Journal of Tea Science Research, 2024, Vol.14, No.6, 335-343 http://hortherbpublisher.com/index.php/jtsr 338 3.4 Advances in expression profiling and functional validation of key genes Recent advances include genome-wide identification, transcriptome analysis, and functional validation of flavonoid biosynthetic genes. Co-expression and association studies have revealed that structural genes and transcription factors (e.g., MYB, bHLH) exhibit specific expression patterns during leaf development and in response to environmental cues (Zhu et al., 2020). Functional assays, such as gene overexpression and complementation in model plants, have confirmed the roles of key genes like CHS, UGTs, and 4CL in flavonoid biosynthesis and modification (Dai et al., 2022; Li et al., 2022). 4 Transcription Factor Networks Regulating Flavonoid Biosynthesis 4.1 Dominant role of the MYB family of transcription factors The MYB family plays a central and diverse role in regulating flavonoid biosynthesis in tea plants. Specific MYB transcription factors, such as CsMYB2, CsMYB8, CsMYB23, CsMYB26, CsMYB67, and CsMYB99, have been shown to control the expression of structural genes involved in the biosynthesis of catechins, anthocyanins, and flavonols. These MYBs also participate in shoot development, stress responses, and the regulation of other secondary metabolites, highlighting their functional diversity and importance in tea quality and adaptation (Figure 2) (Li et al., 2022; Chen et al., 2025). Figure 2 Transcriptional expression profiles of key functional genes involved in flavonoid biosynthesis. (A) Expression profiles of genes involved in the transformation from precursor molecules to flavonoids. (B) Expression profiles of genes responsible for flavonoid biosynthesis (Adopted from Chen et al., 2025)
RkJQdWJsaXNoZXIy MjQ4ODYzNA==