GENETIC-ANALYSIS OF ABA SIGNAL-TRANSDUCTION PATHWAYS

The plant hormone abscisic acid (ABA) has been demonstrated to modulat e a variety of physiological processes, including seed dormancy, leaf water relations and adaptation to environmental stresses such as cold, drought and salinity. Recent analysis of Arabidopsis mutants with alt ered responses to ABA is now beginning to indicate the molecular mecha nisms of ABA action. The signaling components so far studied show some genetic redundancy, defining a signaling pathway with multiple inputs and outputs. The complexity of these pathways must be taken into acco unt when modeling ABA signal transduction or designing new genetic scr eens for identifying other signaling components.