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Ali Z, Hakeem S, Wiehle M, Saddique MAB, Habib-ur-Rahman M. Prioritizing strategies for wheat biofortification: Inspiration from underutilized species. Heliyon 2023; 9:e20208. [PMID: 37818015 PMCID: PMC10560789 DOI: 10.1016/j.heliyon.2023.e20208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/06/2023] [Accepted: 09/13/2023] [Indexed: 10/12/2023] Open
Abstract
The relationship between malnutrition and climate change is still poorly understood but a comprehensive knowledge of their interactions is needed to address the global public health agenda. Limited studies have been conducted to propose robust and economic-friendly strategies to augment the food basket with underutilized species and biofortify the staples for nutritional security. Sea-buckthorn is a known "superfood" rich in vitamin C and iron content. It is found naturally in northern hemispherical temperate Eurasia and can be utilized as a model species for genetic biofortification in cash crops like wheat. This review focuses on the impacts of climate change on inorganic (iron, zinc) and organic (vitamin C) micronutrient malnutrition employing wheat as highly domesticated crop and processed food commodity. As iron and zinc are particularly stored in the outer aleurone and endosperm layers, they are prone to processing losses. Moreover, only 5% Fe and 25% Zn are bioavailable once consumed calling to enhance the bioavailability of these micronutrients. Vitamin C converts non-available iron (Fe3+) to available form (Fe2+) and helps in the synthesis of ferritin while protecting it from degradation at the same time. Similarly, reduced phytic acid content also enhances its bioavailability. This relation urges scientists to look for a common mechanism and genes underlying biosynthesis of vitamin C and uptake of Fe/Zn to biofortify these micronutrients concurrently. The study proposes to scale up the biofortification breeding strategies by focusing on all dimensions i.e., increasing micronutrient content and boosters (vitamin C) and simultaneously reducing anti-nutritional compounds (phytic acid). Mutually, this review identified that genes from the Aldo-keto reductase family are involved both in Fe/Zn uptake and vitamin C biosynthesis and can potentially be targeted for genetic biofortification in crop plants.
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Affiliation(s)
- Zulfiqar Ali
- Institute of Plant Breeding and Biotechnology, MNS University of Agriculture, Multan, Pakistan
- Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
- Programs and Projects Department, Islamic Organization for Food Security, Mangilik Yel Ave. 55/21 AIFC, Unit 4, C4.2, Astana, Kazakhstan
| | - Sadia Hakeem
- Institute of Plant Breeding and Biotechnology, MNS University of Agriculture, Multan, Pakistan
| | - Martin Wiehle
- Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Steinstrasse 19, D-37213, Witzenhausen, Germany
- Centre for International Rural Development, University of Kassel, Steinstrasse 19, D-37213, Witzenhausen, Germany
| | | | - Muhammad Habib-ur-Rahman
- Institute of Plant Breeding and Biotechnology, MNS University of Agriculture, Multan, Pakistan
- Institute of Crop Science and Resource Conservation (INRES), Crop Science Group, University of Bonn, Germany
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Singh A, Pankaczi F, Rana D, May Z, Tolnai G, Fodor F. Coated Hematite Nanoparticles Alleviate Iron Deficiency in Cucumber in Acidic Nutrient Solution and as Foliar Spray. PLANTS (BASEL, SWITZERLAND) 2023; 12:3104. [PMID: 37687350 PMCID: PMC10490057 DOI: 10.3390/plants12173104] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 08/25/2023] [Accepted: 08/27/2023] [Indexed: 09/10/2023]
Abstract
Micronutrient iron (Fe) deficiency poses a widespread agricultural challenge with global implications. Fe deficiency affects plant growth and immune function, leading to reduced yields and contributing to the global "hidden hunger." While conventional Fe-based fertilizers are available, their efficacy is limited under certain conditions. Most recently, nanofertilizers have been shown as promising alternatives to conventional fertilizers. In this study, three nanohematite/nanoferrihydrite preparations (NHs) with different coatings were applied through the roots and shoots to Fe-deficient cucumber plants. To enhance Fe mobilization to leaves during foliar treatment, the plants were pre-treated with various acids (citric acid, ascorbic acid, and glycine) at a concentration of 0.5 mM. Multiple physiological parameters were examined, revealing that both root and foliar treatments resulted in improved chlorophyll content, biomass, photosynthetic parameters, and reduced ferric chelate reductase activity. The plants also significantly accumulated Fe in their developing leaves and its distribution after NHs treatment, detected by X-ray fluorescence mapping, implied long-distance mobilization in their veins. These findings suggest that the applied NHs effectively mitigated Fe deficiency in cucumber plants through both modes of application, highlighting their potential as nanofertilizers on a larger scale.
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Affiliation(s)
- Amarjeet Singh
- Department of Plant Physiology and Molecular Plant Biology, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary; (A.S.); (F.P.); (D.R.)
- Doctoral School of Biological Sciences, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary
| | - Fruzsina Pankaczi
- Department of Plant Physiology and Molecular Plant Biology, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary; (A.S.); (F.P.); (D.R.)
- Doctoral School of Biological Sciences, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary
| | - Deepali Rana
- Department of Plant Physiology and Molecular Plant Biology, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary; (A.S.); (F.P.); (D.R.)
- Doctoral School of Environmental Sciences, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/a, 1117 Budapest, Hungary
| | - Zoltán May
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Eötvös Loránd Research Network, Magyar Tudósok Blvd. 2, 1117 Budapest, Hungary;
| | | | - Ferenc Fodor
- Department of Plant Physiology and Molecular Plant Biology, ELTE Eötvös Loránd University, Pázmány Péter Lane 1/c, 1117 Budapest, Hungary; (A.S.); (F.P.); (D.R.)
