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Stanton C, Rodríguez-Celma J, Krämer U, Sanders D, Balk J. BRUTUS-LIKE (BTSL) E3 ligase-mediated fine-tuning of Fe regulation negatively affects Zn tolerance of Arabidopsis. J Exp Bot 2023; 74:5767-5782. [PMID: 37393944 PMCID: PMC10540732 DOI: 10.1093/jxb/erad243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 07/01/2023] [Indexed: 07/04/2023]
Abstract
The mineral micronutrients zinc (Zn) and iron (Fe) are essential for plant growth and human nutrition, but interactions between the homeostatic networks of these two elements are not fully understood. Here we show that loss of function of BTSL1 and BTSL2, which encode partially redundant E3 ubiquitin ligases that negatively regulate Fe uptake, confers tolerance to Zn excess in Arabidopsis thaliana. Double btsl1 btsl2 mutant seedlings grown on high Zn medium accumulated similar amounts of Zn in roots and shoots to the wild type, but suppressed the accumulation of excess Fe in roots. RNA-sequencing analysis showed that roots of mutant seedlings had relatively higher expression of genes involved in Fe uptake (IRT1, FRO2, and NAS) and in Zn storage (MTP3 and ZIF1). Surprisingly, mutant shoots did not show the transcriptional Fe deficiency response which is normally induced by Zn excess. Split-root experiments suggested that within roots the BTSL proteins act locally and downstream of systemic Fe deficiency signals. Together, our data show that constitutive low-level induction of the Fe deficiency response protects btsl1 btsl2 mutants from Zn toxicity. We propose that BTSL protein function is disadvantageous in situations of external Zn and Fe imbalances, and formulate a general model for Zn-Fe interactions in plants.
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Affiliation(s)
- Camilla Stanton
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK
| | | | - Ute Krämer
- Faculty of Biology and Biotechnology, Ruhr University Bochum, D-44801 Bochum, Germany
| | - Dale Sanders
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK
| | - Janneke Balk
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
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Mankotia S, Singh D, Monika K, Kalra M, Meena H, Meena V, Yadav RK, Pandey AK, Satbhai SB. ELONGATED HYPOCOTYL 5 regulates BRUTUS and affects iron acquisition and homeostasis in Arabidopsis thaliana. Plant J 2023; 114:1267-1284. [PMID: 36920240 DOI: 10.1111/tpj.16191] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 06/17/2023]
Abstract
Iron (Fe) is an essential micronutrient for both plants and animals. Fe-limitation significantly reduces crop yield and adversely impacts on human nutrition. Owing to limited bioavailability of Fe in soil, plants have adapted different strategies that not only regulate Fe-uptake and homeostasis but also bring modifications in root system architecture to enhance survival. Understanding the molecular mechanism underlying the root growth responses will have critical implications for plant breeding. Fe-uptake is regulated by a cascade of basic helix-loop-helix (bHLH) transcription factors (TFs) in plants. In this study, we report that HY5 (Elongated Hypocotyl 5), a member of the basic leucine zipper (bZIP) family of TFs, plays an important role in the Fe-deficiency signaling pathway in Arabidopsis thaliana. The hy5 mutant failed to mount optimum Fe-deficiency responses, and displayed root growth defects under Fe-limitation. Our analysis revealed that the induction of the genes involved in Fe-uptake pathway (FIT-FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR, FRO2-FERRIC REDUCTION OXIDASE 2 and IRT1-IRON-REGULATED TRANSPORTER1) is reduced in the hy5 mutant as compared with the wild-type plants under Fe-deficiency. Moreover, we also found that the expression of coumarin biosynthesis genes is affected in the hy5 mutant under Fe-deficiency. Our results also showed that HY5 negatively regulates BRUTUS (BTS) and POPEYE (PYE). Chromatin immunoprecipitation followed by quantitative polymerase chain reaction revealed direct binding of HY5 to the promoters of BTS, FRO2 and PYE. Altogether, our results showed that HY5 plays an important role in the regulation of Fe-deficiency responses in Arabidopsis.
