1
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Webster SS, Guerinot ML. How plants iron out the competing interests of growth and defence. Nature 2024; 625:671-672. [PMID: 38200336 DOI: 10.1038/d41586-023-03995-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
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2
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Smieska L, Guerinot ML, Olson Hoal K, Reid M, Vatamaniuk O. Synchrotron science for sustainability: life cycle of metals in the environment. Metallomics 2023; 15:mfad041. [PMID: 37370221 DOI: 10.1093/mtomcs/mfad041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
The movement of metals through the environment links together a wide range of scientific fields: from earth sciences and geology as weathering releases minerals; to environmental sciences as metals are mobilized and transformed, cycling through soil and water; to biology as living things take up metals from their surroundings. Studies of these fundamental processes all require quantitative analysis of metal concentrations, locations, and chemical states. Synchrotron X-ray tools can address these requirements with high sensitivity, high spatial resolution, and minimal sample preparation. This perspective describes the state of fundamental scientific questions in the lifecycle of metals, from rocks to ecosystems, from soils to plants, and from environment to animals. Key X-ray capabilities and facility infrastructure for future synchrotron-based analytical resources serving these areas are summarized, and potential opportunities for future experiments are explored.
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Affiliation(s)
- Louisa Smieska
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Karin Olson Hoal
- Department of Earth & Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Matthew Reid
- School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Olena Vatamaniuk
- School of Integrative Plant Science Plant Biology Section, Cornell University, Ithaca NY 14853, USA
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3
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Lee S, Lee J, Ricachenevsky FK, Punshon T, Tappero R, Salt DE, Guerinot ML. Redundant roles of four ZIP family members in zinc homeostasis and seed development in Arabidopsis thaliana. Plant J 2021; 108:1162-1173. [PMID: 34559918 PMCID: PMC8613002 DOI: 10.1111/tpj.15506] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/29/2021] [Accepted: 09/08/2021] [Indexed: 05/28/2023]
Abstract
Zinc (Zn) is essential for normal plant growth and development. The Zn-regulated transporter, iron-regulated transporter (IRT)-like protein (ZIP) family members are involved in Zn transport and cellular Zn homeostasis throughout the domains of life. In this study, we have characterized four ZIP transporters from Arabidopsis thaliana (IRT3, ZIP4, ZIP6, and ZIP9) to better understand their functional roles. The four ZIP proteins can restore the growth defect of a yeast Zn uptake mutant and are upregulated under Zn deficiency. Single and double mutants show no phenotypes under Zn-sufficient or Zn-limited growth conditions. In contrast, triple and quadruple mutants show impaired growth irrespective of external Zn supply due to reduced Zn translocation from root to shoot. All four ZIP genes are highly expressed during seed development, and siliques from all single and higher-order mutants exhibited an increased number of abnormal seeds and decreased Zn levels in mature seeds relative to wild type. The seed phenotypes could be reversed by supplementing the soil with Zn. Our data demonstrate that IRT3, ZIP4, ZIP6, and ZIP9 function redundantly in maintaining Zn homeostasis and seed development in A. thaliana.
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Affiliation(s)
- Sichul Lee
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
- Center for Plant Aging Research, Institute for Basic Science (IBS), Daegu, 42988, Korea
| | - Joohyun Lee
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, 215306, China
| | - Felipe K. Ricachenevsky
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
- Botany Department, Biosciences Institute; and Graduate Program in Cell and Molecular Biology, Biotechnology Center, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
| | | | - David E. Salt
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
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4
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Xu L, Dong Z, Chiniquy D, Pierroz G, Deng S, Gao C, Diamond S, Simmons T, Wipf HML, Caddell D, Varoquaux N, Madera MA, Hutmacher R, Deutschbauer A, Dahlberg JA, Guerinot ML, Purdom E, Banfield JF, Taylor JW, Lemaux PG, Coleman-Derr D. Genome-resolved metagenomics reveals role of iron metabolism in drought-induced rhizosphere microbiome dynamics. Nat Commun 2021; 12:3209. [PMID: 34050180 PMCID: PMC8163885 DOI: 10.1038/s41467-021-23553-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 04/27/2021] [Indexed: 02/04/2023] Open
Abstract
Recent studies have demonstrated that drought leads to dramatic, highly conserved shifts in the root microbiome. At present, the molecular mechanisms underlying these responses remain largely uncharacterized. Here we employ genome-resolved metagenomics and comparative genomics to demonstrate that carbohydrate and secondary metabolite transport functionalities are overrepresented within drought-enriched taxa. These data also reveal that bacterial iron transport and metabolism functionality is highly correlated with drought enrichment. Using time-series root RNA-Seq data, we demonstrate that iron homeostasis within the root is impacted by drought stress, and that loss of a plant phytosiderophore iron transporter impacts microbial community composition, leading to significant increases in the drought-enriched lineage, Actinobacteria. Finally, we show that exogenous application of iron disrupts the drought-induced enrichment of Actinobacteria, as well as their improvement in host phenotype during drought stress. Collectively, our findings implicate iron metabolism in the root microbiome's response to drought and may inform efforts to improve plant drought tolerance to increase food security.
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Affiliation(s)
- Ling Xu
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA ,grid.22935.3f0000 0004 0530 8290State Key Laboratory of Plant Physiology and Biochemistry, Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhaobin Dong
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Dawn Chiniquy
- grid.184769.50000 0001 2231 4551Department of Energy, Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Grady Pierroz
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Siwen Deng
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Cheng Gao
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Spencer Diamond
- grid.47840.3f0000 0001 2181 7878Department of Earth and Planetary Science, University of California, Berkeley, CA USA
| | - Tuesday Simmons
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Heidi M.-L. Wipf
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Daniel Caddell
- grid.507310.0Plant Gene Expression Center, USDA-ARS, Albany, CA USA
| | - Nelle Varoquaux
- grid.463716.10000 0004 4687 1979CNRS, University Grenoble Alpes, TIMC-IMAG, Grenoble, France
| | - Mary A. Madera
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Robert Hutmacher
- grid.27860.3b0000 0004 1936 9684Westside Research & Extension Center, UC Department of Plant Sciences, University of California, Davis, CA USA
| | - Adam Deutschbauer
- grid.184769.50000 0001 2231 4551Department of Energy, Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | | | - Mary Lou Guerinot
- grid.254880.30000 0001 2179 2404Department of Biological Scienes, Dartmouth College, Hanover, NH USA
| | - Elizabeth Purdom
- grid.47840.3f0000 0001 2181 7878Department of Statistics, University of California, Berkeley, CA USA
| | - Jillian F. Banfield
- grid.47840.3f0000 0001 2181 7878Department of Earth and Planetary Science, University of California, Berkeley, CA USA
| | - John W. Taylor
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Peggy G. Lemaux
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Devin Coleman-Derr
- grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA ,grid.507310.0Plant Gene Expression Center, USDA-ARS, Albany, CA USA
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5
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Vert G, Grotz N, Dédaldéchamp F, Gaymard F, Guerinot ML, Briat JF, Curie C. CORRECTION: IRT1, an arabidopsis transporter essential for iron uptake from the soil and for plant growth. Plant Cell 2021; 33:439-440. [PMID: 33866371 PMCID: PMC8136910 DOI: 10.1093/plcell/koaa033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
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Abstract
Iron (Fe) is one of the essential micronutrients required by both plants and animals. In humans, Fe deficiency causes anemia, the most prevalent nutritional disorder. Most people rely on plant-based foods as their major Fe source, but plants are a poor source of dietary Fe. Therefore, there is a critical need to better understand the mechanisms involved in the uptake and trafficking of Fe and how plants adapt to Fe deficiency. Fe participates in key cellular functions such as photosynthesis and respiration. Perturbations of Fe uptake, transport, or storage affect plant growth as well as crop yield and plant product quality. Excess Fe has toxic effects due to its high redox activity. Plants, therefore, tightly regulate Fe uptake, distribution, and allocation. Here, we review the regulatory mechanisms involved at the transcriptional and post-translational levels that are critical to prevent Fe uptake except when plants experience Fe deficiency. We discuss the key regulatory network of basic helix-loop-helix (bHLH) transcription factors, including FIT, subgroup Ib, subgroup IVc, and URI (bHLH121), crucial for regulating Fe uptake in Arabidopsis thaliana. Furthermore, we describe the regulators of these transcription factors that either activate or inhibit their function, ensuring optimal Fe uptake that is essential for plant growth.
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Affiliation(s)
- Nabila Riaz
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
- Correspondence:
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7
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Ricachenevsky FK, Punshon T, Salt DE, Fett JP, Guerinot ML. Arabidopsis thaliana zinc accumulation in leaf trichomes is correlated with zinc concentration in leaves. Sci Rep 2021; 11:5278. [PMID: 33674630 PMCID: PMC7935932 DOI: 10.1038/s41598-021-84508-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/17/2021] [Indexed: 11/21/2022] Open
Abstract
Zinc (Zn) is a key micronutrient for plants and animals, and understanding Zn homeostasis in plants can improve both agriculture and human health. While root Zn transporters in plant model species have been characterized in detail, comparatively little is known about shoot processes controlling Zn concentrations and spatial distribution. Previous work showed that Zn hyperaccumulator species such as Arabidopsis halleri accumulate Zn and other metals in leaf trichomes. To date there is no systematic study regarding Zn accumulation in the trichomes of the non-accumulating, genetic model species A. thaliana. Here, we used Synchrotron X-Ray Fluorescence mapping to show that Zn accumulates at the base of trichomes of A. thaliana. Using transgenic and natural accessions of A thaliana that vary in bulk leaf Zn concentration, we demonstrate that higher leaf Zn increases total Zn found at the base of trichome cells. Our data indicates that Zn accumulation in trichomes is a function of the Zn status of the plant, and provides the basis for future studies on a genetically tractable plant species to understand the molecular steps involved in Zn spatial distribution in leaves.
