Biosynthesis of α- and β-ionone, prominent scent compounds, in flowers of Osmanthus fragrans.

Carotenoid derived volatiles are important fragrance compounds, which contribute to the scents of flowers from diverse taxa. A famous example is represented by the flowers of Osmanthus fragrans where apocarotenoids account for more than 20% of all volatiles. In the recent years, bio-degradation of carotenoids has been shown to be an important route for apocarotenoids formation. Here, we report on the contribution the O. fragrans carotenoid cleavage dioxygenase 1 to the synthesis of the two predominant C(13)-apocarotenoids, α- and β-ionone, derived from α-and β-carotene, respectively.