<span>The hormone which is being produced under a water-deficit condition which triggers a drought response is known as Abscisic Acid or ABA.
Abscisic acid is termed as a plant hormone. The main functions in the development of plants include 1. Stomatal closure. 2. Control of organ size. 3. Bud dormancy. It responds to environmental stresses in plants, which include heat stress, freezing tolerance, cold tolerance, soil salinity, and drought.</span>
Abscisic acid (ABA) is a plant hormone, which is produced by plants during stress conditions, such as drought (water-deficit conditions), thus, also known as stress hormone.
In dry conditions, it reduces water loss from plant leaves by reducing the rate of transpiration. ABA causes alteration in the osmotic pressure of stomatal guard cells of leaves. It leads to shrinking and closing of stomata, due to which transpiration is reduced.