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Affiliation(s)
- Felipe K Ricachenevsky
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande Do Sul, Porto Alegre, Brazil. .,Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, Porto Alegre, RS, 9500, Brazil. .,Department of Biological Sciences, Life Sciences Center, Dartmouth College, 78 College St, Hanover, NH, 03755, USA.
| | - Tracy Punshon
- Department of Biological Sciences, Life Sciences Center, Dartmouth College, 78 College St, Hanover, NH, 03755, USA
| | - David E Salt
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK
| | - Janette P Fett
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande Do Sul, Porto Alegre, Brazil.,Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, Porto Alegre, RS, 9500, Brazil
| | - Mary Lou Guerinot
- Department of Biological Sciences, Life Sciences Center, Dartmouth College, 78 College St, Hanover, NH, 03755, USA.
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8
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Fischer S, Sánchez-Bermejo E, Xu X, Flis P, Ramakrishna P, Guerinot ML, Zhao FJ, Salt DE. Targeted expression of the arsenate reductase HAC1 identifies cell type specificity of arsenic metabolism and transport in plant roots. J Exp Bot 2021; 72:415-425. [PMID: 33038235 PMCID: PMC7853597 DOI: 10.1093/jxb/eraa465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/05/2020] [Indexed: 05/14/2023]
Abstract
High Arsenic Concentration 1 (HAC1), an Arabidopsis thaliana arsenate reductase, plays a key role in arsenate [As(V)] tolerance. Through conversion of As(V) to arsenite [As(III)], HAC1 enables As(III) export from roots, and restricts translocation of As(V) to shoots. To probe the ability of different root tissues to detoxify As(III) produced by HAC1, we generated A. thaliana lines expressing HAC1 in different cell types. We investigated the As(V) tolerance phenotypes: root growth, As(III) efflux, As translocation, and As chemical speciation. We showed that HAC1 can function in the outer tissues of the root (epidermis, cortex, and endodermis) to confer As(V) tolerance, As(III) efflux, and limit As accumulation in shoots. HAC1 is less effective in the stele at conferring As(V) tolerance phenotypes. The exception is HAC1 activity in the protoxylem, which we found to be sufficient to restrict As translocation, but not to confer As(V) tolerance. In conclusion, we describe cell type-specific functions of HAC1 that spatially separate the control of As(V) tolerance and As translocation. Further, we identify a key function of protoxylem cells in As(V) translocation, consistent with the model where endodermal passage cells, above protoxylem pericycle cells, form a 'funnel' loading nutrients and potentially toxic elements into the vasculature.
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Affiliation(s)
- Sina Fischer
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, UK
| | - Eduardo Sánchez-Bermejo
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, UK
| | - Xuejie Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Paulina Flis
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, UK
| | - Priya Ramakrishna
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, UK
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Fang-Jie Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - David E Salt
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Nottingham, UK
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9
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Mu S, Yamaji N, Sasaki A, Luo L, Du B, Che J, Shi H, Zhao H, Huang S, Deng F, Shen Z, Guerinot ML, Zheng L, Ma JF. A transporter for delivering zinc to the developing tiller bud and panicle in rice. Plant J 2021; 105:786-799. [PMID: 33169459 DOI: 10.1111/tpj.15073] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 10/26/2020] [Accepted: 11/03/2020] [Indexed: 05/07/2023]
Abstract
Tiller number is one of the most important agronomic traits that determine rice (Oryza sativa) yield. Active growth of tiller bud (TB) requires high amount of mineral nutrients; however, the mechanism underlying the distribution of mineral nutrients to TB with low transpiration is unknown. Here, we found that the distribution of Zn to TB is mediated by OsZIP4, one of the ZIP (ZRT, IRT-like protein) family members. The expression of OsZIP4 was highly detected in TB and nodes, and was induced by Zn deficiency. Immunostaining analysis revealed that OsZIP4 was mainly expressed in phloem of diffuse vascular bundles in the nodes and the axillary meristem. The mutation of OsZIP4 did not affect the total Zn uptake, but altered Zn distribution; less Zn was delivered to TB and new leaf, but more Zn was retained in the basal stems at the vegetative growth stage. Bioimaging analysis showed that the mutant aberrantly accumulated Zn in enlarged and transit vascular bundles of the basal node, whereas in wild-type high accumulation of Zn was observed in the meristem part. At the reproductive stage, mutation of OsZIP4 resulted in delayed panicle development, which is associated with decreased Zn distribution to the panicles. Collectively, OsZIP4 is involved in transporting Zn to the phloem of diffuse vascular bundles in the nodes for subsequent distribution to TBs and other developing tissues. It also plays a role in transporting Zn to meristem cells in the TBs.
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Affiliation(s)
- Shuai Mu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Naoki Yamaji
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Akimasa Sasaki
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Le Luo
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Binbin Du
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jing Che
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Huichao Shi
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haoqiang Zhao
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Sheng Huang
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
| | - Fenglin Deng
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou, 434025, China
| | - Zhenguo Shen
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Luqing Zheng
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan
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10
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Liu H, Long SX, Pinson SRM, Tang Z, Guerinot ML, Salt DE, Zhao FJ, Huang XY. Univariate and Multivariate QTL Analyses Reveal Covariance Among Mineral Elements in the Rice Ionome. Front Genet 2021; 12:638555. [PMID: 33569081 PMCID: PMC7868434 DOI: 10.3389/fgene.2021.638555] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/06/2021] [Indexed: 11/27/2022] Open
Abstract
Rice provides more than one fifth of daily calories for half of the world’s human population, and is a major dietary source of both essential mineral nutrients and toxic elements. Rice grains are generally poor in some essential nutrients but may contain unsafe levels of some toxic elements under certain conditions. Identification of quantitative trait loci (QTLs) controlling the concentrations of mineral nutrients and toxic trace metals (the ionome) in rice will facilitate development of nutritionally improved rice varieties. However, QTL analyses have traditionally considered each element separately without considering their interrelatedness. In this study, we performed principal component analysis (PCA) and multivariate QTL analyses to identify the genetic loci controlling the covariance among mineral elements in the rice ionome. We resequenced the whole genomes of a rice recombinant inbred line (RIL) population, and performed univariate and multivariate QTL analyses for the concentrations of 16 elements in grains, shoots and roots of the RIL population grown in different conditions. We identified a total of 167 unique elemental QTLs based on analyses of individual elemental concentrations as separate traits, 53 QTLs controlling covariance among elemental concentrations within a single environment/tissue (PC-QTLs), and 152 QTLs which determined covariation among elements across environments/tissues (aPC-QTLs). The candidate genes underlying the QTL clusters with elemental QTLs, PC-QTLs and aPC-QTLs co-localized were identified, including OsHMA4 and OsNRAMP5. The identification of both elemental QTLs and PC QTLs will facilitate the cloning of underlying causal genes and the dissection of the complex regulation of the ionome in rice.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Su-Xian Long
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shannon R M Pinson
- USDA-ARS Dale Bumpers National Rice Research Center, Stuttgart, AR, United States
| | - Zhong Tang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - David E Salt
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Fang-Jie Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xin-Yuan Huang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
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11
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Ruang-Areerate P, Travis AJ, Pinson SRM, Tarpley L, Eizenga GC, Guerinot ML, Salt DE, Douglas A, Price AH, Norton GJ. Genome-wide association mapping for grain manganese in rice (Oryza sativa L.) using a multi-experiment approach. Heredity (Edinb) 2020; 126:505-520. [PMID: 33235293 DOI: 10.1038/s41437-020-00390-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 11/06/2020] [Accepted: 11/06/2020] [Indexed: 11/09/2022] Open
Abstract
Manganese (Mn) is an essential trace element for plants and commonly contributes to human health; however, the understanding of the genes controlling natural variation in Mn in crop plants is limited. Here, the integration of two of genome-wide association study approaches was used to increase the identification of valuable quantitative trait loci (QTL) and candidate genes responsible for the concentration of grain Mn across 389 diverse rice cultivars grown in Arkansas and Texas, USA, in multiple years. Single-trait analysis was initially performed using three different SNP datasets. As a result, significant loci could be detected using the high-density SNP dataset. Based on the 5.2 M SNP dataset, major QTLs were located on chromosomes 3 and 7 for Mn containing six candidate genes. In addition, the phenotypic data of grain Mn concentration were combined from three flooded-field experiments from the two sites and 3 years using multi-experiment analysis based on the 5.2 M SNP dataset. Two previous QTLs on chromosome 3 were identified across experiments, whereas new Mn QTLs were identified that were not found in individual experiments, on chromosomes 3, 4, 9 and 11. OsMTP8.1 was identified in both approaches and is a good candidate gene that could be controlling grain Mn concentration. This work demonstrates the utilisation of multi-experiment analysis to identify constitutive QTLs and candidate genes associated with the grain Mn concentration. Hence, the approach should be advantageous to facilitate genomic breeding programmes in rice and other crops considering QTLs and genes associated with complex traits in natural populations.
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Affiliation(s)
- Panthita Ruang-Areerate
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK. .,National Omics Center, National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Anthony J Travis
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
| | - Shannon R M Pinson
- USDA-ARS Dale Bumpers National Rice Research Center, Stuttgart, AR, 72160, USA
| | - Lee Tarpley
- Texas A&M System AgriLife Research Center, Beaumont, TX, 77713, USA
| | - Georgia C Eizenga
- USDA-ARS Dale Bumpers National Rice Research Center, Stuttgart, AR, 72160, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - David E Salt
- Future Food Beacon of Excellence and the School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
| | - Adam H Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
| | - Gareth J Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
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12
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Huang XY, Liu H, Zhu YF, Pinson SRM, Lin HX, Guerinot ML, Zhao FJ, Salt DE. Natural variation in a molybdate transporter controls grain molybdenum concentration in rice. New Phytol 2019; 221:1983-1997. [PMID: 30339276 DOI: 10.1111/nph.15546] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 10/07/2018] [Indexed: 05/07/2023]
Abstract
Molybdenum (Mo) is an essential micronutrient for most living organisms, including humans. Cereals such as rice (Oryza sativa) are the major dietary source of Mo. However, little is known about the genetic basis of the variation in Mo content in rice grain. We mapped a quantitative trait locus (QTL) qGMo8 that controls Mo accumulation in rice grain by using a recombinant inbred line population and a backcross introgression line population. We identified a molybdate transporter, OsMOT1;1, as the causal gene for this QTL. OsMOT1;1 exhibits transport activity for molybdate, but not sulfate, when heterogeneously expressed in yeast cells. OsMOT1;1 is mainly expressed in roots and is involved in the uptake and translocation of molybdate under molybdate-limited condition. Knockdown of OsMOT1;1 results in less Mo being translocated to shoots, lower Mo concentration in grains and higher sensitivity to Mo deficiency. We reveal that the natural variation of Mo concentration in rice grains is attributed to the variable expression of OsMOT1;1 due to sequence variation in its promoter. Identification of natural allelic variation in OsMOT1;1 may facilitate the development of rice varieties with Mo-enriched grain for dietary needs and improve Mo nutrition of rice on Mo-deficient soils.