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Coelho DG, da Silva VM, Gomes Filho AAP, Oliveira LA, de Araújo HH, Farnese FDS, Araújo WL, de Oliveira JA. Bioaccumulation and physiological traits qualify Pistia stratiotes as a suitable species for phytoremediation and bioindication of iron-contaminated water. JOURNAL OF HAZARDOUS MATERIALS 2023; 446:130701. [PMID: 36603425 DOI: 10.1016/j.jhazmat.2022.130701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/12/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Serious concerns have recently been raised regarding the association of Fe excess with neurodegenerative diseases in mammals and nutritional and oxidative disorders in plants. Therefore, the current study aimed to understand the physiological changes induced by Fe excess in Pistia stratiotes, a species often employed in phytoremediation studies. P. stratiotes were subjected to five concentrations of Fe: 0.038 (control), 1.0, 3.0, 5.0 and 7.0 mM. Visual symptoms of Fe-toxicity such as bronzing of leaf edges in 5.0 and 7.0 mM-grown plants were observed after 5 days. Nevertheless, no major changes were observed in photosynthesis-related parameters at this time-point. In contrast, plants growing for 10 days in high Fe concentrations showed decreased chlorophyll concentrations and lower net CO2 assimilation rate. Notwithstanding, P. stratiotes accumulated high amounts of Fe, especially in roots (maximum of 10,000 µg g-1 DW) and displayed a robust induction of the enzymatic antioxidant system. In conclusion, we demonstrated that P. stratiotes can be applied to clean up Fe-contaminated water, as the species displays high Fe bioaccumulation, mostly in root apoplasts, and can maintain physiological processes under Fe excess. Our results further revealed that by monitoring visual symptoms, P. stratiotes could be applied for bioindication purposes.
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Affiliation(s)
- Daniel Gomes Coelho
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil
| | - Vinicius Melo da Silva
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil
| | | | | | - Hugo Humberto de Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil
| | | | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil
| | - Juraci Alves de Oliveira
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil.
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4
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Vélez-Bermúdez IC, Schmidt W. Iron sensing in plants. FRONTIERS IN PLANT SCIENCE 2023; 14:1145510. [PMID: 36968364 PMCID: PMC10032465 DOI: 10.3389/fpls.2023.1145510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
The ease of accepting or donating electrons is the raison d'être for the pivotal role iron (Fe) plays in a multitude of vital processes. In the presence of oxygen, however, this very property promotes the formation of immobile Fe(III) oxyhydroxides in the soil, which limits the concentration of Fe that is available for uptake by plant roots to levels well below the plant's demand. To adequately respond to a shortage (or, in the absence of oxygen, a possible surplus) in Fe supply, plants have to perceive and decode information on both external Fe levels and the internal Fe status. As a further challenge, such cues have to be translated into appropriate responses to satisfy (but not overload) the demand of sink (i.e., non-root) tissues. While this seems to be a straightforward task for evolution, the multitude of possible inputs into the Fe signaling circuitry suggests diversified sensing mechanisms that concertedly contribute to govern whole plant and cellular Fe homeostasis. Here, we review recent progress in elucidating early events in Fe sensing and signaling that steer downstream adaptive responses. The emerging picture suggests that Fe sensing is not a central event but occurs in distinct locations linked to distinct biotic and abiotic signaling networks that together tune Fe levels, Fe uptake, root growth, and immunity in an interwoven manner to orchestrate and prioritize multiple physiological readouts.
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Affiliation(s)
| | - Wolfgang Schmidt
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
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Kobayashi T, Maeda K, Suzuki Y, Nishizawa NK. Simultaneous Enhancement of iron Deficiency Tolerance and Iron Accumulation in Rice by Combining the Knockdown of OsHRZ Ubiquitin Ligases with the Introduction of Engineered Ferric-chelate Reductase. RICE (NEW YORK, N.Y.) 2022; 15:54. [PMID: 36315339 PMCID: PMC9622965 DOI: 10.1186/s12284-022-00598-w] [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: 07/14/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Iron is an essential micronutrient for living organisms, but its solubility is extremely low under alkaline conditions. Plants often suffer from iron deficiency chlorosis in calcareous soils, which consist of approximately 30% of the world's cultivated area, severely limiting plant productivity. Iron deficiency anemia is also a widespread problem in humans, especially in Asian and African people who take up iron mainly from staple foods containing low iron concentrations. Transgenic manipulation of genes involved in plant iron uptake, translocation, and storage has made improvements in enhancing iron deficiency tolerance or iron accumulation in edible parts, but these two properties have been characterized separately. We previously produced transgenic rice lines, with concomitant improvement of iron deficiency tolerance and grain iron accumulation by knocking-down OsHRZ ubiquitin ligases, which negatively regulate iron deficiency response and iron accumulation in rice. In the present report, we aimed to further improve the iron deficiency tolerance and grain iron accumulation of OsHRZ knockdown rice by the simultaneous introduction of the engineered ferric-chelate reductase gene Refre1/372 under the control of the OsIRT1 promoter for further enhancement of iron uptake. We obtained several transgenic rice lines with repressed OsHRZ expression and induced Refre1/372 expression. These lines showed a variable degree of iron deficiency tolerance in calcareous soils, with increased iron accumulation in brown seeds under both iron-deficient and iron-sufficient soil cultures. Selected OsHRZ knockdown plus Refre1/372 lines showed similar or better growth compared with that of singly introduced OsHRZ knockdown or Refre1/372 lines in calcareous soils under both non-submerged and submerged conditions. After submerged calcareous soil cultivation, these OsHRZ knockdown plus Refre1/372 lines accumulated 2.5-4.3 times and 17-23 times more iron concentrations than that of non-transformants in brown rice and straw, respectively, which was comparable or superior to a single OsHRZ knockdown line. Our results indicate that the combined introduction of OsHRZ knockdown and OsIRT1 promoter-Refre1/372 is highly effective in further improving the iron deficiency tolerance without compromising the iron accumulation of the OsHRZ knockdown effects.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
| | - Keisuke Maeda
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Yutaro Suzuki
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
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6
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Kobayashi T, Shinkawa H, Nagano AJ, Nishizawa NK. The basic leucine zipper transcription factor OsbZIP83 and the glutaredoxins OsGRX6 and OsGRX9 facilitate rice iron utilization under the control of OsHRZ ubiquitin ligases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1731-1750. [PMID: 35411594 DOI: 10.1111/tpj.15767] [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: 04/03/2022] [Accepted: 04/06/2022] [Indexed: 05/16/2023]
Abstract
