Selenium nanoparticles enhance plant tolerance to salinity and protect from postharvest fungal infection Sierra, Sandra Ortega-Muñoz, Mariano Sánchez Aranda, Patricia Castro-Cegrí, Alejandro Sampedro Quesada, María Inmaculada Pérez-Bueno, María Luisa Garrido Garrido, Dolores Palma Martín, Francisco José Selenite Nanotechnology Antioxidant Nanotechnology is an emerging alternative to conventional phytochemicals for improving crop productivity and maintaining the postharvest fruit quality sustainably. In this work, selenium nanoparticles (SeNPs) were synthesized by reduction of sodium selenite with ascorbic acid and stabilized with the natural polysaccharide dextrin. These SeNPs averaged 27 nm in diameter and featured an amorphous structure, exhibiting a high antioxidant capacity at ≥ 10 mg L− 1 , and effective scavenging activity for reactive oxygen species (hydroxyl radical and hydrogen peroxide) at concentrations as low as 1 mg L− 1 . Applied to seedlings of edible leaf plant (lettuce), these SeNPs enhanced plant growth, particularly root growth, and salinity tolerance, being 5 mg L− 1 the optimum concentration. The SeNPs also showed antifungal activity against Botrytis cinerea, the main causal agent of gray mold in postharvest fruits: in vitro, SeNPs at 1 mg L− 1 caused a complete growth inhibition of B. cinerea, while in vivo, SeNPs at 10 mg L− 1 proved effective in preventing gray mold on grapes, raspberries and strawberries. As selenium could be incorporated into edible parts of the plant, and due to the interest in selenium fortification, the toxicity of SeNPs in humans was checked using Caenorhabditis elegans as a model system. Their low toxicity in this animal model, together with the positive effect on seedlings growth and salinity tolerance, and postharvest antifungal activity, lay the foundation for future research in the implementation of these SeNPs in the agri-food industry. 2025-11-18T11:15:53Z 2025-11-18T11:15:53Z 2025-11 journal article Sierra, S., Ortega-Muñoz, M., Sánchez, P., Castro-Cegrí, A., Sampedro, I., Pérez-Bueno, M. L., Garrido, D., & Palma, F. (2025). Selenium nanoparticles enhance plant tolerance to salinity and protect from postharvest fungal infection. Plant Nano Biology, 14(100217), 100217. https://doi.org/10.1016/j.plana.2025.100217 https://hdl.handle.net/10481/108062 10.1016/j.plana.2025.100217 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Elsevier