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Cai Y, Ping H, Zhao J, Li C, Li Y, Liang G. IRON MAN interacts with Cu-DEFICIENCY INDUCED TRANSCRIPTION FACTOR 1 to maintain copper homeostasis. THE NEW PHYTOLOGIST 2024; 242:1206-1217. [PMID: 38031525 DOI: 10.1111/nph.19439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023]
Abstract
Copper (Cu) is essential for plant growth and development. IRON MAN (IMA) is a family of small peptides that can bind both iron (Fe) and Cu ions. It was reported that IMAs mediate Fe homeostasis in Arabidopsis thaliana. However, it remains unclear whether IMAs are involved in Cu homeostasis. The transcript abundance of IMA genes decreased in response to Cu deficiency. The combined disruption of all IMA genes caused enhanced tolerance to Cu deficiency and resulted in an increase in the transcript abundance of Cu uptake genes, whereas the overexpression of IMA1 or IMA3 led to the opposite results. Protein interaction assays indicated that IMAs interact with Cu-DEFICIENCY INDUCED TRANSCRIPTION FACTOR1 (CITF1), which is a positive regulator of the Cu uptake genes. Further studies showed that IMAs not only interfere with the DNA binding of CITF1 but also repress the transcriptional activation activity of CITF1, hence resulting in downregulation of the Cu uptake genes. Genetic analyses indicated that IMAs modulate Cu homeostasis in a CITF1-dependent manner. Our findings indicate that IMAs inhibit the functions of CITF1 in regulating Cu deficiency responses, thereby providing a conceptual framework for comprehending the regulation of Cu homeostasis.
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Affiliation(s)
- Yuerong Cai
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Huaqian Ping
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Junhui Zhao
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Chenyang Li
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Yang Li
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Gang Liang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
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Grillet L, Hsieh EJ, Schmidt W. Transcriptome analysis of iron over-accumulating Arabidopsis genotypes uncover putative novel regulators of systemic and retrograde signaling. THE PLANT GENOME 2024; 17:e20411. [PMID: 38054209 DOI: 10.1002/tpg2.20411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 12/07/2023]
Abstract
On account of its competence to accept and donate electrons, iron (Fe) is an essential element across all forms of life, including plants. Maintaining Fe homeostasis requires precise orchestration of its uptake, trafficking, and translocation in order to meet the demand for Fe sinks such as plastids. Plants harboring defects in the systemic Fe transporter OPT3 (OLIGOPEPTIDE TRANSPORTER 3) display constitutive Fe deficiency responses and accumulate toxic levels of Fe in their leaves. Similarly, ectopic expression of IRONMAN (IMA) genes, encoding a family of phloem-localized signaling peptides, triggers the uptake and accumulation of Fe by inhibiting the putative Fe sensor BRUTUS. This study aims at elucidating the mechanisms operating between OPT3-mediated systemic Fe transport, activation of IMA genes in the phloem, and activation of Fe uptake in the root epidermis. Transcriptional profiling of opt3-2 mutant and IMA1/IMA3 overexpressing (IMA Ox) lines uncovered a small subset of genes that were consistently differentially expressed across all three genotypes and Fe-deficient control plants, constituting potential novel regulators of cellular Fe homeostasis. In particular, expression of the the F-box protein At1g73120 was robustly induced in all genotypes, suggesting a putative function in the posttranslational regulation of cellular Fe homeostasis. As further constituents of this module, two plastid-encoded loci that putatively produce transfer ribonucleic acid (tRNA)-derived small ribonucleic acids are possibly involved in retrograde control of root Fe uptake.