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Affiliation(s)
- Xin-Yuan Huang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huan Liu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yu-Fei Zhu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shannon R M Pinson
- USDA-ARS Dale Bumpers National Rice Research Center, Stuttgart, AR, 72160, USA
| | - Hong-Xuan Lin
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai, 200032, China
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Fang-Jie Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - David E Salt
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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Nachman KE, Punshon T, Rardin L, Signes-Pastor AJ, Murray CJ, Jackson BP, Guerinot ML, Burke TA, Chen CY, Ahsan H, Argos M, Cottingham KL, Cubadda F, Ginsberg GL, Goodale BC, Kurzius-Spencer M, Meharg AA, Miller MD, Nigra AE, Pendergrast CB, Raab A, Reimer K, Scheckel KG, Schwerdtle T, Taylor VF, Tokar EJ, Warczak TM, Karagas MR. Opportunities and Challenges for Dietary Arsenic Intervention. Environ Health Perspect 2018; 126:84503. [PMID: 30235424 PMCID: PMC6375412 DOI: 10.1289/ehp3997] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/16/2018] [Accepted: 07/20/2018] [Indexed: 05/18/2023]
Abstract
The diet is emerging as the dominant source of arsenic exposure for most of the U.S. population. Despite this, limited regulatory efforts have been aimed at mitigating exposure, and the role of diet in arsenic exposure and disease processes remains understudied. In this brief, we discuss the evidence linking dietary arsenic intake to human disease and discuss challenges associated with exposure characterization and efforts to quantify risks. In light of these challenges, and in recognition of the potential longer-term process of establishing regulation, we introduce a framework for shorter-term interventions that employs a field-to-plate food supply chain model to identify monitoring, intervention, and communication opportunities as part of a multisector, multiagency, science-informed, public health systems approach to mitigation of dietary arsenic exposure. Such an approach is dependent on coordination across commodity producers, the food industry, nongovernmental organizations, health professionals, researchers, and the regulatory community. https://doi.org/10.1289/EHP3997.
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Affiliation(s)
- Keeve E Nachman
- Risk Sciences and Public Policy Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- Johns Hopkins Center for a Livable Future, Johns Hopkins University, Baltimore, Maryland, USA
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Dartmouth Children's Environmental Health and Disease Prevention Research Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Laurie Rardin
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
| | - Antonio J Signes-Pastor
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Dartmouth Children's Environmental Health and Disease Prevention Research Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Carolyn J Murray
- Dartmouth Children's Environmental Health and Disease Prevention Research Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Brian P Jackson
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Thomas A Burke
- Risk Sciences and Public Policy Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
| | - Habibul Ahsan
- Department of Public Health Sciences, University of Chicago, Chicago, Illinois, USA
| | - Maria Argos
- Department of Public Health Sciences, University of Chicago, Chicago, Illinois, USA
| | - Kathryn L Cottingham
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Dartmouth Children's Environmental Health and Disease Prevention Research Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Francesco Cubadda
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità - Italian National Institute of Health, Rome, Italy
| | - Gary L Ginsberg
- Yale School of Public Health, 60 College St, New Haven, Connecticut, USA
| | - Britton C Goodale
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Margaret Kurzius-Spencer
- Department of Pediatrics, College of Medicine, University of Arizona, Tucson, Arizona, USA
- Department of Community, Environment and Policy, Mel & Enid College of Public Health, University of Arizona, Tucson, Arizona, USA
| | - Andrew A Meharg
- Institute for Global Food Security, Queen's University Belfast, David Keir Building, Malone Road, Belfast, BT9 5BN, Northern Ireland, UK
| | - Mark D Miller
- Western States Pediatric Environmental Health Specialty Unit, University of California, San Francisco, San Francisco, California, USA
| | - Anne E Nigra
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, New York, USA
| | | | - Andrea Raab
- Department of Chemistry, University of Aberdeen, Aberdeen, UK
| | - Ken Reimer
- Royal Military College, Kingston, Ontario, Canada
| | - Kirk G Scheckel
- Land and Materials Management Division, National Risk Management Research Laboratory, United States Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Tanja Schwerdtle
- Institute of Nutritional Sciences, University of Potsdam, Germany
| | - Vivien F Taylor
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Erik J Tokar
- National Toxicology Program Laboratory, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Todd M Warczak
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Margaret R Karagas
- Dartmouth Superfund Research Program, Hanover, New Hampshire, USA
- Dartmouth Children's Environmental Health and Disease Prevention Research Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Ricachenevsky FK, Punshon T, Lee S, Oliveira BHN, Trenz TS, Maraschin FDS, Hindt MN, Danku J, Salt DE, Fett JP, Guerinot ML. Elemental Profiling of Rice FOX Lines Leads to Characterization of a New Zn Plasma Membrane Transporter, OsZIP7. Front Plant Sci 2018; 9:865. [PMID: 30018622 PMCID: PMC6037872 DOI: 10.3389/fpls.2018.00865] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/04/2018] [Indexed: 05/07/2023]
Abstract
Iron (Fe) and zinc (Zn) are essential micronutrients required for proper development in both humans and plants. Rice (Oryza sativa L.) grains are the staple food for nearly half of the world's population, but a poor source of metals such as Fe and Zn. Populations that rely on milled cereals are especially prone to Fe and Zn deficiencies, the most prevalent nutritional deficiencies in humans. Biofortification is a cost-effective solution for improvement of the nutritional quality of crops. However, a better understanding of the mechanisms underlying grain accumulation of mineral nutrients is required before this approach can achieve its full potential. Characterization of gene function is more time-consuming in crops than in model species such as Arabidopsis thaliana. Aiming to more quickly characterize rice genes related to metal homeostasis, we applied the concept of high throughput elemental profiling (ionomics) to Arabidopsis lines heterologously expressing rice cDNAs driven by the 35S promoter, named FOX (Full Length Over-eXpressor) lines. We screened lines expressing candidate genes that could be used in the development of biofortified grain. Among the most promising candidates, we identified two lines ovexpressing the metal cation transporter OsZIP7. OsZIP7 expression in Arabidopsis resulted in a 25% increase in shoot Zn concentrations compared to non-transformed plants. We further characterized OsZIP7 and showed that it is localized to the plasma membrane and is able to complement Zn transport defective (but not Fe defective) yeast mutants. Interestingly, we showed that OsZIP7 does not transport Cd, which is commonly transported by ZIP proteins. Importantly, OsZIP7-expressing lines have increased Zn concentrations in their seeds. Our results indicate that OsZIP7 is a good candidate for developing Zn biofortified rice. Moreover, we showed the use of heterologous expression of genes from crops in A. thaliana as a fast method for characterization of crop genes related to the ionome and potentially useful in biofortification strategies.
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Affiliation(s)
- Felipe K. Ricachenevsky
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Departamento de Biologia, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
- *Correspondence: Felipe K. Ricachenevsky,
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - Sichul Lee
- Center for Plant Aging Research, Institute for Basic Science (IBS), Daegu, South Korea
| | - Ben Hur N. Oliveira
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Thomaz S. Trenz
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Maria N. Hindt
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - John Danku
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - David E. Salt
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Janette P. Fett
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Departamento de Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
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Hindt MN, Akmakjian GZ, Pivarski KL, Punshon T, Baxter I, Salt DE, Guerinot ML. BRUTUS and its paralogs, BTS LIKE1 and BTS LIKE2, encode important negative regulators of the iron deficiency response in Arabidopsis thaliana. Metallomics 2017; 9:876-890. [PMID: 28620661 PMCID: PMC5558852 DOI: 10.1039/c7mt00152e] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Iron (Fe) is required for plant health, but it can also be toxic when present in excess. Therefore, Fe levels must be tightly controlled. The Arabidopsis thaliana E3 ligase BRUTUS (BTS) is involved in the negative regulation of the Fe deficiency response and we show here that the two A. thaliana BTS paralogs, BTS LIKE1 (BTSL1) and BTS LIKE2 (BTSL2) encode proteins that act redundantly as negative regulators of the Fe deficiency response. Loss of both of these E3 ligases enhances tolerance to Fe deficiency. We further generated a triple mutant with loss of both BTS paralogs and a partial loss of BTS expression that exhibits even greater tolerance to Fe-deficient conditions and increased Fe accumulation without any resulting Fe toxicity effects. Finally, we identified a mutant carrying a novel missense mutation of BTS that exhibits an Fe deficiency response in the root when grown under both Fe-deficient and Fe-sufficient conditions, leading to Fe toxicity when plants are grown under Fe-sufficient conditions.
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Affiliation(s)
- Maria N Hindt
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
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16
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Punshon T, Jackson BP, Meharg AA, Warczack T, Scheckel K, Guerinot ML. Understanding arsenic dynamics in agronomic systems to predict and prevent uptake by crop plants. Sci Total Environ 2017; 581-582:209-220. [PMID: 28043702 PMCID: PMC5303541 DOI: 10.1016/j.scitotenv.2016.12.111] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 05/20/2023]
Abstract
This review is on arsenic in agronomic systems, and covers processes that influence the entry of arsenic into the human food supply. The scope is from sources of arsenic (natural and anthropogenic) in soils, biogeochemical and rhizosphere processes that control arsenic speciation and availability, through to mechanisms of uptake by crop plants and potential mitigation strategies. This review makes a case for taking steps to prevent or limit crop uptake of arsenic, wherever possible, and to work toward a long-term solution to the presence of arsenic in agronomic systems. The past two decades have seen important advances in our understanding of how biogeochemical and physiological processes influence human exposure to soil arsenic, and this must now prompt an informed reconsideration and unification of regulations to protect the quality of agricultural and residential soils.
