title: Abscisic Acid Analogues That Act as Universal or Selective Antagonists of Phytohormone Receptors.
abstract: The plant hormone abscisic acid (ABA) plays many important roles in controlling plant development and physiology, from flowering to senescence. ABA is now known to exert its effects through a family of soluble ABA receptors, which in Arabidopsis thaliana has 13 members divided into three clades. Homologues of these receptors are present in other plants, also in relatively large numbers. Investigation of the roles of each homologue in mediating the diverse physiological roles of ABA is hampered by this genetic redundancy. We report herein the in vitro screening of a targeted ABA-like analogue library and identification of novel antagonist hits, including the analogue PBI686 that had been developed previously as a probe for identifying ABA-binding proteins. Further in vitro characterization of PBI686 and development of second-generation leads yielded both receptor-selective and universal antagonist hits. In planta assays in different species have demonstrated that these antagonist leads can overcome various ABA-induced physiological changes. While the general antagonists open up a hitherto unexplored avenue for controlling plant growth through inhibition of ABA-regulated physiological processes, the receptor-selective antagonist can be developed into chemical probes to explore the physiological roles of individual receptors.
authors: National Research Council of Canada , 110 Gymnasium Place, Saskatoon, SK, Canada S7N 0W9.
authors: Nandhakishore
authors: N
authors: Rajagopalan
authors: National Research Council of Canada , 110 Gymnasium Place, Saskatoon, SK, Canada S7N 0W9.|Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, SK, Canada S7N 5C9.
authors: Ken M
authors: KM
authors: Nelson
authors: National Research Council of Canada , 110 Gymnasium Place, Saskatoon, SK, Canada S7N 0W9.
authors: Amy F
authors: AF
authors: Douglas
authors: National Research Council of Canada , 110 Gymnasium Place, Saskatoon, SK, Canada S7N 0W9.
authors: Vishal
authors: V
authors: Jheengut
authors: Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, SK, Canada S7N 5C9.
authors: Idralyn Q
authors: IQ
authors: Alarcon
authors: Department of Chemistry, University of Manitoba ,144 Dysart Road, Winnipeg, MB, Canada R3T 2N2.
authors: Sean A
authors: SA
authors: McKenna
authors: Valent BioSciences Corporation , 870 Technology Way, Libertyville, Illinois 60048, United States.
authors: Marci
authors: M
authors: Surpin
authors: National Research Council of Canada , 100 Sussex Drive, Ottawa, ON, Canada K1N 5A2.|Department of Biochemistry, University of Saskatchewan , 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5.
authors: Michele C
authors: MC
authors: Loewen
authors: Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, SK, Canada S7N 5C9.
authors: Suzanne R
authors: SR
authors: Abrams
mesh_terms: D000040:Abscisic Acid / Q000737:chemistry / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D000040:Abscisic Acid