Oxidative tailoring of carotenoids: a prospect towards novel functions in plants.

Carotenoids not only play a crucial role in their intact form but also are an important reservoir of lipid-derived bioactive mediators. The process is initiated by tailoring enzymes that cleave carotenoids into apocarotenoids. Apocarotenoids act as visual or volatile signals to attract pollinating and seed dispersal agents, and are also key players in allelopathic interactions and plant defense. Recent studies show that the loss of these cleavage enzymes induces the development of axillary branches, indicating that apocarotenoids convey signals that regulate plant architecture. Here, we describe these molecules and the current understanding of their biosynthesis and functions.