Journal Article

TIR1/AFB-Aux/IAA auxin perception mediates rapid cell wall acidification and growth of Arabidopsis hypocotyls

Gary Stacey, Fendrych, Matyas, Institut Jean-Pierre Bourgin (IJPB) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Institute of Science and Technology [Klosterneuburg, Austria] (IST Austria), Leung, Jeffrey, European Research Council [ERC-2011-StG-20101109-PSDP]; Marie Curie Actions FP7 REA grant, Friml, Jiri

2016

Overview

Despite being composed of immobile cells, plants reorient along directional stimuli. The hormone auxin is redistributed in stimulated organs leading to differential growth and bending. Auxin application triggers rapid cell wall acidification and elongation of aerial organs of plants, but the molecular players mediating these effects are still controversial. Here we use genetically-encoded pH and auxin signaling sensors, pharmacological and genetic manipulations available for Arabidopsis etiolated hypocotyls to clarify how auxin is perceived and the downstream growth executed. We show that auxin-induced acidification occurs by local activation of H+-ATPases, which in the context of gravity response is restricted to the lower organ side. This auxin-stimulated acidification and growth require TIR1/AFB-Aux/IAA nuclear auxin perception. In addition, auxin-induced gene transcription and specifically SAUR proteins are crucial downstream mediators of this growth. Our study provides strong experimental support for the acid growth theory and clarified the contribution of the upstream auxin perception mechanisms.

• Publisher: CCSD,eLife Sciences Publication,eLife Science Publications, Ltd,eLife Sciences Publications Ltd,eLife Sciences Publications, Ltd
• Subject: Acidification / Arabidopsis / Arabidopsis - drug effects / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Auxin / Cell Biology / Cell division / cell wall / Cell Wall - metabolism / Cell walls / Enzyme Activation / F-Box Proteins - genetics / F-Box Proteins - metabolism / Gene Expression Regulation, Plant - drug effects / growth / Hydrogen-Ion Concentration / hypocotyl / Hypocotyl - cytology / Hypocotyl - drug effects / Hypocotyl - growth & development / Hypocotyls / Indoleacetic acid / Indoleacetic Acids - metabolism / Indoleacetic Acids - pharmacology / Life Sciences / Perception / Perceptions / pH effects / Physiological aspects / Plant Biology / Plant cell walls / Plant cells / Plant cells and tissues / Plant Growth Regulators - pharmacology / Proteins / Proton-Translocating ATPases - drug effects / Proton-Translocating ATPases - metabolism / Receptors, Cell Surface - genetics / Receptors, Cell Surface - metabolism / Signal Transduction - drug effects / Time series / Transcription
• ISBN: 0003855591000