title: Negative regulation of abscisic acid signaling by the Brassica oleracea ABI1 ortholog.
abstract: ABI1 (ABA Insensitive 1) is an important component of the core regulatory network in early ABA (Abscisic acid) signaling. Here, we investigated the functions of an ABI1 ortholog in Brassica oleracea (BolABI1). The expression of BolABI1 was dramatically induced by drought, and constitutive expression of BolABI1 confers ABA insensitivity upon the wild-type. Subcellular localization and phosphatase assays reveal that BolABI1 is predominantly localized in the nucleus and harbors phosphatase activity. Furthermore, BolABI1 interacts with a homolog of OST1 (OPEN STOMATA 1) in B. oleracea (BolOST1) and can dephosphorylate ABI5 (ABA Insensitive 5) in vitro. Overall, these results suggest that BolABI1 is a functional PP2C-type protein phosphatase that is involved in the negative modulation of the ABA signaling pathway.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Yuan
authors.forename: Mengyao
authors.initials: M
authors.lastname: Wang
authors.forename: Hongmei
authors.initials: H
authors.lastname: Hao
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Huixian
authors.initials: H
authors.lastname: Zhao
authors.forename: Aiguang
authors.initials: A
authors.lastname: Guo
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Xiaona
authors.initials: X
authors.lastname: Zhou
authors.forename: Chang Gen
authors.initials: CG
authors.lastname: Xie
mesh_terms: D000040:Abscisic Acid / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001937:Brassica / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D055864:Droughts; D025461:Feedback, Physiological; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D025941:Protein Interaction Mapping; D011494:Protein Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000040:Abscisic Acid; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases
keywords: ABA signaling; ABI1; ABI5; BolABI1; BolOST1