Ripening-related gene expression during fruit ripening in Vitis vinifera L. cv. Cabernet Sauvignon and Clairette blanche

The gene expression patterns in ripening fruit of a high quality wine cultivar (Cabernet Sauvignon) and a poor quality wine cultivar (Clairette blanche) were studied using cDNA-AFLP fingerprinting. Total RNA from "immature" (14-weeks post flowering) and "mature" (18-weeks post flowering) berries were used to study ripening-related gene expression in post-veraison stages of berry development. A total of 1,276 fragments were analysed, of which 175 appeared to be ripening-related. Average pairwise differences of the fragments amplified from "immature" and "mature" Cabernet Sauvignon and Clairette blanche berries, revealed a high level of similarity between the two cultivars. 70% of the ripening-related fragments were cultivar-specific. The number of cultivar-specific and/or ripening-related fragments amplified, depended on the selective nucleotides of the primers used in the cDNA-AFLP analysis. Reverse slot blot and northern blot analysis confirmed that the expression of the identified genes were ripening-related.