title: A Novel Chemical Inhibitor of ABA Signaling Targets All ABA Receptors.
abstract: Abscisic acid (ABA), the most important stress-induced phytohormone, regulates seed dormancy, germination, plant senescence, and the abiotic stress response. ABA signaling is repressed by group A type 2C protein phosphatases (PP2Cs), and then ABA binds to its receptor of the ACTIN RESISTANCE1 (PYR1), PYR1-LIKE (PYL), and REGULATORY COMPONENTS OF ABA RECEPTORS (RCAR) family, which, in turn, inhibits PP2Cs and activates downstream ABA signaling. The agonist/antagonist of ABA receptors have the potential to reveal the ABA signaling machinery and to become lead compounds for agrochemicals; however, until now, no broad-spectrum antagonists of ABA receptors blocking all PYR/PYL-PP2C interactions have been identified. Here, using chemical genetics screenings, we identified ABA ANTAGONIST1 (AA1), the first broad-spectrum antagonist of ABA receptors in Arabidopsis (Arabidopsis thaliana). Physiological analyses revealed that AA1 is sufficiently active to block ABA signaling. AA1 interfered with all the PYR/PYL-HAB1 interactions, and the diminished PYR/PYL-HAB1 interactions, in turn, restored the activity of HAB1. AA1 binds to all 13 members. Molecular dockings, the non-AA1-bound PYL2 variant, and competitive binding assays demonstrated that AA1 enters into the ligand-binding pocket of PYL2. Using AA1, we tested the genetic relationships of ABA receptors with other core components of ABA signaling, demonstrating that AA1 is a powerful tool with which to sidestep this genetic redundancy of PYR/PYLs. In addition, the application of AA1 delays leaf senescence. Thus, our study developed an efficient broad-spectrum antagonist of ABA receptors and demonstrated that plant senescence can be chemically controlled through AA1, with a simple and easy-to-synthesize structure, allowing its availability and utility as a chemical probe synthesized in large quantities, indicating its potential application in agriculture.
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Yajin
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Lijuan
authors.identifier: 0000-0003-0107-5648
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Deqiang
authors.initials: D
authors.lastname: Li
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Minjie
authors.initials: M
authors.lastname: Cao
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Haifeng
authors.initials: H
authors.lastname: Chen
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.).|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.).|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.).
authors.forename: Lin
authors.identifier: 0000-0003-4718-1286
authors.initials: L
authors.lastname: Xu
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; zhu132@purdue.edu yangzhaotoronto@sina.com.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.); zhu132@purdue.edu yangzhaotoronto@sina.com.|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.); zhu132@purdue.edu yangzhaotoronto@sina.com.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and zhu132@purdue.edu yangzhaotoronto@sina.com.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.) zhu132@purdue.edu yangzhaotoronto@sina.com.
authors.forename: Jian-Kang
authors.initials: JK
authors.lastname: Zhu
authors.affiliation: Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; zhu132@purdue.edu yangzhaotoronto@sina.com.|University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.); zhu132@purdue.edu yangzhaotoronto@sina.com.|Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.); zhu132@purdue.edu yangzhaotoronto@sina.com.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and zhu132@purdue.edu yangzhaotoronto@sina.com.|State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.) zhu132@purdue.edu yangzhaotoronto@sina.com.
authors.forename: Yang
authors.identifier: 0000-0001-8697-5148
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D016573:Agrochemicals / Q000737:chemistry / Q000494:pharmacology; D000814:Aniline Compounds / Q000737:chemistry / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D000071636:Protein Phosphatase 2C / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000737:chemistry / Q000494:pharmacology; D020798:Two-Hybrid System Techniques
chemical_list: C493772:2,6-Bis(4-anilino)-4-(4-N,N-dimethylanilino)thiopyrylium chloride; D016573:Agrochemicals; D000814:Aniline Compounds; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; C587488:PYL4 protein, Arabidopsis; D010937:Plant Growth Regulators; C540976:AT4G17870 protein, Arabidopsis; C540972:RCAR1 protein, Arabidopsis; D011956:Receptors, Cell Surface; D013876:Thiophenes; D000040:Abscisic Acid; D000071636:Protein Phosphatase 2C