Multicellular organisms rely on the movement of signaling molecules across cells, tissues, and organs to communicate among distal sites. In plants, localized leaf damage activates jasmonic acid (JA)-dependent transcriptional reprogramming in both harmed and unharmed tissues. Although it has been indicated that JA species can translocate from damaged into distal sites, the identity of the mobile compound(s), the tissues through which they translocate, and the effect of their relocation remain unknown. Here, we found that following shoot wounding, the relocation of endogenous jasmonates through the phloem is essential to initiate JA signaling and stunt growth in unharmed roots of Arabidopsis thaliana. By employing grafting experiments and hormone profiling, we uncovered that the hormone precursor cis-12-oxo-phytodienoic acid (OPDA) and its derivatives, but not the bioactive JA-Ile conjugate, translocate from wounded shoots into undamaged roots. Upon root relocation, the mobile precursors cooperatively regulated JA responses through their conversion into JA-Ile and JA signaling activation. Collectively, our findings demonstrate the existence of long-distance translocation of endogenous OPDA and its derivatives, which serve as mobile molecules to coordinate shoot-to-root responses, and highlight the importance of a controlled redistribution of hormone precursors among organs during plant stress acclimation.

多细胞生物依靠信号分子在细胞，组织和器官之间的移动来在远端部位之间进行通信。在植物中，局部叶损伤会在受损和未受损的组织中激活茉莉酸（JA）依赖的转录重编程。尽管已经表明JA物种可以从受损位置转移到远端部位，但移动化合物的身份，它们通过其转移的组织以及其迁移的影响仍然未知。在这里，我们发现芽伤后，内生茉莉花通过韧皮部的重新定位对于启动JA信号传导和在拟南芥未受损根中阻碍特技生长至关重要。通过进行嫁接实验和激素分析，我们发现了激素前体顺式-12-氧代植物二烯酸（OPDA）及其衍生物（而不是具有生物活性的JA-Ile共轭物）从受伤的芽移到未损坏的根中。根重新定位后，移动前体通过将其转换为JA-Ile和JA信令激活来共同调节JA响应。总的来说，我们的发现证明了内源性OPDA及其衍生物的远距离转移，它们可作为移动分子来协调从根到根的反应，并强调了在植物逆境适应过程中在器官之间进行受控的激素前体重新分配的重要性。 。