Transcriptional reprogramming plays a key role in drought stress responses, preceding the onset of morphological and physiological acclimation. The best-characterised signal regulating gene expression in response to drought is the phytohormone abscisic acid (ABA). ABA-regulated gene expression, biosynthesis and signalling are highly organised in a diurnal cycle, so that ABA-regulated physiological traits occur at the appropriate time of the day. The mechanisms that underpin such diel oscillations in ABA signals are poorly characterised. Here we uncover GIGANTEA (GI) as a key gatekeeper of ABA-regulated transcriptional and physiological responses. Time-resolved gene expression profiling by RNA sequencing under different irrigation scenarios indicates that gi mutants produce an exaggerated ABA response, despite accumulating wild-type levels of ABA. Comparisons with ABA-deficient mutants confirm the role of GI in controlling ABA-regulated genes and the analysis of leaf temperature, a read-out for transpiration, supports a role for GI in the control of ABA-regulated physiological processes. Promoter regions of GI/ABA-regulated transcripts are directly targeted by different classes of transcription factors, especially PHYTOCHROME-INTERACTING FACTORs, and (ABRE)-BINDING FACTOR, together with GI itself. We propose a model whereby diel changes in GI control oscillations in ABA responses. Peak GI accumulation at midday contributes to establishing a phase of reduced ABA sensitivity and related physiological responses, by gating DNA binding or function of different classes of transcription factors that cooperate or compete with GI at target regions.

GIGANTEA is a Negative Regulator of Abscisic Acid Transcriptional Responses and Sensitivity in Arabidopsis / B. Siemiatkowska, M. Chiara, B.G. Badiger, M. Riboni, F. D'Avila, D. Braga, M.A.A. Salem, D. Martignago, S. Colanero, M. Galbiati, P. Giavalisco, C. Tonelli, T.E. Juenger, L. Conti. - In: PLANT AND CELL PHYSIOLOGY. - ISSN 0032-0781. - (2022). [Epub ahead of print] [10.1093/pcp/pcac102]

GIGANTEA is a Negative Regulator of Abscisic Acid Transcriptional Responses and Sensitivity in Arabidopsis

B. Siemiatkowska
Primo
;
M. Chiara
Secondo
;
M. Riboni;F. D'Avila;D. Braga;D. Martignago;S. Colanero;C. Tonelli;L. Conti
Ultimo
2022

Abstract

Transcriptional reprogramming plays a key role in drought stress responses, preceding the onset of morphological and physiological acclimation. The best-characterised signal regulating gene expression in response to drought is the phytohormone abscisic acid (ABA). ABA-regulated gene expression, biosynthesis and signalling are highly organised in a diurnal cycle, so that ABA-regulated physiological traits occur at the appropriate time of the day. The mechanisms that underpin such diel oscillations in ABA signals are poorly characterised. Here we uncover GIGANTEA (GI) as a key gatekeeper of ABA-regulated transcriptional and physiological responses. Time-resolved gene expression profiling by RNA sequencing under different irrigation scenarios indicates that gi mutants produce an exaggerated ABA response, despite accumulating wild-type levels of ABA. Comparisons with ABA-deficient mutants confirm the role of GI in controlling ABA-regulated genes and the analysis of leaf temperature, a read-out for transpiration, supports a role for GI in the control of ABA-regulated physiological processes. Promoter regions of GI/ABA-regulated transcripts are directly targeted by different classes of transcription factors, especially PHYTOCHROME-INTERACTING FACTORs, and (ABRE)-BINDING FACTOR, together with GI itself. We propose a model whereby diel changes in GI control oscillations in ABA responses. Peak GI accumulation at midday contributes to establishing a phase of reduced ABA sensitivity and related physiological responses, by gating DNA binding or function of different classes of transcription factors that cooperate or compete with GI at target regions.
Arabidopsis thaliana; Circadian rhythms; Drought stress; Transcription factors;
Settore BIO/18 - Genetica
21-lug-2022
https://academic.oup.com/pcp/advance-article/doi/10.1093/pcp/pcac102/6647599?login=true
Article (author)
File in questo prodotto:
File Dimensione Formato  
2a Siemiatkowska et al.pdf

accesso aperto

Descrizione: Text file
Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 232.79 kB
Formato Adobe PDF
232.79 kB Adobe PDF Visualizza/Apri
Figures cleaned_REVISED.pdf

accesso aperto

Descrizione: Figures
Tipologia: Altro
Dimensione 813.97 kB
Formato Adobe PDF
813.97 kB Adobe PDF Visualizza/Apri
Supp Figures cleaned.pdf

accesso aperto

Descrizione: Suppl. Figures
Tipologia: Altro
Dimensione 1.49 MB
Formato Adobe PDF
1.49 MB Adobe PDF Visualizza/Apri
Supplementary materials legends.pdf

accesso aperto

Descrizione: Supp. Fig Legends
Tipologia: Altro
Dimensione 84.08 kB
Formato Adobe PDF
84.08 kB Adobe PDF Visualizza/Apri
S1 Table.xlsx

accesso aperto

Descrizione: Table S1
Tipologia: Altro
Dimensione 2.31 MB
Formato Microsoft Excel XML
2.31 MB Microsoft Excel XML Visualizza/Apri
S2 Table.xls

accesso aperto

Descrizione: Table S2
Tipologia: Altro
Dimensione 596 kB
Formato Microsoft Excel
596 kB Microsoft Excel Visualizza/Apri
S3 Table.xls

accesso aperto

Descrizione: Table S3
Tipologia: Altro
Dimensione 66 kB
Formato Microsoft Excel
66 kB Microsoft Excel Visualizza/Apri
S4 Table.xlsx

accesso aperto

Descrizione: Table S4
Tipologia: Altro
Dimensione 12.57 kB
Formato Microsoft Excel XML
12.57 kB Microsoft Excel XML Visualizza/Apri
S5 Table.xls

accesso aperto

Descrizione: Table S5
Tipologia: Altro
Dimensione 13 kB
Formato Microsoft Excel
13 kB Microsoft Excel Visualizza/Apri
S6 Table.xlsx

accesso aperto

Descrizione: Table S6
Tipologia: Altro
Dimensione 9.15 kB
Formato Microsoft Excel XML
9.15 kB Microsoft Excel XML Visualizza/Apri
pcac102(2).pdf

embargo fino al 21/07/2023

Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 2.15 MB
Formato Adobe PDF
2.15 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/934588
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact