Multi-Omics Analysis Provides Insights into Developmental Tepal Coloration in Gloriosa superba 'Passion Flame'

Gloriosa superba 'Passion Flame' (flame lily) is a distinctive ornamental plant characterized by its striking floral structure and vivid coloration. During flower development, flame lily tepals undergo a pronounced color transition from green at the bud stage to bright red with a yellow base at maturity, providing an excellent system for studying flower pigmentation in monocots. Here, we applied a multi-omics approach to examine metabolite accumulation and gene expression dynamics across four stages of flower development. Metabolomic profiling identified 240 flavonoids and four anthocyanins, among which pelargonidin-3-O-glucoside showed the highest relative abundance among red pigmentation. Transcriptome analysis revealed that seven key anthocyanin structural genes showed strong correlations with anthocyanin accumulation. In parallel, several chlorophyll degradation genes, including GsSGR and GsPPH, were upregulated during tepal maturation, suggesting transcriptional activation of chlorophyll degradation pathways concurrent with pigment accumulation. Co-expression network analysis further identified GsMYB75 and GsMYB114 as temporally distinct regulators associated with anthocyanin biosynthesis, acting together with bHLH, NAC, and AP2/ERF transcription factors. This study provides new insights into the pigment regulation in G. superba 'Passion Flame' and offers candidate regulatory components for future functional studies and the improvement of ornamental traits in monocotyledonous plants.