关键词: 彩叶植物,  红枫,  花青素,  基因调控

Abstract: INTRODUCTION: The formation of plant leaf color is associated with the content and proportion of various pigments, among which the accumulation of anthocyanin serves as a key factor determining red, purple, and similar hues in plant tissues or organs. Acer palmatum is an important color-leafed plant widely used in urban landscaping. Clarifying the impact of light on the leaf color of red maple holds significant importance for its breeding.  RATIONALE: Anthocyanin metabolism is dually regulated by genetic and environmental factors. Among environmental factors, light is considered a key element influencing anthocyanin synthesis or degradation. Different plant species exhibit varying responses to light, which constitutes an important molecular basis for the diversity of leaf coloration in colored-leaf plants. Anthocyanin biosynthesis involves a series of key enzymes, and these structural genes are regulated by transcription factors, including WRKY. However, the regulatory functions of WRKY transcription factors vary significantly across different species.  RESULTS: Through field observations and shading treatments, it was observed that the leaves of Acer palmatum turned green after shading, with a significant decrease in anthocyanin content. Transcriptome sequencing and quantitative real-time PCR (qRT-PCR) results indicated that the expression of key genes involved in the anthocyanin biosynthesis pathway (ApC4H, ApCHS, ApF3'H, ApDFR, and ApANS) was significantly downregulated. Concurrently, eight WRKY transcription factor members were identified as differentially expressed after shading. Further yeast one-hybrid and dual-luciferase assays demonstrated that the ApWRKY33 transcription factor can directly bind to the promoter of the ApDFR gene and inhibit its expression. The experiments confirmed that ApWRKY33 responds to light signals and represses anthocyanin biosynthesis by downregulating ApDFR under shading.  CONCLUSION: This study reveals the role of the ApWRKY33-ApDFR module in regulating leaf color in red maple. Future research should focus on elucidating how upstream light signals activate ApWRKY33 and employing techniques such as ChIP-seq to genome-widely identify its downstream targets, thereby refining the regulatory network. Protein interaction studies could help clarify the molecular basis of its functional specificity. Ultimately, the function of this module should be validated in vivo through genetic transformation systems, while molecular breeding techniques such as gene editing should be utilized to develop new cultivars of colored-leaf plants with stable leaf color traits and enhanced ornamental value.

Key words: colorful-leaf plants,  Acer palmatum,  anthocyanin,  gene regulation