title: Soybean Trihelix transcription factors GmGT-2A and GmGT-2B improve plant tolerance to abiotic stresses in transgenic Arabidopsis.
abstract: BACKGROUND
  Trihelix transcription factors play important roles in light-regulated responses and other developmental processes. However, their functions in abiotic stress response are largely unclear. In this study, we identified two trihelix transcription factor genes GmGT-2A and GmGT-2B from soybean and further characterized their roles in abiotic stress tolerance.
  
  
  RESULTS
  Both genes can be induced by various abiotic stresses, and the encoded proteins were localized in nuclear region. In yeast assay, GmGT-2B but not GmGT-2A exhibits ability of transcriptional activation and dimerization. The N-terminal peptide of 153 residues in GmGT-2B was the minimal activation domain and the middle region between the two trihelices mediated the dimerization of the GmGT-2B. Transactivation activity of the GmGT-2B was also confirmed in plant cells. DNA binding analysis using yeast one-hybrid assay revealed that GmGT-2A could bind to GT-1bx, GT-2bx, mGT-2bx-2 and D1 whereas GmGT-2B could bind to the latter three elements. Overexpression of the GmGT-2A and GmGT-2B improved plant tolerance to salt, freezing and drought stress in transgenic Arabidopsis plants. Moreover, GmGT-2B-transgenic plants had more green seedlings compared to Col-0 under ABA treatment. Many stress-responsive genes were altered in GmGT-2A- and GmGT-2B-transgenic plants.
  
  
  CONCLUSIONS
  These results indicate that GmGT-2A and GmGT-2B confer stress tolerance through regulation of a common set of genes and specific sets of genes. GmGT-2B also affects ABA sensitivity.
authors.affiliation: National Key Laboratory of Plant Genomics, Plant Gene Research Center, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zong-Ming
authors.initials: ZM
authors.lastname: Xie
authors.forename: Hong-Feng
authors.initials: HF
authors.lastname: Zou
authors.forename: Gang
authors.initials: G
authors.lastname: Lei
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Qi-Yun
authors.initials: QY
authors.lastname: Zhou
authors.forename: Can-Fang
authors.initials: CF
authors.lastname: Niu
authors.forename: Yong
authors.initials: Y
authors.lastname: Liao
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Tian
authors.forename: Biao
authors.initials: B
authors.lastname: Ma
authors.forename: Wan-Ke
authors.initials: WK
authors.lastname: Zhang
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Zhang
authors.forename: Shou-Yi
authors.initials: SY
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D019281:Dimerization; D055864:Droughts; D020224:Expressed Sequence Tags; D008957:Models, Genetic; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques; D010940:Plant Proteins
chemical_list: D004268:DNA-Binding Proteins; D014157:Transcription Factors; C077393:rice nuclear protein GT-2; D010940:Plant Proteins