title: An ABA-increased interaction of the PYL6 ABA receptor with MYC2 Transcription Factor: A putative link of ABA and JA signaling.
abstract: Abscisic acid (ABA) is a plant hormone that mediates abiotic stress tolerance and regulates growth and development. ABA binds to members of the PYL/RCAR ABA receptor family that initiate signal transduction inhibiting type 2C protein phosphatases. Although crosstalk between ABA and the hormone Jasmonic Acid (JA) has been shown, the molecular entities that mediate this interaction have yet to be fully elucidated. We report a link between ABA and JA signaling through a direct interaction of the ABA receptor PYL6 (RCAR9) with the basic helix-loop-helix transcription factor MYC2. PYL6 and MYC2 interact in yeast two hybrid assays and the interaction is enhanced in the presence of ABA. PYL6 and MYC2 interact in planta based on bimolecular fluorescence complementation and co-immunoprecipitation of the proteins. Furthermore, PYL6 was able to modify transcription driven by MYC2 using JAZ6 and JAZ8 DNA promoter elements in yeast one hybrid assays. Finally, pyl6 T-DNA mutant plants show an increased sensitivity to the addition of JA along with ABA in cotyledon expansion experiments. Overall, the present study identifies a direct mechanism for transcriptional modulation mediated by an ABA receptor different from the core ABA signaling pathway, and a putative mechanistic link connecting ABA and JA signaling pathways.
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Aleman
authors.affiliation: Plant Biology Laboratory, Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, California, 92037 USA.
authors.forename: Junshi
authors.initials: J
authors.lastname: Yazaki
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lee
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California, USA.|Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Plant Biology Laboratory, Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, California, 92037 USA.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Kim
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California, USA.
authors.forename: Zixing
authors.initials: Z
authors.lastname: Li
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Kinoshita
authors.affiliation: Plant Biology Laboratory, Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, California, 92037 USA.|Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California, 92037 USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Ecker
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California, USA.
authors.forename: Julian I
authors.initials: JI
authors.lastname: Schroeder
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008041:Linoleic Acids / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D047908:Intracellular Signaling Peptides and Proteins; D008041:Linoleic Acids; C473611:MYC2 protein, Arabidopsis; C000627572:PYL6 protein, Arabidopsis; C452082:jasminic acid; D000040:Abscisic Acid