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Sinha D, Datta S, Mishra R, Agarwal P, Kumari T, Adeyemi SB, Kumar Maurya A, Ganguly S, Atique U, Seal S, Kumari Gupta L, Chowdhury S, Chen JT. Negative Impacts of Arsenic on Plants and Mitigation Strategies. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091815. [PMID: 37176873 PMCID: PMC10181087 DOI: 10.3390/plants12091815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023]
Abstract
Arsenic (As) is a metalloid prevalent mainly in soil and water. The presence of As above permissible levels becomes toxic and detrimental to living organisms, therefore, making it a significant global concern. Humans can absorb As through drinking polluted water and consuming As-contaminated food material grown in soil having As problems. Since human beings are mobile organisms, they can use clean uncontaminated water and food found through various channels or switch from an As-contaminated area to a clean area; but plants are sessile and obtain As along with essential minerals and water through roots that make them more susceptible to arsenic poisoning and consequent stress. Arsenic and phosphorus have many similarities in terms of their physical and chemical characteristics, and they commonly compete to cause physiological anomalies in biological systems that contribute to further stress. Initial indicators of arsenic's propensity to induce toxicity in plants are a decrease in yield and a loss in plant biomass. This is accompanied by considerable physiological alterations; including instant oxidative surge; followed by essential biomolecule oxidation. These variables ultimately result in cell permeability and an electrolyte imbalance. In addition, arsenic disturbs the nucleic acids, the transcription process, and the essential enzymes engaged with the plant system's primary metabolic pathways. To lessen As absorption by plants, a variety of mitigation strategies have been proposed which include agronomic practices, plant breeding, genetic manipulation, computer-aided modeling, biochemical techniques, and the altering of human approaches regarding consumption and pollution, and in these ways, increased awareness may be generated. These mitigation strategies will further help in ensuring good health, food security, and environmental sustainability. This article summarises the nature of the impact of arsenic on plants, the physio-biochemical mechanisms evolved to cope with As stress, and the mitigation measures that can be employed to eliminate the negative effects of As.
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Affiliation(s)
- Dwaipayan Sinha
- Department of Botany, Government General Degree College, Mohanpur 721436, Paschim Medinipur, West Bengal, India
| | - Soumi Datta
- Bioactive Natural Product Laboratory, School of Interdisciplinary Sciences and Technology, Jamia Hamdard, Hamdard Nagar, New Delhi 110062, India
| | - Reema Mishra
- Department of Botany, Gargi College, University of Delhi, New Delhi 110049, India
| | - Preeti Agarwal
- Department of Botany, Gargi College, University of Delhi, New Delhi 110049, India
| | - Tripti Kumari
- Department of Chemistry, Gargi College, University of Delhi, New Delhi 110049, India
| | - Sherif Babatunde Adeyemi
- Ethnobotany/Phytomedicine Laboratory, Department of Plant Biology, Faculty of Life Sciences, University of Ilorin, Ilorin PMB 1515, Kwara State, Nigeria
| | - Arun Kumar Maurya
- Department of Botany, Multanimal Modi College, Modinagar, Ghaziabad 201204, Uttar Pradesh, India
| | - Sharmistha Ganguly
- University Department of Botany, Ranchi University, Ranchi 834008, Jharkhand, India
| | - Usman Atique
- Department of Bioscience and Biotechnology, College of Biological Systems, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Sanchita Seal
- Department of Botany, Polba Mahavidyalaya, Polba 712148, West Bengal, India
| | - Laxmi Kumari Gupta
- Bioprocess Development Laboratory, Department of Biotechnology, National Institute of Technology Warangal, Warangal 506004, Telangana, India
| | - Shahana Chowdhury
- Department of Biotechnology, Faculty of Engineering Sciences, German University Bangladesh, TNT Road, Telipara, Chandona Chowrasta, Gazipur 1702, Bangladesh
| | - Jen-Tsung Chen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung 811, Taiwan
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Lee SB, Kim GJ, Shin JD, Chung W, Park SK, Choi GH, Park SW, Park YJ. Genome-Scale Profiling and High-Throughput Analyses Unravel the Genetic Basis of Arsenic Content Variation in Rice. FRONTIERS IN PLANT SCIENCE 2022; 13:905842. [PMID: 35958208 PMCID: PMC9361212 DOI: 10.3389/fpls.2022.905842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Ionomics, the study of the composition of mineral nutrients and trace elements in organisms that represent the inorganic component of cells and tissues, has been widely studied to explore to unravel the molecular mechanism regulating the elemental composition of plants. However, the genetic factors of rice subspecies in the interaction between arsenic and functional ions have not yet been explained. Here, the correlation between As and eight essential ions in a rice core collection was analyzed, taking into account growing condition and genetic factors. The results demonstrated that the correlation between As and essential ions was affected by genetic factors and growing condition, but it was confirmed that the genetic factor was slightly larger with the heritability for arsenic content at 53%. In particular, the cluster coefficient of japonica (0.428) was larger than that of indica (0.414) in the co-expression network analysis for 23 arsenic genes, and it was confirmed that the distance between genes involved in As induction and detoxification of japonica was far than that of indica. These findings provide evidence that japonica populations could accumulate more As than indica populations. In addition, the cis-eQTLs of AIR2 (arsenic-induced RING finger protein) were isolated through transcriptome-wide association studies, and it was confirmed that AIR2 expression levels of indica were lower than those of japonica. This was consistent with the functional haplotype results for the genome sequence of AIR2, and finally, eight rice varieties with low AIR2 expression and arsenic content were selected. In addition, As-related QTLs were identified on chromosomes 5 and 6 under flooded and intermittently flooded conditions through genome-scale profiling. Taken together, these results might assist in developing markers and breeding plans to reduce toxic element content and breeding high-quality rice varieties in future.
