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Zhang X, Ma Y, Lai D, He M, Zhang X, Zhang W, Ji M, Zhu Y, Wang Y, Liu L, Xu L. RsPDR8, a member of ABCG subfamily, plays a positive role in regulating cadmium efflux and tolerance in radish (Raphanus sativus L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 205:108149. [PMID: 37939545 DOI: 10.1016/j.plaphy.2023.108149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/16/2023] [Accepted: 10/27/2023] [Indexed: 11/10/2023]
Abstract
Radish (Raphanus sativus L.) is one of the most vital root vegetable crops worldwide. Cadmium (Cd), a non-essential and toxic heavy metal, can dramatically restrict radish taproot quality and safety. Although the Peiotrpic Drug Resistance (PDR) genes play crucial roles in heavy metal accumulation and transport in plants, the systematic identification and functional characterization of RsPDRs remain largely unexplored in radish. Herein, a total of 19 RsPDR genes were identified from the radish genome. A few RsPDRs, including RsPDR1, RsPDR8 and RsPDR12, showed significant differential expression under Cd and lead (Pb) stress in the 'NAU-YH' genotype. Interestingly, the plasma membrane-localized RsPDR8 exhibited significantly up-regulated expression and enhanced promoter activity under Cd exposure. Ectopic expression of RsPDR8 conferred Cd tolerance via reducing Cd accumulation in yeast cells. Moreover, the transient transformation of RsPDR8 revealed that it positively regulated Cd tolerance by promoting ROS scavenging and enhancing membrane permeability in radish. In addition, overexpression of RsPDR8 increased root elongation but deceased Cd accumulation compared with the WT plants in Arabidopsis, demonstrating that it could play a positive role in mediating Cd efflux and tolerance in plants. Together, these results would facilitate deciphering the molecular mechanism underlying RsPDR8-mediated Cd tolerance and detoxification in radish.
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Affiliation(s)
- Xinyu Zhang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Yingfei Ma
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Deqiang Lai
- Cangzhou Academy of Agriculture and Forestry Sciences, Cangzhou, 061001, PR China
| | - Min He
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Xiaoli Zhang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Weilan Zhang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Mingmei Ji
- Cangzhou Academy of Agriculture and Forestry Sciences, Cangzhou, 061001, PR China
| | - Yuelin Zhu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Yan Wang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Liwang Liu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China; College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, 225009, PR China
| | - Liang Xu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, PR China.
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Yao X, Chen H, Zhang B, Lu L. Transcriptome Analysis Reveals Differentially Expressed Genes Involved in Aluminum, Copper and Cadmium Accumulation in Tea 'Qianmei 419' and 'Qianfu 4'. PLANTS (BASEL, SWITZERLAND) 2023; 12:2580. [PMID: 37447140 DOI: 10.3390/plants12132580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023]
Abstract
Tea, as a global nonalcoholic beverage, is widely consumed due to its economic, health and cultural importance. Polyploids have the ability to solve the problems of low yield, cold resistance and insect resistance in tea tree varieties. However, the response mechanism to aluminum and heavy metal remains unclear. In this study, the content of Al, Cu and Cd were measured in the leaves and roots of 'Qianmei 419' and 'Qianfu 4', respectively. The content of Al, Cd and Cu in the roots of the 'Qianmei 419' tea variety were significantly higher than in 'Qianfu 4' roots. Only the content of Cu in the leaves of the 'Qianmei 419' tea variety was significantly higher than that in the roots of the 'Qianfu 4' tea variety. Moreover, we found that the content of Al, Cu and Cd in the soil around the root of 'Qianfu 4' were higher than in the soil around the root of 'Qianmei 419'. RNA-seq was performed to identify the DEGs involved in the accumulation of Al, Cu and Cd between 'Qianmei 419' and 'Qianfu 4'. A total of 23,813 DEGs were identified in the triploid tea variety, including 16,459 upregulated DEGs and 7354 downregulated DEGs. Among them, by analyzing the expression levels of some metal transporter genes, it was found that most of the metal transporter genes were downregulated in the triploid tea plants. In short, through the analysis of transcriptome data and metal content, it was found that changes in metal transporter gene expression affect the accumulation of metals in tea plants. These results provide candidate genes to enhance multi-metal tolerance through genetic engineering technology.
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Affiliation(s)
- Xinzhuan Yao
- Institute of Plant Health & Medicine, College of Tea Sciences, Guizhou University, Guiyang 550025, China
| | - Hufang Chen
- Institute of Plant Health & Medicine, College of Tea Sciences, Guizhou University, Guiyang 550025, China
| | - Baohui Zhang
- Guizhou Academy of Agricultural Sciences, Guiyang 550006, China
| | - Litang Lu
- Institute of Plant Health & Medicine, College of Tea Sciences, Guizhou University, Guiyang 550025, China
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Zhang C, Tong C, Cao L, Zheng P, Tang X, Wang L, Miao M, Liu Y, Cao S. Regulatory module WRKY33-ATL31-IRT1 mediates cadmium tolerance in Arabidopsis. PLANT, CELL & ENVIRONMENT 2023; 46:1653-1670. [PMID: 36738191 DOI: 10.1111/pce.14558] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/21/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Cadmium (Cd) is one of the most dangerous environmental pollutants among heavy metals, and threatens food safety and human health by accumulating in plant sink tissues. Here, we report a novel regulatory cascade that profoundly influences Cd tolerance in Arabidopsis. Phenotypic analysis showed that an insertional knockdown mutation at the Arabidopsis Tóxicos en Levadura 31 (ATL31) locus resulted in hypersensitivity to Cd stress, most likely due to a significant increase in Cd accumulation. Consistently, ATL31-overexpressing lines exhibited enhanced Cd stress tolerance and reduced Cd accumulation. Further, IRON-REGULATED TRANSPORTER 1 (IRT1) was identified, and yeast two-hybrid, co-immunoprecipitation and bimolecular fluorescence complementation assays demonstrated its interaction with ATL31. Biochemical, molecular, and genetic analyses showed that IRT1 is targeted by ATL31 for ubiquitin-conjugated degradation in response to Cd stress. Intriguingly, transcription of ATL31 was strongly induced by Cd stress. In addition, transgenic and molecular analyses showed that WRKY33 directly activated the transcription of ATL31 in response to Cd stress and positively regulated Cd tolerance. Genetic analysis indicated that ATL31 acts upstream of IRT1 and downstream of WRKY33 to regulate Cd tolerance. Our study revealed that the WRKY33-ATL31-IRT1 module plays a crucial role in timely blocking Cd absorption to prevent metal toxicity in Arabidopsis.
