Multi-omics analysis reveals the regulatory mechanism of shading on quality-related metabolites in Camellia sinensis cv. Lifeng.

Shading enhances green tea quality by promoting the accumulation of amino acids and reducing the synthesis of catechin. We hypothesize that the expression of amino acid-related genes is related to the accumulation of amino acids in tea plants after shading. To explore the regulatory mechanism of shading-induced amino acid biosynthesis, we performed RNA-Seq and qRT-PCR analyses to examine the expression of amino acid metabolism-related genes. Our results revealed significant upregulation of genes associated with theanine biosynthesis and transport. In addition, non-targeted metabolomics and biochemical quantification revealed that the content of theanine and other amino acids significantly increased after shading. Furthermore, shading was found to promote coordinated regulation between light signaling components (e.g., UVR8, HY5, COP1) and transcription factors (such as CsMYB1/4/7/12 and CsPIF3). These findings reveal key molecular mechanisms behind shade-induced amino acid metabolism and provides new insights into our understanding of regulatory mechanisms for shading enhanced tea quality.