Multi-omics analysis of the mechanisms of abundant theacrine and EGCG3"Me in tea (Camellia sinensis).

Theacrine and epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me) are notable secondary metabolites in tea (Camellia sinensis), celebrated for their unique flavors and significant health effects. Theacrine has a mild effect on nerve stimulation, while EGCG3"Me exhibits better stability, higher oral bioavailability and stronger biological activity. However, tea plant varieties naturally rich in both theacrine and EGCG3"Me are rare. This study unveils a unique tea variety 'Anxi kucha', which is abundant in both theacrine and EGCG3"Me. Through integrated transcriptome-proteome-metabolome analysis, SAMS3, APRT1, IMPDH, and TCS1 were identified as critical enzymes for theacrine synthesis; while CHI1, CHI2, FLS2 and LAR1 were key for EGCG3"Me synthesis. Additionally, transcription factor analysis revealed that MYB4 and bHLH74 were positively correlated with the contents of theacrine and EGCG3"Me. This study provides valuable materials for further exploring theacrine and EGCG3"Me in tea plants, and establishes a theoretical basis for their biosynthesis.