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Affiliation(s)
- Tracy Punshon
- Dartmouth College, Department of Biology, 78 College Street, Hanover, NH 03755, USA.
| | - Brian P Jackson
- Dartmouth College, Department of Earth Sciences, Hanover, NH 03755, USA.
| | - Andrew A Meharg
- Institute for Global Food Security, Queen's University Belfast, Belfast BT9 5HN, United Kingdom.
| | - Todd Warczack
- Dartmouth College, Department of Biology, 78 College Street, Hanover, NH 03755, USA.
| | - Kirk Scheckel
- USEPA Office of Research and Development, National Risk Management Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45224, USA.
| | - Mary Lou Guerinot
- Dartmouth College, Department of Biology, 78 College Street, Hanover, NH 03755, USA.
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18
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Stanton BA, Caldwell K, Congdon CB, Disney J, Donahue M, Ferguson E, Flemings E, Golden M, Guerinot ML, Highman J, James K, Kim C, Lantz RC, Marvinney RG, Mayer G, Miller D, Navas-Acien A, Nordstrom DK, Postema S, Rardin L, Rosen B, SenGupta A, Shaw J, Stanton E, Susca P. MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic. Curr Environ Health Rep 2015; 2:329-37. [PMID: 26231509 PMCID: PMC4522277 DOI: 10.1007/s40572-015-0057-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This report is the outcome of the meeting "Environmental and Human Health Consequences of Arsenic" held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13-15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food, and more than 200 million people ingest arsenic via drinking water at concentrations greater than international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 μg/L in public water supplies and the WHO has recommended an upper limit of 10 μg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies.
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Affiliation(s)
- Bruce A Stanton
- Center for the Environmental Health Sciences, Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA,
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Mary V, Schnell Ramos M, Gillet C, Socha AL, Giraudat J, Agorio A, Merlot S, Clairet C, Kim SA, Punshon T, Guerinot ML, Thomine S. Bypassing Iron Storage in Endodermal Vacuoles Rescues the Iron Mobilization Defect in the natural resistance associated-macrophage protein3natural resistance associated-macrophage protein4 Double Mutant. Plant Physiol 2015; 169:748-59. [PMID: 26232490 PMCID: PMC4577389 DOI: 10.1104/pp.15.00380] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/29/2015] [Indexed: 05/03/2023]
Abstract
To improve seed iron (Fe) content and bioavailability, it is crucial to decipher the mechanisms that control Fe storage during seed development. In Arabidopsis (Arabidopsis thaliana) seeds, most Fe is concentrated in insoluble precipitates, with phytate in the vacuoles of cells surrounding the vasculature of the embryo. NATURAL RESISTANCE ASSOCIATED-MACROPHAGE PROTEIN3 (AtNRAMP3) and AtNRAMP4 function redundantly in Fe retrieval from vacuoles during germination. When germinated under Fe-deficient conditions, development of the nramp3nramp4 double mutant is arrested as a consequence of impaired Fe mobilization. To identify novel genes involved in seed Fe homeostasis, we screened an ethyl methanesulfonate-mutagenized population of nramp3nramp4 seedlings for mutations suppressing their phenotypes on low Fe. Here, we report that, among the suppressors, two independent mutations in the VACUOLAR IRON TRANSPORTER1 (AtVIT1) gene caused the suppressor phenotype. The AtVIT1 transporter is involved in Fe influx into vacuoles of endodermal and bundle sheath cells. This result establishes a functional link between Fe loading in vacuoles by AtVIT1 and its remobilization by AtNRAMP3 and AtNRAMP4. Moreover, analysis of subcellular Fe localization indicates that simultaneous disruption of AtVIT1, AtNRAMP3, and AtNRAMP4 limits Fe accumulation in vacuolar globoids.
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Affiliation(s)
- Viviane Mary
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Magali Schnell Ramos
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Cynthia Gillet
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Amanda L Socha
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Jérôme Giraudat
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Astrid Agorio
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Sylvain Merlot
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Colin Clairet
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Sun A Kim
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Tracy Punshon
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Mary Lou Guerinot
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
| | - Sébastien Thomine
- Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.)
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20
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Zhai Z, Gayomba SR, Jung HI, Vimalakumari NK, Piñeros M, Craft E, Rutzke MA, Danku J, Lahner B, Punshon T, Guerinot ML, Salt DE, Kochian LV, Vatamaniuk OK. OPT3 Is a Phloem-Specific Iron Transporter That Is Essential for Systemic Iron Signaling and Redistribution of Iron and Cadmium in Arabidopsis. Plant Cell 2014; 26:2249-2264. [PMID: 24867923 PMCID: PMC4079381 DOI: 10.1105/tpc.114.123737] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/31/2014] [Accepted: 04/22/2014] [Indexed: 05/18/2023]
Abstract
Iron is essential for both plant growth and human health and nutrition. Knowledge of the signaling mechanisms that communicate iron demand from shoots to roots to regulate iron uptake as well as the transport systems mediating iron partitioning into edible plant tissues is critical for the development of crop biofortification strategies. Here, we report that OPT3, previously classified as an oligopeptide transporter, is a plasma membrane transporter capable of transporting transition ions in vitro. Studies in Arabidopsis thaliana show that OPT3 loads iron into the phloem, facilitates iron recirculation from the xylem to the phloem, and regulates both shoot-to-root iron signaling and iron redistribution from mature to developing tissues. We also uncovered an aspect of crosstalk between iron homeostasis and cadmium partitioning that is mediated by OPT3. Together, these discoveries provide promising avenues for targeted strategies directed at increasing iron while decreasing cadmium density in the edible portions of crops and improving agricultural productivity in iron deficient soils.
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Affiliation(s)
- Zhiyang Zhai
- Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
| | - Sheena R Gayomba
- Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
| | - Ha-Il Jung
- Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
| | | | - Miguel Piñeros
- Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853
| | - Eric Craft
- Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853
| | - Michael A Rutzke
- Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853 Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853
| | - John Danku
- Institute of Biological and Environmental Sciences, University of Aberdeen, AS24 3UU Scotland, United Kingdom
| | - Brett Lahner
- Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
| | - David E Salt
- Institute of Biological and Environmental Sciences, University of Aberdeen, AS24 3UU Scotland, United Kingdom
| | - Leon V Kochian
- Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853
| | - Olena K Vatamaniuk
- Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
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21
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Norton GJ, Douglas A, Lahner B, Yakubova E, Guerinot ML, Pinson SRM, Tarpley L, Eizenga GC, McGrath SP, Zhao FJ, Islam MR, Islam S, Duan G, Zhu Y, Salt DE, Meharg AA, Price AH. Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites. PLoS One 2014; 9:e89685. [PMID: 24586963 PMCID: PMC3934919 DOI: 10.1371/journal.pone.0089685] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 01/22/2014] [Indexed: 11/19/2022] Open
Abstract
The mineral concentrations in cereals are important for human health, especially for individuals who consume a cereal subsistence diet. A number of elements, such as zinc, are required within the diet, while some elements are toxic to humans, for example arsenic. In this study we carry out genome-wide association (GWA) mapping of grain concentrations of arsenic, copper, molybdenum and zinc in brown rice using an established rice diversity panel of ∼300 accessions and 36.9 k single nucleotide polymorphisms (SNPs). The study was performed across five environments: one field site in Bangladesh, one in China and two in the US, with one of the US sites repeated over two years. GWA mapping on the whole dataset and on separate subpopulations of rice revealed a large number of loci significantly associated with variation in grain arsenic, copper, molybdenum and zinc. Seventeen of these loci were detected in data obtained from grain cultivated in more than one field location, and six co-localise with previously identified quantitative trait loci. Additionally, a number of candidate genes for the uptake or transport of these elements were located near significantly associated SNPs (within 200 kb, the estimated global linkage disequilibrium previously employed in this rice panel). This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally-variable traits in a highly genetically structured diversity panel.
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Affiliation(s)
- Gareth J. Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Brett Lahner
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Elena Yakubova
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Shannon R. M. Pinson
- USDA ARS, Dale Bumpers National Rice Research Center, Stuttgart, Arkansas, United States of America
| | - Lee Tarpley
- Texas A&M University System, Texas A&M AgriLife Research, Beaumont, Texas, United States of America
| | - Georgia C. Eizenga
- USDA ARS, Dale Bumpers National Rice Research Center, Stuttgart, Arkansas, United States of America
| | | | - Fang-Jie Zhao
- Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - M. Rafiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Shofiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Guilan Duan
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Yongguan Zhu
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - David E. Salt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Andrew A. Meharg
- Institute for Global Food Security, Queen’s University Belfast, David Keir Building, Belfast, United Kingdom
| | - Adam H. Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
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22
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Socha AL, Guerinot ML. Mn-euvering manganese: the role of transporter gene family members in manganese uptake and mobilization in plants. Front Plant Sci 2014; 5:106. [PMID: 24744764 PMCID: PMC3978347 DOI: 10.3389/fpls.2014.00106] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/05/2014] [Indexed: 05/18/2023]
Abstract
Manganese (Mn), an essential trace element, is important for plant health. In plants, Mn serves as a cofactor in essential processes such as photosynthesis, lipid biosynthesis and oxidative stress. Mn deficient plants exhibit decreased growth and yield and are more susceptible to pathogens and damage at freezing temperatures. Mn deficiency is most prominent on alkaline soils with approximately one third of the world's soils being too alkaline for optimal crop production. Despite the importance of Mn in plant development, relatively little is known about how it traffics between plant tissues and into and out of organelles. Several gene transporter families have been implicated in Mn transport in plants. These transporter families include NRAMP (natural resistance associated macrophage protein), YSL (yellow stripe-like), ZIP (zinc regulated transporter/iron-regulated transporter [ZRT/IRT1]-related protein), CAX (cation exchanger), CCX (calcium cation exchangers), CDF/MTP (cation diffusion facilitator/metal tolerance protein), P-type ATPases and VIT (vacuolar iron transporter). A combination of techniques including mutant analysis and Synchrotron X-ray Fluorescence Spectroscopy can assist in identifying essential transporters of Mn. Such knowledge would vastly improve our understanding of plant Mn homeostasis.