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Affiliation(s)
- Cheng Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Chenchen Tong
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Lei Cao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Pengpeng Zheng
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Xiaofeng Tang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Lihuan Wang
- School of Horticulture, Anhui Agricultural University, Hefei, China
| | - Min Miao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Yongsheng Liu
- School of Horticulture, Anhui Agricultural University, Hefei, China
| | - Shuqing Cao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, China
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Zang H, He J, Zhang Q, Li X, Wang T, Bi X, Zhang Y. Ectopic Expression of PvHMA2.1 Enhances Cadmium Tolerance in Arabidopsis thaliana. Int J Mol Sci 2023; 24:ijms24043544. [PMID: 36834955 PMCID: PMC9966247 DOI: 10.3390/ijms24043544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023] Open
Abstract
Cadmium (Cd) in soil inhibits plant growth and development and even harms human health through food chain transmission. Switchgrass (Panicum virgatum L.), a perennial C4 biofuel crop, is considered an ideal plant for phytoremediation due to its high efficiency in removing Cd and other heavy metals from contaminated soil. The key to understanding the mechanisms of switchgrass Cd tolerance is to identify the genes involved in Cd transport. Heavy-metal ATPases (HMAs) play pivotal roles in heavy metal transport, including Cd, in Arabidopsis thaliana and Oryza sativa, but little is known about the functions of their orthologs in switchgrass. Therefore, we identified 22 HMAs in switchgrass, which were distributed on 12 chromosomes and divided into 4 groups using a phylogenetic analysis. Then, we focused on PvHMA2.1, which is one of the orthologs of the rice Cd transporter OsHMA2. We found that PvHMA2.1 was widely expressed in roots, internodes, leaves, spikelets, and inflorescences, and was significantly induced in the shoots of switchgrass under Cd treatment. Moreover, PvHMA2.1 was found to have seven transmembrane domains and localized at the cell plasma membrane, indicating that it is a potential transporter. The ectopic expression of PvHMA2.1 alleviated the reduction in primary root length and the loss of fresh weight of Arabidopsis seedlings under Cd treatment, suggesting that PvHMA2.1 enhanced Cd tolerance in Arabidopsis. The higher levels of relative water content and chlorophyll content of the transgenic lines under Cd treatment reflected that PvHMA2.1 maintained water retention capacity and alleviated photosynthesis inhibition under Cd stress in Arabidopsis. The roots of the PvHMA2.1 ectopically expressed lines accumulated less Cd compared to the WT, while no significant differences were found in the Cd contents of the shoots between the transgenic lines and the WT under Cd treatment, suggesting that PvHMA2.1 reduced Cd absorption from the environment through the roots in Arabidopsis. Taken together, our results showed that PvHMA2.1 enhanced Cd tolerance in Arabidopsis, providing a promising target that could be engineered in switchgrass to repair Cd-contaminated soil.
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Zheng P, Cao L, Zhang C, Pan W, Wang W, Yu X, Li Y, Fan T, Miao M, Tang X, Liu Y, Cao S. MYB43 as a novel substrate for CRL4 PRL1 E3 ligases negatively regulates cadmium tolerance through transcriptional inhibition of HMAs in Arabidopsis. THE NEW PHYTOLOGIST 2022; 234:884-901. [PMID: 35129221 DOI: 10.1111/nph.18020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in plants. A key regulatory system for protein stability is given by the CULLIN-RING E3 ligases (CRLs). In this work, MYB43 is identified as a novel target of a CUL4-DDB1-PRL1 (PLEIOTROPIC REGULATORY LOCUS 1)-RING E3 ligase (CRL4PRL1 E3 ligase). Its stability depends on the presence of PRL1, a WD40-containing protein functioning as a substrate receptor of the CRL4 E3 ligases. Genetic studies have indicated that MYB43 is a negative regulator of cadmium (Cd) tolerance in Arabidopsis by transcriptional inhibition of important Cd transporters (HMA2, HMA3 and HMA4), while PRL1 and CUL4 positively regulate Cd tolerance. Expression of CUL4 and PRL1 was enhanced in response to Cd stress, and PRL1 can interact with and target MYB43 for degradation depending on assembly of CRL4PRL1 E3 ligase, and consequently increase the expression of HMA2, HMA3 and HMA4 through attenuating the transcriptional inhibition. HMA2 and HMA4 are shown to transport cadmium ion (Cd2+ ) from the roots of plants to the shoots through the xylem, ultimately increasing the plants' tolerance to Cd stress.
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Affiliation(s)
- Pengpeng Zheng
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Lei Cao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Cheng Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Weicheng Pan
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Wei Wang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Xin Yu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Yaping Li
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Tingting Fan
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Min Miao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Xiaofeng Tang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Yongsheng Liu
- School of Horticulture, Anhui Agricultural University, Hefei, 230036, China
| | - Shuqing Cao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
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Feki K, Tounsi S, Mrabet M, Mhadhbi H, Brini F. Recent advances in physiological and molecular mechanisms of heavy metal accumulation in plants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:64967-64986. [PMID: 34599711 DOI: 10.1007/s11356-021-16805-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/24/2021] [Indexed: 05/27/2023]
Abstract
Among abiotic stress, the toxicity of metals impacts negatively on plants' growth and productivity. This toxicity promotes various perturbations in plants at different levels. To withstand stress, plants involve efficient mechanisms through the implication of various signaling pathways. These pathways enhance the expression of many target genes among them gene coding for metal transporters. Various metal transporters which are localized at the plasma membrane and/or at the tonoplast are crucial in metal stress response. Furthermore, metal detoxification is provided by metal-binding proteins like phytochelatins and metallothioneins. The understanding of the molecular basis of metal toxicities signaling pathways and tolerance mechanisms is crucial for genetic engineering to produce transgenic plants that enhance phytoremediation. This review presents an overview of the recent advances in our understanding of metal stress response. Firstly, we described the effect of metal stress on plants. Then, we highlight the mechanisms involved in metal detoxification and the importance of the regulation in the response to heavy metal stress. Finally, we mentioned the importance of genetic engineering for enhancing the phytoremediation technique. In the end, the response to heavy metal stress is complex and implicates various components. Thus, further studies are needed to better understand the mechanisms involved in response to this abiotic stress.
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Affiliation(s)
- Kaouthar Feki
- Laboratory of Legumes and Sustainable Agrosystem (L2AD), Center of Biotechnology of Borj-Cédria, BP901, 2050, Hammam-Lif, Tunisia
| | - Sana Tounsi
- Biotechnology and Plant Improvement Laboratory, Center of Biotechnology of Sfax (CBS), University of Sfax, B.P "1177", 3018, Sfax, Tunisia
| | - Moncef Mrabet
- Laboratory of Legumes and Sustainable Agrosystem (L2AD), Center of Biotechnology of Borj-Cédria, BP901, 2050, Hammam-Lif, Tunisia
| | - Haythem Mhadhbi
- Laboratory of Legumes and Sustainable Agrosystem (L2AD), Center of Biotechnology of Borj-Cédria, BP901, 2050, Hammam-Lif, Tunisia
| | - Faiçal Brini
- Biotechnology and Plant Improvement Laboratory, Center of Biotechnology of Sfax (CBS), University of Sfax, B.P "1177", 3018, Sfax, Tunisia.
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Ali S, Tyagi A, Bae H. Ionomic Approaches for Discovery of Novel Stress-Resilient Genes in Plants. Int J Mol Sci 2021; 22:7182. [PMID: 34281232 PMCID: PMC8267685 DOI: 10.3390/ijms22137182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 01/03/2023] Open
Abstract
Plants, being sessile, face an array of biotic and abiotic stresses in their lifespan that endanger their survival. Hence, optimized uptake of mineral nutrients creates potential new routes for enhancing plant health and stress resilience. Recently, minerals (both essential and non-essential) have been identified as key players in plant stress biology, owing to their multifaceted functions. However, a realistic understanding of the relationship between different ions and stresses is lacking. In this context, ionomics will provide new platforms for not only understanding the function of the plant ionome during stresses but also identifying the genes and regulatory pathways related to mineral accumulation, transportation, and involvement in different molecular mechanisms under normal or stress conditions. This article provides a general overview of ionomics and the integration of high-throughput ionomic approaches with other "omics" tools. Integrated omics analysis is highly suitable for identification of the genes for various traits that confer biotic and abiotic stress tolerance. Moreover, ionomics advances being used to identify loci using qualitative trait loci and genome-wide association analysis of element uptake and transport within plant tissues, as well as genetic variation within species, are discussed. Furthermore, recent developments in ionomics for the discovery of stress-tolerant genes in plants have also been addressed; these can be used to produce more robust crops with a high nutritional value for sustainable agriculture.
