AAO ABSCISIC ALDEHYDE OXIDASE ABA1-4 ABSCISIC ACID DEFICIENT 1–4 ABCG ATP-BINDING CASSETTE G ABF ABSCISIC ACID-RESPONSIVE ELEMENT BINDING FACTOR ABI ABSCISIC ACID INSENSITIVE Abscisic Acid Implication in Plant Growth and Stress Responses

L.-S.P. Tran and S. Pal (eds.), Phytohormones: A Window to Metabolism, Signaling and Biotechnological Applications, DOI 10.1007/978-1-4939-0491-4_2, © Springer Science+Business Media New York 2014 Abstract Abscisic acid (ABA) is an important phytohormone regulating various physiological aspects in plants such as seed maturation, dormancy, seedling growth, and stomatal behaviour. In this chapter, a global picture with recent fi ndings in ABA metabolism and responses is overviewed. Because of putting the priority on simplicity, to understand historical importance, you should refer to other reviews such as Cutler et al. (Annu Rev Plant Biol 61:651–79, 2010). In recent years, many enzymes responsible for the synthesis and catabolism of ABA have been identifi ed, almost completing the main pathway of ABA production. In ABA-responding cells, there are sets of core components in the ABA reception system, which regulates multiple responses including induction of gene expression and alteration of ion transport. Many players modify the core components to produce sophisticated reactions. The possibility of modifi cation of the pathways at the molecular level to improve crop productivity will be discussed in the fi nal section.