The DAG1 transcription factor negatively regulates the seed-to-seedling transition in Arabidopsis acting on ABA and GA levels.
In seeds, the transition from dormancy to germination is regulated by abscisic acid (ABA) and gibberellins (GAs), and involves chromatin remodelling. Particularly, the repressive mark H3K27 trimethylation (H3K27me3) has been shown to target many master regulators of this transition. DAG1 (DOF AFFECTING GERMINATION1), is a negative regulator of seed germination in Arabidopsis, and directly represses the GA biosynthetic gene GA3ox1 (gibberellin 3-β-dioxygenase 1). We set to investigate the role of DAG1 in seed dormancy and maturation with respect to epigenetic and hormonal control.



We show that DAG1 expression is controlled at the epigenetic level through the H3K27me3 mark during the seed-to-seedling transition, and that DAG1 directly represses also the ABA catabolic gene CYP707A2; consistently, the ABA level is lower while the GA level is higher in dag1 mutant seeds. Furthermore, both DAG1 expression and protein stability are controlled by GAs.



Our results point to DAG1 as a key player in the control of the developmental switch between seed dormancy and germination.
Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy.|Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Alessandra
A
Boccaccini
Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy.|Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Riccardo
R
Lorrai
Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Veronica
V
Ruta
Institut Jean-Pierre Bourgin, UMR1318, INRA, AgroParisTech, Université Paris-Saclay, RD10, 78026, Versailles, Cedex, France.
Anne
A
Frey
Institut Jean-Pierre Bourgin, UMR1318, INRA, AgroParisTech, Université Paris-Saclay, RD10, 78026, Versailles, Cedex, France.
Stephanie
S
Mercey-Boutet
Institut Jean-Pierre Bourgin, UMR1318, INRA, AgroParisTech, Université Paris-Saclay, RD10, 78026, Versailles, Cedex, France.
Annie
A
Marion-Poll
Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 11, CZ-783 71, Olomouc, Czech Republic.
Danuše
D
Tarkowská
Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 11, CZ-783 71, Olomouc, Czech Republic.
Miroslav
M
Strnad
Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Paolo
P
Costantino
Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy. paola.vittorioso@uniroma1.it.|Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy. paola.vittorioso@uniroma1.it.
Paola
0000-0002-4189-5168
P
Vittorioso
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005875:Gibberellins / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C407526:DAG1 protein, Arabidopsis; D004268:DNA-Binding Proteins; D005875:Gibberellins; D014157:Transcription Factors; D000040:Abscisic Acid
ABA; Arabidopsis thaliana; Chromatin remodelling; DAG1; DOF proteins; GA; Seed development