Metabolomic insights into the function and nutritional quality of special rice.

The global demand for nutrient-rich functional rice is rapidly increasing. However, the metabolic mechanisms underlying the high-nutrient functionality of special rice remain inadequately understood. In this study, we developed 26 novel special rice accessions. Using a widely targeted metabolomics approach, we identified and classified 1347 metabolites. The metabolite profiles of these accessions exhibited substantial differentiation, with 204-629 differentially accumulated metabolites identified. Notably, pigmented giant embryo glutinous (PGEG) rice integrated a diverse array of bioactive compounds and nutrients from pigmented rice and giant embryo glutinous rice. It was particularly enriched in γ-aminobutyric acid (GABA), flavonoids, phenolic acids, alkaloids, and other physiologically active substances. Key metabolic pathways (including the biosynthesis of flavone, flavonol, and flavonoid) were significantly enriched in differential metabolites between white/glutinous and PGEG rice. These findings provide a comprehensive understanding of the metabolite profiles of special rice varieties and offer valuable insights for breeding future high-nutrient functional rice.