Dual GATA Regulators for ABA Homoeostasis Mediated Bud Dormancy in Tree Peony

Bud dormancy poses a major constraint for tree peony growth and flowering, especially in off-season cultivation. While GATA transcription factors regulate ABA-mediated seed dormancy, their role in bud dormancy remains unclear. In this study, we characterized the GATA family in tree peony and identified two key transcription regulators, PlGATA1 and PlGATA6, that displayed antagonistic expression patterns in dormant and non-dormant buds of Paeonia × lemoinei 'High Noon'. Exogenous ABA treatment induced PlGATA1 expression while suppressing PlGATA6, indicating divergent roles in ABA signalling. Heterologous expression in Arabidopsis revealed that PlGATA1 enhanced seed dormancy, whereas PlGATA6 suppressed it. Transient transformation assays in tree peony showed that PlGATA1 overexpression or PlGATA6 silencing induced bud dormancy and altered the expression of the ABA metabolism gene. Critically, in vivo and in vitro binding assays confirmed that PlGATA1 activates the PlABI5 promoter, while PlGATA6 activates the PlCYP707A2-1 promoter. Collectively, our results establish PlGATA1 and PlGATA6 as an antagonistic transcriptional module that fine-tunes ABA homoeostasis, thereby acting as a molecular switch controlling bud dormancy in tree peony. This study provides novel insights into the transcriptional regulation of bud dormancy and suggests potential targets for improving off-season cultivation in woody plants.