Assembly of an Evolutionarily New Pathway for α-Pyrone Biosynthesis in Arabidopsis

Making Arabidopyrones Plants possess specialized metabolic systems that rapidly explore new chemical space as a means to adapt to their environments. Weng et al. (p. 960 ) describe the evolutionary trajectory underlying the emergence of a class of α-pyrone-bearing metabolites—arabidopyrones—in the model plant Arabidopsis . The first step of the arabidopyrone synthesis pathway is catalyzed by a cytochrome P450 enzyme neofunctionalized following a recent gene duplication event. This development led to the synthesis of a catechol-substituted substrate, which became a new substrate for a highly conserved extradiol ring-cleavage dioxygenase. Thus, plants can rapidly assemble a specialized metabolic pathway by substituting a new biological activity into an existing catalytic framework.