title: Expression profiling of the 14-3-3 gene family in response to salt stress and potassium and iron deficiencies in young tomato (Solanum lycopersicum) roots: analysis by real-time RT-PCR.
abstract: BACKGROUND AND AIMS Mineral nutrient deficiencies and salinity constitute major limitations for crop plant growth on agricultural soils. 14-3-3 proteins are phosphoserine-binding proteins that regulate the activities of a wide array of targets via direct protein-protein interactions and may play an important role in responses to mineral nutrients deficiencies and salt stress. In the present study, the expression profiling of the 14-3-3 gene family in response to salt stress and potassium and iron deficiencies in young tomato (Solanum lycopersicum) roots was investigated in order to analyse the 14-3-3 roles of the proteins in these abiotic stresses.
  
  
  METHODS
  Sequence identities and phylogenetic tree creation were performed using DNAMAN version 4.0 (Lynnon Biosoft Company). Real-time RT-PCR was used to examine the expression of each 14-3-3 gene in response to salt stress and potassium and iron deficiencies in young tomato roots.
  
  
  RESULTS
  The phylogenetic tree shows that the 14-3-3 gene family falls into two major groups in tomato plants. By using real-time RT-PCR, it was found that (a) under normal growth conditions, there were significant differences in the mRNA levels of 14-3-3 gene family members in young tomato roots and (b) 14-3-3 proteins exhibited diverse patterns of gene expression in response to salt stress and potassium and iron deficiencies in tomato roots.
  
  
  CONCLUSIONS
  The results suggest that (a) 14-3-3 proteins may be involved in the salt stress and potassium and iron deficiency signalling pathways in young tomato roots, (b) the expression pattern of 14-3-3 gene family members in tomato roots is not strictly related to the position of the corresponding proteins within a phylogenetic tree, (c) gene-specific expression patterns indicate that isoform-specificity may exist in the 14-3-3 gene family of tomato roots, and (d) 14-3-3 proteins (TFT7) might mediate cross-talk between the salt stress and potassium and iron-deficiency signalling pathways in tomato roots.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Wei Feng
authors.initials: WF
authors.lastname: Xu
authors.forename: Wei Ming
authors.initials: WM
authors.lastname: Shi
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D020869:Gene Expression Profiling; D007501:Iron / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; D017931:DNA Primers; D012965:Sodium Chloride; D007501:Iron; D011188:Potassium