Jasmone Hydroxylase, a Key Enzyme in the Synthesis of the Alcohol Moiety of Pyrethrin Insecticides.

Pyrethrins are synthesized by the plant pyrethrum (), a chrysanthemum relative. These compounds possess efficient insecticidal properties and are not toxic to humans and most vertebrates. Pyrethrum flowers, and to a smaller extent leaves, synthesize six main types of pyrethrins, which are all esters of a monoterpenoid acid moiety and an alcohol moiety derived from jasmonic acid. Here, we identified and characterized the enzyme responsible for the conversion of jasmone, a derivative of jasmonic acid, to jasmolone. Feeding pyrethrum flowers with jasmone resulted in a 4-fold increase in the concentration of free jasmolone as well as smaller but significant proportional increases in free pyrethrolone and all three type I pyrethrins. We used floral transcriptomic data to identify cytochrome P450 genes whose expression patterns were most highly correlated with that of a key gene in pyrethrin biosynthesis, The candidate genes were screened for jasmone hydroxylase activity through transient expression in leaves fed with jasmone. The expression of only one of these candidate genes produced jasmolone; therefore, this gene was named () and given the CYP designation CYP71AT148. The protein encoded by localized to the endoplasmic reticulum, and microsomal preparations from leaves expressing were capable of catalyzing the hydroxylation of jasmone to jasmolone in vitro, with a value of 53.9 µm was expressed almost exclusively in trichomes of floral ovaries and was induced in leaves by jasmonate.