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Affiliation(s)
- Amanda L. Socha
- *Correspondence: Amanda L. Socha, Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03766, USA e-mail:
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23
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Zhang M, Pinson SRM, Tarpley L, Huang XY, Lahner B, Yakubova E, Baxter I, Guerinot ML, Salt DE. Mapping and validation of quantitative trait loci associated with concentrations of 16 elements in unmilled rice grain. Theor Appl Genet 2014; 127:137-65. [PMID: 24231918 PMCID: PMC4544570 DOI: 10.1007/s00122-013-2207-5] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/03/2013] [Indexed: 05/18/2023]
Abstract
QTLs controlling the concentrations elements in rice grain were identified in two mapping populations. The QTLs were clustered such that most genomic regions were associated with more than one element. In this study, quantitative trait loci (QTLs) affecting the concentrations of 16 elements in whole, unmilled rice (Oryza sativa L.) grain were identified. Two rice mapping populations, the ‘Lemont’ × ‘TeQing’ recombinant inbred lines (LT-RILs), and the TeQing-into-Lemont backcross introgression lines (TILs) were used. To increase opportunity to detect and characterize QTLs, the TILs were grown under two contrasting field conditions, flooded and irrigated-but-unflooded. Correlations between the individual elements and between each element with grain shape, plant height, and time of heading were also studied. Transgressive segregation was observed among the LT-RILs for all elements. The 134 QTLs identified as associated with the grain concentrations of individual elements were found clustered into 39 genomic regions, 34 of which were found associated with grain element concentration in more than one population and/or flooding treatment. More QTLs were found significant among flooded TILs (92) than among unflooded TILs (47) or among flooded LT-RILs (40). Twenty-seven of the 40 QTLs identified among the LT-RILs were associated with the same element among the TILs. At least one QTL per element was validated in two or more population/environments. Nearly all of the grain element loci were linked to QTLs affecting additional elements, supporting the concept of element networks within plants. Several of the grain element QTLs co-located with QTLs for grain shape, plant height, and days to heading; but did not always differ for grain elemental concentration as predicted by those traits alone. A number of interesting patterns were found, including a strong Mg–P–K complex.
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Affiliation(s)
- Min Zhang
- Department of Statistics, Purdue University, 150 N. University Street, West Lafayette, IN 47907-2067 USA
| | - Shannon R. M. Pinson
- USDA-ARS, Dale Bumpers National Rice Research Center, 2890 Highway 130 East, Stuttgart, AR 72160 USA
| | - Lee Tarpley
- Texas A&M AgriLife Research, Texas A&M University System, 1509 Aggie Dr., Beaumont, TX 77713 USA
| | - Xin-Yuan Huang
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, Scotland AB24 3UU UK
| | - Brett Lahner
- Department of Horticulture, Purdue University, 625 Agriculture Mall Dr., West Lafayette, IN 479072010 USA
| | - Elena Yakubova
- Horticulture and Landscape Architecture Department, Purdue University, West Lafayette, IN 47907 USA
| | - Ivan Baxter
- USDA-ARS Plant Genetics Research Unit, Donald Danforth Plant Science Center, St. Louis, MO 63132 USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755 USA
| | - David E. Salt
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, Scotland AB24 3UU UK
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24
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Norton GJ, Douglas A, Lahner B, Yakubova E, Guerinot ML, Pinson SRM, Tarpley L, Eizenga GC, McGrath SP, Zhao FJ, Islam MR, Islam S, Duan G, Zhu Y, Salt DE, Meharg AA, Price AH. Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites. PLoS One 2014. [PMID: 24586963 DOI: 10.137/journalpone.0089685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
The mineral concentrations in cereals are important for human health, especially for individuals who consume a cereal subsistence diet. A number of elements, such as zinc, are required within the diet, while some elements are toxic to humans, for example arsenic. In this study we carry out genome-wide association (GWA) mapping of grain concentrations of arsenic, copper, molybdenum and zinc in brown rice using an established rice diversity panel of ∼ 300 accessions and 36.9 k single nucleotide polymorphisms (SNPs). The study was performed across five environments: one field site in Bangladesh, one in China and two in the US, with one of the US sites repeated over two years. GWA mapping on the whole dataset and on separate subpopulations of rice revealed a large number of loci significantly associated with variation in grain arsenic, copper, molybdenum and zinc. Seventeen of these loci were detected in data obtained from grain cultivated in more than one field location, and six co-localise with previously identified quantitative trait loci. Additionally, a number of candidate genes for the uptake or transport of these elements were located near significantly associated SNPs (within 200 kb, the estimated global linkage disequilibrium previously employed in this rice panel). This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally-variable traits in a highly genetically structured diversity panel.
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Affiliation(s)
- Gareth J Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Brett Lahner
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Elena Yakubova
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Shannon R M Pinson
- USDA ARS, Dale Bumpers National Rice Research Center, Stuttgart, Arkansas, United States of America
| | - Lee Tarpley
- Texas A&M University System, Texas A&M AgriLife Research, Beaumont, Texas, United States of America
| | - Georgia C Eizenga
- USDA ARS, Dale Bumpers National Rice Research Center, Stuttgart, Arkansas, United States of America
| | - Steve P McGrath
- Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Fang-Jie Zhao
- Rothamsted Research, Harpenden, Hertfordshire, United Kingdom ; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - M Rafiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Shofiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Guilan Duan
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Yongguan Zhu
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - David E Salt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Andrew A Meharg
- Institute for Global Food Security, Queen's University Belfast, David Keir Building, Belfast, United Kingdom
| | - Adam H Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
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25
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Zhang M, Pinson SRM, Tarpley L, Huang XY, Lahner B, Yakubova E, Baxter I, Guerinot ML, Salt DE. Mapping and validation of quantitative trait loci associated with concentrations of 16 elements in unmilled rice grain. Theor Appl Genet 2014; 127:137-165. [PMID: 24231918 DOI: 10.1007/s0012-013-2207-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/03/2013] [Indexed: 05/27/2023]
Abstract
QTLs controlling the concentrations elements in rice grain were identified in two mapping populations. The QTLs were clustered such that most genomic regions were associated with more than one element. In this study, quantitative trait loci (QTLs) affecting the concentrations of 16 elements in whole, unmilled rice (Oryza sativa L.) grain were identified. Two rice mapping populations, the ‘Lemont’ × ‘TeQing’ recombinant inbred lines (LT-RILs), and the TeQing-into-Lemont backcross introgression lines (TILs) were used. To increase opportunity to detect and characterize QTLs, the TILs were grown under two contrasting field conditions, flooded and irrigated-but-unflooded. Correlations between the individual elements and between each element with grain shape, plant height, and time of heading were also studied. Transgressive segregation was observed among the LT-RILs for all elements. The 134 QTLs identified as associated with the grain concentrations of individual elements were found clustered into 39 genomic regions, 34 of which were found associated with grain element concentration in more than one population and/or flooding treatment. More QTLs were found significant among flooded TILs (92) than among unflooded TILs (47) or among flooded LT-RILs (40). Twenty-seven of the 40 QTLs identified among the LT-RILs were associated with the same element among the TILs. At least one QTL per element was validated in two or more population/environments. Nearly all of the grain element loci were linked to QTLs affecting additional elements, supporting the concept of element networks within plants. Several of the grain element QTLs co-located with QTLs for grain shape, plant height, and days to heading; but did not always differ for grain elemental concentration as predicted by those traits alone. A number of interesting patterns were found, including a strong Mg–P–K complex.
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26
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Palmer CM, Hindt MN, Schmidt H, Clemens S, Guerinot ML. MYB10 and MYB72 are required for growth under iron-limiting conditions. PLoS Genet 2013; 9:e1003953. [PMID: 24278034 PMCID: PMC3836873 DOI: 10.1371/journal.pgen.1003953] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 09/27/2013] [Indexed: 12/21/2022] Open
Abstract
Iron is essential for photosynthesis and is often a limiting nutrient for plant productivity. Plants respond to conditions of iron deficiency by increasing transcript abundance of key genes involved in iron homeostasis, but only a few regulators of these genes have been identified. Using genome-wide expression analysis, we searched for transcription factors that are induced within 24 hours after transferring plants to iron-deficient growth conditions. Out of nearly 100 transcription factors shown to be up-regulated, we identified MYB10 and MYB72 as the most highly induced transcription factors. Here, we show that MYB10 and MYB72 are functionally redundant and are required for plant survival in alkaline soil where iron availability is greatly restricted. myb10myb72 double mutants fail to induce transcript accumulation of the nicotianamine synthase gene NAS4. Both myb10myb72 mutants and nas4-1 mutants have reduced iron concentrations, chlorophyll levels, and shoot mass under iron-limiting conditions, indicating that these genes are essential for proper plant growth. The double myb10myb72 mutant also showed nickel and zinc sensitivity, similar to the nas4 mutant. Ectopic expression of NAS4 rescues myb10myb72 plants, suggesting that loss of NAS4 is the primary defect in these plants and emphasizes the importance of nicotianamine, an iron chelator, in iron homeostasis. Overall, our results provide evidence that MYB10 and MYB72 act early in the iron-deficiency regulatory cascade to drive gene expression of NAS4 and are essential for plant survival under iron deficiency.
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Affiliation(s)
- Christine M. Palmer
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Maria N. Hindt
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Holger Schmidt
- Department of Plant Physiology, University of Bayreuth, Bayreuth, Germany
| | - Stephan Clemens
- Department of Plant Physiology, University of Bayreuth, Bayreuth, Germany
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
- * E-mail:
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27
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Hosmani PS, Kamiya T, Danku J, Naseer S, Geldner N, Guerinot ML, Salt DE. Dirigent domain-containing protein is part of the machinery required for formation of the lignin-based Casparian strip in the root. Proc Natl Acad Sci U S A 2013; 110:14498-14503. [PMID: 23940370 DOI: 10.1073/pnas.13084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
Abstract
The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where the Casparian strip forms. Here, we show that the dirigent-domain containing protein, enhanced suberin1 (ESB1), is part of this machinery, playing an essential role in the correct formation of Casparian strips. ESB1 is localized to Casparian strips in a CASP-dependent manner, and in the absence of ESB1, disordered and defective Casparian strips are formed. In addition, loss of ESB1 disrupts the localization of the CASP1 protein at the casparian strip domain, suggesting a reciprocal requirement for both ESB1 and CASPs in forming the casparian strip domain.
