The Vacuolar Localization of Grapevine Peroxidase Isoenzymes Capable of Oxidizing 4-Hydroxystilbenes

Abstract

Keywords A study of the subcellular localization of peroxidase isoenzymes capable of oxidizing 4-hydroxystilbenes to viniferin-type compounds has been carried out in cultured cells derived from Vitis vinifera cv. Gamay berries. The study revealed that these isoenzymes are apparently located, in soluble form, in the vacuolar sap and are strongly inhibited by vacuolar anthocyani( di)ns in the concentration range found in planta. These results suggest that the inhibition of the 4-HS peroxidase system in vacuoles, as a consequence of anthocyani(di)n accumulation, could be responsible for the loss of viniferin production potential which accompanies grape berry veraison.