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Affiliation(s)
- Sajad Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Korea;
| | - Anshika Tyagi
- National Institute for Plant Biotechnology, New Delhi 110012, India;
| | - Hanhong Bae
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Korea;
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Neri A, Traversari S, Andreucci A, Francini A, Sebastiani L. The Role of Aquaporin Overexpression in the Modulation of Transcription of Heavy Metal Transporters under Cadmium Treatment in Poplar. PLANTS 2020; 10:plants10010054. [PMID: 33383680 PMCID: PMC7824648 DOI: 10.3390/plants10010054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/10/2020] [Accepted: 12/25/2020] [Indexed: 12/25/2022]
Abstract
Populus alba ‘Villafranca’ clone is well-known for its tolerance to cadmium (Cd). To determine the mechanisms of Cd tolerance of this species, wild-type (wt) plants were compared with transgenic plants over-expressing an aquaporin (aqua1, GenBank GQ918138). Plants were maintained in hydroponic conditions with Hoagland’s solution and treated with 10 µM of Cd, renewed every 5 d. The transcription levels of heavy metal transporter genes (PaHMA2, PaNRAMP1.3, PaNRAMP2, PaNRAMP3.1, PaNRAMP3.2, PaABCC9, and PaABCC13) were analyzed at 1, 7, and 60 d of treatment. Cd application did not induce visible toxicity symptoms in wt and aqua1 plants even after 2 months of treatment confirming the high tolerance of this poplar species to Cd. Most of the analyzed genes showed in wt plants a quick response in transcription at 1 d of treatment and an adaptation at 60 d. On the contrary, a lower transcriptional response was observed in aqua1 plants in concomitance with a higher Cd concentration in medial leaves. Moreover, PaHMA2 showed at 1 d an opposite trend within organs since it was up-regulated in root and stem of wt plants and in leaves of aqua1 plants. In summary, aqua1 overexpression in poplar improved Cd translocation suggesting a lower Cd sensitivity of aqua1 plants. This different response might be due to a different transcription of PaNRAMP3 genes that were more transcribed in wt line because of the importance of this gene in Cd compartmentalization.
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Affiliation(s)
- Andrea Neri
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy; (A.N.); (S.T.); (L.S.)
| | - Silvia Traversari
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy; (A.N.); (S.T.); (L.S.)
| | - Andrea Andreucci
- Department of Biology, University of Pisa, via Luca Ghini 13, 56126 Pisa, Italy
- Correspondence: (A.A.); (A.F.)
| | - Alessandra Francini
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy; (A.N.); (S.T.); (L.S.)
- Correspondence: (A.A.); (A.F.)
| | - Luca Sebastiani
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy; (A.N.); (S.T.); (L.S.)
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Ibuot A, Webster RE, Williams LE, Pittman JK. Increased metal tolerance and bioaccumulation of zinc and cadmium in Chlamydomonas reinhardtii expressing a AtHMA4 C-terminal domain protein. Biotechnol Bioeng 2020; 117:2996-3005. [PMID: 32579250 DOI: 10.1002/bit.27476] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/05/2020] [Accepted: 06/23/2020] [Indexed: 02/03/2023]
Abstract
The use of microalgal biomass for metal pollutant bioremediation might be improved by genetic engineering to modify the selectivity or capacity of metal biosorption. A plant cadmium (Cd) and zinc (Zn) transporter (AtHMA4) was used as a transgene to increase the ability of Chlamydomonas reinhardtii to tolerate 0.2 mM Cd and 0.3 mM Zn exposure. The transgenic cells showed increased accumulation and internalization of both metals compared to wild-type. AtHMA4 was expressed either as the full-length (FL) protein or just the C-terminal (CT) tail, which is known to have metal-binding sites. Similar Cd and Zn tolerance and accumulation was observed with expression of either the FL protein or CT domain, suggesting that enhanced metal tolerance was mainly due to increased metal binding rather than metal transport. The effectiveness of the transgenic cells was further examined by immobilization in calcium alginate to generate microalgal beads that could be added to a metal contaminated solution. Immobilization maintained metal tolerance, while AtHMA4-expressing cells in alginate showed a concentration-dependent increase in metal biosorption that was significantly greater than alginate beads composed of wild-type cells. This demonstrates that expressing AtHMA4 FL or CT has great potential as a strategy for bioremediation using microalgal biomass.
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Affiliation(s)
- Aniefon Ibuot
- Department of Science Technology, Akwa Ibom State Polytechnic, Ikot Ekpene, Akwa Ibom, Nigeria
| | - Rachel E Webster
- The Manchester Museum, The University of Manchester, Manchester, UK
| | | | - Jon K Pittman
- Department of Earth and Environmental Sciences, School of Natural Sciences, The University of Manchester, Manchester, UK
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Cao Y, Zhao X, Liu Y, Wang Y, Wu W, Jiang Y, Liao C, Xu X, Gao S, Shen Y, Lan H, Zou C, Pan G, Lin H. Genome-wide identification of ZmHMAs and association of natural variation in ZmHMA2 and ZmHMA3 with leaf cadmium accumulation in maize. PeerJ 2019; 7:e7877. [PMID: 31660268 PMCID: PMC6815194 DOI: 10.7717/peerj.7877] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 09/12/2019] [Indexed: 12/04/2022] Open
Abstract
P1B-type ATPases, known as heavy metal ATPases (HMAs), play an important role in the control of cadmium (Cd) accumulation in plants. In this study, a total of 12 ZmHMA genes were identified in the maize genome and particularly classified into six clusters based on their phylogenetic relationship and motif compositions. Furthermore, the expression patterns of different ZmHMA genes varied with developmental stages, and were tissue specific under normal conditions. ZmHMA2 and ZmHMA3 genes exhibited significant up-regulation under Cd treatment. Eventually, the association analysis between 103 inbred lines and alleles in ZmHMA2 and ZmHMA3 revealed that one insertion–deletion (InDel) in the intron from ZmHMA2 was associated with leaf Cd concentration under low Cd condition at the seedling stage. Twenty polymorphisms in ZmHMA3 were significantly associated with leaf Cd concentration under various Cd levels at seedling and maturing stages. Five single nucleotide polymorphisms (SNPs) and two InDels of these significantly associated polymorphic loci from ZmHMA3 caused the amino acid substitutions and insertion or deletion events. Importantly, the proteins encoded by ZmHMA2 and ZmHMA3 genes were located in the plasma membrane. This comprehensive analysis will provide an important theoretical basis for future functional verification of ZmHMA genes to unravel the mechanisms of Cd accumulation in leaves of maize. Additionally, the favorable alleles in ZmHMA3 will lay a foundation for the marker-assisted selection of low Cd accumulation in maize.
