title: Ectopic expression of dehydration responsive element binding proteins (StDREB2) confers higher tolerance to salt stress in potato.
abstract: Dehydration responsive element binding proteins (DREB) are members of a larger family of transcription factors, many of which have been reported to contribute to plant responses to abiotic stresses in several species. While, little is known about their role in potato (Solanum tuberosum). This report describes the cloning and characterization of a DREB transcription factor cDNA, StDREB2, isolated from potato (cv Nicola) plants submitted to salt treatment. Based on a multiple sequence alignment, this protein was classified into the A-5 group of DREB subfamily. Expression studies revealed that StDREB2 was induced in leaves, roots and stems upon various abiotic stresses and in response to exogenous treatment with abscisic acid (ABA). In agreement with this expression pattern, over-expression of StDREB2 in transgenic potato plants resulted in enhanced tolerance to salt stress. These data suggest that the isolated StDREB2 encodes a functional protein involved in plant response to different abiotic stresses. An electrophoretic mobility shift assay (EMSA) indicated that the StDREB2 protein bound specifically to the DRE core element (ACCGAGA) in vitro. Moreover, Semi quantitative RT-PCR analysis revealed that the transcript level of a putative target gene i.e. δ(1)-pyrroline-5-carboxylate synthase (P5CS) was up-regulated in transgenic plants submitted to salt stress conditions. A concomitant increase in proline accumulation was also observed under these conditions. Taking together, all these data suggest that StDREB2 takes part in the processes underlying plant responses to abiotic stresses probably via the regulation of ABA hormone signaling and through a mechanism allowing proline synthesis.
authors.affiliation: Laboratoire des Biotechnologies Végétales Appliquées à l'Amélioration des Cultures, Ecole Nationale d'Ingénieurs de Sfax, Route Soukra Km 4, BP 1173, 3038 Sfax, Tunisia. donia.bouaziz@yahoo.fr
authors.forename: Donia
authors.initials: D
authors.lastname: Bouaziz
authors.forename: Julien
authors.initials: J
authors.lastname: Pirrello
authors.forename: Hela
authors.initials: H
authors.lastname: Ben Amor
authors.forename: Asma
authors.initials: A
authors.lastname: Hammami
authors.forename: Mariam
authors.initials: M
authors.lastname: Charfeddine
authors.forename: Amina
authors.initials: A
authors.lastname: Dhieb
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.forename: Radhia
authors.initials: R
authors.lastname: Gargouri-Bouzid
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000378:metabolism; D003080:Cold Temperature; D003681:Dehydration; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D009953:Ornithine-Oxo-Acid Transaminase / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D035261:Plant Components, Aerial / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D011392:Proline / Q000032:analysis / Q000378:metabolism; D011485:Protein Binding; D055049:Salt Tolerance; D016415:Sequence Alignment; D015398:Signal Transduction; D011198:Solanum tuberosum / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D014157:Transcription Factors; D002734:Chlorophyll; D000040:Abscisic Acid; D011392:Proline; D009953:Ornithine-Oxo-Acid Transaminase