Altering flower color in transgenic plants by RNAi-mediated engineering of flavonoid biosynthetic pathway.

Flower color is mainly determined by the structure of flavonoids, a group of secondary metabolites of plants. The biosynthetic pathway and the genes involved in the pathway are well characterized such that it is possible to change flower color by engineering the pathway by overexpression of heterologous genes and/or suppression of endogenous genes in transgenic plants. Trimming an unnecessary pathway by suppression of endogenous genes is often essential to achieve successful engineering of the pathway and the resultant accumulation of desirable compounds. RNAi by transcription of double-stranded RNA (dsRNA) is a powerful and efficient method to command such suppression and is widely used for artificial gene suppression in transgenic plants.