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Affiliation(s)
- Yanhua Cao
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiongwei Zhao
- College of Life Sciences, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Yajuan Liu
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yalong Wang
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Wenmei Wu
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yiwei Jiang
- Department of Agronomy, Purdue University, West Lafayette, IN, USA
| | - Changjian Liao
- Crop Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, China
| | - Xiaoxun Xu
- College of Environment Sciences, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shibin Gao
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yaou Shen
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Hai Lan
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Chaoying Zou
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Guangtang Pan
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Haijian Lin
- Maize Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, China
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11
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Blasco B, Navarro-León E, Ruiz JM. Study of Zn accumulation and tolerance of HMA4 TILLING mutants of Brassica rapa grown under Zn deficiency and Zn toxicity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 287:110201. [PMID: 31481218 DOI: 10.1016/j.plantsci.2019.110201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Nowadays, Zinc (Zn) deficiency is the most widespread micronutrient deficiency but simultaneously Zn toxicity is produced due to environmental pollution. A potential method to alleviate Zn deficiency and to reduce Zn concentration in soils is through the generation of plants with enhanced capacity for Zn accumulation and higher tolerance. This could be achieved through the modification of HMA4 transporter. BraA.hma4a-3 is a TILLING mutant plant that presents one modification in HMA4 transporter. Thus, in this study we analyzed the potential of BraA.hma4a-3 for Zn accumulation and Zn deficiency and toxicity tolerance. BraA.hma4a-3 and parental R-o-18 plants were grown with different Zn doses: 1 μM ZnSO4 (Control), 0.01 μM ZnSO4 (Zn deficiency) and 100 μM ZnSO4 (Zn toxicity). Parameters of biomass, Zn concentration, photosynthesis, oxidative stress, N metabolism and amino acids (AAs) were measured. BraA.hma4a-3 did not affect plant biomass but did increase Zn accumulation in leaves under an adequate Zn supply and Fe under control and Zn deficiency doses. Regarding stress tolerance parameters and N metabolism, BraA.hma4a did not produce alterations under control conditions. In addition, under Zn toxicity, parameters suggest a greater tolerance. Briefly, the obtained results point to BraA.hma4a-3 as a useful mutant to increase Zn accumulation.
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Affiliation(s)
- Begoña Blasco
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
| | - Eloy Navarro-León
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
| | - Juan Manuel Ruiz
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
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12
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Navarro-León E, Oviedo-Silva J, Ruiz JM, Blasco B. Possible role of HMA4a TILLING mutants of Brassica rapa in cadmium phytoremediation programs. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 180:88-94. [PMID: 31078020 DOI: 10.1016/j.ecoenv.2019.04.081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 05/15/2023]
Abstract
Cadmium (Cd) is a dangerous transition element that causes environmental and health problems due to its high mobility in the soil-plant system. In plants, Cd causes serious alterations in physiological processes, affecting different vital functions such as photosynthesis. Species such as Brassica juncea and Brassica rapa have been selected as suitable plants for phytoremediation purposes due to their ability to tolerate the toxic effect of heavy metals. In order to improve this strategy, techniques of plant mutagenesis such as TILLING (Targeting Induced Local Lessions in Genomes) have been employed. In the present work we studied the role of the HMA4 gene in the tolerance to Cd toxicity (100 μM CdCl2) using a TILLING mutant of B. rapa (BraA.hma4a-3). These mutant plants presented a lower biomass reduction and a higher Cd concentration in leaves. An increase in the GSH/GSSG ratio, in the content of photosynthetic pigments and a reduction of oxidative stress was observed, as well as a better photosynthetic index, confirming that BraA.hma4a-3 plants showed a higher tolerance to Cd. In conclusion, according to the results obtained in this work, BraA.hma4a-3 plants could be used for phytoremediation purposes of Cd contaminated soils.
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Affiliation(s)
- Eloy Navarro-León
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
| | - Jhonnatan Oviedo-Silva
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
| | - Juan Manuel Ruiz
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
| | - Begoña Blasco
- Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
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13
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Zhao J, Xia B, Meng Y, Yang Z, Pan L, Zhou M, Zhang X. Transcriptome Analysis to Shed Light on the Molecular Mechanisms of Early Responses to Cadmium in Roots and Leaves of King Grass ( Pennisetum americanum × P. purpureum). Int J Mol Sci 2019; 20:E2532. [PMID: 31126029 PMCID: PMC6567004 DOI: 10.3390/ijms20102532] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 11/28/2022] Open
Abstract
King grass, a hybrid grass between pearl millet and elephant grass, has many excellent characteristics such as high biomass yield, great stress tolerance, and enormous economic and ecological value, which makes it ideal for development of phytoremediation. At present, the physiological and molecular response of king grass to cadmium (Cd) stress is poorly understood. Transcriptome analysis of early response (3 h and 24 h) of king grass leaves and roots to high level Cd (100 µM) has been investigated and has shed light on the molecular mechanism underlying Cd stress response in this hybrid grass. Our comparative transcriptome analysis demonstrated that in combat with Cd stress, king grass roots have activated the glutathione metabolism pathway by up-regulating glutathione S-transferases (GSTs) which are a multifunctional family of phase II enzymes that detoxify a variety of environmental chemicals, reactive intermediates, and secondary products of oxidative damages. In roots, early inductions of phenylpropanoid biosynthesis and phenylalanine metabolism pathways were observed to be enriched in differentially expressed genes (DEGs). Meanwhile, oxidoreductase activities were significantly enriched in the first 3 h to bestow the plant cells with resistance to oxidative stress. We also found that transporter activities and jasmonic acid (JA)-signaling might be activated by Cd in king grass. Our study provided the first-hand information on genome-wide transcriptome profiling of king grass and novel insights on phytoremediation.
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Affiliation(s)
- Junming Zhao
- Department of Grassland Science, Sichuan Agricultural University, Chengdu 611130, China.
| | - Bo Xia
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634-0318, USA.
| | - Yu Meng
- College of Natural, Applied and Health Sciences, Wenzhou Kean University, Wenzhou 325060, China.
| | - Zhongfu Yang
- Department of Grassland Science, Sichuan Agricultural University, Chengdu 611130, China.
| | - Ling Pan
- Department of Grassland Science, Sichuan Agricultural University, Chengdu 611130, China.
| | - Man Zhou
- College of Natural, Applied and Health Sciences, Wenzhou Kean University, Wenzhou 325060, China.
| | - Xinquan Zhang
- Department of Grassland Science, Sichuan Agricultural University, Chengdu 611130, China.
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14
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Zhao H, Wang L, Zhao FJ, Wu L, Liu A, Xu W. SpHMA1 is a chloroplast cadmium exporter protecting photochemical reactions in the Cd hyperaccumulator Sedum plumbizincicola. PLANT, CELL & ENVIRONMENT 2019; 42:1112-1124. [PMID: 30311663 DOI: 10.1111/pce.13456] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 09/25/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
Sedum plumbizincicola is able to hyperaccumulate cadmium (Cd), a nonessential and highly toxic metal, in the above-ground tissues, but the mechanisms for its Cd hypertolerance are not fully understood. Here, we show that the heavy metal ATPase 1 (SpHMA1) of S. plumbizincicola plays an important role in chloroplast Cd detoxification. Compared with the HMA1 ortholog in the Cd nonhyperaccumulating ecotype of Sedum alfredii, the expression of SpHMA1 in the leaves of S. plumbizincicola was >200 times higher. Heterologous expression of SpHMA1 in Saccharomyces cerevisiae increased Cd sensitivity and Cd transport activity in the yeast cells. The SpHMA1 protein was localized to the chloroplast envelope. SpHMA1 RNA interference transgenic plants and CRISPR/Cas9-induced mutant lines showed significantly increased Cd accumulation in the chloroplasts compared with wild-type plants. Chlorophyll fluorescence imaging analysis revealed that the photosystem II of SpHMA1 knockdown and knockout lines suffered from a much higher degree of Cd toxicity than wild type. Taken together, these results suggest that SpHMA1 functions as a chloroplast Cd exporter and protects photosynthesis by preventing Cd accumulation in the chloroplast in S. plumbizincicola and hyperexpression of SpHMA1 is an important component contributing to Cd hypertolerance in S. plumbizincicola.