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Affiliation(s)
- Prashant S Hosmani
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
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28
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McDowell SC, Akmakjian G, Sladek C, Mendoza-Cozatl D, Morrissey JB, Saini N, Mittler R, Baxter I, Salt DE, Ward JM, Schroeder JI, Guerinot ML, Harper JF. Elemental concentrations in the seed of mutants and natural variants of Arabidopsis thaliana grown under varying soil conditions. PLoS One 2013; 8:e63014. [PMID: 23671651 PMCID: PMC3646034 DOI: 10.1371/journal.pone.0063014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/27/2013] [Indexed: 01/11/2023] Open
Abstract
The concentrations of mineral nutrients in seeds are critical to both the life cycle of plants as well as human nutrition. These concentrations are strongly influenced by soil conditions, as shown here by quantifying the concentration of 14 elements in seeds from Arabidopsis thaliana plants grown under four different soil conditions: standard, or modified with NaCl, heavy metals, or alkali. Each of the modified soils resulted in a unique change to the seed ionome (the mineral nutrient content of the seeds). To help identify the genetic networks regulating the seed ionome, changes in elemental concentrations were evaluated using mutants corresponding to 760 genes as well as 10 naturally occurring accessions. The frequency of ionomic phenotypes supports an estimate that as much as 11% of the A. thaliana genome encodes proteins of functional relevance to ion homeostasis in seeds. A subset of mutants were analyzed with two independent alleles, providing five examples of genes important for regulation of the seed ionome: SOS2, ABH1, CCC, At3g14280 and CNGC2. In a comparison of nine different accessions to a Col-0 reference, eight accessions were observed to have reproducible differences in elemental concentrations, seven of which were dependent on specific soil conditions. These results indicate that the A. thaliana seed ionome is distinct from the vegetative ionome, and that elemental analysis is a sensitive approach to identify genes controlling ion homeostasis, including those that regulate gene expression, phospho-regulation, and ion transport.
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Affiliation(s)
- Stephen C McDowell
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada, United States of America
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29
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Schroeder JI, Delhaize E, Frommer WB, Guerinot ML, Harrison MJ, Herrera-Estrella L, Horie T, Kochian LV, Munns R, Nishizawa NK, Tsay YF, Sanders D. Using membrane transporters to improve crops for sustainable food production. Nature 2013; 497:60-6. [PMID: 23636397 PMCID: PMC3954111 DOI: 10.1038/nature11909] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 01/11/2013] [Indexed: 02/05/2023]
Abstract
With the global population predicted to grow by at least 25 per cent by 2050, the need for sustainable production of nutritious foods is critical for human and environmental health. Recent advances show that specialized plant membrane transporters can be used to enhance yields of staple crops, increase nutrient content and increase resistance to key stresses, including salinity, pathogens and aluminium toxicity, which in turn could expand available arable land.
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Affiliation(s)
- Julian I Schroeder
- Division of Biological Sciences, Food and Fuel for the 21st Century Center, University of California San Diego, La Jolla, California 92093-0116, USA.
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30
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Hong S, Kim SA, Guerinot ML, McClung CR. Reciprocal interaction of the circadian clock with the iron homeostasis network in Arabidopsis. Plant Physiol 2013; 161:893-903. [PMID: 23250624 PMCID: PMC3561027 DOI: 10.1104/pp.112.208603] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/17/2012] [Indexed: 05/18/2023]
Abstract
In plants, iron (Fe) uptake and homeostasis are critical for survival, and these processes are tightly regulated at the transcriptional and posttranscriptional levels. Circadian clocks are endogenous oscillating mechanisms that allow an organism to anticipate environmental changes to coordinate biological processes both with one another and with the environmental day/night cycle. The plant circadian clock controls many physiological processes through rhythmic expression of transcripts. In this study, we examined the expression of three Fe homeostasis genes (IRON REGULATED TRANSPORTER1 [IRT1], BASIC HELIX LOOP HELIX39, and FERRITIN1) in Arabidopsis (Arabidopsis thaliana) using promoter:LUCIFERASE transgenic lines. Each of these promoters showed circadian regulation of transcription. The circadian clock monitors a number of clock outputs and uses these outputs as inputs to modulate clock function. We show that this is also true for Fe status. Fe deficiency results in a lengthened circadian period. We interrogated mutants impaired in the Fe homeostasis response, including irt1-1, which lacks the major high-affinity Fe transporter, and fit-2, which lacks Fe deficiency-induced TRANSCRIPTION FACTOR1, a basic helix-loop-helix transcription factor necessary for induction of the Fe deficiency response. Both mutants exhibit symptoms of Fe deficiency, including lengthened circadian period. To determine which components are involved in this cross talk between the circadian and Fe homeostasis networks, we tested clock- or Fe homeostasis-related mutants. Mutants defective in specific clock gene components were resistant to the change in period length under different Fe conditions observed in the wild type, suggesting that these mutants are impaired in cross talk between Fe homeostasis and the circadian clock.
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31
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Hindt MN, Guerinot ML. Getting a sense for signals: regulation of the plant iron deficiency response. Biochim Biophys Acta 2012; 1823:1521-30. [PMID: 22483849 PMCID: PMC4008143 DOI: 10.1016/j.bbamcr.2012.03.010] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 11/30/2022]
Abstract
Understanding the Fe deficiency response in plants is necessary for improving both plant health and the human diet, which relies on Fe from plant sources. In this review we focus on the regulation of the two major strategies for iron acquisition in plants, exemplified by the model plants Arabidopsis and rice. Critical to our knowledge of Fe homeostasis in plants is determining how Fe is sensed and how this signal is transmitted and integrated into a response. We will explore the evidence for an Fe sensor in plants and summarize the recent findings on hormones and signaling molecules which contribute to the Fe deficiency response. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Affiliation(s)
- Maria N. Hindt
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
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32
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Abstract
By identifying the relationship between calcium location in the plant cell and nutrient bioavailability, the plant characteristics leading to maximal calcium absorption by humans can be identified. Knowledge of plant cellular and molecular targets controlling calcium location in plants is emerging. These insights should allow for better strategies for increasing the nutritional content of foods. In particular, the use of preparation-free elemental imaging technologies such as synchrotron X-ray fluorescence (SXRF) microscopy in plant biology may allow researchers to understand the relationship between subcellular location and nutrient bioavailability. These approaches may lead to better strategies for altering the location of calcium within the plant to maximize its absorption from fruits and vegetables. These modified foods could be part of a diet for children and adults identified as at-risk for low calcium intake or absorption with the ultimate goal of decreasing the incidence and severity of inadequate bone mineralization.
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Affiliation(s)
- Jian Yang
- United States Department of Agriculture/Agriculture Research Service Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA; (T.P.); (M.L.G.)
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA; (T.P.); (M.L.G.)
| | - Kendal D. Hirschi
- United States Department of Agriculture/Agriculture Research Service Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77845, USA
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33
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Donner E, Punshon T, Guerinot ML, Lombi E. Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology. Anal Bioanal Chem 2012; 402:3287-98. [PMID: 22200921 PMCID: PMC3913160 DOI: 10.1007/s00216-011-5624-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/25/2011] [Accepted: 11/28/2011] [Indexed: 02/03/2023]
Abstract
Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus for phytoremediation, crop biofortification and food security research. Recent advances in X-ray focussing optics and fluorescence detection have greatly improved the potential to use synchrotron techniques in plant science research. With use of methods such as micro X-ray fluorescence mapping, micro computed tomography and micro X-ray absorption near edge spectroscopy, metal(loids) can be imaged in vivo in hydrated plant tissues at submicron resolution, and laterally resolved metal(loid) speciation can also be determined under physiologically relevant conditions. This article focuses on the benefits of combining molecular biology and synchrotron-based techniques. By using molecular techniques to probe the location of gene expression and protein production in combination with laterally resolved synchrotron techniques, one can effectively and efficiently assign functional information to specific genes. A review of the state of the art in this field is presented, together with examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. The article concludes with a summary of the technical challenges still remaining for synchrotron-based hard X-ray plant science research, particularly those relating to subcellular level research.
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Affiliation(s)
- Erica Donner
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, Mawson Lakes, SA 5095, Australia.
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34
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Lee S, Ryoo N, Jeon JS, Guerinot ML, An G. Activation of rice Yellow Stripe1-Like 16 (OsYSL16) enhances iron efficiency. Mol Cells 2012; 33:117-26. [PMID: 22228180 PMCID: PMC3887722 DOI: 10.1007/s10059-012-2165-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/16/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022] Open
Abstract
Graminaceous plants release ferric-chelating phytosiderophores that bind to iron. These ferric-phytosiderophore complexes are transported across the plasma membrane by a protein produced from Yellow Stripe 1 (YS1). Here, we report the characterization of OsYSL16, one of the YS1-like genes in rice. Real-time analysis revealed that this gene was constitutively expressed irrespective of metal status. Promoter fusions of OsYSL16 to β-glucuronidase (GUS) showed that OsYSL16 was highly expressed in the vascular tissues of the root, leaf, and spikelet, and in leaf mesophyll cells. The OsYSL16-green fluorescence protein (GFP) fusion protein was localized to the plasma membrane. From a pool of rice T-DNA insertional lines, we identified two independent activation-tagging mutants in OsYSL16. On an Fe-deficient medium, those mutants retained relatively high chlorophyll concentrations compared with the wild-type (WT) controls, indicating that they are more tolerant to a lack of iron. The Fe concentration in shoots was also higher in the OsYSL16 activation lines than in the WT. During germination, the rate of Fe-utilization from the seeds was higher in the OsYSL16 activation lines than in the WT seeds. Our results suggest that the function of OsYSL16 in Fe-homeostasis is to enable distribution of iron within a plant.
