Fig. 1.

Schematic overview of flavonoid pathway engineering in tomato. Solid black arrows represent the active pathway in tomato fruit peel. Anthocyanin production is occasionally found in vegetative tissues (dotted arrow). Increased flavonol biosynthesis was obtained by upregulating the pathway in fruit flesh using the transcription factor genes Lc and C1, or by relieving the block in the pathway in fruit peel using the petunia CHI gene (blue arrows). An RNAi approach was used to block specific steps in the pathway (red crosses). Newly introduced flavonoid branches are depicted in green