title: The antagonistic regulation of abscisic acid-inhibited root growth by brassinosteroids is partially mediated via direct suppression of ABSCISIC ACID INSENSITIVE 5 expression by BRASSINAZOLE RESISTANT 1.
abstract: Brassinosteroids (BRs) and abscisic acid (ABA) are plant hormones that antagonistically regulate many aspects of plant growth and development; however, the mechanisms that regulate the crosstalk of these two hormones are still not well understood. BRs regulate plant growth and development by activating BRASSINAZOLE RESISTANT 1 (BZR1) family transcription factors. Here we show that the crosstalk between BRs and ABA signalling is partially mediated by BZR1 regulated gene expression. bzr1-1D is a dominant mutant with enhanced BR signalling; our results showed that bzr1-1D mutant is less sensitive to ABA-inhibited primary root growth. By RNA sequencing, a subset of BZR1 regulated ABA-responsive root genes were identified. Of these genes, the expression of a major ABA signalling component ABA INSENSITIVE 5 (ABI5) was found to be suppressed by BR and by BZR1. Additional evidences showed that BZR1 could bind strongly with several G-box cis-elements in the promoter of ABI5, suppress the expression of ABI5 and make plants less sensitive to ABA. Our study demonstrated that ABI5 is a direct target gene of BZR1, and modulating the expression of ABI5 by BZR1 plays important roles in regulating the crosstalk between the BR and ABA signalling pathways.
authors.affiliation: Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050016, China.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Computer Science and Technology, Harbin Institute of Technology, Harbin, 150001, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050016, China.
authors.forename: Jianxiu
authors.initials: J
authors.lastname: Shang
authors.affiliation: Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050016, China.
authors.forename: Ruijiao
authors.initials: R
authors.lastname: Xin
authors.affiliation: Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050016, China.
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Tang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development; D011494:Protein Kinases / Q000378:metabolism; D020239:Receptor Cross-Talk
chemical_list: D000040:Abscisic Acid; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D060406:Brassinosteroids; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011494:Protein Kinases; C454444:BZR1 protein, Arabidopsis; C000625493:abscisic acid insensitive 5 protein, Arabidopsis; C448985:At4g18710 protein, Arabidopsis
keywords: ABI5; Abscisic acid; BZR1; brassinosteroid; drought; signaling