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Affiliation(s)
- Louis Grillet
- Department of Agricultural Chemistry, College of Agriculture and Bioresources, National Taiwan University, Taipei, Taiwan
| | - En-Jung Hsieh
- Department of Agricultural Chemistry, College of Agriculture and Bioresources, National Taiwan University, Taipei, Taiwan
| | - Wolfgang Schmidt
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan
- Genome and Systems Biology Degree Program, College of Life Science, National Taiwan University, Taipei, Taiwan
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Mai HJ, Baby D, Bauer P. Black sheep, dark horses, and colorful dogs: a review on the current state of the Gene Ontology with respect to iron homeostasis in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2023; 14:1204723. [PMID: 37554559 PMCID: PMC10406446 DOI: 10.3389/fpls.2023.1204723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/04/2023] [Indexed: 08/10/2023]
Abstract
Cellular homeostasis of the micronutrient iron is highly regulated in plants and responsive to nutrition, stress, and developmental signals. Genes for iron management encode metal and other transporters, enzymes synthesizing chelators and reducing substances, transcription factors, and several types of regulators. In transcriptome or proteome datasets, such iron homeostasis-related genes are frequently found to be differentially regulated. A common method to detect whether a specific cellular pathway is affected in the transcriptome data set is to perform Gene Ontology (GO) enrichment analysis. Hence, the GO database is a widely used resource for annotating genes and identifying enriched biological pathways in Arabidopsis thaliana. However, iron homeostasis-related GO terms do not consistently reflect gene associations and levels of evidence in iron homeostasis. Some genes in the existing iron homeostasis GO terms lack direct evidence of involvement in iron homeostasis. In other aspects, the existing GO terms for iron homeostasis are incomplete and do not reflect the known biological functions associated with iron homeostasis. This can lead to potential errors in the automatic annotation and interpretation of GO term enrichment analyses. We suggest that applicable evidence codes be used to add missing genes and their respective ortholog/paralog groups to make the iron homeostasis-related GO terms more complete and reliable. There is a high likelihood of finding new iron homeostasis-relevant members in gene groups and families like the ZIP, ZIF, ZIFL, MTP, OPT, MATE, ABCG, PDR, HMA, and HMP. Hence, we compiled comprehensive lists of genes involved in iron homeostasis that can be used for custom enrichment analysis in transcriptomic or proteomic studies, including genes with direct experimental evidence, those regulated by central transcription factors, and missing members of small gene families or ortholog/paralog groups. As we provide gene annotation and literature alongside, the gene lists can serve multiple computational approaches. In summary, these gene lists provide a valuable resource for researchers studying iron homeostasis in A. thaliana, while they also emphasize the importance of improving the accuracy and comprehensiveness of the Gene Ontology.
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Affiliation(s)
- Hans-Jörg Mai
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Dibin Baby
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
- Heinrich Heine University, Center of Excellence on Plant Sciences (CEPLAS), Düsseldorf, Germany
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Azemin WA, Alias N, Ali AM, Shamsir MS. Structural and functional characterisation of HepTH1-5 peptide as a potential hepcidin replacement. J Biomol Struct Dyn 2023; 41:681-704. [PMID: 34870559 DOI: 10.1080/07391102.2021.2011415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hepcidin is a principal regulator of iron homeostasis and its dysregulation has been recognised as a causative factor in cancers and iron disorders. The strategy of manipulating the presence of hepcidin peptide has been used for cancer treatment. However, this has demonstrated poor efficiency and has been short-lived in patients. Many studies reported using minihepcidin therapy as an alternative way to treat hepcidin dysregulation, but this was only applied to non-cancer patients. Highly conserved fish hepcidin protein, HepTH1-5, was investigated to determine its potential use in developing a hepcidin replacement for human hepcidin (Hepc25) and as a therapeutic agent by targeting the tumour suppressor protein, p53, through structure-function analysis. The authors found that HepTH1-5 is stably bound to ferroportin, compared to Hepc25, by triggering the ferroportin internalisation via Lys42 and Lys270 ubiquitination, in a similar manner to the Hepc25 activity. Moreover, the residues Ile24 and Gly24, along with copper and zinc ligands, interacted with similar residues, Lys24 and Asp1 of Hepc25, respectively, showing that those molecules are crucial to the hepcidin replacement strategy. HepTH1-5 interacts with p53 and activates its function through phosphorylation. This finding shows that HepTH1-5 might be involved in the apoptosis signalling pathway upon a DNA damage response. This study will be very helpful for understanding the mechanism of the hepcidin replacement and providing insights into the HepTH1-5 peptide as a new target for hepcidin and cancer therapeutics.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Wan-Atirah Azemin
- School of Agriculture Science and Biotechnology, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut, Terengganu, Malaysia.,Bioinformatics Research Group (BIRG), Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Nadiawati Alias
- School of Agriculture Science and Biotechnology, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut, Terengganu, Malaysia
| | - Abdul Manaf Ali
- School of Agriculture Science and Biotechnology, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut, Terengganu, Malaysia
| | - Mohd Shahir Shamsir
- Bioinformatics Research Group (BIRG), Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia.,Faculty of Applied Sciences and Technology, Universiti Tun Hussein Onn Malaysia, Pagoh Higher Education Hub, Muar, Johor, Malaysia
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Hunter C, Stewart JJ, Gleason SM, Pilon M. Age Dependent Partitioning Patterns of Essential Nutrients Induced by Copper Feeding Status in Leaves and Stems of Poplar. FRONTIERS IN PLANT SCIENCE 2022; 13:930344. [PMID: 35865294 PMCID: PMC9294533 DOI: 10.3389/fpls.2022.930344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Copper (Cu) is an essential micronutrient, and its deficiency can cause plants to undergo metabolic changes at several levels of organization. It has been shown that leaf age can play a role in nutrient partitioning along the shoot axis of poplar. In this study, we investigated the effect of Cu deficiency on the altered partitioning of essential macro and micronutrients in leaves and stems of different age. Cu deficiency was associated with higher concentrations of calcium, magnesium, sulfur, iron, zinc, manganese, and molybdenum in leaves and relatively higher concentrations of calcium, phosphorus, iron, and zinc in stems. Leaf and stem age had significant effects on nutrient partitioning. Principal component analyses revealed patterns that point to inverse influences in leaves and stems on nutrient partitioning. Specifically, these analyses revealed that nutrient partitioning in leaves was influenced by Cu feeding status more than developmental stage, whereas nutrient partitioning in stems was influenced by developmental stage more than Cu feeding status. These results suggest that Cu deficiency and developmental stage can significantly influence the partitioning and homeostasis of macro and micronutrients in poplar organs.
