FRU (BHLH029) is required for induction of iron mobilization genes in Arabidopsis thaliana.
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.
Jakoby
Marc
M
Max-Planck Institute for Plant Breeding, Carl-von Linné-Weg 10, D-50829 Köln, Germany.
Wang
Hong-Yu
HY
Reidt
Wim
W
Weisshaar
Bernd
B
Bauer
Petra
P
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005809:Genes, Regulator; D005821:Genetic Techniques; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D008967:Molecular Biology / Q000379:methods; D008969:Molecular Sequence Data; D009154:Mutation; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D007501:Iron; D014157:Transcription Factors; C501411:FIT1 protein, Arabidopsis