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Affiliation(s)
- Haixia Zhao
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Liangsheng Wang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fang-Jie Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Longhua Wu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Anna Liu
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Wenzhong Xu
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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15
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Lekeux G, Crowet JM, Nouet C, Joris M, Jadoul A, Bosman B, Carnol M, Motte P, Lins L, Galleni M, Hanikenne M. Homology modeling and in vivo functional characterization of the zinc permeation pathway in a heavy metal P-type ATPase. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:329-341. [PMID: 30418580 PMCID: PMC6305203 DOI: 10.1093/jxb/ery353] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/01/2018] [Indexed: 05/26/2023]
Abstract
The P1B ATPase heavy metal ATPase 4 (HMA4) is responsible for zinc and cadmium translocation from roots to shoots in Arabidopsis thaliana. It couples ATP hydrolysis to cytosolic domain movements, enabling metal transport across the membrane. The detailed mechanism of metal permeation by HMA4 through the membrane remains elusive. Here, homology modeling of the HMA4 transmembrane region was conducted based on the crystal structure of a ZntA bacterial homolog. The analysis highlighted amino acids forming a metal permeation pathway, whose importance was subsequently investigated functionally through mutagenesis and complementation experiments in plants. Although the zinc pathway displayed overall conservation among the two proteins, significant differences were observed, especially in the entrance area with altered electronegativity and the presence of a ionic interaction/hydrogen bond network. The analysis also newly identified amino acids whose mutation results in total or partial loss of the protein function. In addition, comparison of zinc and cadmium accumulation in shoots of A. thaliana complemented lines revealed a number of HMA4 mutants exhibiting different abilities in zinc and cadmium translocation. These observations could be instrumental to design low cadmium-accumulating crops, hence decreasing human cadmium exposure.
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Affiliation(s)
- Gilles Lekeux
- InBioS - Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, Liège, Belgium
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Jean-Marc Crowet
- Laboratory of Molecular Biophysics at Interfaces, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Cécile Nouet
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Marine Joris
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Alice Jadoul
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Bernard Bosman
- InBioS - PhytoSystems, Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, Liège, Belgium
| | - Monique Carnol
- InBioS - PhytoSystems, Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, Liège, Belgium
| | - Patrick Motte
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Laurence Lins
- Laboratory of Molecular Biophysics at Interfaces, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Moreno Galleni
- InBioS - Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, Liège, Belgium
| | - Marc Hanikenne
- InBioS - PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
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16
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Lekeux G, Laurent C, Joris M, Jadoul A, Jiang D, Bosman B, Carnol M, Motte P, Xiao Z, Galleni M, Hanikenne M. di-Cysteine motifs in the C-terminus of plant HMA4 proteins confer nanomolar affinity for zinc and are essential for HMA4 function in vivo. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:5547-5560. [PMID: 30137564 PMCID: PMC6255694 DOI: 10.1093/jxb/ery311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/13/2018] [Indexed: 05/22/2023]
Abstract
The PIB ATPase heavy metal ATPase 4 (HMA4) has a central role in the zinc homeostasis network of Arabidopsis thaliana. This membrane protein loads metal from the pericycle cells into the xylem in roots, thereby allowing root to shoot metal translocation. Moreover, HMA4 is key for zinc hyperaccumulation as well as zinc and cadmium hypertolerance in the pseudometallophyte Arabidopsis halleri. The plant-specific cytosolic C-terminal extension of HMA4 is rich in putative metal-binding residues and has substantially diverged between A. thaliana and A. halleri. To clarify the function of the domain in both species, protein variants with truncated C-terminal extension, as well as with mutated di-Cys motifs and/or a His-stretch, were functionally characterized. We show that di-Cys motifs, but not the His-stretch, contribute to high affinity zinc binding and function in planta. We suggest that the HMA4 C-terminal extension is at least partly responsible for protein targeting to the plasma membrane. Finally, we reveal that the C-terminal extensions of both A. thaliana and A. halleri HMA4 proteins share similar function, despite marginally different zinc-binding capacity.
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Affiliation(s)
- Gilles Lekeux
- InBioS – Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, Liège, Belgium
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Clémentine Laurent
- InBioS – Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, Liège, Belgium
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
- Present address: EyeD Pharma, Quartier Hôpital, Avenue Hippocrate, 54000 Liège, Belgium
| | - Marine Joris
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Alice Jadoul
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Dan Jiang
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Bernard Bosman
- InBioS – PhytoSystems, Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, Liège, Belgium
| | - Monique Carnol
- InBioS – PhytoSystems, Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, Liège, Belgium
| | - Patrick Motte
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
| | - Zhiguang Xiao
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
- Present address: Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Moreno Galleni
- InBioS – Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, Liège, Belgium
| | - Marc Hanikenne
- InBioS – PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, Liège, Belgium
- Correspondence:
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17
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Qiao K, Gong L, Tian Y, Wang H, Chai T. The metal-binding domain of wheat heavy metal ATPase 2 (TaHMA2) is involved in zinc/cadmium tolerance and translocation in Arabidopsis. PLANT CELL REPORTS 2018; 37:1343-1352. [PMID: 29936635 DOI: 10.1007/s00299-018-2316-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
Cysteine in the N-terminal metal-binding domain (N-MBD) of TaHMA2 participates in Zn2+/Cd2+ binding and translocation in Arabidopsis. Wheat heavy metal ATPase 2 (TaHMA2) can transport Zn2+ and Cd2+ across membranes. A previous study showed that cysteine (Cys) and glutamate residues in the N-terminal metal-binding domain (N-MBD) were necessary for metal-binding and translocation of TaHMA2 in yeast. However, the function of TaHMA2 in plants was not fully revealed. In this study, we investigated the roles of the CCxxE and CPC motifs in the N-MBD and the N/C-terminal regions of TaHMA2 in Zn2+/Cd2+ translocation in root and shoot of Arabidopsis. Compared with the wild type, overexpression of TaHMA2 and the TaHMA2 derivative (glutamic substituted for alanine from CCxxE) in Arabidopsis increased root length, fresh weight and enhanced Zn2+/Cd2+ root-to-shoot translocation. The plants with a truncated N/C-terminal of TaHMA2 were impaired in Zn2+/Cd2+ tolerance and translocation, while mutagenesis of Cys in the N-MBD reduced the tolerance and transport activity of TaHMA2, suggesting the involvement of Cys in Zn2+/Cd2+ binding and translocation in Arabidopsis. This study therefore provides a theoretical possibility for the application of TaHMA2 in transgenic breeding to regulate metal element balance in crop plants.
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Affiliation(s)
- Kun Qiao
- College of Life Science, University of the Chinese Academy of Sciences, Beijing, China
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen, China
| | - Liang Gong
- College of Life Science, University of the Chinese Academy of Sciences, Beijing, China
| | - Yanbao Tian
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hong Wang
- College of Life Science, University of the Chinese Academy of Sciences, Beijing, China.
| | - Tuanyao Chai
- College of Life Science, University of the Chinese Academy of Sciences, Beijing, China.
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
- The Innovative Academy of Seed Design (INASEED), Chinese Academy of Sciences, Beijing, China.
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Science, Yezin, Nay Pyi Taw, 05282, Myanmar.