Under low iron availability, plants induce the expression of various genes for iron uptake and translocation. The rice (Oryza sativa) ubiquitin ligases OsHRZ1 and OsHRZ2 cause overall repression of these iron-related genes at the transcript level, but their protein-level regulation is unclear. We conducted a proteome analysis to identify key regulators whose abundance was regulated by OsHRZs at the protein level. In response to iron deficiency or OsHRZ knockdown, many genes showed differential regulation between the transcript and protein levels, including the TGA-type basic leucine zipper transcription factor OsbZIP83. We also identified two glutaredoxins, OsGRX6 and OsGRX9, as OsHRZ-interacting proteins in yeast and plant cells. OsGRX6 also interacted with OsbZIP83. Our in vitro degradation assay suggested that OsbZIP83, OsGRX6 and OsGRX9 proteins are subjected to 26S proteasome- and OsHRZ-dependent degradation. Proteome analysis and our in vitro degradation assay also suggested that OsbZIP83 protein was preferentially degraded under iron-deficient conditions in rice roots. Transgenic rice lines overexpressing OsGRX9 and OsbZIP83 showed improved tolerance to iron deficiency. Expression of iron-related genes was affected in the OsGRX9 and OsGRX6 knockdown lines, suggesting disturbed iron utilization and signaling. OsbZIP83 overexpression lines showed enhanced expression of OsYSL2 and OsNAS3, which are involved in internal iron translocation, in addition to OsGRX9 and genes related to phytoalexin biosynthesis and the salicylic acid pathway. The results suggest that OsbZIP83, OsGRX6 and OsGRX9 facilitate iron utilization downstream of the OsHRZ pathway.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Haruka Shinkawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Otsu, Shiga, 520-2194, Japan
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
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Mackinnon E, Stone SL. The Ubiquitin Proteasome System and Nutrient Stress Response. FRONTIERS IN PLANT SCIENCE 2022; 13:867419. [PMID: 35665152 PMCID: PMC9161090 DOI: 10.3389/fpls.2022.867419] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Plants utilize different molecular mechanisms, including the Ubiquitin Proteasome System (UPS) that facilitates changes to the proteome, to mitigate the impact of abiotic stresses on growth and development. The UPS encompasses the ubiquitination of selected substrates followed by the proteasomal degradation of the modified proteins. Ubiquitin ligases, or E3s, are central to the UPS as they govern specificity and facilitate the attachment of one or more ubiquitin molecules to the substrate protein. From recent studies, the UPS has emerged as an important regulator of the uptake and translocation of essential macronutrients and micronutrients. In this review, we discuss select E3s that are involved in regulating nutrient uptake and responses to stress conditions, including limited or excess levels of nitrogen, phosphorus, iron, and copper.
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Genome-Wide Identification of Cassava Glyoxalase I Genes and the Potential Function of MeGLYⅠ-13 in Iron Toxicity Tolerance. Int J Mol Sci 2022; 23:ijms23095212. [PMID: 35563603 PMCID: PMC9104206 DOI: 10.3390/ijms23095212] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 02/01/2023] Open
Abstract
Glyoxalase I (GLYI) is a key enzyme in the pathway of the glyoxalase system that degrades the toxic substance methylglyoxal, which plays a crucial part in plant growth, development, and stress response. A total of 19 GLYI genes were identified from the cassava genome, which distributed randomly on 11 chromosomes. These genes were named MeGLYI-1–19 and were systematically characterized. Transcriptome data analysis showed that MeGLYIs gene expression is tissue-specific, and MeGLYI-13 is the dominant gene expressed in young tissues, while MeGLYI-19 is the dominant gene expressed in mature tissues and organs. qRT-PCR analysis showed that MeGLYI-13 is upregulated under 2 h excess iron stress, but downregulated under 6, 12, and 20 h iron stress. Overexpression of MeGLYI-13 enhanced the growth ability of transgenic yeast under iron stress. The root growth of transgenic Arabidopsis seedlings was less inhibited by iron toxicity than that of the wild type (WT). Potted transgenic Arabidopsis blossomed and podded under iron stress, but flowering of the WT was significantly delayed. The GLYI activity in transgenic Arabidopsis was improved under both non-iron stress and iron stress conditions compared to the WT. The SOD activity in transgenic plants was increased under iron stress, while the POD and CAT activity and MDA content were decreased compared to that in the WT. These results provide a basis for the selection of candidate genes for iron toxicity tolerance in cassava, and lay a theoretical foundation for further studies on the functions of these MeGLYI genes.
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Kirk GJD, Manwaring HR, Ueda Y, Semwal VK, Wissuwa M. Below-ground plant-soil interactions affecting adaptations of rice to iron toxicity. PLANT, CELL & ENVIRONMENT 2022; 45:705-718. [PMID: 34628670 DOI: 10.1111/pce.14199] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
Iron toxicity is a major constraint to rice production, particularly in highly weathered soils of inland valleys in sub-Saharan Africa where the rice growing area is rapidly expanding. There is a wide variation in tolerance of iron toxicity in the rice germplasm. However, the introgression of tolerance traits into high-yielding germplasm has been slow owing to the complexity of the tolerance mechanisms and large genotype-by-environment effects. We review current understanding of tolerance mechanisms, particularly those involving below-ground plant-soil interactions. Until now these have been less studied than above-ground mechanisms. We cover processes in the rhizosphere linked to exclusion of toxic ferrous iron by oxidation, and resulting effects on the mobility of nutrient ions. We also cover the molecular physiology of below-ground processes controlling iron retention in roots and root-shoot transport, and also plant iron sensing. We conclude that future breeding programmes should be based on well-characterized molecular markers for iron toxicity tolerance traits. To successfully identify such markers, the complex tolerance response should be broken down into its components based on understanding of tolerance mechanisms, and tailored screening methods should be developed for individual mechanisms.
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Affiliation(s)
- Guy J D Kirk
- School of Water, Energy and Environment, Cranfield University, Cranfield, UK
| | - Hanna R Manwaring
- School of Water, Energy and Environment, Cranfield University, Cranfield, UK
| | - Yoshiaki Ueda
- Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Japan
| | | | - Matthias Wissuwa
- Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Japan
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10
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Mining of Potential Gene Resources for Breeding Nutritionally Improved Maize. PLANTS 2022; 11:plants11050627. [PMID: 35270097 PMCID: PMC8912576 DOI: 10.3390/plants11050627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
Maize is one of the leading food crops and its kernel is rich in starch, lipids, protein and other energy substances. In addition, maize kernels also contain many trace elements that are potentially beneficial to human health, such as vitamins, minerals and other secondary metabolites. However, gene resources that could be applied for nutrient improvement are limited in maize. In this review, we summarized 107 genes that are associated with nutrient content from different plant species and identified 246 orthologs from the maize genome. In addition, we constructed physical maps and performed a detailed expression pattern analysis for the 246 maize potential gene resources. Combining expression profiles and their potential roles in maize nutrient improvement, genetic engineering by editing or ectopic expression of these genes in maize are expected to improve resistant starch, oil, essential amino acids, vitamins, iron, zinc and anthocyanin levels of maize grains. Thus, this review provides valuable gene resources for maize nutrient improvement.