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Affiliation(s)
- Samriti Mankotia
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Dhriti Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Kumari Monika
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Muskan Kalra
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Himani Meena
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Varsha Meena
- Department of Biotechnology, National Agri-Food Biotechnology Institute, Sector 81, Sahibzada Ajit Singh Nagar, 140306, India
| | - Ram Kishor Yadav
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
| | - Ajay Kumar Pandey
- Department of Biotechnology, National Agri-Food Biotechnology Institute, Sector 81, Sahibzada Ajit Singh Nagar, 140306, India
| | - Santosh B Satbhai
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Mohali, Punjab, 140306, India
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Choi B, Hyeon DY, Lee J, Long TA, Hwang D, Hwang I. E3 ligase BRUTUS Is a Negative Regulator for the Cellular Energy Level and the Expression of Energy Metabolism-Related Genes Encoded by Two Organellar Genomes in Leaf Tissues. Mol Cells 2022; 45:294-305. [PMID: 35422451 PMCID: PMC9095504 DOI: 10.14348/molcells.2022.2029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/16/2021] [Accepted: 12/26/2021] [Indexed: 11/27/2022] Open
Abstract
E3 ligase BRUTUS (BTS), a putative iron sensor, is expressed in both root and shoot tissues in seedlings of Arabidopsis thaliana. The role of BTS in root tissues has been well established. However, its role in shoot tissues has been scarcely studied. Comparative transcriptome analysis with shoot and root tissues revealed that BTS is involved in regulating energy metabolism by modulating expression of mitochondrial and chloroplast genes in shoot tissues. Moreover, in shoot tissues of bts-1 plants, levels of ADP and ATP and the ratio of ADP/ATP were greatly increased with a concomitant decrease in levels of soluble sugar and starch. The decreased starch level in bts-1 shoot tissues was restored to the level of shoot tissues of wild-type plants upon vanadate treatment. Through this study, we expand the role of BTS to regulation of energy metabolism in the shoot in addition to its role of iron deficiency response in roots.
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Affiliation(s)
- Bongsoo Choi
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Do Young Hyeon
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Juhun Lee
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Terri A. Long
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Daehee Hwang
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
- Bioinformatics Institute, Seoul National University, Seoul 08826, Korea
| | - Inhwan Hwang
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
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Selote D, Matthiadis A, Gillikin JW, Sato MH, Long TA. The E3 ligase BRUTUS facilitates degradation of VOZ1/2 transcription factors. Plant Cell Environ 2018; 41:2463-2474. [PMID: 29878379 DOI: 10.1111/pce.13363] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/30/2018] [Accepted: 06/01/2018] [Indexed: 05/08/2023]
Abstract
BRUTUS (BTS) is an iron binding E3 ligase that has been shown to bind to and influence the accumulation of target basic helix-loop-helix transcription factors through 26S proteasome-mediated degradation in Arabidopsis thaliana. Vascular Plant One-Zinc finger 1 (VOZ1) and Vascular plant One-Zinc finger 2 (VOZ2) are NAM, ATAF1/2 and CUC2 (NAC) domain transcription factors that negatively regulate drought and cold stress responses in plants and have previously been shown to be degraded via the 26S proteasome. However, the mechanism that initializes this degradation is unknown. Here, we show that BTS interacts with VOZ1 and VOZ2 and that the presence of the BTS RING domain is essential for these interactions. Through cell-free degradation and immunodetection analyses, we demonstrate that BTS facilitates the degradation of Vascular plant One-Zinc finger 1/2 (VOZ1/2) protein in the nucleus particularly under drought and cold stress conditions. In addition to its known role in controlling the iron-deficiency response in plants, here, we report that BTS may play a role in drought and possibly other abiotic stress responses by facilitating the degradation of transcription factors, VOZ1/2.
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Affiliation(s)
- Devarshi Selote
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Anna Matthiadis
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Jeffrey W Gillikin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Masa H Sato
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Terri A Long
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
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