Abscisic acid (ABA) is involved in many developmental processes and the plant life cycle in their adaptation to environmental stress conditions . An excellent model system for the study of perception and signal transduction of ABA are stomatal cells . Stomatal cell responses to ABA suggests that ABA perception may occur both in plazmolemie , as well as the cytoplasm , however, the receptor proteins have not previously been known. In recent years there has been considerable progress in identifying components of ABA signaling pathways .
