**Abscisic Acid Signalling as a Target for Enhancing Drought Tolerance**

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Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/61317

#### **Abstract**

Abscisic acid (ABA) is a vital hormone that confers abiotic stress tolerance in plants. The identification of PYR/PYL/RCAR proteins as bona fide ABA recep‐ tors and the subsequent elucidation of the structural mechanisms of the core ABA signalling pathway in recent years has provided new and powerful in‐ sights in targeting ABA signalling to enhance abiotic stress tolerance in agri‐ culture. This chapter reviews the components and molecular mechanisms of the core ABA signalling pathway, as revealed by X-ray crystallography stud‐ ies, and how these knowledge led to preliminary efforts in novel biotechnolog‐ ical developments to improve stress tolerance in plants.

**Keywords:** Abscisic acid signalling, ABA receptors, PYL/PYR/RCAR, abiotic stress tolerance
