The recent discovery of genes involved in abscisic acid (ABA) biosynthesis and responses heralds a new era for seed physiology. Our understanding of the regulation of ABA biosynthesis is moving from a linear metabolic pathway to a spatial and temporal network that governs ABA action in seeds. Transcription factors involved in ABA signaling have been identified, together with their target sequences. This allows further analysis of the specificity of ABA signaling in a complex system of interacting factors.