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Yang W, Wu K, Wang B, Liu H, Guo S, Guo X, Luo W, Sun S, Ouyang Y, Fu X, Chong K, Zhang Q, Xu Y. The RING E3 ligase CLG1 targets GS3 for degradation via the endosome pathway to determine grain size in rice. MOLECULAR PLANT 2021; 14:1699-1713. [PMID: 34216830 DOI: 10.1016/j.molp.2021.06.027] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/26/2021] [Accepted: 06/27/2021] [Indexed: 05/02/2023]
Abstract
G-protein signaling and ubiquitin-dependent degradation are both involved in grain development in rice, but how these pathways are coordinated in regulating this process is unknown. Here, we show that Chang Li Geng 1 (CLG1), which encodes an E3 ligase, regulates grain size by targeting the Gγ protein GS3, a negative regulator of grain length, for degradation. Overexpression of CLG1 led to increased grain length, while overexpression of mutated CLG1 with changes in three conserved amino acids decreased grain length. We found that CLG1 physically interacts with and ubiquitinats GS3which is subsequently degraded through the endosome degradation pathway, leading to increased grain size. Furthermore, we identified a critical SNP in the exon 3 of CLG1 that is significantly associated with grain size variation in a core collection of cultivated rice. This SNP results in an amino acid substitution from Arg to Ser at position 163 of CLG1 that enhances the E3 ligase activity of CLG1 and thus increases rice grain size. Both the expression level of CLG1 and the SNP CLG1163S may be useful variations for manipulating grain size in rice.
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Affiliation(s)
- Wensi Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Wu
- The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huanhuan Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Siyi Guo
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyu Guo
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Luo
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Shengyuan Sun
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Yidan Ouyang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiangdong Fu
- The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Kang Chong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China; Innovation Academy for Seed Design, CAS, Beijing 100101, China
| | - Qifa Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yunyuan Xu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; Innovation Academy for Seed Design, CAS, Beijing 100101, China.
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12
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Zahra N, Hafeez MB, Shaukat K, Wahid A, Hasanuzzaman M. Fe toxicity in plants: Impacts and remediation. PHYSIOLOGIA PLANTARUM 2021; 173:201-222. [PMID: 33547807 DOI: 10.1111/ppl.13361] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/17/2021] [Accepted: 02/01/2021] [Indexed: 05/07/2023]
Abstract
Fe is the fourth abundant element in the earth crust. Fe toxicity is not often discussed in plant science though it causes severe morphological and physiological disorders, including reduced germination percentage, interferes with enzymatic activities, nutritional imbalance, membrane damage, and chloroplast ultrastructure. It also causes severe toxicity to important biomolecules, which leads to ferroptotic cell death and induces structural changes in the photosynthetic apparatus, which results in retardation of carbon metabolism. However, some agronomic practices like soil remediation through chemicals, nutrients, and organic amendments and some breeding and genetic approaches can provide fruitful results in enhancing crop production in Fe-contaminated soils. Some quantitative trait loci have been reported for Fe tolerance in plants but the function of underlying genes is just emerging. Physiological and molecular mechanism of Fe uptake, translocation, toxicity, and remediation techniques are still under experimentation. In this review, the toxic effects of Fe on seed germination, carbon assimilation, water relations, nutrient uptake, oxidative damages, enzymatic activities, and overall plant growth and development have been discussed. The Fe dynamics in soil rhizosphere and role of remediation strategies, that is, biological, physical, and chemical, have also been described. Use of organic amendments, microbe, phytoremediation, and biological strategies is considered to be both cost and environment friendly for the purification of Fe-contaminated soil, while to ensure better crop yield and quality the manipulation of agronomic practices are suggested.
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Affiliation(s)
- Noreen Zahra
- Department of Botany, University of Agriculture, Faisalabad, Pakistan
| | | | - Kanval Shaukat
- Department of Botany, University of Balochistan, Quetta, Pakistan
| | - Abdul Wahid
- Department of Botany, University of Agriculture, Faisalabad, Pakistan
| | - Mirza Hasanuzzaman
- Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
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Kakei Y, Masuda H, Nishizawa NK, Hattori H, Aung MS. Elucidation of Novel cis-Regulatory Elements and Promoter Structures Involved in Iron Excess Response Mechanisms in Rice Using a Bioinformatics Approach. FRONTIERS IN PLANT SCIENCE 2021; 12:660303. [PMID: 34149757 PMCID: PMC8207140 DOI: 10.3389/fpls.2021.660303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/06/2021] [Indexed: 05/24/2023]
Abstract
Iron (Fe) excess is a major constraint on crop production in flooded acidic soils, particularly in rice cultivation. Under Fe excess, plants activate a complex mechanism and network regulating Fe exclusion by roots and isolation in various tissues. In rice, the transcription factors and cis-regulatory elements (CREs) that regulate Fe excess response mechanisms remain largely elusive. We previously reported comprehensive microarray analyses of several rice tissues in response to various levels of Fe excess stress. In this study, we further explored novel CREs and promoter structures in rice using bioinformatics approaches with this microarray data. We first performed network analyses to predict Fe excess-related CREs through the categorization of the gene expression patterns of Fe excess-responsive transcriptional regulons, and found four major expression clusters: Fe storage type, Fe chelator type, Fe uptake type, and WRKY and other co-expression type. Next, we explored CREs within these four clusters of gene expression types using a machine-learning method called microarray-associated motif analyzer (MAMA), which we previously established. Through a comprehensive bioinformatics approach, we identified a total of 560 CRE candidates extracted by MAMA analyses and 42 important conserved sequences of CREs directly related to the Fe excess response in various rice tissues. We explored several novel cis-elements as candidate Fe excess CREs including GCWGCWGC, CGACACGC, and Myb binding-like motifs. Based on the presence or absence of candidate CREs using MAMA and known PLACE CREs, we found that the Boruta-XGBoost model explained expression patterns with high accuracy of about 83%. Enriched sequences of both novel MAMA CREs and known PLACE CREs led to high accuracy expression patterns. We also found new roles of known CREs in the Fe excess response, including the DCEp2 motif, IDEF1-, Zinc Finger-, WRKY-, Myb-, AP2/ERF-, MADS- box-, bZIP and bHLH- binding sequence-containing motifs among Fe excess-responsive genes. In addition, we built a molecular model and promoter structures regulating Fe excess-responsive genes based on new finding CREs. Together, our findings about Fe excess-related CREs and conserved sequences will provide a comprehensive resource for discovery of genes and transcription factors involved in Fe excess-responsive pathways, clarification of the Fe excess response mechanism in rice, and future application of the promoter sequences to produce genotypes tolerant of Fe excess.
