The transcription factor POPEYE negatively regulates the expression of bHLH Ib genes to maintain iron homeostasis
© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissionsoup.com.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 74(2023), 8 vom: 18. Apr., Seite 2754-2767 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
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2023
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) Fe homeostasis POPEYE bHLH IVc bHLH Ib Arabidopsis Proteins Basic Helix-Loop-Helix Transcription Factors bHLH101 protein, Arabidopsis mehr... |
| Zusammenfassung: | © The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissionsoup.com. Iron (Fe) is an essential trace element for plants. When suffering from Fe deficiency, plants modulate the expression of Fe deficiency-responsive genes to promote Fe uptake. POPEYE (PYE) is a key bHLH (basic helix-loop-helix) transcription factor involved in Fe homeostasis. However, the molecular mechanism of PYE regulating the Fe deficiency response remains elusive in Arabidopsis. We found that the overexpression of PYE attenuates the expression of Fe deficiency-responsive genes. PYE directly represses the transcription of bHLH Ib genes (bHLH38, bHLH39, bHLH100, and bHLH101) by associating with their promoters. Although PYE contains an ethylene response factor-associated amphiphilic repression (EAR) motif, it does not interact with the transcriptional co-repressors TOPLESS/TOPLESS-RELATED (TPL/TPRs). Sub-cellular localization analysis indicated that PYE localizes in both the cytoplasm and nucleus. PYE contains a nuclear export signal (NES) which is required for the cytoplasmic localization of PYE. Mutation of the NES amplifies the repression function of PYE, resulting in down-regulation of Fe deficiency-responsive genes. Co-expression assays indicated that three bHLH IVc members (bHLH104, bHLH105/ILR3, and bHLH115) facilitate the nuclear accumulation of PYE. Conversely, PYE indirectly represses the transcription activation ability of bHLH IVc. Additionally, PYE directly negatively regulates its own transcription. This study provides new insights into the Fe deficiency response signalling pathway and enhances the understanding of PYE functions in Arabidopsis |
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| Beschreibung: | Date Completed 25.08.2023 Date Revised 21.01.2024 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erad057 |