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Affiliation(s)
- Sang-Beom Lee
- Crop Foundation Research Division, National Institute of Crop Science, Wanju, South Korea
| | - Gyeong-Jin Kim
- Residual Agrochemical Assessment Division, National Institute of Agriculture Science, Wanju, South Korea
| | - Jung-Du Shin
- Bio-Technology of Multidisciplinary Sciences Co., Wanju, South Korea
| | - Woojin Chung
- Department of Environmental Energy Engineering, Kyonggi University, Suwon, South Korea
| | - Soo-Kwon Park
- Crop Foundation Research Division, National Institute of Crop Science, Wanju, South Korea
| | - Geun-Hyoung Choi
- Residual Agrochemical Assessment Division, National Institute of Agriculture Science, Wanju, South Korea
| | - Sang-Won Park
- Reserch Policy Bureau, Rural Development Administration, Wanju, South Korea
| | - Yong-Jin Park
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan, South Korea
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Sharma SS, Kumar V, Dietz KJ. Emerging Trends in Metalloid-Dependent Signaling in Plants. TRENDS IN PLANT SCIENCE 2021; 26:452-471. [PMID: 33257259 DOI: 10.1016/j.tplants.2020.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 10/12/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Metalloids are semiconducting elements that constitute a small group in the periodic table of elements. Their occurrence in nature either poses an environmental threat or benefit to plants. The precise mechanisms or manner of crosstalk of metalloid interference and sensing remain open questions. Standard plant nutrient solutions contain the metalloid boron (B) as a micronutrient, while silicon (Si) is considered a beneficial element routinely supplied only to some plants such as grasses. By contrast, arsenic (As) is a severe environmental hazard to most organisms, including plants, while the less abundant metalloids germanium (Ge), antimony (Sb), and tellurium (Te) display variable degrees of toxicity. Here we review the molecular events and mechanisms that could explain the contrasting (or overlapping) action of metalloids on the cell and cell signaling.
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Affiliation(s)
- Shanti S Sharma
- Department of Botany, School of Life Sciences, Sikkim University, Gangtok 737102, Sikkim, India
| | - Vijay Kumar
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, Bielefeld, Germany; Department of Biosciences, Himachal Pradesh University, Shimla 171005, India
| | - Karl-Josef Dietz
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, Bielefeld, Germany.
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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. JOURNAL OF EXPERIMENTAL BOTANY 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] [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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Ashraf MA, Umetsu K, Ponomarenko O, Saito M, Aslam M, Antipova O, Dolgova N, Kiani CD, Nehzati S, Tanoi K, Minegishi K, Nagatsu K, Kamiya T, Fujiwara T, Luschnig C, Tanino K, Pickering I, George GN, Rahman A. PIN FORMED 2 Modulates the Transport of Arsenite in Arabidopsis thaliana. PLANT COMMUNICATIONS 2020; 1:100009. [PMID: 33404549 PMCID: PMC7747963 DOI: 10.1016/j.xplc.2019.100009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 10/15/2019] [Accepted: 11/18/2019] [Indexed: 05/23/2023]
Abstract
Arsenic contamination is a major environmental issue, as it may lead to serious health hazard. The reduced trivalent form of inorganic arsenic, arsenite, is in general more toxic to plants compared with the fully oxidized pentavalent arsenate. The uptake of arsenite in plants has been shown to be mediated through a large subfamily of plant aquaglyceroporins, nodulin 26-like intrinsic proteins (NIPs). However, the efflux mechanisms, as well as the mechanism of arsenite-induced root growth inhibition, remain poorly understood. Using molecular physiology, synchrotron imaging, and root transport assay approaches, we show that the cellular transport of trivalent arsenicals in Arabidopsis thaliana is strongly modulated by PIN FORMED 2 (PIN2) auxin efflux transporter. Root transport assay using radioactive arsenite, X-ray fluorescence imaging (XFI) coupled with X-ray absorption spectroscopy (XAS), and inductively coupled plasma mass spectrometry analysis revealed that pin2 plants accumulate higher concentrations of arsenite in roots compared with the wild-type. At the cellular level, arsenite specifically targets intracellular sorting of PIN2 and thereby alters the cellular auxin homeostasis. Consistently, loss of PIN2 function results in arsenite hypersensitivity in roots. XFI coupled with XAS further revealed that loss of PIN2 function results in specific accumulation of arsenical species, but not the other metals such as iron, zinc, or calcium in the root tip. Collectively, these results suggest that PIN2 likely functions as an arsenite efflux transporter for the distribution of arsenical species in planta.