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18
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Chen ZR, Kuang L, Gao YQ, Wang YL, Salt DE, Chao DY. AtHMA4 Drives Natural Variation in Leaf Zn Concentration of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2018; 9:270. [PMID: 29545819 PMCID: PMC5839161 DOI: 10.3389/fpls.2018.00270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/15/2018] [Indexed: 05/22/2023]
Abstract
Zinc (Zn) is an essential element for plant growth and development, and Zn derived from crop plants in the diet is also important for human health. Here, we report that genetic variation in Heavy Metal-ATPase 4 (HMA4) controls natural variation in leaf Zn content. Investigation of the natural variation in leaf Zn content in a world-wide collection of 349 Arabidopsis thaliana wild collected accessions identified two accessions, Van-0 and Fab-2, which accumulate significantly lower Zn when compared with Col-0. Both quantitative trait loci (QTL) analysis and bulked segregant analysis (BSA) identified HMA4 as a strong candidate accounting for this variation in leaf Zn concentration. Genetic complementation experiments confirmed this hypothesis. Sequence analysis revealed that a 1-bp deletion in the third exon of HMA4 from Fab-2 is responsible for the lose of function of HMA4 driving the low Zn observed in Fab-2. Unlike in Fab-2 polymorphisms in the promoter region were found to be responsible for the weak function of HMA4 in Van-0. This is supported by both an expression analysis of HMA4 in Van-0 and through a series of T-DNA insertion mutants which generate truncated HMA4 promoters in the Col-0 background. In addition, we also observed that Fab-2, Van-0 and the hma4-2 null mutant in the Col-0 background show enhanced resistance to a combination of high Zn and high Cd in the growth medium, raising the possibility that variation at HMA4 may play a role in environmental adaptation.
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Affiliation(s)
- Zi-Ru Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lu Kuang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Yi-Qun Gao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ya-Ling Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - David E. Salt
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Dai-Yin Chao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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19
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Bothe H, Słomka A. Divergent biology of facultative heavy metal plants. JOURNAL OF PLANT PHYSIOLOGY 2017; 219:45-61. [PMID: 29028613 DOI: 10.1016/j.jplph.2017.08.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 05/04/2023]
Abstract
Among heavy metal plants (the metallophytes), facultative species can live both in soils contaminated by an excess of heavy metals and in non-affected sites. In contrast, obligate metallophytes are restricted to polluted areas. Metallophytes offer a fascinating biology, due to the fact that species have developed different strategies to cope with the adverse conditions of heavy metal soils. The literature distinguishes between hyperaccumulating, accumulating, tolerant and excluding metallophytes, but the borderline between these categories is blurred. Due to the fact that heavy metal soils are dry, nutrient limited and are not uniform but have a patchy distribution in many instances, drought-tolerant or low nutrient demanding species are often regarded as metallophytes in the literature. In only a few cases, the concentrations of heavy metals in soils are so toxic that only a few specifically adapted plants, the genuine metallophytes, can cope with these adverse soil conditions. Current molecular biological studies focus on the genetically amenable and hyperaccumulating Arabidopsis halleri and Noccaea (Thlaspi) caerulescens of the Brassicaceae. Armeria maritima ssp. halleri utilizes glands for the excretion of heavy metals and is, therefore, a heavy metal excluder. The two endemic zinc violets of Western Europe, Viola lutea ssp. calaminaria of the Aachen-Liège area and Viola lutea ssp. westfalica of the Pb-Cu-ditch of Blankenrode, Eastern Westphalia, as well as Viola tricolor ecotypes of Eastern Europe, keep their cells free of excess heavy metals by arbuscular mycorrhizal fungi which bind heavy metals. The Caryophyllaceae, Silene vulgaris f. humilis and Minuartia verna, apparently discard leaves when overloaded with heavy metals. All Central European metallophytes have close relatives that grow in areas outside of heavy metal soils, mainly in the Alps, and have, therefore, been considered as relicts of the glacial epoch in the past. However, the current literature favours the idea that hyperaccumulation of heavy metals serves plants as deterrent against attack by feeding animals (termed elemental defense hypothesis). The capability to hyperaccumulate heavy metals in A. halleri and N. caerulescens is achieved by duplications and alterations of the cis-regulatory properties of genes coding for heavy metal transporting/excreting proteins. Several metallophytes have developed ecotypes with a varying content of such heavy metal transporters as an adaption to the specific toxicity of a heavy metal site.
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Affiliation(s)
- Hermann Bothe
- Botanical Institute, The University of Cologne, Zuelpicher Str. 47b, 50674 Cologne, Germany.
| | - Aneta Słomka
- Department of Plant Cytology and Embryology, Jagiellonian University, Gronostajowa 9 Str., 30-387 Cracow, Poland.
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20
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OsMTP11 is localised at the Golgi and contributes to Mn tolerance. Sci Rep 2017; 7:15258. [PMID: 29127328 PMCID: PMC5681648 DOI: 10.1038/s41598-017-15324-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 10/20/2017] [Indexed: 11/22/2022] Open
Abstract
Membrane transporters play a key role in obtaining sufficient quantities of manganese (Mn) but also in protecting against Mn toxicity. We have characterized OsMTP11, a member of the Cation Diffusion Facilitator/Metal Tolerance Protein (CDF/MTP) family of metal cation transporters in Oryza sativa. We demonstrate that OsMTP11 functions in alleviating Mn toxicity as its expression can rescue the Mn-sensitive phenotype of the Arabidopsis mtp11-3 knockout mutant. When expressed stably in Arabidopsis and transiently in rice and tobacco, it localises to the Golgi. OsMTP11 partially rescues the Mn-hypersensitivity of the pmr1 yeast mutant but only slightly alleviates the Zn sensitivity of the zrc1 cot1 yeast mutant. Overall, these results suggest that OsMTP11 predominantly functions as a Mn-transporting CDF with lower affinity for Zn. Site-directed mutagenesis studies revealed four substitutions in OsMTP11 that appear to alter its transport activity. OsMTP11 harbouring a substitution of leucine 150 to a serine fully rescued pmr1 Mn-sensitivity at all concentrations tested. The other substitutions, including those at conserved DxxxD domains, reduced complementation of pmr1 to different levels. This indicates their importance for OsMTP11 function and is a starting point for refining transporter activity/specificity.
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21
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Nazri AZ, Griffin JH, Peaston KA, Alexander‐Webber DG, Williams LE. F-group bZIPs in barley-a role in Zn deficiency. PLANT, CELL & ENVIRONMENT 2017; 40:2754-2770. [PMID: 28763829 PMCID: PMC5656896 DOI: 10.1111/pce.13045] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 07/09/2017] [Indexed: 05/13/2023]
Abstract
Zinc (Zn) deficiency negatively impacts the development and health of plants and affects crop yield. When experiencing low Zn, plants undergo an adaptive response to maintain Zn homeostasis. We provide further evidence for the role of F-group transcription factors, AtbZIP19 and AtbZIP23, in responding to Zn deficiency in Arabidopsis and demonstrate the sensitivity and specificity of this response. Despite their economic importance, the role of F-group bZIPs in cereal crops is largely unknown. Here, we provide new insights by functionally characterizing these in barley (Hordeum vulgare), demonstrating an expanded number of F-group bZIPs (seven) compared to Arabidopsis. The F-group barley bZIPs, HvbZIP56 and HvbZIP62, partially rescue the Zn-dependent growth phenotype and ZIP-transporter gene regulation of an Arabidopsis bzip19-4 bzip23-2 mutant. This supports a conserved mechanism of action in adapting to Zn deficiency. HvbZIP56 localizes to the cytoplasm and nucleus when expressed in Arabidopsis and tobacco. Promoter analysis demonstrates that the barley ZIP transporters that are upregulated under Zn deficiency contain cis Zn-deficiency response elements (ZDREs). ZDREs are also found in particular barley bZIP promoters. This study represents a significant step forward in understanding the mechanisms controlling Zn responses in cereal crops, and will aid in developing strategies for crop improvement.
