Abstract
Flavonoids are secondary matabolites with a lot of functions in plants, such as acting as pigment and UV-B protectants. Although much is known about flavonoid biosynthesis in the cytosol, the steps involved in their sequestration into the vacuole are poorly understood. We have isolated novel Arabidopsis mutants with a reduced level of flavonoid pigments (tt19 mutants), which were induced by ion beam irradiation. The TT19 gene was isolated by chromosome walking and the gene candidate approach, and was shown to be a member of the Arabidopsis glutathione S-transferase (GST) gene family. We show here that TT19 participates in the vacuolar accumulation of flavonoids in Arabidopsis. Subcellular localization of the TT19 protein is also discussed based on the observation of the GFP-TT19 fusion protein.
