Journal Article

Axial and Radial Oxylipin Transport

Stolz, Stéphanie, Wolfender, Jean-Luc, Kurenda, Andrzej, Gasperini, Debora, Acosta, Ivan F., Farmer, Edward E., Chételat, Aurore, Chauvin, Adeline

2015

Overview

Jasmonates are oxygenated lipids (oxylipins) that control defense gene expression in response to cell damage in plants. How mobile are these potent mediators within tissues? Exploiting a series of13-lipoxygenase(13-lox) mutants in Arabidopsis (Arabidopsis thaliana) that displays impaired jasmonic acid (JA) synthesis in specific cell types and using JA-inducible reporters, we mapped the extent of the transport of endogenous jasmonates across the plant vegetative growth phase. In seedlings, we found that jasmonate (or JA precursors) could translocate axially from wounded shoots to unwounded roots in a LOX2-dependent manner. Grafting experiments with the wild type and JA-deficient mutants confirmed shoot-to-root oxylipin transport. Next, we used rosettes to investigate radial cell-to-cell transport of jasmonates. After finding that the LOX6 protein localized to xylem contact cells was not wound inducible, we used thelox234triple mutant to genetically isolate LOX6 as the only JA precursor-producing LOX in the plant. When a leaf of this mutant was wounded, the JA reporter gene was expressed in distal leaves. Leaf sectioning showed that JA reporter expression extended from contact cells throughout the vascular bundle and into extravascular cells, revealing a radial movement of jasmonates. Our results add a crucial element to a growing picture of how the distal wound response is regulated in rosettes, showing that both axial (shoot-to-root) and radial (cell-to-cell) transport of oxylipins plays a major role in the wound response. The strategies developed herein provide unique tools with which to identify intercellular jasmonate transport routes.

• Publisher: American Society of Plant Biologists
• Subject: Arabidopsis - enzymology / Arabidopsis - genetics / Arabidopsis - physiology / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Biological Transport / Biology / Cotyledons / Cyclopentanes - metabolism / Gene Expression Regulation, Plant / Graftage / Journalism / Leaves / Lipoxygenase - genetics / Lipoxygenase - metabolism / Lipoxygenases - genetics / Lipoxygenases - metabolism / Mesophyll cells / Oxylipins - metabolism / Plant Growth Regulators - metabolism / Plant Leaves - enzymology / Plant Leaves - genetics / Plant Leaves - physiology / Plant roots / Plant Roots - enzymology / Plant Roots - genetics / Plant Roots - physiology / Plant Shoots - enzymology / Plant Shoots - genetics / Plant Shoots - physiology / Plants / Seedlings / Seedlings - enzymology / Seedlings - genetics / Seedlings - physiology / SIGNALING AND RESPONSE / Stress, Physiological / Xylem / Xylem - enzymology / Xylem - genetics / Xylem - physiology