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Affiliation(s)
- Sichul Lee
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire,
USA
| | - Nayeon Ryoo
- Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701,
Korea
| | - Jong-Seong Jeon
- Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701,
Korea
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire,
USA
| | - Gynheung An
- Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701,
Korea
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35
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Norton GJ, Pinson SRM, Alexander J, Mckay S, Hansen H, Duan GL, Rafiqul Islam M, Islam S, Stroud JL, Zhao FJ, McGrath SP, Zhu YG, Lahner B, Yakubova E, Guerinot ML, Tarpley L, Eizenga GC, Salt DE, Meharg AA, Price AH. Variation in grain arsenic assessed in a diverse panel of rice (Oryza sativa) grown in multiple sites. New Phytol 2012; 193:650-664. [PMID: 22142234 DOI: 10.1111/j.1469-8137.2011.03983.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
• Inorganic arsenic (As(i) ) in rice (Oryza sativa) grains is a possible threat to human health, with risk being strongly linked to total dietary rice consumption and consumed rice As(i) content. This study aimed to identify the range and stability of genetic variation in grain arsenic (As) in rice. • Six field trials were conducted (one each in Bangladesh and China, two in Arkansas, USA over 2 yr, and two in Texas, USA comparing flooded and nonflood treatments) on a large number of common rice cultivars (c. 300) representing genetic diversity among international rice cultivars. • Within each field there was a 3-34 fold range in grain As concentration which varied between rice subpopulations. Importantly, As(i) correlated strongly with total As among a subset of 40 cultivars harvested in Bangladesh and China. • Genetic variation at all field sites was a large determining factor for grain As concentration, indicating that cultivars low in grain As could be developed through breeding. The temperate japonicas exhibited lower grain As compared with other subpopulations. Effects for year, location and flooding management were also statistically significant, suggesting that breeding strategies must take into account environmental factors.
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Affiliation(s)
- Gareth J Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | | | - Jill Alexander
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Susan Mckay
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Helle Hansen
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Gui-Lan Duan
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - M Rafiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Shofiqul Islam
- Department of Soil Science, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
| | - Jacqueline L Stroud
- Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Fang-Jie Zhao
- Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Steve P McGrath
- Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Yong-Guan Zhu
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Brett Lahner
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Elena Yakubova
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Lee Tarpley
- Texas A&M System AgriLife Research Center, Beaumont, TX 77713, USA
| | - Georgia C Eizenga
- USDA ARS, Dale Bumpers National Rice Research Center, Stuttgart, AR 72160, USA
| | - David E Salt
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Andrew A Meharg
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Adam H Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
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36
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Punshon T, Hirschi K, Yang J, Lanzirotti A, Lai B, Guerinot ML. The role of CAX1 and CAX3 in elemental distribution and abundance in Arabidopsis seed. Plant Physiol 2012; 158:352-362. [PMID: 22086421 DOI: 10.1104/pp.111./184812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ability to alter nutrient partitioning within plants cells is poorly understood. In Arabidopsis (Arabidopsis thaliana), a family of endomembrane cation exchangers (CAXs) transports Ca(2+) and other cations. However, experiments have not focused on how the distribution and partitioning of calcium (Ca) and other elements within seeds are altered by perturbed CAX activity. Here, we investigate Ca distribution and abundance in Arabidopsis seed from cax1 and cax3 loss-of-function lines and lines expressing deregulated CAX1 using synchrotron x-ray fluorescence microscopy. We conducted 7- to 10-μm resolution in vivo x-ray microtomography on dry mature seed and 0.2-μm resolution x-ray microscopy on embryos from lines overexpressing deregulated CAX1 (35S-sCAX1) and cax1cax3 double mutants only. Tomograms showed an increased concentration of Ca in both the seed coat and the embryo in cax1, cax3, and cax1cax3 lines compared with the wild type. High-resolution elemental images of the mutants showed that perturbed CAX activity altered Ca partitioning within cells, reducing Ca partitioning into organelles and/or increasing Ca in the cytosol and abolishing tissue-level Ca gradients. In comparison with traditional volume-averaged metal analysis, which confirmed subtle changes in seed elemental composition, the collection of spatially resolved data at varying resolutions provides insight into the impact of altered CAX activity on seed metal distribution and indicates a cell type-specific function of CAX1 and CAX3 in partitioning Ca into organelles. This work highlights a powerful technology for inferring transport function and quantifying nutrient changes.
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Affiliation(s)
- Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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37
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Stockwell SB, Reutimann L, Guerinot ML. A role for Bradyrhizobium japonicum ECF16 sigma factor EcfS in the formation of a functional symbiosis with soybean. Mol Plant Microbe Interact 2012; 25:119-28. [PMID: 21879796 DOI: 10.1094/mpmi-07-11-0188] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Alternative sigma (σ) factors, proteins that recruit RNA polymerase core enzyme to target promoters, are one mechanism by which bacteria transcriptionally regulate groups of genes in response to environmental stimuli. A class of σ(70) proteins, termed extracytoplasmic function (ECF) σ factors, are involved in cellular processes such as bacterial stress responses and virulence. Here, we describe an ECF16 σ factor, EcfS (Blr4928) from the gram-negative soil bacterium Bradyrhizobium japonicum USDA110, that plays a critical role in the establishment of a functional symbiosis with soybean. Nonpolar insertional mutants of ecfS form immature nodules that do not fix nitrogen, a defect that can be successfully complemented by expression of ecfS. Overexpression of the cocistronic gene, tmrS (blr4929), phenocopies the ecfS mutant in planta and, therefore, we propose that TmrS is a negative regulator of EcfS, a determination consistent with the prediction that it encodes an anti-σ factor. Microarray analysis of the ecfS mutant and tmrS overexpressor was used to identify 40 transcripts misregulated in both strains. These transcripts primarily encode proteins of unknown and transport-related functions and may provide insights into the symbiotic defect in these strains.
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MESH Headings
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Bradyrhizobium/genetics
- Bradyrhizobium/metabolism
- Bradyrhizobium/physiology
- DNA, Complementary/genetics
- Gene Expression/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Bacterial/genetics
- Genes, Bacterial/genetics
- Genetic Complementation Test
- Mutagenesis, Insertional
- Nitrogen Fixation
- Oligonucleotide Array Sequence Analysis
- Phenotype
- Plant Leaves/microbiology
- RNA, Bacterial/genetics
- RNA, Messenger/genetics
- Root Nodules, Plant/microbiology
- Root Nodules, Plant/ultrastructure
- Sigma Factor/genetics
- Sigma Factor/metabolism
- Glycine max/microbiology
- Glycine max/ultrastructure
- Stress, Physiological
- Symbiosis
- Transcription, Genetic
- Transcriptome
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Affiliation(s)
- S B Stockwell
- Biological Sciences Department, Dartmouth College, Hanover, NH, USA.
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38
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Punshon T, Hirschi K, Yang J, Lanzirotti A, Lai B, Guerinot ML. The role of CAX1 and CAX3 in elemental distribution and abundance in Arabidopsis seed. Plant Physiol 2012; 158:352-62. [PMID: 22086421 PMCID: PMC3252103 DOI: 10.1104/pp.111.184812] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 11/13/2011] [Indexed: 05/04/2023]
Abstract
The ability to alter nutrient partitioning within plants cells is poorly understood. In Arabidopsis (Arabidopsis thaliana), a family of endomembrane cation exchangers (CAXs) transports Ca(2+) and other cations. However, experiments have not focused on how the distribution and partitioning of calcium (Ca) and other elements within seeds are altered by perturbed CAX activity. Here, we investigate Ca distribution and abundance in Arabidopsis seed from cax1 and cax3 loss-of-function lines and lines expressing deregulated CAX1 using synchrotron x-ray fluorescence microscopy. We conducted 7- to 10-μm resolution in vivo x-ray microtomography on dry mature seed and 0.2-μm resolution x-ray microscopy on embryos from lines overexpressing deregulated CAX1 (35S-sCAX1) and cax1cax3 double mutants only. Tomograms showed an increased concentration of Ca in both the seed coat and the embryo in cax1, cax3, and cax1cax3 lines compared with the wild type. High-resolution elemental images of the mutants showed that perturbed CAX activity altered Ca partitioning within cells, reducing Ca partitioning into organelles and/or increasing Ca in the cytosol and abolishing tissue-level Ca gradients. In comparison with traditional volume-averaged metal analysis, which confirmed subtle changes in seed elemental composition, the collection of spatially resolved data at varying resolutions provides insight into the impact of altered CAX activity on seed metal distribution and indicates a cell type-specific function of CAX1 and CAX3 in partitioning Ca into organelles. This work highlights a powerful technology for inferring transport function and quantifying nutrient changes.
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Affiliation(s)
- Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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39
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Carey AM, Norton GJ, Deacon C, Scheckel KG, Lombi E, Punshon T, Guerinot ML, Lanzirotti A, Newville M, Choi Y, Price AH, Meharg AA. Phloem transport of arsenic species from flag leaf to grain during grain filling. New Phytol 2011. [PMID: 21658183 DOI: 10.1111/j.1469-8137.2011.03789.x/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
• Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. • Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. • Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. • These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.
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Affiliation(s)
- Anne-Marie Carey
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Gareth J Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Claire Deacon
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Kirk G Scheckel
- National Risk Management Research Laboratory, US Environmental Protection Agency, 5995 Centre Hill Avenue, Cincinnati, OH 45224, USA
| | - Enzo Lombi
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus Mawson Lakes, S. Australia, SA-5095 Australia
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Antonio Lanzirotti
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Matt Newville
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Yongseong Choi
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Adam H Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Andrew A Meharg
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
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40
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Carey AM, Norton GJ, Deacon C, Scheckel KG, Lombi E, Punshon T, Guerinot ML, Lanzirotti A, Newville M, Choi Y, Price AH, Meharg AA. Phloem transport of arsenic species from flag leaf to grain during grain filling. New Phytol 2011; 192:87-98. [PMID: 21658183 PMCID: PMC3932528 DOI: 10.1111/j.1469-8137.2011.03789.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
• Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. • Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. • Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. • These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.
