Résumé
A potential Carotenoid Cleavage Dioxygenase (CCD) gene was identified among a Vitis vinifera L. EST collection and a full-length cDNA (VvCCD1) was isolated. Recombinant expression of VvCCD1 confirmed that the gene encoded a functional CCD. Experimental evidence was obtained that VvCCD1 cleaves zeaxanthin symmetrically yielding 3-hydroxy-beta-ionone, a C-13-norisoprenoidic compound, and a C-14-dialdehyde. Expression of the gene was studied by real-time PCR at different developmental stages of grape berries from Muscat of Alexandria and Shiraz cultivars. A significant induction of the gene expression approaching veraison was observed in both cultivars. In parallel, the C-13-norisoprenoid level increased from veraison to maturity in both cultivars.