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The Transcription Factor bHLH121 Interacts with bHLH105 (ILR3) and Its Closest Homologs to Regulate Iron Homeostasis in Arabidopsis.
- Source :
-
The Plant cell [Plant Cell] 2020 Feb; Vol. 32 (2), pp. 508-524. Date of Electronic Publication: 2019 Nov 27. - Publication Year :
- 2020
-
Abstract
- Iron (Fe) is an essential micronutrient for plant growth and development. Any defects in the maintenance of Fe homeostasis will alter plant productivity and the quality of their derived products. In Arabidopsis ( Arabidopsis thaliana ), the transcription factor ILR3 plays a central role in controlling Fe homeostasis. In this study, we identified bHLH121 as an ILR3-interacting transcription factor. Interaction studies showed that bHLH121 also interacts with the three closest homologs of ILR3 (i.e., basic-helix-loop-helix 34 [bHLH34], bHLH104, and bHLH115). bhlh121 loss-of-function mutants displayed severe defects in Fe homeostasis that could be reverted by exogenous Fe supply. bHLH121 acts as a direct transcriptional activator of key genes involved in the Fe regulatory network, including bHLH38 , bHLH39 , bHLH100 , bHLH101 , POPEYE , BRUTUS , and BRUTUS LIKE1 , as well as IRONMAN1 and IRONMAN2 In addition, bHLH121 is necessary for activating the expression of transcription factor gene FIT in response to Fe deficiency via an indirect mechanism. bHLH121 is expressed throughout the plant body, and its expression is not affected by Fe availability. By contrast, Fe availability affects the cellular localization of bHLH121 protein in roots. Altogether, these data show that bHLH121 is a regulator of Fe homeostasis that acts upstream of FIT in concert with ILR3 and its closest homologs.<br /> (© 2020 American Society of Plant Biologists. All rights reserved.)
- Subjects :
- Arabidopsis genetics
Arabidopsis Proteins genetics
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
Basic Helix-Loop-Helix Transcription Factors genetics
Gene Expression Regulation, Plant
Gene Knockout Techniques
Gene Regulatory Networks
Homeostasis genetics
Hydroponics
Nuclear Proteins
Plant Roots genetics
Plant Roots metabolism
Plants, Genetically Modified
Transcription Factors genetics
Transcriptome
Ubiquitin-Protein Ligases
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Basic Helix-Loop-Helix Transcription Factors metabolism
Homeostasis physiology
Iron metabolism
Transcription Factors metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1532-298X
- Volume :
- 32
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 31776233
- Full Text :
- https://doi.org/10.1105/tpc.19.00541