Tea - genes enhance catechin biosynthesis through activating R2R3-MYB transcription factor.

The biosynthesis of catechins, a major type of flavonoids accumulated in tea, is mediated by developmental cues and environmental stimuli. Light enhances but shading treatment reduces catechin accumulation in tea leaves. However, the transcription factors involved in light-mediated catechin biosynthesis remain to be identified. Two genes from tea plant ( and ) were isolated and characterized in both tomato and tea plants. Transcripts of both and were affected by light intensity in tea plants. Overexpression of and promoted chloroplast development and carotenoid accumulation in tomato fruits. An integrated metabolomic and transcriptomic approach revealed that both catechin content and related biosynthetic genes were upregulated in overexpressing tomato leaves. Our further studies in tea plants indicated that s directly regulate the transcription of , a transcription factor involved in catechin biosynthesis. Suppression of s in tea leaves led to the reduction of both expression and catechin accumulation. Taken together, the results show that s are involved in light-regulated catechin accumulation in tea plants by regulating expression of and have great potential for enhancing the accumulation of both carotenoids and flavonoids in fruits of horticultural crops.