Arabidopsis zinc-finger protein 2 is a negative regulator of ABA signaling during seed germination

The hormone abscisic acid (ABA) mediates plant development and adaptation to environmental stresses. ABA-dependent transcription factors are central regulators of ABA signaling. Here, we report on the identification of the ABA-induced transcriptional repressor Arabidopsis zinc-finger protein 2 (AZF2) as ABA signaling component. We isolated azf2-1 mutants lacking AZF2 full-length transcripts that were hypersensitive to ABA during seed germination. In line with a function of AZF2 in seed germination and seedling development, AZF2-promoter activity was observed in radicles and young cotyledons of AZF2-promoter:GUS plants. Our results indicate that AZF2 is a negative regulator of ABA signaling in seeds.