Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots
Root development is regulated by the tripeptide glutathione (GSH), a strong non-enzymatic antioxidant found in plants but with a poorly understood function in roots. Here, Arabidopsis mutants deficient in GSH biosynthesis (<i>cad2</i>, <i>rax1</i>, and <i>rml1</i>...
Main Authors: | , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2020-11-01
|
Series: | Biomolecules |
Subjects: | |
Online Access: | https://www.mdpi.com/2218-273X/10/11/1550 |
id |
doaj-51afdc27e4c24927b65a898fd87ab517 |
---|---|
record_format |
Article |
spelling |
doaj-51afdc27e4c24927b65a898fd87ab5172020-11-25T04:03:32ZengMDPI AGBiomolecules2218-273X2020-11-01101550155010.3390/biom10111550Glutathione Enhances Auxin Sensitivity in Arabidopsis RootsTaras Pasternak0Klaus Palme1Ivan A. Paponov2Institute of Biology II/Molecular Plant Physiology, Centre for BioSystems Analysis, BIOSS Centre for Biological Signalling Studies University of Freiburg, 79104 Freiburg, GermanyInstitute of Biology II/Molecular Plant Physiology, Centre for BioSystems Analysis, BIOSS Centre for Biological Signalling Studies University of Freiburg, 79104 Freiburg, GermanyDepartment of Food Science, Aarhus University, 8200 Aarhus N, DenmarkRoot development is regulated by the tripeptide glutathione (GSH), a strong non-enzymatic antioxidant found in plants but with a poorly understood function in roots. Here, Arabidopsis mutants deficient in GSH biosynthesis (<i>cad2</i>, <i>rax1</i>, and <i>rml1</i>) and plants treated with the GSH biosynthesis inhibitor buthionine sulfoximine (BSO) showed root growth inhibition, significant alterations in the root apical meristem (RAM) structure (length and cell division), and defects in lateral root formation. Investigation of the molecular mechanisms of GSH action showed that GSH deficiency modulated total ubiquitination of proteins and inhibited the auxin-related, ubiquitination-dependent degradation of Aux/IAA proteins and the transcriptional activation of early auxin-responsive genes. However, the DR5 auxin transcriptional response differed in root apical meristem (RAM) and pericycle cells. The RAM DR5 signal was increased due to the up-regulation of the auxin biosynthesis TAA1 protein and down-regulation of PIN4 and PIN2, which can act as auxin sinks in the root tip. The transcription auxin response (the DR5 signal and expression of auxin responsive genes) in isolated roots, induced by a low (0.1 µM) auxin concentration, was blocked following GSH depletion of the roots by BSO treatment. A higher auxin concentration (0.5 µM) offset this GSH deficiency effect on DR5 expression, indicating that GSH deficiency does not completely block the transcriptional auxin response, but decreases its sensitivity. The ROS regulation of GSH, the active GSH role in cell proliferation, and GSH cross-talk with auxin assume a potential role for GSH in the modulation of root architecture under stress conditions.https://www.mdpi.com/2218-273X/10/11/1550auxinauxin responseglutathne (GSH)auxin transportroot apical meristemlateral root formation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Taras Pasternak Klaus Palme Ivan A. Paponov |
spellingShingle |
Taras Pasternak Klaus Palme Ivan A. Paponov Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots Biomolecules auxin auxin response glutathne (GSH) auxin transport root apical meristem lateral root formation |
author_facet |
Taras Pasternak Klaus Palme Ivan A. Paponov |
author_sort |
Taras Pasternak |
title |
Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots |
title_short |
Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots |
title_full |
Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots |
title_fullStr |
Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots |
title_full_unstemmed |
Glutathione Enhances Auxin Sensitivity in Arabidopsis Roots |
title_sort |
glutathione enhances auxin sensitivity in arabidopsis roots |
publisher |
MDPI AG |
series |
Biomolecules |
issn |
2218-273X |
publishDate |
2020-11-01 |
description |
Root development is regulated by the tripeptide glutathione (GSH), a strong non-enzymatic antioxidant found in plants but with a poorly understood function in roots. Here, Arabidopsis mutants deficient in GSH biosynthesis (<i>cad2</i>, <i>rax1</i>, and <i>rml1</i>) and plants treated with the GSH biosynthesis inhibitor buthionine sulfoximine (BSO) showed root growth inhibition, significant alterations in the root apical meristem (RAM) structure (length and cell division), and defects in lateral root formation. Investigation of the molecular mechanisms of GSH action showed that GSH deficiency modulated total ubiquitination of proteins and inhibited the auxin-related, ubiquitination-dependent degradation of Aux/IAA proteins and the transcriptional activation of early auxin-responsive genes. However, the DR5 auxin transcriptional response differed in root apical meristem (RAM) and pericycle cells. The RAM DR5 signal was increased due to the up-regulation of the auxin biosynthesis TAA1 protein and down-regulation of PIN4 and PIN2, which can act as auxin sinks in the root tip. The transcription auxin response (the DR5 signal and expression of auxin responsive genes) in isolated roots, induced by a low (0.1 µM) auxin concentration, was blocked following GSH depletion of the roots by BSO treatment. A higher auxin concentration (0.5 µM) offset this GSH deficiency effect on DR5 expression, indicating that GSH deficiency does not completely block the transcriptional auxin response, but decreases its sensitivity. The ROS regulation of GSH, the active GSH role in cell proliferation, and GSH cross-talk with auxin assume a potential role for GSH in the modulation of root architecture under stress conditions. |
topic |
auxin auxin response glutathne (GSH) auxin transport root apical meristem lateral root formation |
url |
https://www.mdpi.com/2218-273X/10/11/1550 |
work_keys_str_mv |
AT taraspasternak glutathioneenhancesauxinsensitivityinarabidopsisroots AT klauspalme glutathioneenhancesauxinsensitivityinarabidopsisroots AT ivanapaponov glutathioneenhancesauxinsensitivityinarabidopsisroots |
_version_ |
1724439765482209280 |