CYP94B3 activity against jasmonic acid amino acid conjugates and the elucidation of 12-O-β-glucopyranosyl-jasmonoyl-l-isoleucine as an additional metabolite

Abstract

The hormonal action of jasmonate in plants is controlled by the precise balance between its biosynthesis and inactivation. Oxidation of jasmonoyl-l-isoleucine at the C-12 position, which is catalyzed by cytochrome P450s CYP94B3 and CYP94C1, is thought to be one of the main inactivation pathways. In this study, an additional function of CYP94B3 was elucidated, as well additional jasmonoyl-l-isoleucine metabolites being investigated. It was found that CYP94B3 also catalyzes the hydroxylation of jasmonoyl-l-valine and jasmonoyl-l-phenylalanine, and that these hydroxyl compounds accumulated after wounding and possessed lower activity than non-hydroxylated compounds. Additionally, 12-O-β-glucopyranosyl-jasmonoyl-l-isoleucine accumulated after wounding, suggesting that it is a metabolite of jasmonoyl-l-isoleucine.