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Research article - Peer-reviewed, 2021

A network of stress-related genes regulates hypocotyl elongation downstream of selective auxin perception

Rigal, Adeline; Doyle, Siamsa M.; Ritter, Andres; Raggi, Sara; Vain, Thomas; O'Brien, Jose Antonio; Goossens, Alain; Pauwels, Laurens; Robert, Stephanie

Abstract

The plant hormone auxin, a master coordinator of development, regulates hypocotyl elongation during seedling growth. We previously identified the synthetic molecule RubNeddin 1 (RN1), which induces degradation of the AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors INDOLE-3-ACETIC ACID-INDUCIBLE3 (IAA3) and IAA7 in planta and strongly promotes hypocotyl elongation. In the present study, we show that despite the structural similarity of RN1 to the synthetic auxin 2,4-dichlorophenoxyacetic-acid (2,4-D), direct treatments with these compounds in Arabidopsis (Arabidopsis thaliana) result in distinct effects, possibly due to enhanced uptake of RN1 and low-level, chronic release of 2,4-D from RN1 in planta. We confirm RN1-induced hypocotyl elongation occurs via specific TRANSPORT INHIBITOR RESISTANT1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) receptor-mediated auxin signaling involving TIR1, AFB2, and AFB5. Using a transcriptome profiling strategy and candidate gene approach, we identify the genes ZINC FINGER OF ARABIDOPSIS THALIANA10 (ZAT10), ARABIDOPSIS TOXICOS EN LEVADURA31 (ATL31), and WRKY DNA-BINDING PROTEIN33 (WRKY33) as being rapidly upregulated by RN1, despite being downregulated by 2,4-D treatment. RN1-induced expression of these genes also occurs via TIR1/AFB-mediated auxin signaling. Our results suggest both hypocotyl elongation and transcription of these genes are induced by RN1 via the promoted degradation of the AUX/IAA transcriptional repressor IAA7. Moreover, these three genes, which are known to be stress-related, act in an inter-dependent transcriptional regulatory network controlling hypocotyl elongation. Together, our results suggest ZAT10, ATL31, and WRKY33 take part in a common gene network regulating hypocotyl elongation in Arabidopsis downstream of a selective auxin perception module likely involving TIR1, AFB2, and AFB5 and inducing the degradation of IAA7.

Published in

Plant Physiology
2021, volume: 187, number: 1, pages: 430-445
Publisher: OXFORD UNIV PRESS INC

Authors' information

Rigal, Adeline
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Ritter, Andres
Ghent University
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Vain, Thomas
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
O'Brien, Jose Antonio
Pontificia Universidad Catolica de Chile
Goossens, Alain
Ghent University
Pauwels, Laurens
Ghent University
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology

UKÄ Subject classification

Botany

Publication Identifiers

DOI: https://doi.org/10.1093/plphys/kiab269

URI (permanent link to this page)

https://res.slu.se/id/publ/113798