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Affiliation(s)
- Mohammad Arif Ashraf
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate, Japan
| | - Kana Umetsu
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | - Olena Ponomarenko
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Michiko Saito
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | - Mohammad Aslam
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | - Olga Antipova
- Argonne National Lab, Advanced Photon Source, XSD-MIC, Lemont, IL, USA
| | - Natalia Dolgova
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Cheyenne D. Kiani
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Susan Nehzati
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Keitaro Tanoi
- Isotope Facility for Agricultural Education and Research, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Katsuyuki Minegishi
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Inage, Chiba, Japan
| | - Kotaro Nagatsu
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Inage, Chiba, Japan
| | - Takehiro Kamiya
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Toru Fujiwara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Christian Luschnig
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1180 Wien, Austria
| | - Karen Tanino
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ingrid Pickering
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Graham N. George
- Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Abidur Rahman
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate, Japan
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
- Agri-Innovation Center, Iwate University, Morioka, Iwate, Japan
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Arsenic Uptake and Accumulation Mechanisms in Rice Species. PLANTS 2020; 9:plants9020129. [PMID: 31972985 PMCID: PMC7076356 DOI: 10.3390/plants9020129] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 12/15/2022]
Abstract
Rice consumption is a source of arsenic (As) exposure, which poses serious health risks. In this study, the accumulation of As in rice was studied. Research shows that As accumulation in rice in Taiwan and Bangladesh is higher than that in other countries. In addition, the critical factors influencing the uptake of As into rice crops are defined. Furthermore, determining the feasibility of using effective ways to reduce the accumulation of As in rice was studied. AsV and AsIII are transported to the root through phosphate transporters and nodulin 26-like intrinsic channels. The silicic acid transporter may have a vital role in the entry of methylated As, dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA), into the root. Amongst As species, DMA(V) is particularly mobile in plants and can easily transfer from root to shoot. The OsPTR7 gene has a key role in moving DMA in the xylem or phloem. Soil properties can affect the uptake of As by plants. An increase in organic matter and in the concentrations of sulphur, iron, and manganese reduces the uptake of As by plants. Amongst the agronomic strategies in diminishing the uptake and accumulation of As in rice, using microalgae and bacteria is the most efficient.
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Clemens S. Safer food through plant science: reducing toxic element accumulation in crops. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5537-5557. [PMID: 31408148 DOI: 10.1093/jxb/erz366] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/31/2019] [Indexed: 05/24/2023]
Abstract
Natural processes and human activities have caused widespread background contamination with non-essential toxic elements. The uptake and accumulation of cadmium (Cd), arsenic (As), and lead (Pb) by crop plants results in chronic dietary exposure and is associated with various health risks. Current human intake levels are close to what is provisionally regarded as safe. This has recently triggered legislative actions to introduce or lower limits for toxic elements in food. Arguably, the most effective way to reduce the risk of slow poisoning is the breeding of crops with much lower accumulation of contaminants. The past years have seen tremendous progress in elucidating molecular mechanisms of toxic element transport. This was achieved in the model systems Arabidopsis thaliana and, most importantly, rice, the major source of exposure to As and Cd for a large fraction of the global population. Many components of entry and sequestration pathways have been identified. This knowledge can now be applied to engineer crops with reduced toxic element accumulation especially in edible organs. Most obvious in the case of Cd, it appears likely that subtle genetic intervention has the potential to reduce human exposure to non-essential toxic elements almost immediately. This review outlines the risks and discusses our current state of knowledge with emphasis on transgenic and gene editing approaches.
