Distinct OPDA Biosynthesis Pathways in the Liverwort Marchantia polymorpha and the Moss Physcomitrium patens

Vascular plants use the hormone jasmonoyl-L-isoleucine (JA-Ile) to regulate growth and defense responses. In contrast, the liverwort Marchantia polymorpha (M. polymorpha) employs dn-cis-OPDA and dn-iso-OPDA as active jasmonates instead of JA-Ile. The moss Physcomitrium patens (P. patens) also contains dn-OPDAs, suggesting that these compounds are widely conserved jasmonate hormones among bryophytes. However, the biosynthetic pathways leading to dn-OPDAs in bryophytes have remained unclear. Here, we performed metabolic analyses using deuterium-labeled OPDAs to trace their conversion in M. polymorpha and P. patens. Our results revealed distinct biosynthetic routes: in M. polymorpha, cis-OPDA is predominantly converted to dn-iso-OPDA via dn-cis-OPDA, whereas in P. patens, the major pathway proceeds through iso-OPDA before β-oxidation to dn-iso-OPDA. These findings indicate that bryophyte species differ in their jasmonate biosynthesis pathways and suggest evolutionary and environmental adaptations in hormone metabolism. This study provides new insights into the diversity and complexity of jasmonate signaling in early land plants.