Abscisic acid (ABA) is a key phytohormone that plays a central role in plant responses to abiotic stress. It regulates various physiological processes, including stomatal closure, seed dormancy, germination, root architecture, and leaf senescence. ABA is synthesized in the plastids and cytosol through a series of enzymatic reactions, and its levels increase under stress conditions such as drought, salinity, and cold. ABA signaling involves a complex network of receptors, protein phosphatases, and kinases, with the PYR/PYL/RCAR receptors playing a critical role in ABA perception. These receptors interact with PP2C phosphatases, which act as negative regulators, and SnRK2 kinases, which function as positive regulators. The interaction between these components leads to the activation of ABA-responsive genes, enabling plants to adapt to stress conditions. ABA also influences gene expression, root development, and stomatal regulation, which are essential for plant survival under abiotic stress. Recent studies have shown that manipulating ABA signaling or synthesis can enhance stress tolerance in crops, making ABA a key target for improving agricultural productivity in the face of increasing environmental challenges.Abscisic acid (ABA) is a key phytohormone that plays a central role in plant responses to abiotic stress. It regulates various physiological processes, including stomatal closure, seed dormancy, germination, root architecture, and leaf senescence. ABA is synthesized in the plastids and cytosol through a series of enzymatic reactions, and its levels increase under stress conditions such as drought, salinity, and cold. ABA signaling involves a complex network of receptors, protein phosphatases, and kinases, with the PYR/PYL/RCAR receptors playing a critical role in ABA perception. These receptors interact with PP2C phosphatases, which act as negative regulators, and SnRK2 kinases, which function as positive regulators. The interaction between these components leads to the activation of ABA-responsive genes, enabling plants to adapt to stress conditions. ABA also influences gene expression, root development, and stomatal regulation, which are essential for plant survival under abiotic stress. Recent studies have shown that manipulating ABA signaling or synthesis can enhance stress tolerance in crops, making ABA a key target for improving agricultural productivity in the face of increasing environmental challenges.