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Affiliation(s)
| | | | - Kerry A. Peaston
- Biological SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
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22
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Zeng L, Zhu T, Gao Y, Wang Y, Ning C, Björn LO, Chen D, Li S. Effects of Ca addition on the uptake, translocation, and distribution of Cd in Arabidopsis thaliana. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 139:228-237. [PMID: 28152404 DOI: 10.1016/j.ecoenv.2017.01.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 05/07/2023]
Abstract
Cadmium (Cd) pollution poses a risk to human health for its accumulation in soil and crops, but this can be alleviated by calcium (Ca) addition. However, its mechanism remains unclear yet. In this study, Arabidopsis thaliana was used to explore the alleviating effects of Ca on Cd toxicity and its specific function during uptake, upward-translocation, and distribution of Cd. Supplementing plants with 5mM CaCl2 alleviated the intoxication symptoms caused by 50μM CdCl2, such as smaller leaves, early bolting and root browning. Ca addition decreased uptake of Cd, possibly by reducing the physical adsorption of Cd since the root cell membrane was well maintained and lignin deposition was decreased as well, and by decreasing symplastic Cd transport. Expression of the genes involved (AtZIP2 and AtZIP4) was also decreased. In addition, Ca accumulated in the plant shoot to help facilitating the upward-translocation of Cd, with evidence of higher translocation factor and expression of genes that were involved in Ca transport (AtPCR1) and Cd xylem loading (AtHMA2 and AtHMA4). Dithizone-staining of Cd in leaves showed that in Cd+Ca-treated plants, Ca addition initially protected the leaf stomata by preventing Cd from entering guard cells, but with prolonged Cd treatment facilitated the Cd accumulation around trichomes and maybe its excretion. We conclude that Ca promotes the upward-translocation of Cd and changes its distribution in leaves. The results may have relevance for bioremediation.
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Affiliation(s)
- Lihua Zeng
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Ting Zhu
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Ya Gao
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yutao Wang
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Chanjuan Ning
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Lars Olof Björn
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China; Department of Biology, Molecular Cell Biology, Lund University, Lund 22467, Sweden
| | - Da Chen
- Cooperative Wildlife Research Laboratory and Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
| | - Shaoshan Li
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China.
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23
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Keeran NS, Ganesan G, Parida AK. A novel heavy metal ATPase peptide from Prosopis juliflora is involved in metal uptake in yeast and tobacco. Transgenic Res 2017; 26:247-261. [PMID: 27888434 DOI: 10.1007/s11248-016-0002-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 11/13/2016] [Indexed: 12/01/2022]
Abstract
Heavy metal pollution of agricultural soils is one of the most severe ecological problems in the world. Prosopis juliflora, a phreatophytic tree species, grows well in heavy metal laden industrial sites and is known to accumulate heavy metals. Heavy Metal ATPases (HMAs) are ATP driven heavy metal pumps that translocate heavy metals across biological membranes thus helping the plant in heavy metal tolerance and phytoremediation. In the present study we have isolated and characterized a novel 28.9 kDa heavy metal ATPase peptide (PjHMT) from P. juliflora which shows high similarity to the C-terminal region of P1B ATPase HMA1. It also shows the absence of the invariant signature sequence DKTGT, and the metal binding CPX motif but the presence of conserved regions like MVGEGINDAPAL (ATP binding consensus sequence), HEGGTLLVCLNS (metal binding domain) and MLTGD, GEGIND and HEGG motifs which play important roles in metal transport or ATP binding. PjHMT, was found to be upregulated under cadmium and zinc stress. Heterologous expression of PjHMT in yeast showed a higher accumulation and tolerance of heavy metals in yeast. Further, transgenic tobacco plants constitutively expressing PjHMT also showed increased accumulation and tolerance to cadmium. Thus, this study suggests that the transport peptide from P. juliflora may have an important role in Cd uptake and thus in phytoremediation.
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Affiliation(s)
- Nisha S Keeran
- Plant Molecular Biology Lab, M S Swaminathan Research Foundation, 3rd Cross Street, Institutional Area, Taramani, Chennai, Tamil Nadu, 600 113, India
| | - G Ganesan
- Plant Molecular Biology Lab, M S Swaminathan Research Foundation, 3rd Cross Street, Institutional Area, Taramani, Chennai, Tamil Nadu, 600 113, India
- Department of Genetic Engineering, SRM University, Kattankulathur, Tamil Nadu, 603 203, India
| | - Ajay K Parida
- Plant Molecular Biology Lab, M S Swaminathan Research Foundation, 3rd Cross Street, Institutional Area, Taramani, Chennai, Tamil Nadu, 600 113, India.
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24
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Elena López-Calcagno P, Omar Abuzaid A, Lawson T, Anne Raines C. Arabidopsis CP12 mutants have reduced levels of phosphoribulokinase and impaired function of the Calvin-Benson cycle. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2285-2298. [PMID: 28430985 PMCID: PMC5447874 DOI: 10.1093/jxb/erx084] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
CP12 is a small, redox-sensitive protein, the most detailed understanding of which is the thioredoxin-mediated regulation of the Calvin-Benson cycle, where it facilitates the formation of a complex between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) in response to changes in light intensity. In most organisms, CP12 proteins are encoded by small multigene families, where the importance of each individual CP12 gene in vivo has not yet been reported. We used Arabidopsis thaliana T-DNA mutants and RNAi transgenic lines with reduced levels of CP12 transcript to determine the relative importance of each of the CP12 genes. We found that single cp12-1, cp12-2, and cp12-3 mutants do not develop a severe photosynthetic or growth phenotype. In contrast, reductions of both CP12-1 and CP12-2 transcripts lead to reductions in photosynthetic capacity and to slower growth and reduced seed yield. No clear phenotype for CP12-3 was evident. Additionally, the levels of PRK protein are reduced in the cp12-1, cp12-1/2, and multiple mutants. Our results suggest that there is functional redundancy between CP12-1 and CP12-2 in Arabidopsis where these proteins have a role in determining the level of PRK in mature leaves and hence photosynthetic capacity.
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Affiliation(s)
| | - Amani Omar Abuzaid
- Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Tracy Lawson
- Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Christine Anne Raines
- Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
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25
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Guo Q, Meng L, Humphreys MW, Scullion J, Mur LAJ. Expression of FlHMA3, a P 1B2-ATPase from Festulolium loliaceum, correlates with response to cadmium stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 112:270-277. [PMID: 28113076 DOI: 10.1016/j.plaphy.2017.01.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/12/2017] [Accepted: 01/12/2017] [Indexed: 05/04/2023]
Abstract
Heavy metal ATPase 3 (HMA3), a P1B2-ATPase, is a key tonoplast transporter involved in mediating the vacuolar sequestration of cadmium (Cd) to detoxify the intake of this element by plants. HMA3 expression in response to Cd stress has not been previously examined in the grass hybrid species Festulolium loliaceum (Huds.) P. Fourn. In this study, FlHMA3 isolated from F. loliaceum was found to comprise 833 amino acid residues with 77% homology to the rice OsHMA3. Transient expression of FlHMA3 fused to enhanced green fluorescent protein in Arabidopsis protoplasts suggested its localization to vacuolar membranes. Quantitative real-time RT-PCR analysis of F. loliaceum revealed that FlHMA3 is expressed predominantly within roots and up-regulated by excess Cd. Over the 168 h treatment, Cd content of F. loliaceum roots was significantly higher than that of shoots, regardless of external CdCl2 concentrations. A significant positive correlation was found between FlHMA3 expression and Cd accumulation in roots of F. loliaceum seedlings subjected to 10-100 mg L-1 CdCl2 for 168 h or, in a separate experiment, to 25 or 100 mg L-1 CdCl2 for the same duration. These findings provide evidence that FlHMA3 encodes a vacuolar P1B2-ATPase that may play an important role in Cd2+ sequestration into root cell vacuoles, thereby limiting the entry of Cd2+ into the cytoplasm and reducing Cd2+ toxicity.
