Abiotic stresses consist of heavy metals, drought, heat (thermal) stress, low temperature (cold stress), high salinity, and radiations; all are critical environmental stresses which create a drastic effect on plant production as well as growth. Plants’ growth and development are decreased under these conditions of stress, which eventually affect the yield. Abscisic acid (ABA) is a major plant hormone that crucially used for the growth and development of plants as well as plays a central role in assimilating several signals of stress which control the stress reactions by different mitigation strategies. Plants ought to adjust the constant level of ABA in response to abiotic stress conditions. Therefore, there are several approaches that have been manipulated to provoke tolerance in the plants against abiotic stresses. Up to now, the mechanisms for adjusting ABA levels in response to abiotic stress remain obscure. Hence, to improve the capacity of stress tolerance in all plants, an imperative understanding of the molecular mechanism involved in the regulation of ABA is required. Therefore, that chapter enlightens on the importance of ABA, regulation of the ABA biosynthesis, and signaling role regarding several abiotic stresses. Additionally, it also deals with the role of ABA accompanied by the transcription factors in stress tolerance.
