Genetic analysis of ABA signal transduction pathways

The plant hormone abscisic acid (ABA) has been demonstrated to modulate 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 altered responses to ABA is now beginning to indicate the molecular mechanisms 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 account when modeling ABA signal transduction or designing new genetic screens for identifying other signaling components.