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Affiliation(s)
- Stephan Clemens
- Department of Plant Physiology, and Bayreuth Center of Ecology and Environmental Research, University of Bayreuth, Bayreuth, Germany
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Three Genes Define a Bacterial-Like Arsenic Tolerance Mechanism in the Arsenic Hyperaccumulating Fern Pteris vittata. Curr Biol 2019; 29:1625-1633.e3. [PMID: 31080078 DOI: 10.1016/j.cub.2019.04.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/15/2019] [Accepted: 04/10/2019] [Indexed: 12/21/2022]
Abstract
Arsenic is a carcinogenic contaminant of water and food and a growing threat to human health in many regions of the world. This study focuses on the fern Pteris vittata (Pteridaceae), which is extraordinary in its ability to tolerate and hyperaccumulate very high levels of arsenic that would kill any other plant or animal outside the Pteridaceae. Here, we use RNA-seq to identify three genes (GLYCERALDEHYDE 3-PHOSPHATE DEHYDROGENASE (PvGAPC1), ORGANIC CATION TRANSPORTER 4 (PvOCT4), and GLUTATHIONE S-TRANSFERASE (PvGSTF1) that are highly upregulated by arsenic and are necessary for arsenic tolerance, as demonstrated by RNAi. The proteins encoded by these genes have unexpected properties: PvGAPC1 has an unusual active site and a much greater affinity for arsenate than phosphate; PvGSTF1 has arsenate reductase activity; and PvOCT4 localizes as puncta in the cytoplasm. Surprisingly, PvGAPC1, PvGSTF1, and arsenate localize in a similar pattern. These results are consistent with a model that describes the fate of arsenate once it enters the cell. It involves the conversion of arsenate into 1-arseno-3-phosphoglycerate by PvGAPC1. This "chemically trapped" arsenate is pumped into specific arsenic metabolizing vesicles by the PvOCT4 protein. Once inside these vesicles, 1-arseno-3-phosphoglycerate hydrolyses to release arsenate, which is then reduced by PvGSTF1 to arsenite, the form of arsenic stored in the vacuoles of this fern. This mechanism is strikingly similar to one recently described Pseudomonas aeruginosa, whose tolerance to arsenic also involves the biosynthesis and transport of 1-arseno-3-phosphoglycerate, indicating that P. vittata has evolved a simple, bacterial-like mechanism for arsenic tolerance.
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Luan M, Liu J, Liu Y, Han X, Sun G, Lan W, Luan S. Vacuolar Phosphate Transporter 1 (VPT1) Affects Arsenate Tolerance by Regulating Phosphate Homeostasis in Arabidopsis. PLANT & CELL PHYSIOLOGY 2018; 59:1345-1352. [PMID: 29420798 DOI: 10.1093/pcp/pcy025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/22/2018] [Indexed: 05/24/2023]
Abstract
Arsenate [As(V)] is toxic to nearly all organisms. Soil-borne As(V) enters plant cells mainly through the plasma membrane-localized phosphate (Pi) transporter PHT1 family proteins due to its chemical similarity to Pi. We report here that VPT1, a major vacuolar phosphate transporter which contributes to vacuolar Pi sequestration, is associated with As(V) tolerance in Arabidopsis. vpt1 mutants displayed enhanced tolerance to As(V) toxicity, whereas plants overexpressing VPT1 were more sensitive to As(V) as compared with the wild-type plants. Measurements of arsenic content indicated that vpt1 mutants accumulated less arsenic and, in contrast, up-regulating VPT1 expression contributed to higher levels of arsenic accumulation in plants. To examine further how VPT1 may modulate arsenic contents in plants, we surveyed the expression patterns of all the PHT1 family members that play roles in As(V) uptake, and found that many of the PHT1 genes were down-regulated in the vpt1 mutant as compared with the wild type under Pi-sufficient conditions, but not when Pi levels were low in the medium. Interestingly, As(V) sensitivity assays indicated that As(V) resistance in vpt1 mutants was prominent only under Pi-sufficient but not under Pi-deficient conditions. These results suggest that under Pi-sufficient conditions, loss of VPT1 leads to elevated levels of Pi in the cytosol, which in turn suppressed the expression of PHT1-type transporters and reduced accumulation of arsenic.
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Affiliation(s)
- Mingda Luan
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing, PR China
| | - Jinlong Liu
- College of Animal Science & Technology, Northwest A&F University, Yangling, Shanxi, PR China
| | - Yuewen Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing, PR China
| | - Xingbao Han
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing, PR China
| | - Guangfang Sun
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing, PR China
| | - Wenzhi Lan
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing, PR China
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
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