title: Salt tolerance-related protein STO binds to a Myb transcription factor homologue and confers salt tolerance in Arabidopsis.
abstract: Regulating the intracellular Na+/K+ ratio is an essential process for salinity tolerance. The yeast mutant, can, which is deficient in calcineurin, can not grow on medium containing Na+ because it is unable to regulate the intracellular Na+/K+ ratio. Expression of the STO gene of Arabidopsis thaliana in the can mutant complements the salt-sensitive phenotype. A protein of Arabidopsis, an H-protein promoter binding factor (HPPBF-1), that binds to STO protein was isolated. HPPBF-1 cDNA has a sequence encoding a Myb DNA binding-motif and its gene expression is induced by salt stress. Furthermore, HPPBF-1 protein is localized in the nucleus. Although, the expression level of STO is not induced under salt-stress conditions, overexpression of STO in a transgenic Arabidopsis plant gave it a higher salt tolerance than was observed in the wild type. When STO transgenic plants and wild-type plants were subjected to salt stress, root growth was increased by 33-70% in the transgenic plants under salt stress. These results suggest that STO is involved in salt-stress responses in Arabidopsis.
authors.affiliation: Asian Natural Environmental Science Center, The University of Tokyo, University Farm, 1-1-1 Midori-cho, Nishitokyo-shi, Tokyo 188-0002, Japan.
authors.forename: Shuuichi
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Takano
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C511988:ATR1 protein, Arabidopsis; D029681:Arabidopsis Proteins; C511989:CPC protein, Arabidopsis; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C481238:H-protein promoter binding factor 1, Arabidopsis; D009687:Nuclear Proteins; D010940:Plant Proteins; D020598:Proto-Oncogene Proteins c-myb; C100336:STO protein, Arabidopsis; D014157:Transcription Factors; D012965:Sodium Chloride