Abscisic Acid (ABA) -Widespread in plant body – moves readily through plant. -ABA appears to be synthesized (made) by the leaves. -promotes leaf detachment, induces seed and bud dormancy, and inhibits germination. -Involved with leaf and fruit abscission (fall), onset of dormancy in -seeds and onset of dormancy (rest period) in perennial flowers and shrubs -is effective in inducing closure of stomata in leaves, indicating a role in the stress physiology in plants. ex: increases in ABA following water, heat and high salinity stress to the plant)