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Affiliation(s)
- Yusuke Kakei
- Institute of Vegetable and Floriculture Science, Research Center for Agricultural Information Technology, National Agriculture and Food Research Organization, Ibaraki, Japan
| | - Hiroshi Masuda
- Faculty of Bioresource Sciences, Department of Biological Production, Akita Prefectural University, Akita, Japan
| | - Naoko K. Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Ishikawa, Japan
| | - Hiroyuki Hattori
- Faculty of Bioresource Sciences, Department of Biological Production, Akita Prefectural University, Akita, Japan
| | - May Sann Aung
- Faculty of Bioresource Sciences, Department of Biological Production, Akita Prefectural University, Akita, Japan
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Ishikawa, Japan
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14
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Sharma S, Prasad A, Sharma N, Prasad M. Role of ubiquitination enzymes in abiotic environmental interactions with plants. Int J Biol Macromol 2021; 181:494-507. [PMID: 33798570 DOI: 10.1016/j.ijbiomac.2021.03.185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/08/2021] [Accepted: 03/27/2021] [Indexed: 12/14/2022]
Abstract
Ubiquitination, a post-translational modification, plays a crucial role in various aspects of plant development and stress responses. Protein degradation by ubiquitination is well established and ubiquitin is the main underlying component directing the turnover of proteins. Recent reports have also revealed the non-proteolytic roles of ubiquitination in plants. In the past decade, ubiquitination has emerged to be one of the most important players in modulating plant's responses to abiotic stresses, which led to identification of specific E3 ligases and their targets involved in the process. Most of the E3 ligases play regulatory roles by modifying the stability and accumulation of stress responsive regulatory proteins, such as transcription factors, thus, modifying the downstream responses, or by degrading the proteins involved in the downstream cascade itself. In this review, we summarize and highlight the recent advances in the field of ubiquitination-mediated regulation of plant's responses to various abiotic stresses including limited nutrient availability and metal toxicity. The non-proteolytic role of ubiquitination in epigenetic regulation of abiotic stress induced response has also been discussed.
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Affiliation(s)
- Shambhavi Sharma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ashish Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Namisha Sharma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Manoj Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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15
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Bashir K, Ahmad Z, Kobayashi T, Seki M, Nishizawa NK. Roles of subcellular metal homeostasis in crop improvement. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2083-2098. [PMID: 33502492 DOI: 10.1093/jxb/erab018] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Improvement of crop production in response to rapidly changing environmental conditions is a serious challenge facing plant breeders and biotechnologists. Iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) are essential micronutrients for plant growth and reproduction. These minerals are critical to several cellular processes including metabolism, photosynthesis, and cellular respiration. Regulating the uptake and distribution of these minerals could significantly improve plant growth and development, ultimately leading to increased crop production. Plant growth is limited by mineral deficiency, but on the other hand, excess Fe, Mn, Cu, and Zn can be toxic to plants; therefore, their uptake and distribution must be strictly regulated. Moreover, the distribution of these metals among subcellular organelles is extremely important for maintaining optimal cellular metabolism. Understanding the mechanisms controlling subcellular metal distribution and availability would enable development of crop plants that are better adapted to challenging and rapidly changing environmental conditions. Here, we describe advances in understanding of subcellular metal homeostasis, with a particular emphasis on cellular Fe homeostasis in Arabidopsis and rice, and discuss strategies for regulating cellular metabolism to improve plant production.
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Affiliation(s)
- Khurram Bashir
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore, Pakistan
- Plant Genomics Network Research Team, Center for Sustainable Resource Science, Suehiro, Tsurumi Ku, Yokohama, Kanagawa, Japan
| | - Zarnab Ahmad
- Plant Genomics Network Research Team, Center for Sustainable Resource Science, Suehiro, Tsurumi Ku, Yokohama, Kanagawa, Japan
| | - Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa, Japan
| | - Motoaki Seki
- Plant Genomics Network Research Team, Center for Sustainable Resource Science, Suehiro, Tsurumi Ku, Yokohama, Kanagawa, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
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16
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Kobayashi T, Nagano AJ, Nishizawa NK. Iron deficiency-inducible peptide-coding genes OsIMA1 and OsIMA2 positively regulate a major pathway of iron uptake and translocation in rice. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2196-2211. [PMID: 33206982 DOI: 10.1093/jxb/eraa546] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/12/2020] [Indexed: 05/16/2023]
Abstract
Under low iron (Fe) availability, plants transcriptionally induce various genes responsible for Fe uptake and translocation to obtain adequate amounts of Fe. Although transcription factors and ubiquitin ligases involved in these Fe deficiency responses have been identified, the mechanisms coordinating these pathways have not been clarified in rice. Recently identified Fe-deficiency-inducible IRON MAN (IMA)/FE UPTAKE-INDUCING PEPTIDE (FEP) positively regulates many Fe-deficiency-inducible genes for Fe uptake in Arabidopsis. Here, we report that the expression of two IMA/FEP genes in rice, OsIMA1 and OsIMA2, is strongly induced under Fe deficiency, positively regulated by the transcription factors IDEF1, OsbHLH058, and OsbHLH059, as well as OsIMA1 and OsIMA2 themselves, and negatively regulated by HRZ ubiquitin ligases. Overexpression of OsIMA1 or OsIMA2 in rice conferred tolerance to Fe deficiency and accumulation of Fe in leaves and seeds. These OsIMA-overexpressing rice exhibited enhanced expression of all of the known Fe-deficiency-inducible genes involved in Fe uptake and translocation, except for OsYSL2, a Fe-nicotianamine transporter gene, in roots but not in leaves. Knockdown of OsIMA1 or OsIMA2 caused minor effects, including repression of some Fe uptake- and translocation-related genes in OsIMA1 knockdown roots. These results indicate that OsIMA1 and OsIMA2 play key roles in enhancing the major pathway of the Fe deficiency response in rice.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi, Ishikawa, Japan
| | | | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi, Ishikawa, Japan
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17
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Senoura T, Kobayashi T, An G, Nakanishi H, Nishizawa NK. Defects in the rice aconitase-encoding OsACO1 gene alter iron homeostasis. PLANT MOLECULAR BIOLOGY 2020; 104:629-645. [PMID: 32909184 DOI: 10.1007/s11103-020-01065-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/30/2020] [Indexed: 05/16/2023]
Abstract
Rice aconitase gene OsACO1 is involved in the iron deficiency-signaling pathway for the expression of iron deficiency-inducible genes, either thorough enzyme activity or possible specific RNA binding for post-transcriptional regulation. Iron (Fe) is an essential element for virtually all living organisms. When plants are deficient in Fe, Fe acquisition systems are activated to maintain Fe homeostasis, and this regulation is mainly executed at the gene transcription level. Many molecules responsible for Fe uptake, translocation, and storage in plants have been identified and characterized. However, how plants sense Fe status within cells and then induce a transcriptional response is still unclear. In the present study, we found that knockdown of the OsACO1 gene, which encodes an aconitase in rice, leads to the down-regulation of selected Fe deficiency-inducible genes involved in Fe uptake and translocation in roots, and a decrease in Fe concentration in leaves, even when grown under Fe-sufficient conditions. OsACO1 knockdown plants showed a delayed transcriptional response to Fe deficiency compared to wild-type plants. In contrast, overexpression of OsACO1 resulted in the opposite effects. These results suggest that OsACO1 is situated upstream of the Fe deficiency-signaling pathway. Furthermore, we found that the OsACO1 protein potentially has RNA-binding activity. In vitro screening of RNA interactions with OsACO1 revealed that RNA potentially forms a unique stem-loop structure that interacts with OsACO1 via a conserved GGUGG motif within the loop structure. These results suggest that OsACO1 regulate Fe deficiency response either thorough enzyme activity catalyzing isomerization of citrate, or specific RNA binding for post-transcriptional regulation.
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Affiliation(s)
- Takeshi Senoura
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
| | - Gynheung An
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Hiromi Nakanishi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
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Aung MS, Masuda H. How Does Rice Defend Against Excess Iron?: Physiological and Molecular Mechanisms. FRONTIERS IN PLANT SCIENCE 2020; 11:1102. [PMID: 32849682 PMCID: PMC7426474 DOI: 10.3389/fpls.2020.01102,] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/03/2020] [Indexed: 05/29/2023]
Abstract
Iron (Fe) is an essential nutrient for all living organisms but can lead to cytotoxicity when present in excess. Fe toxicity often occurs in rice grown in submerged paddy fields with low pH, leading dramatical increases in ferrous ion concentration, disrupting cell homeostasis and impairing growth and yield. However, the underlying molecular mechanisms of Fe toxicity response and tolerance in plants are not well characterized yet. Microarray and genome-wide association analyses have shown that rice employs four defense systems to regulate Fe homeostasis under Fe excess. In defense 1, Fe excess tolerance is implemented by Fe exclusion as a result of suppression of genes involved in Fe uptake and translocation such as OsIRT1, OsYSL2, OsTOM1, OsYSL15, OsNRAMP1, OsNAS1, OsNAS2, OsNAAT1, OsDMAS1, and OsIRO2. The Fe-binding ubiquitin ligase, HRZ, is a key regulator that represses Fe uptake genes in response to Fe excess in rice. In defense 2, rice retains Fe in the root system rather than transporting it to shoots. In defense 3, rice compartmentalizes Fe in the shoot. In defense 2 and 3, the vacuolar Fe transporter OsVIT2, Fe storage protein ferritin, and the nicotinamine synthase OsNAS3 mediate the isolation or detoxification of excess Fe. In defense 4, rice detoxifies the ROS produced within the plant body in response to excess Fe. Some OsWRKY transcription factors, S-nitrosoglutathione-reductase variants, p450-family proteins, and OsNAC4, 5, and 6 are implicated in defense 4. These knowledge will facilitate the breeding of tolerant crops with increased productivity in low-pH, Fe-excess soils.
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Aung MS, Masuda H. How Does Rice Defend Against Excess Iron?: Physiological and Molecular Mechanisms. FRONTIERS IN PLANT SCIENCE 2020; 11:1102. [PMID: 32849682 PMCID: PMC7426474 DOI: 10.3389/fpls.2020.01102] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/03/2020] [Indexed: 05/25/2023]
Abstract
Iron (Fe) is an essential nutrient for all living organisms but can lead to cytotoxicity when present in excess. Fe toxicity often occurs in rice grown in submerged paddy fields with low pH, leading dramatical increases in ferrous ion concentration, disrupting cell homeostasis and impairing growth and yield. However, the underlying molecular mechanisms of Fe toxicity response and tolerance in plants are not well characterized yet. Microarray and genome-wide association analyses have shown that rice employs four defense systems to regulate Fe homeostasis under Fe excess. In defense 1, Fe excess tolerance is implemented by Fe exclusion as a result of suppression of genes involved in Fe uptake and translocation such as OsIRT1, OsYSL2, OsTOM1, OsYSL15, OsNRAMP1, OsNAS1, OsNAS2, OsNAAT1, OsDMAS1, and OsIRO2. The Fe-binding ubiquitin ligase, HRZ, is a key regulator that represses Fe uptake genes in response to Fe excess in rice. In defense 2, rice retains Fe in the root system rather than transporting it to shoots. In defense 3, rice compartmentalizes Fe in the shoot. In defense 2 and 3, the vacuolar Fe transporter OsVIT2, Fe storage protein ferritin, and the nicotinamine synthase OsNAS3 mediate the isolation or detoxification of excess Fe. In defense 4, rice detoxifies the ROS produced within the plant body in response to excess Fe. Some OsWRKY transcription factors, S-nitrosoglutathione-reductase variants, p450-family proteins, and OsNAC4, 5, and 6 are implicated in defense 4. These knowledge will facilitate the breeding of tolerant crops with increased productivity in low-pH, Fe-excess soils.
