title: Overexpression of wheat dehydrin DHN-5 enhances tolerance to salt and osmotic stress in Arabidopsis thaliana.
abstract: Late Embryogenesis Abundant (LEA) proteins are associated with tolerance to water-related stress. A wheat (Triticum durum) group 2 LEA proteins, known also as dehydrin (DHN-5), has been previously shown to be induced by salt and abscisic acid (ABA). In this report, we analyze the effect of ectopic expression of Dhn-5 cDNA in Arabidopsis thaliana plants and their response to salt and osmotic stress. When compared to wild type plants, the Dhn-5 transgenic plants exhibited stronger growth under high concentrations of NaCl or under water deprivation, and showed a faster recovery from mannitol treatment. Leaf area and seed germination rate decreased much more in wild type than in transgenic plants subjected to salt stress. Moreover, the water potential was more negative in transgenic than in wild type plants. In addition, the transgenic plants have higher proline contents and lower water loss rate under water stress. Also, Na(+) and K(+) accumulate to higher contents in the leaves of the transgenic plants. Our data strongly support the hypothesis that Dhn-5, by its protective role, contributes to an improved tolerance to salt and drought stress through osmotic adjustment.
authors.affiliation: Plant Molecular Genetics Unit, Centre of Biotechnology of Sfax, B.P'K', 3038, Sfax, Tunisia.
authors.forename: Faïçal
authors.initials: F
authors.lastname: Brini
authors.forename: Moez
authors.initials: M
authors.lastname: Hanin
authors.forename: Victoria
authors.initials: V
authors.lastname: Lumbreras
authors.forename: Imen
authors.initials: I
authors.lastname: Amara
authors.forename: Habib
authors.initials: H
authors.lastname: Khoudi
authors.forename: Afif
authors.initials: A
authors.lastname: Hassairi
authors.forename: Montserrat
authors.initials: M
authors.lastname: Pagès
authors.forename: Khaled
authors.initials: K
authors.lastname: Masmoudi
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D008353:Mannitol / Q000494:pharmacology; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D011188:Potassium / Q000378:metabolism; D012492:Salts / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism; D014908:Triticum / Q000235:genetics; D014867:Water / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012492:Salts; D014867:Water; C070556:dehydrin proteins, plant; D008353:Mannitol; D012964:Sodium; D011188:Potassium