Abstract
The plant hormone jasmonoyl-isoleucine (JA-Ile) reallocates resources from growth towards induced defenses upon microbial or herbivore attacks or other environmental threats. JA-Ile and its precursor jasmonic acid (JA) undergo complex enzymatic turnover that shape hormonal dynamics for optimal signaling. JA-Ile is inactivated through gradual oxidation by CYP94 mono-oxygenases, followed by 12-OH-JA-Ile deconjugation towards 12-OH-JA. 12-OH-JA was believed to originate also from direct JA hydroxylation by JAO/JOX dioxy-genases. Here we investigate the nature and origins of hydroxy-JAs and their derivatives upon stress responses in Arabidopsis. Using a set of analytical methods to explore enzyme assays and multiple pathway-impaired mutants, we show that JAO enzymes produce exclusively 11-OH-JA rather than 12-OH-JA and de ne a separate branch in JA catabolism. Upon leaf wounding, the CYP94/AH and, to a lesser extent, the JAO pathways direct the respective accumulation of 12- and 11-OH-JAs and their 11/12-glucosylated and 12-sulfated derivatives with isoform-speci c occurrences. In contrast, Botrytis infection triggers the exclu-sive accumulation of 11-OH-JA and 11-Glc-O-JA with complex patterns of HSO4-JA. Finally, treatment of jar1 seedlings with 11-OH-JA does not trigger transcriptional changes, reinforcing the notion that the JAO/11-OH-JA pathway represents a metabolic sink modulating JA-Ile formation. Our ndings elucidate the 11-OH-JA biosynthetic pathway and highlight stress-speci c hydroxylation signatures.
Reference
The 11-hydroxy-jasmonic acid pathway expands jasmonate catabolic repertoire for stress-specific hormone attenuation in Arabidopsis
Thierry Heitz, Valentin Marquis, Julie Zumsteg, Katheline Baksic, Dina Dannawi, Simon Ndecky, Dorian Schutz, Laurence Miesch, Philippe Schaeffer & Pierre Adam
Nature Communications, Published 12 September, 2026 - DOI : https://doi.org/10.1038/s41467-026-77608-8
Contacts
Laurence Miesch, team SOPhy, Institut de Chimie de Strasbourg, UMR 7177.
Pierre Adam, team Biogéochimie Moléculaire, Institut de Chimie de Strasbourg, UMR 7177.