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Affiliation(s)
- Cameron Hunter
- Department of Biology, Colorado State University, Fort Collins, CO, United States
- Water Management and Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Jared J. Stewart
- Water Management and Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, United States
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Boulder, CO, United States
| | - Sean M. Gleason
- Department of Biology, Colorado State University, Fort Collins, CO, United States
- Water Management and Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, United States
| | - Marinus Pilon
- Department of Biology, Colorado State University, Fort Collins, CO, United States
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Banerjee A, Roychoudhury A. Dissecting the phytohormonal, genomic and proteomic regulation of micronutrient deficiency during abiotic stresses in plants. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01099-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Perea-García A, Puig S, Peñarrubia L. The role of post-transcriptional modulators of metalloproteins in response to metal deficiencies. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1735-1750. [PMID: 34849747 DOI: 10.1093/jxb/erab521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
Copper and iron proteins have a wide range of functions in living organisms. Metal assembly into metalloproteins is a complex process, where mismetalation is detrimental and energy consuming to cells. Under metal deficiency, metal distribution is expected to reach a metalation ranking, prioritizing essential versus dispensable metalloproteins, while avoiding interference with other metals and protecting metal-sensitive processes. In this review, we propose that post-transcriptional modulators of metalloprotein mRNA (ModMeR) are good candidates in metal prioritization under metal-limited conditions. ModMeR target high quota or redundant metalloproteins and, by adjusting their synthesis, ModMeR act as internal metal distribution valves. Inappropriate metalation of ModMeR targets could compete with metal delivery to essential metalloproteins and interfere with metal-sensitive processes, such as chloroplastic photosynthesis and mitochondrial respiration. Regulation of ModMeR targets could increase or decrease the metal flow through interconnected pathways in cellular metal distribution, helping to achieve adequate differential metal requirements. Here, we describe and compare ModMeR that function in response to copper and iron deficiencies. Specifically, we describe copper-miRNAs from Arabidopsis thaliana and diverse iron ModMeR from yeast, mammals, and bacteria under copper and iron deficiencies, as well as the influence of oxidative stress. Putative functions derived from their role as ModMeR are also discussed.
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Affiliation(s)
- Ana Perea-García
- Departament de Bioquímica i Biologia Molecular and Institut Universitari de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Lola Peñarrubia
- Departament de Bioquímica i Biologia Molecular and Institut Universitari de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
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Lešková A, Javot H, Giehl RFH. Metal crossroads in plants: modulation of nutrient acquisition and root development by essential trace metals. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1751-1765. [PMID: 34791130 DOI: 10.1093/jxb/erab483] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
The metals iron, zinc, manganese, copper, molybdenum, and nickel are essential for the growth and development of virtually all plant species. Although these elements are required at relatively low amounts, natural factors and anthropogenic activities can significantly affect their availability in soils, inducing deficiencies or toxicities in plants. Because essential trace metals can shape root systems and interfere with the uptake and signaling mechanisms of other nutrients, the non-optimal availability of any of them can induce multi-element changes in plants. Interference by one essential trace metal with the acquisition of another metal or a non-metal nutrient can occur prior to or during root uptake. Essential trace metals can also indirectly impact the plant's ability to capture soil nutrients by targeting distinct root developmental programs and hormone-related processes, consequently inducing largely metal-specific changes in root systems. The presence of metal binding domains in many regulatory proteins also enables essential trace metals to coordinate nutrient uptake by acting at high levels in hierarchical signaling cascades. Here, we summarize the known molecular and cellular mechanisms underlying trace metal-dependent modulation of nutrient acquisition and root development, and highlight the importance of considering multi-element interactions to breed crops better adapted to non-optimal trace metal availabilities.
