Fig. 4

Pathways of the three main secondary metabolites in tea and oil tea. a Core reactions of flavonoid biosynthesis involved in the biosynthesis of catechins. Compound names are shown below each arrow. Abbreviations beside the arrows indicate the enzymes catalyzing the transfer. The gene expression levels detected by qRT-PCR are shown in the histograms within the corresponding circles. Transcription level is indicated as the mean (2^ΔCt) ± SD. b Core reactions of the theanine biosynthesis pathway. (C) Core reactions of the caffeine biosynthesis pathway