Abstract:

Flower color is the core of the ornamental and commercial value of orchids, and its formation is closely associated with the types, content, and deposition patterns of floral pigments. To systematically elucidate the regulatory mechanisms underlying pigment deposition in orchid flowers, this review summarizes the main pigment substances (flavonoids, carotenoids, and chlorophylls), with a particular focus on the molecular regulatory mechanisms of structural and regulatory genes in the anthocyanin and carotenoid biosynthesis pathways. Structural genes determine flower color types (e.g., red, purple, yellow) and color intensity through their expression patterns and levels, while regulatory genes control pigmentation patterns such as petal background color, spots, patches, and venation via spatiotemporally specific expression. Among these, the synergistic interaction between MYB and bHLH transcription factors plays a key role in the formation of pigmentation patterns. Additionally, this review analyzes how environmental factors such as light, temperature, and exogenous chemicals indirectly influence floral pigment metabolism by modulating the expression of key genes. Further efforts should aim to refine the molecular dynamic regulatory network of pigment synthesis in orchids and explore specific regulatory mechanisms underlying pigmentation patterns. This study aims to provide theoretical insights and practical support for future directed breeding and gene editing in orchids.

Key words: orchid, coloration pattern, floral color pattern, floral color pigmentation, anthocyanin, carotenoid, molecular mechanism, structural genes, regulatory genes