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Affiliation(s)
- Alexandra Lešková
- Aix Marseille Univ, CEA, CNRS, Bioscience and Biotechnology Institut of Aix-Marseille (BIAM), SAVE, Saint Paul-Lez-Durance, F-13108, France
| | - Hélène Javot
- Aix Marseille Univ, CEA, CNRS, Bioscience and Biotechnology Institut of Aix-Marseille (BIAM), SAVE, Saint Paul-Lez-Durance, F-13108, France
| | - Ricardo F H Giehl
- Department of Physiology & Cell Biology, Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, Germany
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Cai Y, Li Y, Liang G. FIT and bHLH Ib transcription factors modulate iron and copper crosstalk in Arabidopsis. PLANT, CELL & ENVIRONMENT 2021; 44:1679-1691. [PMID: 33464620 DOI: 10.1111/pce.14000] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 05/22/2023]
Abstract
Although the crosstalk between iron (Fe) and copper (Cu) homeostasis signalling networks exists in plants, the underlined molecular mechanism remains unclear. FIT (FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR) and four bHLH Ib members (bHLH38, bHLH39, bHLH100 and bHLH101) are the key regulators of Fe homeostasis. Here, we reveal that FIT and bHLH Ib control the up-regulation of Cu-uptake genes (COPT2, FRO4 and FRO5) by Fe deficiency, and Cu is required for improving plant growth under Fe-deficiency conditions. The induction of Cu-uptake gene expression and the elevation of Cu concentration are inhibited in the fit-2 or bhlh4x (the quadruple mutant of four bHLH Ib genes) under Fe-deficiency conditions. The dual overexpression of both bHLH38 (or bHLH39) and FIT activates the expression of COPT2, FRO4 and FRO5 and increases Cu accumulation. Furthermore, bHLH Ib proteins directly bind to the promoters of COPT2, FRO4 and FRO5. Either Cu supplement or overexpression of COPT2 or FRO4 improves the growth of fit-2 under Fe-deficiency conditions. Moreover, the induction of COPT2, FRO4 and FRO5 by Fe deficiency is independent of SPL7, a central regulator of Cu-deficiency responses. This work through the link between bHLH Ib/FIT and COPT2/FRO4/FRO5 under Fe-deficiency conditions establishes a new relationship between Cu and Fe homeostasis.
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Affiliation(s)
- Yuerong Cai
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Kunming, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, China
- The College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yang Li
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Kunming, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, China
| | - Gang Liang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Kunming, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, China
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Bernal M, Krämer U. Involvement of Arabidopsis Multi-Copper Oxidase-Encoding LACCASE12 in Root-to-Shoot Iron Partitioning: A Novel Example of Copper-Iron Crosstalk. FRONTIERS IN PLANT SCIENCE 2021; 12:688318. [PMID: 34707625 PMCID: PMC8544784 DOI: 10.3389/fpls.2021.688318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/23/2021] [Indexed: 05/17/2023]
Abstract
Numerous central biological processes depend on the participation of the essential elements iron (Fe) or copper (Cu), including photosynthesis, respiration, cell wall remodeling and oxidative stress protection. Yet, both Fe and Cu metal cations can become toxic when accumulated in excess. Because of the potent ligand-binding and redox chemistries of these metals, there is a need for the tight and combined homeostatic control of their uptake and distribution. Several known examples pinpoint an inter-dependence of Fe and Cu homeostasis in eukaryotes, mostly in green algae, yeast and mammals, but this is less well understood in multicellular plants to date. In Arabidopsis, Cu deficiency causes secondary Fe deficiency, and this is associated with reduced in vitro ferroxidase activity and decreased root-to-shoot Fe translocation. Here we summarize the current knowledge of the cross-talk between Cu and Fe homeostasis and present a partial characterization of LACCASE12 (LAC12) that encodes a member of the multicopper oxidase (MCO) protein family in Arabidopsis. LAC12 transcript levels increase under Fe deficiency. The phenotypic characterization of two mutants carrying T-DNA insertions suggests a role of LAC12 in root-to-shoot Fe partitioning and in maintaining growth on Fe-deficient substrates. A molecular understanding of the complex interactions between Fe and Cu will be important for combating Fe deficiency in crops and for advancing biofortification approaches.
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Affiliation(s)
- María Bernal
- Department of Molecular Genetics and Physiology of Plants, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
- Department of Plant Nutrition, Estación Experimental de Aula Dei-CSIC, Zaragoza, Spain
- *Correspondence: María Bernal,
| | - Ute Krämer
- Department of Molecular Genetics and Physiology of Plants, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
- Ute Krämer,
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