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Affiliation(s)
- Anne-Marie Carey
- Institute of Biological and Environmental Sciences, University of
Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, UK
| | - Gareth J. Norton
- Institute of Biological and Environmental Sciences, University of
Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, UK
| | - Claire Deacon
- Institute of Biological and Environmental Sciences, University of
Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, UK
| | - Kirk G. Scheckel
- National Risk Management Research Laboratory, US Environmental
Protection Agency, 5995 Centre Hill Avenue, Cincinnati, Ohio 45224, USA
| | - Enzo Lombi
- Centre for Environmental Risk Assessment and Remediation, University
of South Australia, Building X, Mawson Lakes Campus Mawson Lakes, S. Australia,
SA-5095 Australia
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH
03755, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH
03755, USA
| | - Antonio Lanzirotti
- Centre for Advanced Radiation Sources, the University of Chicago,
Chicago, IL 60637, USA
| | - Matt Newville
- Centre for Advanced Radiation Sources, the University of Chicago,
Chicago, IL 60637, USA
| | - Yongseong Choi
- Centre for Advanced Radiation Sources, the University of Chicago,
Chicago, IL 60637, USA
| | - Adam H. Price
- Institute of Biological and Environmental Sciences, University of
Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, UK
| | - Andrew A. Meharg
- Institute of Biological and Environmental Sciences, University of
Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, UK
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41
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Carey AM, Norton GJ, Deacon C, Scheckel KG, Lombi E, Punshon T, Guerinot ML, Lanzirotti A, Newville M, Choi Y, Price AH, Meharg AA. Phloem transport of arsenic species from flag leaf to grain during grain filling. New Phytol 2011. [PMID: 21658183 DOI: 10.1111/j.1469-8137.2011.03789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
• Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. • Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. • Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. • These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.
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Affiliation(s)
- Anne-Marie Carey
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Gareth J Norton
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Claire Deacon
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Kirk G Scheckel
- National Risk Management Research Laboratory, US Environmental Protection Agency, 5995 Centre Hill Avenue, Cincinnati, OH 45224, USA
| | - Enzo Lombi
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus Mawson Lakes, S. Australia, SA-5095 Australia
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Antonio Lanzirotti
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Matt Newville
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Yongseong Choi
- Centre for Advanced Radiation Sources, the University of Chicago, Chicago, IL 60637, USA
| | - Adam H Price
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Andrew A Meharg
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
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Chao DY, Gable K, Chen M, Baxter I, Dietrich CR, Cahoon EB, Guerinot ML, Lahner B, Lü S, Markham JE, Morrissey J, Han G, Gupta SD, Harmon JM, Jaworski JG, Dunn TM, Salt DE. Sphingolipids in the root play an important role in regulating the leaf ionome in Arabidopsis thaliana. Plant Cell 2011; 23:1061-81. [PMID: 21421810 PMCID: PMC3082254 DOI: 10.1105/tpc.110.079095] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 01/19/2011] [Accepted: 02/14/2011] [Indexed: 05/18/2023]
Abstract
Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10Δ mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis.
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Affiliation(s)
- Dai-Yin Chao
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47906, USA
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Lee S, Jeong HJ, Kim SA, Lee J, Guerinot ML, An G. OsZIP5 is a plasma membrane zinc transporter in rice. Plant Mol Biol 2010; 73:507-17. [PMID: 20419467 DOI: 10.1007/s11103-010-9637-0] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Accepted: 04/09/2010] [Indexed: 05/08/2023]
Abstract
Zinc is essential for normal plant growth and development. To understand its transport in rice, we characterized OsZIP5, which is inducible under Zn deficiency. OsZIP5 complemented the growth defect of a yeast Zn-uptake mutant, indicating that OsZIP5 is a Zn transporter. The OsZIP5-GFP fusion protein was localized to the plasma membrane. Transgenic plants overexpressing the gene grew less well. Overexpression of the gene decreased the Zn concentration in shoots, but caused it to rise in the roots. Knockout plants showed no visible phenotypic changes under either normal or deficient conditions. However, they were tolerant to excess Zn and contained less Zn. In contrast, overexpressing transgenics were sensitive to excess Zn. These results indicate that OsZIP5 plays a role in Zn distribution within rice.
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Affiliation(s)
- Sichul Lee
- Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Republic of Korea
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Guerinot ML, Chelm BK. Bacterial delta-aminolevulinic acid synthase activity is not essential for leghemoglobin formation in the soybean/Bradyrhizobium japonicum symbiosis. Proc Natl Acad Sci U S A 2010; 83:1837-41. [PMID: 16593670 PMCID: PMC323179 DOI: 10.1073/pnas.83.6.1837] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Previous studies of legume nodules have indicated that formation of the heme moiety of leghemoglobin is a function of the bacterial symbiont. We now show that a hemA mutant of Bradyrhizobium japonicum that cannot carry out the first step in heme biosynthesis forms fully effective nodules on soybeans. The bacterial mutant strain was constructed by first isolating the wild-type hemA gene encoding delta-aminolevulinic acid synthase (EC 2.3.1.37) from a cosmid library, using a fragment of the Rhizobium meliloti hemA gene as a hybridization probe. A deletion of the hemA gene region, generated in vitro, then was used to construct the analogous chromosomal mutation by gene-directed mutagenesis. The mutant strain had no delta-aminolevulinic acid synthase activity and was unable to grow in minimal medium unless delta-aminolevulinic acid was added. Despite its auxotrophy, the mutant strain incited nodules that appeared normal, contained heme, and were capable of high levels of acetylene reduction. These results rule out bacterial delta-aminolevulinic acid synthase activity as the exclusive source of delta-aminolevulinic acid for heme formation in soybean nodules.
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Affiliation(s)
- M L Guerinot
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
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Abstract
Bradyrhizobium japonicum USDA 110 and 61A152 can utilize the hydroxamate-type siderophores ferrichrome and rhodotorulate, in addition to ferric citrate, to overcome iron starvation. These strains can also utilize the pyoverdin-type siderophore pseudobactin St3. The ability to utilize another organism's siderophores may confer a selective advantage in the rhizosphere.
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Affiliation(s)
- O Plessner
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
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Abstract
Marine pelagic N(2)-fixing bacteria have not, in general, been identified or quantified, since low or negligible rates of N(2) fixation have been recorded for seawater when blue-green algae (cyanobacteria) are absent. In the study reported here, marine N(2)-fixing bacteria were found in all samples of seawater collected and were analyzed by using a most-probable-number (MPN) method. Two different media were used which allowed growth of microaerophiles, as well as that of aerobes and facultative anaerobes. MPN values obtained for N(2)-fixing bacteria ranged from 0.4 to 1 x 10 per liter for water collected off the coast of Puerto Rico and from 2 to 5.5 x 10 per liter for Chesapeake Bay water. Over 100 strains of N(2)-fixing bacteria were isolated from the MPN tubes and classified, yielding four major groups of NaCl-requiring bacteria based on biochemical characteristics. Results of differential filtration studies indicate that N(2)-fixing bacteria may be associated with phytoplankton. In addition, when N(2)-fixing bacteria were inoculated into unfiltered seawater and incubated in situ, nitrogenase activity could be detected within 1 h. However, no nitrogenase activity was detected in uninoculated seawater or when bacteria were incubated in 0.2-mum-filtered (phytoplankton-free) seawater. The ability of these isolates to fix N(2) at ambient conditions in seawater and the large variety of N(2)-fixing bacteria isolated and identified lead to the conclusion that N(2) fixation in the ocean may occur to a greater degree than previously believed.
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Affiliation(s)
- M L Guerinot
- Department of Microbiology, University of Maryland, College Park, Maryland 20742
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Buescher E, Achberger T, Amusan I, Giannini A, Ochsenfeld C, Rus A, Lahner B, Hoekenga O, Yakubova E, Harper JF, Guerinot ML, Zhang M, Salt DE, Baxter IR. Natural genetic variation in selected populations of Arabidopsis thaliana is associated with ionomic differences. PLoS One 2010; 5:e11081. [PMID: 20559418 PMCID: PMC2885407 DOI: 10.1371/journal.pone.0011081] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 05/07/2010] [Indexed: 11/19/2022] Open
Abstract
Controlling elemental composition is critical for plant growth and development as well as the nutrition of humans who utilize plants for food. Uncovering the genetic architecture underlying mineral ion homeostasis in plants is a critical first step towards understanding the biochemical networks that regulate a plant's elemental composition (ionome). Natural accessions of Arabidopsis thaliana provide a rich source of genetic diversity that leads to phenotypic differences. We analyzed the concentrations of 17 different elements in 12 A. thaliana accessions and three recombinant inbred line (RIL) populations grown in several different environments using high-throughput inductively coupled plasma- mass spectroscopy (ICP-MS). Significant differences were detected between the accessions for most elements and we identified over a hundred QTLs for elemental accumulation in the RIL populations. Altering the environment the plants were grown in had a strong effect on the correlations between different elements and the QTLs controlling elemental accumulation. All ionomic data presented is publicly available at www.ionomicshub.org.
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Affiliation(s)
- Elizabeth Buescher
- Department of Agronomy, Purdue University, West Lafayette, Indiana, United States of America
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Lee S, Kim SA, Lee J, Guerinot ML, An G. Zinc deficiency-inducible OsZIP8 encodes a plasma membrane-localized zinc transporter in rice. Mol Cells 2010; 29:551-8. [PMID: 20496122 DOI: 10.1007/s10059-010-0069-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 02/11/2010] [Accepted: 02/11/2010] [Indexed: 10/19/2022] Open
Abstract
Zinc is an essential micronutrient for several physiological and biochemical processes. To investigate its transport in rice, we characterized OsZIP8, a rice ZIP (Zrt, Irt-like Protein) gene that is strongly up-regulated in shoots and roots under Zn deficiency. OsZIP8 could complement the growth defect of Zn-uptake yeast mutant. The OsZIP8-GFP fusion proteins were localized to the plasma membrane, suggesting that OsZIP8 is a plasma membrane zinc transporter in rice. Activation and overexpression of this gene disturbed the zinc distribution in rice plants, resulting in lower levels in shoots and mature seeds, but an increase in the roots. Field-grown transgenic plants were shorter than the WT. Under treatment with excess zinc, transgenics contained less zinc in their shoots but accumulated more in the roots. Altogether, these results demonstrate that OsZIP8 is a zinc transporter that functions in Zn uptake and distribution. Furthermore, zinc homeostasis is important to the proper growth and development of rice.
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Affiliation(s)
- Sichul Lee
- Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 790-784, Korea
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Affiliation(s)
- Joe Morrissey
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
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