FRU (BHLH029) is required for induction of iron mobilization genes in Arabidopsis thaliana

FEBS Lett. 2004 Nov 19;577(3):528-34. doi: 10.1016/j.febslet.2004.10.062.


Iron mobilization responses are induced by low iron supply at transcriptional level. In tomato, the basic helix-loop-helix gene FER is required for induction of iron mobilization. Using molecular-genetic techniques, we analyzed the function of BHLH029, named FRU (FER-like regulator of iron uptake), the Arabidopsis thaliana homolog of the tomato FER gene. The FRU gene was mainly expressed in roots in a cell-specific pattern and induced by iron deficiency. FRU mutant plants were chlorotic, and the FRU gene was found necessary for induction of the essential iron mobilization genes FRO2 (ferric chelate reductase gene) and IRT1 (iron-regulated transporter gene). Overexpression of FRU resulted in an increase of iron mobilization responses at low iron supply. Thus, the FRU gene is a mediator in induction of iron mobilization responses in Arabidopsis, indicating that regulation of iron uptake is conserved in dicot species.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Basic Helix-Loop-Helix Transcription Factors
  • Conserved Sequence
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Genes, Regulator*
  • Genetic Techniques
  • Helix-Loop-Helix Motifs / genetics
  • Iron / deficiency
  • Iron / metabolism*
  • Molecular Biology / methods
  • Molecular Sequence Data
  • Mutation
  • Plant Roots / cytology
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Plants, Genetically Modified
  • Promoter Regions, Genetic
  • Protein Structure, Tertiary
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Homology, Amino Acid
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Up-Regulation


  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • FIT1 protein, Arabidopsis
  • Transcription Factors
  • Iron