Radish microgreen metabolomic profile in response to zinc biofortification and light intensity

Authors: POUDEL, PRADIP - Pennsylvania State University; Jeffries, Kristen; Bai, Jinhe; Dorado, Christina; Rosskopf, Erin; DI GIOIA, FRANCESCO - Pennsylvania State University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2025
Publication Date: 6/29/2025
Citation: Poudel, P., Jeffries, K.A., Bai, J., Dorado, C., Rosskopf, E.N., Di Gioia, F. Radish microgreen metabolomic profile in response to zinc biofortification and light intensity. Journal of Agricultural and Food Chemistry. 2025. https://doi.org/10.1021/acs.jafc.5c03574.
DOI: https://doi.org/10.1021/acs.jafc.5c03574

Interpretive Summary: Zinc (Zn) deficiency is a global health issue, and Zn agronomic biofortification is a promising strategy to enhance bioaccessible Zn in edible crops. Microgreens, with their short growth cycle, high nutrient density, and low anti-nutrient content are ideal candidates for Zn enrichment through fertigation. Controlled environment conditions allow modulation of light intensity to optimize yield and nutritional quality. However, limited information exists on how Zn enrichment via fertigation, combined with varying light intensities, affects the biosynthesis of metabolic compounds influencing microgreen nutritional value. High light intensity increased flavonoid and phenolic acid accumulation, enhancing antioxidant defenses against oxidative stress while reducing amino acids and glucosinolates, indicating a resource shift toward stress mitigation. These findings improve our understanding of plant metabolic responses to Zn enrichment and light intensity, providing insights into optimal agronomic strategies for producing Zn-biofortified, nutrient-dense radish microgreens under controlled conditions.

Technical Abstract: Zinc (Zn) deficiency is a global health issue, and Zn agronomic biofortification is a promising strategy to enhance bioaccessible Zn in edible crops. Microgreens, with their short growth cycle, high nutrient density, and low anti-nutrient content (e.g., phytic acid), are ideal candidates for Zn enrichment through fertigation. Controlled environment conditions allow modulation of light intensity to optimize yield and nutritional quality. However, limited information exists on how Zn enrichment via fertigation, combined with varying light intensities, affects the biosynthesis of metabolic compounds influencing microgreen nutritional value. This study examines the metabolic responses of Zn-enriched radish microgreens grown under varying Zn levels (0, 5, 10, and 15 mg/L) and light intensities (100, 200, 300, and 400 µmol/m²/s) using targeted metabolomics. High light intensity increased flavonoid and phenolic acid accumulation, enhancing antioxidant defenses against oxidative stress while reducing amino acids and glucosinolates, indicating a resource shift toward stress mitigation. Zn enrichment modulated phenylpropanoid biosynthesis, nitrogen, and energy metabolism, increasing specific flavonoids, phenolic acids, essential amino acids, and ATP levels, reflecting enhanced stress adaptation. These findings improve our understanding of plant metabolic responses to Zn enrichment and light intensity, providing insights into optimal agronomic strategies for producing Zn-biofortified, nutrient-dense radish microgreens under controlled conditions. As mild stressors, high light intensity and Zn biofortification can be leveraged to enhance the metabolic profile of radish microgreens, contributing to the development of nutrient-dense functional foods.