title: ABA perception and signalling.
abstract: Plant productivity is continuously challenged by pathogen attack and abiotic stress such as drought and salt stress. The phytohormone abscisic acid (ABA) is a key endogenous messenger in plants' responses to such stresses and understanding ABA signalling is essential for improving plant performance in the future. Since the discovery of ABA as a leaf abscission- and seed dormancy-promoting sesquiterpenoid in the 1960s, our understanding of the action of the phytohormone ABA has come a long way. Recent breakthroughs in the field of ABA signalling now unfold a unique hormone perception mechanism where binding of ABA to the ABA receptors RCARs/PYR1/PYLs leads to inactivation of type 2C protein phosphatases such as ABI1 and ABI2. The protein phosphatases seem to function as coreceptors and their inactivation launches SNF1-type kinase action which targets ABA-dependent gene expression and ion channels.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India.
authors.forename: Agepati S
authors.initials: AS
authors.lastname: Raghavendra
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Gonugunta
authors.forename: Alexander
authors.initials: A
authors.lastname: Christmann
authors.forename: Erwin
authors.initials: E
authors.lastname: Grill
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000818:Animals; D010937:Plant Growth Regulators / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014158:Transcription, Genetic
chemical_list: D010937:Plant Growth Regulators; D000040:Abscisic Acid