Flavonoids are synthesized on the cytoplasmic surface of the endoplasmic reticulum (ER). As is the case for several other phytochemicals, anthocyanins and other products of the pathway often accumulate in the large central vacuole. This review summarizes recent findings on the possible mechanisms by which flavonoids traffic between the ER and the vacuole, and discusses the frequent localization of anthocyanins in sub-vacuolar structures with variable characteristics.
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