Light intensity and Zinc biofortification differentially impact the metabolomic profile of pea microgreens

Abstract

Zinc (Zn)-enriched microgreens obtained through agronomic biofortification may be used to address Zn-deficiency affecting 17% of the global population. However, little is known on how alternative agronomic biofortification strategies may impact their metabolomic profile. We investigated the metabolic responses of Zn-enriched pea microgreens grown under varying ZnSO₄ rates (0, 5, 10, and 15 mg/L) and light intensities (100, 200, 300, and 400 μmol/m²/s Photosynthetic Photon Flux Density) using targeted metabolomics. Elevated light intensity increased flavonoids and phenolic acids biosynthesis, likely driven by oxidative stress and photoinhibition. Zn-enrichment enhanced sulfur-containing amino acids, and oxalic acid, which may play a role in metal detoxification. Light intensity was the dominant factor influencing metabolic shifts in pea microgreens across different classes of metabolome compared to the Zn application. This study provides critical insights into optimizing Zn-biofortification strategies and enhancing microgreens' nutritional and functional quality, with implications for human health and sustainable functional food production.