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Gupta OP, Pandey V, Saini R, Narwal S, Malik VK, Khandale T, Ram S, Singh GP. Identifying transcripts associated with efficient transport and accumulation of Fe and Zn in hexaploid wheat (T. aestivum L.). J Biotechnol 2020; 316:46-55. [PMID: 32305628 DOI: 10.1016/j.jbiotec.2020.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/06/2020] [Accepted: 03/28/2020] [Indexed: 11/26/2022]
Abstract
Wheat (T. aestivum L.) is the second most important staple food crop consumed in the form of various end-use products across the world. However, it contains lower concentrations of Fe and Zn leading to micronutrient deficiency in human beings where wheat is the sole diet. Therefore, increasing grain Fe/Zn content in wheat has become priority in wheat breeding programmes across the world. Understanding the molecular mechanism of Fe/Zn transport and accumulation in grains is required to expedite the breeding process. For this purpose, whole seedling transcriptome analysis was conducted in four wheat genotypes (CRP 1660, Sonora 64, Vinata, : high, and DBW17: low) differing in grain Fe/Zn content under controlled and Fe/Zn deficient conditions. Twenty eight key transcripts involved in phytosiderophore biosynthesis, Fe/Zn uptake and transport were identified. Expression analysis of 12 of the transcripts using qPCR was conducted in seedling stage and flag leaf which exhibited greater differential accumulation in CRP 1660 followed by Vinata, Sonora 64 and DBW 17 in both flag leaf and seedling. However, there was significantly higher differential accumulation of the transcripts in flag leaf as compared to seedling. In CRP 1660, transcripts pertaining to phytosiderophore biosynthesis like DMAS1-B, NRAMP2 and NAAT2-D showed greater accumulation. Additionally, corresponding miRNAs were also identified for these 28 transcripts. The findings will help in better understanding of molecular basis of Fe/Zn transport and accumulation in grain and subsequent utilization in breeding to improve Fe/Zn content in wheat grain.
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Affiliation(s)
- Om Prakash Gupta
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Vanita Pandey
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Ritu Saini
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Sneh Narwal
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Vipin Kumar Malik
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Tushar Khandale
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Sewa Ram
- Division of Quality and Basic Sciences, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
| | - Gyanendra Pratap Singh
- Director, ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Karnal, 132001, Haryana, India.
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21
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Li Q, Chen L, Yang A. The Molecular Mechanisms Underlying Iron Deficiency Responses in Rice. Int J Mol Sci 2019; 21:E43. [PMID: 31861687 PMCID: PMC6981701 DOI: 10.3390/ijms21010043] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 01/27/2023] Open
Abstract
Iron (Fe) is an essential element required for plant growth and development. Under Fe-deficientconditions, plants have developed two distinct strategies (designated as strategy I and II) to acquire Fe from soil. As a graminaceous species, rice is not a typical strategy II plant, as it not only synthesizes DMA (2'-deoxymugineic acid) in roots to chelate Fe3+ but also acquires Fe2+ through transporters OsIRT1 and OsIRT2. During the synthesis of DMA in rice, there are three sequential enzymatic reactions catalyzed by enzymes NAS (nicotianamine synthase), NAAT (nicotianamine aminotransferase), and DMAS (deoxymugineic acid synthase). Many transporters required for Fe uptake from the rhizosphere and internal translocation have also been identified in rice. In addition, the signaling networks composed of various transcription factors (such as IDEF1, IDEF2, and members of the bHLH (basic helix-loop-helix) family), phytohormones, and signaling molecules are demonstrated to regulate Fe uptake and translocation. This knowledge greatly contributes to our understanding of the molecular mechanisms underlying iron deficiency responses in rice.
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Affiliation(s)
- Qian Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China;
| | - Lei Chen
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China;
| | - An Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China;
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The iron deficiency response in Arabidopsis thaliana requires the phosphorylated transcription factor URI. Proc Natl Acad Sci U S A 2019; 116:24933-24942. [PMID: 31776249 PMCID: PMC6911256 DOI: 10.1073/pnas.1916892116] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Iron is an essential nutrient for plants, but excess iron is toxic due to its catalytic role in the formation of hydroxyl radicals. Thus, iron uptake is highly regulated and induced only under iron deficiency. The mechanisms of iron uptake in roots are well characterized, but less is known about how plants perceive iron deficiency. We show that a basic helix-loop-helix (bHLH) transcription factor Upstream Regulator of IRT1 (URI) acts as an essential part of the iron deficiency signaling pathway in Arabidopsis thaliana The uri mutant is defective in inducing Iron-Regulated Transporter1 (IRT1) and Ferric Reduction Oxidase2 (FRO2) and their transcriptional regulators FER-like iron deficiency-induced transcription factor (FIT) and bHLH38/39/100/101 in response to iron deficiency. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) reveals direct binding of URI to promoters of many iron-regulated genes, including bHLH38/39/100/101 but not FIT While URI transcript and protein are expressed regardless of iron status, a phosphorylated form of URI only accumulates under iron deficiency. Phosphorylated URI is subject to proteasome-dependent degradation during iron resupply, and turnover of phosphorylated URI is dependent on the E3 ligase BTS. The subgroup IVc bHLH transcription factors, which have previously been shown to regulate bHLH38/39/100/101, coimmunoprecipitate with URI mainly under Fe-deficient conditions, suggesting that it is the phosphorylated form of URI that is capable of forming heterodimers in vivo. We propose that the phosphorylated form of URI accumulates under Fe deficiency, forms heterodimers with subgroup IVc proteins, and induces transcription of bHLH38/39/100/101 These transcription factors in turn heterodimerize with FIT and drive the transcription of IRT1 and FRO2 to increase Fe uptake.
