Seed germination and flowering are two critical developmental transitions in the life cycles of plants. These transitions are coordinately regulated by exogenous environmental cues and endogenous hormonal signals to match plant establishment and reproduction to the appropriate seasons. The phytohormones, abscisic acid (ABA) and gibberellins (GAs), are the key players that antagonistically regulate seed dormancy and germination; ABA positively modulates dormancy induction and maintenance, while

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... A stimulates germination. For the control of flowering time, GA has been shown to have a positive role in the modulation of floral transition, whereas both positive and negative roles have been recorded for ABA in this process. DELAY OF GERMINATION 1 (DOG1) delays floral transition and functions in dormancy induction and maintenance, acting in parallel with ABA and/or GA. However, DOG1 is also involved in ABA and GA antagonism through affecting hormone biosynthesis and/or signal transduction pathways. Moreover, the expression of DOG1 is directly regulated by ABA. In this review, we summarize recent developments in seed dormancy and flowering research on the model plant Arabidopsis thaliana, focusing on the crosstalk between ABA, GA, and DOG1. Finally, the open questions and remaining challenges in this field are presented.