Selenium biofortification and LED management in controlled-environment agriculture: advances, synergies and future perspectives

Micronutrient malnutrition, particularly selenium (Se) deficiency, remains a major challenge. Controlled environment agriculture (CEA) and totally controlled environment agriculture (TCEA) systems offer innovative platforms for resource-efficient food production and nutritional enhancement through precise environmental regulation. Among the available agronomic strategies, Se biofortification has proven to be highly effective in improving the Se-related nutritional and functional quality of vegetables and herbs. Concurrently, light-emitting diode (LED) technologies facilitate the dynamic control of spectral quality, intensity and photoperiod to optimize photosynthesis and secondary metabolism. This review summarizes the current evidence regarding the combined effects of Se biofortification and LED spectral management on plant physiology, mineral nutrition and bioactive compound accumulation. Research indicates that appropriate Se concentrations, typically in the micromolar range, enhance antioxidant activity, phenolic and flavonoid content and stress tolerance, whereas excessive Se levels induce phytotoxic responses. LED light spectra, particularly the red-to-blue ratio, have been shown to regulate Se concentration, translocation and nitrate metabolism, thereby influencing both growth and nutritional quality. The integration of Se biofortification with optimized lighting regimes enhances crop yield stability, resource-use efficiency and Se-driven nutritional attributes in hydroponic systems, microgreens and baby-leaf vegetables. Despite these advancements, substantial knowledge gaps persist regarding Se speciation, metabolic regulation under different light spectra and post-harvest bioavailability. Future research should integrate omics technologies, high-resolution analytics and dynamic light modelling to elucidate Se–light interactions at the molecular and physiological levels. This integration represents a decisive step towards reproducible and economically viable Se biofortification protocols applicable to next-generation indoor farming. Significance of this study What is already known on this subject? Biofortification of crops with essential micronutrients, such as selenium (Se), is an effective strategy for enhancing nutritional quality and human health. Controlled environment agriculture (CEA) systems, using light-emitting diode (LED) technologies, enable precise control of spectral quality, intensity and photoperiod, which are known to influence nutrient uptake, redox regulation and secondary metabolism. However, most studies have examined Se nutrition and light quality as separate factors without fully exploring their combined physiological and biochemical effects in controlled environments. What are the new findings? This review provides an integrated synthesis of how LED spectral management, particularly variations in the red-to-blue (R:B) ratio, affects Se uptake, translocation and metabolism in hydroponically and indoor-grown crops. This highlights that optimized Se concentrations (2–10 µmol L −1 ) combined with balanced R:B light spectra increase antioxidant enzyme activity, phenolic biosynthesis and nitrate reduction while maintaining the yield. This work also identifies key gaps in the current research, including Se speciation, genotype-dependent responses and the influence of dynamic or polychromatic light regimes. What is the expected impact on horticulture? Integrating Se biofortification with LED spectral optimisation in CEA and TCEA systems offers a practical pathway for producing high-quality micronutrient-enriched crops in vertical and urban farms. These findings provide a framework for designing standardized and resource-efficient cultivation strategies that enhance crop value and nutritional integrity across species and developmental stages.