Downstream metabolites of (+)-cis-12-oxo-phytodienoic acid function as noncanonical bioactive jasmonates inArabidopsis thaliana

Abstract

Abstract(+)-cis-12-oxo-phytodienoic acid (cis-OPDA) is a biosynthetic precursor of the plant hormone (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile). It functions as an endogenous chemical signal independent of the JA-Ile receptor COI1-JAZ inArabidopsis thaliana. The bioactive form ofcis-OPDA that induces COI1-JAZ-independent gene expression remains unknown.In this study, we hypothesized that the genuine bioactive forms ofcis-OPDA are the downstream metabolites, which upregulate the expression of the OPDA marker genes such asZAT10/ERF5in a JA-Ile-independent manner. These downstream metabolites function independently of the JA-Ile-COI1-JAZ-MYCs canonical jasmonate signaling module, and its electrophilic nature is essential for its bioactivity.