title: Inverse modulation of the energy sensor Snf1-related protein kinase 1 on hypoxia adaptation and salt stress tolerance in Arabidopsis thaliana.
abstract: Terrestrial plants are exposed to complex stresses of high salt-induced abscisic acid (ABA) and submergence-induced hypoxia when seawater floods fields. Many studies have investigated plant responses to individual stress conditions, but not so much for coupled or sequentially imposed stresses. We examined molecular regulatory mechanisms of gene expression underlying the cellular responses involved in crosstalk between salt and hypoxia stresses. Salt/ABA- and AtMYC2-dependent induction of a synthetic ABA-responsive element and the native RD22 promoters were utilized in our cell-based functional assays. Such promoter-based reporter induction was largely inhibited by hypoxia and hypoxia-inducible AKIN10 activity. Biochemical analyses showed that AKIN10 negatively modulates AtMYC2 protein accumulation via proteasome activity upon AKIN10 kinase activity-dependent protein modification. Further genetic analysis using transgenic plants expressing AKIN10 provided evidence that AKIN10 activity undermined AtMYC2-dependent salt tolerance. Our findings unravel a novel molecular interaction between the key signalling constituents leading crosstalk between salt and hypoxia stresses in Arabidopsis thaliana under the detrimental condition of submergence in saltwater.
authors.affiliation: College of Life Sciences and Biotechnology, Korea University, Seoul, 136-713, South Korea.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Im
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Cho
authors.forename: Geun-Don
authors.initials: GD
authors.lastname: Kim
authors.forename: Geun-Ho
authors.initials: GH
authors.lastname: Kang
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Hong
authors.forename: Sang-Dong
authors.initials: SD
authors.lastname: Yoo
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000222:Adaptation, Physiological; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D055049:Salt Tolerance; D012623:Seawater / Q000009:adverse effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological
chemical_list: D000040:Abscisic Acid; D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D010100:Oxygen; D010937:Plant Growth Regulators; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; C473611:MYC2 protein, Arabidopsis; C071570:SNF1-related protein kinases; C531469:At3g01090 protein, Arabidopsis
keywords: AKIN10; AtMYC2; abiotic stress; abscisic acid; flooding; hypoxia; saltwater flooding