Biochem/physiol Actions Plant hormone and growth regulator that is involved in several physiological mechanisms including seed dormancy, leaf abscission, stomatal movement, and plant stress responses. Through complex interactions with several intracellular signaling systems, it can regulate the expression of hundreds of plant genes. Other Notes Natural plant growth regulator1; High-affinity binding sites for abscisic acid on the plasmalemma of Vicia faba guard cells2 |