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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:FRU (BHLH029) is required for induction of iron mobilization genes in Arabidopsis thaliana. 1555 41

Iron acquisition in Arabidopsis depends mainly on AtIRT1, a Fe2+ transporter in the plasma membrane of root cells. However, substrate specificity of AtIRT1 is low, leading to an excess accumulation of other transition metals in iron-deficient plants. In the present study we describe AtIREG2 as a nickel transporter at the vacuolar membrane that counterbalances the low substrate specificity of AtIRT1 and possibly other iron transport systems in iron-deficient root cells. AtIREG2 is co-regulated with AtIRT1 by the transcription factor FRU/FIT1, encodes a membrane protein, which has 10 putative transmembrane domains and shares homology with vertebrate Fe2+ exporters. Heterologous expression of AtIREG2 in various yeast mutants, however, did not demonstrate an iron transport function. Instead, expression in wild-type and nickel-sensitive cot1 yeast cells conferred enhanced tolerance to elevated concentrations of nickel at acidic pH. A role in vacuolar substrate transport was further supported by localization of AtIREG2-GFP fusion proteins to the tonoplast in Arabidopsis suspension cells and root cells of intact plants. Transgenic plants overexpressing AtIREG2 showed an increased tolerance to elevated concentrations of nickel, whereas T-DNA insertion lines lacking AtIREG2 expression were more sensitive to nickel, particularly under iron deficiency, and accumulated less nickel in roots. We therefore propose a role of AtIREG2 in vacuolar loading of nickel under iron deficiency and thus identify it as a novel component in the iron deficiency stress response.
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PMID:AtIREG2 encodes a tonoplast transport protein involved in iron-dependent nickel detoxification in Arabidopsis thaliana roots. 1679 Apr 30

Our groups have previously identified in independent studies the gene At2g28160 as a central transcription factor that is required for up-regulation of iron deficiency responses in Arabidopsis roots. At2g28160 has been named in different ways in our previous studies, namely FRU=FER-LIKE REGULATOR OF IRON UPTAKE [M. Jakoby, H.Y. Wang, W. Reidt, B. Weisshaar, P. Bauer, FRU (BHLH029) is required for induction of iron mobilization genes in Arabidopsis thaliana, FEBS Lett. 577 (2004) 528-534], BHLH029 [M.A. Heim, M. Jakoby, M. Werber, C. Martin, B. Weisshaar, P.C. Bailey, The basic helix-loop-helix transcription factor family in plants: a genome-wide study of protein structure and functional diversity, Mol. Biol. Evol. 20 (2003) 735-747; Y.X. Yuan, J. Zhang, D.W. Wang, H.Q. Ling, AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants, Cell Res. 15 (2005) 613-621] or FIT1=Fe-DEFICIENCY-INDUCED TRANSCRIPTION FACTOR1 [E.P.Colangelo, M.L. Guerinot, The essential basic helix-loop-helix protein FIT1 is required for the iron deficiency response, Plant Cell 12 (2004) 3400-3412.] To avoid any confusion in the future we propose a common name for At2g28160 in Arabidopsis, namely FIT=FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR.
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PMID:FIT, the FER-LIKE IRON DEFICIENCY INDUCED TRANSCRIPTION FACTOR in Arabidopsis. 1746 30