OPDA/dn-OPDA actions: biosynthesis, metabolism, and signaling.

Plants cannot move, so they have evolved sophisticated strategies that integrate the external environmental cues and internal signaling networks for adaptation to dynamic circumstances. Cis-(+)-12-oxo-phytodienoic acid (OPDA) and 2,3-dinor-OPDA (dn-OPDA), the cyclopentenone-containing oxylipins, ubiquitously occur in the green lineage to orchestrate a series of growth and developmental processes as well as various stress and defense responses. OPDA/dn-OPDA are precursors of jasmonate (JA) biosynthesis in vascular plants. Dn-OPDA and its isomer also serve as bioactive JAs perceived by the coronatine insensitive 1/jasmonate ZIM-domain (COI1/JAZ) co-receptor complex in bryophytes and lycophytes. In addition, OPDA/dn-OPDA display signaling activities independent of (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile) and COI1 in both vascular and non-vascular plants. In this review, we discuss recent advances in the biosynthesis, metabolism, and signaling of OPDA/dn-OPDA, and provide an overview of the evolution of OPDA/dn-OPDA actions to obtain a deeper understanding of the pervasive role of OPDA/dn-OPDA in the plant life cycle.