title: Trihelix transcription factor GT-4 mediates salt tolerance via interaction with TEM2 in Arabidopsis.
abstract: BACKGROUND
  Trihelix transcription factor family is plant-specific and plays important roles in developmental processes. However, their function in abiotic stress response is largely unclear.
  
  
  RESULTS
  We studied one member GT-4 from Arabidopsis in relation to salt stress response. GT-4 expression is induced by salt stress and GT-4 protein is localized in nucleus and cytoplasm. GT-4 acts as a transcriptional activator and its C-terminal end is the activation domain. The protein can bind to the cis-elements GT-3 box, GT-3b box and MRE4. GT-4 confers enhanced salt tolerance in Arabidopsis likely through direct binding to the promoter and activation of Cor15A, in addition to possible regulation of other relevant genes. The gt-4 mutant shows salt sensitivity. TEM2, a member of AP2/ERF family was identified to interact with GT-4 in yeast two-hybrid, BiFC and Co-IP assays. Loss-of-function of TEM2 exerts no significant difference on salt tolerance or Cor15A expression in Arabidopsis. However, double mutant gt-4/tem2 shows greater sensitivity to salt stress and lower transcript level of Cor15A than gt-4 single mutant. GT-4 plus TEM2 can synergistically increase the promoter activity of Cor15A.
  
  
  CONCLUSIONS
  GT-4 interacts with TEM2 and then co-regulates the salt responsive gene Cor15A to improve salt stress tolerance.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Wang
authors.forename: Qing-Tian
authors.initials: QT
authors.lastname: Li
authors.forename: Hao-Wei
authors.initials: HW
authors.lastname: Chen
authors.forename: Wan-Ke
authors.initials: WK
authors.lastname: Zhang
authors.forename: Biao
authors.initials: B
authors.lastname: Ma
authors.forename: Shou-Yi
authors.initials: SY
authors.lastname: Chen
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055049:Salt Tolerance / Q000235:genetics*; D012965:Sodium Chloride / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C116166:COR15 protein, Arabidopsis; D004268:DNA-Binding Proteins; C000601553:GT-4 protein, Arabidopsis; C117696:RAV2 protein, Arabidopsis; D015534:Trans-Activators; D012965:Sodium Chloride