title: Characterization of a eukaryotic translation initiation factor 5A homolog from Tamarix androssowii involved in plant abiotic stress tolerance.
abstract: BACKGROUND
  The eukaryotic translation initiation factor 5A (eIF5A) promotes formation of the first peptide bond at the onset of protein synthesis. However, the function of eIF5A in plants is not well understood.
  
  
  RESULTS
  In this study, we characterized the function of eIF5A (TaeIF5A1) from Tamarix androssowii. The promoter of TaeIF5A1 with 1,486 bp in length was isolated, and the cis-elements in the promoter were identified. A WRKY (TaWRKY) and RAV (TaRAV) protein can specifically bind to a W-box motif in the promoter of TaeIF5A1 and activate the expression of TaeIF5A1. Furthermore, TaeIF5A1, TaWRKY and TaRAV share very similar expression pattern and are all stress-responsive gene that functions in the abscisic acid (ABA) signaling pathway, indicating that they are components of a single regulatory pathway. Transgenic yeast and poplar expressing TaeIF5A1 showed elevated protein levels combined with improved abiotic stresses tolerance. Furthermore, TaeIF5A1-transformed plants exhibited enhanced superoxide dismutase (SOD) and peroxidase (POD) activities, lower electrolyte leakage and higher chlorophyll content under salt stress.
  
  
  CONCLUSIONS
  These results suggested that TaeIF5A1 is involved in abiotic stress tolerance, and is likely regulated by transcription factors TaWRKY and TaRAV both of which can bind to the W-box motif. In addition, TaeIF5A1 may mediate stress tolerance by increasing protein synthesis, enhancing ROS scavenging by improving SOD and POD activities, and preventing chlorophyll loss and membrane damage. Therefore, eIF5A may play an important role in plant adaptation to changing environmental conditions.
authors: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), 26 Hexing Road, Harbin, China.
authors: Liuqiang
authors: L
authors: Wang
authors: Chenxi
authors: C
authors: Xu
authors: Chao
authors: C
authors: Wang
authors: Yucheng
authors: Y
authors: Wang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D000222:Adaptation, Physiological; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002734:Chlorophyll / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011401:Promoter Regions, Genetic; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology; D012995:Solubility; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D032363:Tamaricaceae / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic; D000097574:Eukaryotic Translation Initiation Factor 5A
chemical_list: D000040:Abscisic Acid; D002734:Chlorophyll; D010448:Peptide Initiation Factors; D009195:Peroxidase; D010940:Plant Proteins; D016601:RNA-Binding Proteins; D012965:Sodium Chloride; D013482:Superoxide Dismutase; D014157:Transcription Factors; D000097574:Eukaryotic Translation Initiation Factor 5A