Auxin methylation is required for differential growth in Arabidopsis

Asymmetric auxin distribution is instrumental for the differential growth that causes organ bending on tropic stimuli and curvatures during plant development. Local differences in auxin concentrations are achieved mainly by polarized cellular distribution of PIN auxin transporters, but whether other...

Full description

Bibliographic Details
Main Authors: Abbas, Mohamad, Hernández-García, Jorge, Pollmann, Stephan, Samodelov, Sophia L., Kolb, Martina, Friml, Jirí, Hammes, Ulrich Z., Zurbriggen, Matías, Blázquez, Miguel A., Alabadí, David
Format: Article
Published: National Academy of Sciences 2018
Online Access:https://eprints.nottingham.ac.uk/52388/
_version_ 1848798714739556352
author Abbas, Mohamad
Hernández-García, Jorge
Pollmann, Stephan
Samodelov, Sophia L.
Kolb, Martina
Friml, Jirí
Hammes, Ulrich Z.
Zurbriggen, Matías
Blázquez, Miguel A.
Alabadí, David
author_facet Abbas, Mohamad
Hernández-García, Jorge
Pollmann, Stephan
Samodelov, Sophia L.
Kolb, Martina
Friml, Jirí
Hammes, Ulrich Z.
Zurbriggen, Matías
Blázquez, Miguel A.
Alabadí, David
author_sort Abbas, Mohamad
building Nottingham Research Data Repository
collection Online Access
description Asymmetric auxin distribution is instrumental for the differential growth that causes organ bending on tropic stimuli and curvatures during plant development. Local differences in auxin concentrations are achieved mainly by polarized cellular distribution of PIN auxin transporters, but whether other mechanisms involving auxin homeostasis are also relevant for the formation of auxin gradients is not clear. Here we show that auxin methylation is required for asymmetric auxin distribution across the hypocotyl, particularly during its response to gravity. We found that loss-of-function mutants in Arabidopsis IAA CARBOXYL METHYLTRANSFERASE1 (IAMT1) prematurely unfold the apical hook, and that their hypocotyls are impaired in gravitropic reorientation. This defect is linked to an auxin-dependent increase in PIN gene expression, leading to an increased polar auxin transport and lack of asymmetric distribution of PIN3 in the iamt1 mutant. Gravitropic reorientation in the iamt1 mutant could be restored with either endodermis-specific expression of IAMT1 or partial inhibition of polar auxin transport, which also results in normal PIN gene expression levels. We propose that IAA methylation is necessary in gravity-sensing cells to restrict polar auxin transport within the range of auxin levels that allow for differential responses.
first_indexed 2025-11-14T20:24:10Z
format Article
id nottingham-52388
institution University of Nottingham Malaysia Campus
institution_category Local University
last_indexed 2025-11-14T20:24:10Z
publishDate 2018
publisher National Academy of Sciences
recordtype eprints
repository_type Digital Repository
spelling nottingham-523882020-05-04T19:40:14Z https://eprints.nottingham.ac.uk/52388/ Auxin methylation is required for differential growth in Arabidopsis Abbas, Mohamad Hernández-García, Jorge Pollmann, Stephan Samodelov, Sophia L. Kolb, Martina Friml, Jirí Hammes, Ulrich Z. Zurbriggen, Matías Blázquez, Miguel A. Alabadí, David Asymmetric auxin distribution is instrumental for the differential growth that causes organ bending on tropic stimuli and curvatures during plant development. Local differences in auxin concentrations are achieved mainly by polarized cellular distribution of PIN auxin transporters, but whether other mechanisms involving auxin homeostasis are also relevant for the formation of auxin gradients is not clear. Here we show that auxin methylation is required for asymmetric auxin distribution across the hypocotyl, particularly during its response to gravity. We found that loss-of-function mutants in Arabidopsis IAA CARBOXYL METHYLTRANSFERASE1 (IAMT1) prematurely unfold the apical hook, and that their hypocotyls are impaired in gravitropic reorientation. This defect is linked to an auxin-dependent increase in PIN gene expression, leading to an increased polar auxin transport and lack of asymmetric distribution of PIN3 in the iamt1 mutant. Gravitropic reorientation in the iamt1 mutant could be restored with either endodermis-specific expression of IAMT1 or partial inhibition of polar auxin transport, which also results in normal PIN gene expression levels. We propose that IAA methylation is necessary in gravity-sensing cells to restrict polar auxin transport within the range of auxin levels that allow for differential responses. National Academy of Sciences 2018-06-13 Article PeerReviewed Abbas, Mohamad, Hernández-García, Jorge, Pollmann, Stephan, Samodelov, Sophia L., Kolb, Martina, Friml, Jirí, Hammes, Ulrich Z., Zurbriggen, Matías, Blázquez, Miguel A. and Alabadí, David (2018) Auxin methylation is required for differential growth in Arabidopsis. Proceedings of the National Academy of Sciences . ISSN 1091-6490 (In Press) http://www.pnas.org/content/early/2018/06/07/1806565115 doi:10.1073/pnas.1806565115 doi:10.1073/pnas.1806565115
spellingShingle Abbas, Mohamad
Hernández-García, Jorge
Pollmann, Stephan
Samodelov, Sophia L.
Kolb, Martina
Friml, Jirí
Hammes, Ulrich Z.
Zurbriggen, Matías
Blázquez, Miguel A.
Alabadí, David
Auxin methylation is required for differential growth in Arabidopsis
title Auxin methylation is required for differential growth in Arabidopsis
title_full Auxin methylation is required for differential growth in Arabidopsis
title_fullStr Auxin methylation is required for differential growth in Arabidopsis
title_full_unstemmed Auxin methylation is required for differential growth in Arabidopsis
title_short Auxin methylation is required for differential growth in Arabidopsis
title_sort auxin methylation is required for differential growth in arabidopsis
url https://eprints.nottingham.ac.uk/52388/
https://eprints.nottingham.ac.uk/52388/
https://eprints.nottingham.ac.uk/52388/