Role of cytochromes P450 in wine aroma

Overview & Synopsis

A thorough annotation of the P450 superfamily in grapevine, revealed its genomic organization, phylogeny and expression. Specifically, we identified genes showing an activated expression in the ripe grape berry, the stage during which the biosynthesis of many aroma compounds takes place. Among the known oxygenated monoterpenols in grapevine, wine lactone has the lowest odor detection threshold and therefore the largest potential impact on wine aroma. We demonstrated that wine lactone is formed during wine ageing via a slow non-enzymatic reaction from the precursor (E)-8-carboxylinalool. We showed that the accumulation of this precursor in grape berries parallels the expression of several cytochrome P450 genes, among which CYP76F14 has the highest expression. While three of them catalyzed some of the oxidative steps from linalool to (E)-8-carboxylinalool, only CYP76F14 efficiently catalyzed the whole pathway. Taken together, CYP76F14 catalytic activity and expression pattern indicate that it is a prime candidate for the formation of the wine lactone precursor in grape berries.