Se produced by ascorbic acid and chitosan improved barley growth by improving photosynthetic efficiency, optimizing nutrient uptake, enhancing antioxidant capacity, and raising soluble sugar levels, and the amount of nano-Se should not exceed 10μmol/L. Therefore, nano-Se may serve as a promising biofortification agent for improving plant resilience and productivity.