Journal of Tea Science Research, 2024, Vol.14, No.6, 304-312 http://hortherbpublisher.com/index.php/jtsr 307 biosynthetic genes and TFs, as noted by the quick transcriptional reprogramming in oolong tea production and upon UV-B light exposure (Cheng et al., 2022; Zheng et al., 2022) (Figure 2). Figure 2 Characteristics of the transcripts and alternative splicing events in the tea plant (Adopted from Qiao et al., 2019) Image caption: A: Circos visualization of the transcriptomic profiles; B: The coding protein length distribution of the predicted CDS; C: The summary of alternative splicing events; D: The differential alternative splicing (DAS) events in Bud and SL (Adopted from Qiao et al., 2019) 4.2 Multi-layered regulation involving microRNAs and lncRNAs Although the provided papers do not directly address the roles of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in tea quality formation, alternative splicing is highlighted as a key post-transcriptional regulatory mechanism. Alternative splicing events affect a significant proportion of flavor-related genes and TFs, especially during withering, and are closely correlated with changes in aroma compound accumulation. This suggests that multi-layered regulation beyond transcription, including RNA processing, is important for fine-tuning tea quality traits (Gu et al., 2022; Liu et al., 2023). 4.3 Epigenetic modifications and heritable variation Epigenetic marks such as DNA methylation and histone acetylation play critical roles in the regulation of biosynthesis of secondary metabolites in tea. The degree of DNA methylation in promoter regions may regulate TF (e.g., CsMYC2a) binding to the main biosynthetic genes and, therefore, the accumulation of compounds with aromas such as indole. Histone acetylation and methylation regulate the expression of genes for aroma and hormone biosynthesis, especially under stress or postharvest treatment. Erasable and heritable DNA methylation
RkJQdWJsaXNoZXIy MjQ4ODYzNA==