Jasmonate-mediated wound signalling promotes plant regeneration

Wounding is the first event triggering regeneration(1-4). However, the molecular basis of wound signalling pathways in plant regeneration is largely unclear. We previously established a method to study de novo root regeneration (DNRR) in Arabidopsis thaliana(5,6), which provides a platform for analysing wounding. During DNRR, auxin is biosynthe-sized after leaf detachment and promotes cell fate transition to form the root primordium(5-7). Here, we show that jasmonates (JAs) serve as a wound signal during DNRR. Within 2 h of leaf detachment, JA is produced in leaf explants and activates ETHYLENE RESPONSE FACTOR109 (ERF109). ERF109 upregulates ANTHRANILATE SYNTHASE alpha l (ASA1)-a tryptophan biosynthesis gene in the auxin production pathway(8-10)-dependent on the pre-deposition of SET DOMAIN GROUP8 (SDG8)-mediated histone H3 lysine 36 trimethylation (H3K36me3)(11) on the ASA1 locus. After 2 h, ERF109 activity is inhibited by direct interaction with JASMONATEZIM-DOMAIN (JAZ) proteins to prevent hypersensitivity to wounding. Our results suggest that a dynamic JA wave cooperates with histone methylation to upregulate a pulse of auxin production and promote DNRR in response to wounding.