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Kobayashi T, Ozu A, Kobayashi S, An G, Jeon JS, Nishizawa NK. OsbHLH058 and OsbHLH059 transcription factors positively regulate iron deficiency responses in rice. PLANT MOLECULAR BIOLOGY 2019; 101:471-486. [PMID: 31552586 PMCID: PMC6814640 DOI: 10.1007/s11103-019-00917-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/07/2019] [Indexed: 05/03/2023]
Abstract
Subgroup IVc basic helix-loop-helix transcription factors OsbHLH058 and OsbHLH059 positively regulate major iron deficiency responses in rice in a similar but distinct manner, putatively under partial control by OsHRZs. Under low iron availability, plants transcriptionally induce the expression of genes involved in iron uptake and translocation. OsHRZ1 and OsHRZ2 ubiquitin ligases negatively regulate this iron deficiency response in rice. The basic helix-loop-helix (bHLH) transcription factor OsbHLH060 interacts with OsHRZ1, and positively regulates iron deficiency-inducible genes. However, the functions of three other subgroup IVc bHLH transcription factors in rice, OsbHLH057, OsbHLH058, and OsbHLH059, have not yet been characterized. In the present study, we investigated the functions of OsbHLH058 and OsbHLH059 related to iron deficiency response. OsbHLH058 expression was repressed under iron deficiency, whereas the expression of OsbHLH057 and OsbHLH060 was moderately induced. Yeast two-hybrid analysis indicated that OsbHLH058 interacts with OsHRZ1 and OsHRZ2 more strongly than OsbHLH060, whereas OsbHLH059 showed no interaction. An in vitro ubiquitination assay detected no OsbHLH058 and OsbHLH060 ubiquitination by OsHRZ1 and OsHRZ2. Transgenic rice lines overexpressing OsbHLH058 showed tolerance for iron deficiency and higher iron concentration in seeds. These lines also showed enhanced expression of many iron deficiency-inducible genes involved in iron uptake and translocation under iron-sufficient conditions. Conversely, OsbHLH058 knockdown lines showed susceptibility to iron deficiency and reduced expression of many iron deficiency-inducible genes. OsbHLH059 knockdown lines were also susceptible to iron deficiency, and formed characteristic brownish regions in iron-deficient new leaves. OsbHLH059 knockdown lines also showed reduced expression of many iron deficiency-inducible genes. These results indicate that OsbHLH058 and OsbHLH059 positively regulate major iron deficiency responses in a similar but distinct manner, and that this function may be partially controlled by OsHRZs.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
| | - Asami Ozu
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Subaru Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Gynheung An
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Jong-Seong Jeon
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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Kobayashi T. Understanding the Complexity of Iron Sensing and Signaling Cascades in Plants. PLANT & CELL PHYSIOLOGY 2019; 60:1440-1446. [PMID: 30796837 DOI: 10.1093/pcp/pcz038] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 02/12/2019] [Indexed: 05/06/2023]
Abstract
Under iron-deficient conditions, plants induce the expression of a set of genes involved in iron uptake and translocation. This response to iron deficiency is regulated by transcriptional networks mediated by transcription factors (TFs) and protein-level modification of key factors by ubiquitin ligases. Several of the basic helix-loop-helix TFs and the HRZ/BTS ubiquitin ligases are conserved across graminaceous and non-graminaceous plants. Other regulators are specific, such as IDEF1 and IDEF2 in graminaceous plants and FIT/FER and MYB10/72 in non-graminaceous plants. IMA/FEP peptides positively regulate the iron-deficiency responses in a wide range of plants by unknown mechanisms. Direct binding of iron or other metals to some key regulators, including HRZ/BTS and IDEF1, may be responsible for intracellular iron-sensing and -signaling events. In addition, key TFs such as FIT and IDEF1 interact with various proteins involved in signaling pathways of plant hormones, oxidative stress and metal abundance. Thus, FIT and IDEF1 might function as hubs for the integration of environmental signals to modulate the responses to iron deficiency. In addition to local iron signaling, root iron responses are modulated by shoot-derived long-distance signaling potentially mediated by phloem-mobile substances such as iron, iron chelates and IMA/FEP peptides.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, Japan
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25
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Kobayashi T, Nozoye T, Nishizawa NK. Iron transport and its regulation in plants. Free Radic Biol Med 2019; 133:11-20. [PMID: 30385345 DOI: 10.1016/j.freeradbiomed.2018.10.439] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/15/2022]
Abstract
Iron is an essential element for plants as well as other organisms, functioning in various cellular processes, including respiration, chlorophyll biosynthesis, and photosynthesis. Plants take up iron from soil in which iron solubility is extremely low especially under aerobic conditions at high-pH range. Therefore, plants have evolved efficient iron-uptake mechanisms. Because iron is prone to being precipitated and excess ionic iron is cytotoxic, plants also have sophisticated internal iron-transport mechanisms. These transport mechanisms comprise iron chelators including nicotianamine, mugineic acid family phytosiderophores and citrate, and various types of transporters of these chelators, iron-chelate complexes, or free iron ions. To maintain iron homeostasis, plants have developed mechanisms for regulating gene expression in response to iron availability. Expression of various genes involved in iron uptake and translocation is induced under iron deficiency by transcription factor networks and is negatively regulated by the ubiquitin ligase HRZ/BTS. This response is deduced to be mediated by cellular iron sensing as well as long-distance iron signaling. The ubiquitin ligase HRZ/BTS is a candidate intracellular iron sensor because it binds to iron and zinc, and its activity is affected by iron availability. The iron-excess response of plants is thought to be partially independent of the iron-deficiency response. In this review, we summarize and discuss extant knowledge of plant iron transport and its regulation.
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Affiliation(s)
- Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa 921-8836, Japan
| | - Tomoko Nozoye
- Center for Liberal Arts, Meiji Gakuin University, 1518 Kamikurata-cho, Totsuka-ku, Yokohama, Kanagawa 244-8539, Japan; Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Naoko K Nishizawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa 921-8836, Japan; Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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26
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Rodríguez-Celma J, Chou H, Kobayashi T, Long TA, Balk J. Hemerythrin E3 Ubiquitin Ligases as Negative Regulators of Iron Homeostasis in Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:98. [PMID: 30815004 PMCID: PMC6381054 DOI: 10.3389/fpls.2019.00098] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/22/2019] [Indexed: 05/19/2023]
Abstract
Iron (Fe) is an essential nutrient for plants, but at the same time its redox properties can make it a dangerous toxin inside living cells. Homeostasis between uptake, use and storage of Fe must be maintained at all times. A small family of unique hemerythrin E3 ubiquitin ligases found in green algae and plants play an important role in avoiding toxic Fe overload, acting as negative regulators of Fe homeostasis. Protein interaction data showed that they target specific transcription factors for degradation by the 26S proteasome. It is thought that the activity of the E3 ubiquitin ligases is controlled by Fe binding to the N-terminal hemerythrin motifs. Here, we discuss what we have learned so far from studies on the HRZ (Hemerythrin RING Zinc finger) proteins in rice, the homologous BTS (BRUTUS) and root-specific BTSL (BRUTUS-LIKE) in Arabidopsis. A mechanistic model is proposed to help focus future research questions towards a full understanding of the regulatory role of these proteins in Fe homeostasis in plants.
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Affiliation(s)
- Jorge Rodríguez-Celma
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Hsuan Chou
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Takanori Kobayashi
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Japan
| | - Terri A. Long
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Janneke Balk
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
- *Correspondence: Janneke Balk,
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