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Affiliation(s)
- Qiang Guo
- Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China
| | - Lin Meng
- Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
| | - Mike W Humphreys
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA, UK
| | - John Scullion
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA, UK
| | - Luis A J Mur
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA, UK
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26
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Huang XY, Salt DE. Plant Ionomics: From Elemental Profiling to Environmental Adaptation. MOLECULAR PLANT 2016; 9:787-97. [PMID: 27212388 DOI: 10.1016/j.molp.2016.05.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/12/2016] [Accepted: 05/16/2016] [Indexed: 05/03/2023]
Abstract
Ionomics is a high-throughput elemental profiling approach to study the molecular mechanistic basis underlying mineral nutrient and trace element composition (also known as the ionome) of living organisms. Since the concept of ionomics was first introduced more than 10 years ago, significant progress has been made in the identification of genes and gene networks that control the ionome. In this update, we summarize the progress made in using the ionomics approach over the last decade, including the identification of genes by forward genetics and the study of natural ionomic variation. We further discuss the potential application of ionomics to the investigation of the ecological functions of ionomic alleles in adaptation to the environment.
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Affiliation(s)
- Xin-Yuan Huang
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - David E Salt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK.
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27
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Laurent C, Lekeux G, Ukuwela AA, Xiao Z, Charlier JB, Bosman B, Carnol M, Motte P, Damblon C, Galleni M, Hanikenne M. Metal binding to the N-terminal cytoplasmic domain of the PIB ATPase HMA4 is required for metal transport in Arabidopsis. PLANT MOLECULAR BIOLOGY 2016; 90:453-66. [PMID: 26797794 DOI: 10.1007/s11103-016-0429-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/03/2016] [Indexed: 05/26/2023]
Abstract
PIB ATPases are metal cation pumps that transport metals across membranes. These proteins possess N- and C-terminal cytoplasmic extensions that contain Cys- and His-rich high affinity metal binding domains, which may be involved in metal sensing, metal ion selectivity and/or in regulation of the pump activity. The PIB ATPase HMA4 (Heavy Metal ATPase 4) plays a central role in metal homeostasis in Arabidopsis thaliana and has a key function in zinc and cadmium hypertolerance and hyperaccumulation in the extremophile plant species Arabidopsis halleri. Here, we examined the function and structure of the N-terminal cytoplasmic metal-binding domain of HMA4. We mutagenized a conserved CCTSE metal-binding motif in the domain and assessed the impact of the mutations on protein function and localization in planta, on metal-binding properties in vitro and on protein structure by Nuclear Magnetic Resonance spectroscopy. The two Cys residues of the motif are essential for the function, but not for localization, of HMA4 in planta, whereas the Glu residue is important but not essential. These residues also determine zinc coordination and affinity. Zinc binding to the N-terminal domain is thus crucial for HMA4 protein function, whereas it is not required to maintain the protein structure. Altogether, combining in vivo and in vitro approaches in our study provides insights towards the molecular understanding of metal transport and specificity of metal P-type ATPases.
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Affiliation(s)
- Clémentine Laurent
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium
| | - Gilles Lekeux
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium
| | - Ashwinie A Ukuwela
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Zhiguang Xiao
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jean-Benoit Charlier
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium
| | - Bernard Bosman
- Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, 4000, Liège, Belgium
| | - Monique Carnol
- Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, 4000, Liège, Belgium
| | - Patrick Motte
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium
- PhytoSYSTEMS, University of Liège, 4000, Liège, Belgium
| | - Christian Damblon
- Chimie Biologique Structurale, Department of Chemistry, University of Liège, Liège, Belgium
| | - Moreno Galleni
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium
| | - Marc Hanikenne
- Department of Life Sciences, Center for Protein Engineering (CIP), University of Liège, 4000, Liège, Belgium.
- PhytoSYSTEMS, University of Liège, 4000, Liège, Belgium.
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28
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Xiang S, Feng S, Zhang Y, Tan J, Liang S, Chai T. The N-terminal degenerated metal-binding domain is involved in the heavy metal transport activity of TaHMA2. PLANT CELL REPORTS 2015; 34:1615-1628. [PMID: 26037615 DOI: 10.1007/s00299-015-1813-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 04/23/2015] [Accepted: 05/20/2015] [Indexed: 06/04/2023]
Abstract
We identified key residues of TaHMA2, and the N- and C-terminal regions of the protein have different roles in its transport function when heterologously expressed in yeast. TaHMA2, a P1B-type ATPase from wheat (Triticum aestivum L.), plays an important role in heavy metal homeostasis in plants. A previous study showed that overexpressing TaHMA2 in rice (Oryza sativa L.), Arabidopsis thaliana, or tobacco (Nicotiana tabacum L.) resulted in various responses to heavy metals. Here, we report the heterologous expression of TaHMA2 in the yeast Saccharomyces cerevisiae. TaHMA2 expression increased the yeast's sensitivity to Cd, but not to Zn, Pb or Co, and increased Cd accumulation was concurrently observed. The eGFP-TaHMA2 fusion protein was localized to the plasma membrane and showed a discontinuous pattern. Mutagenesis of the cysteine and glutamate residues in the N-terminal metal-binding domain (N-MBD) impaired the function of TaHMA2. Deletion of most of the C terminus (TaHMA2ΔC, 712-1003) partially abolished the protein's function, whereas deletion of the N terminus (TaHMA2ΔN, 2-699) completely abolished Cd sensitivity. These data suggest that cysteine and glutamate residues are important for the metal-binding/translocation function of TaHMA2. Additional studies are needed to further understand the selectivity of TaHMA2 in planta.
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Affiliation(s)
- Shuqin Xiang
- College of Life Science, University of the Chinese Academy of Sciences, Beijing, China
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29
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Nouet C, Charlier JB, Carnol M, Bosman B, Farnir F, Motte P, Hanikenne M. Functional analysis of the three HMA4 copies of the metal hyperaccumulator Arabidopsis halleri. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:5783-95. [PMID: 26044091 PMCID: PMC4566976 DOI: 10.1093/jxb/erv280] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In Arabidopsis halleri, the HMA4 gene has an essential function in Zn/Cd hypertolerance and hyperaccumulation by mediating root-to-shoot translocation of metals. Constitutive high expression of AhHMA4 results from a tandem triplication and cis-activation of the promoter of all three copies. The three AhHMA4 copies possess divergent promoter sequences, but highly conserved coding sequences, and display identical expression profiles in the root and shoot vascular system. Here, an AhHMA4::GFP fusion was expressed under the control of each of the three A. halleri HMA4 promoters in a hma2hma4 double mutant of A. thaliana to individually examine the function of each AhHMA4 copy. The protein showed non-polar localization at the plasma membrane of the root pericycle cells of both A. thaliana and A. halleri. The expression of each AhHMA4::GFP copy complemented the severe Zn-deficiency phenotype of the hma2hma4 mutant by restoring root-to-shoot translocation of Zn. However, each copy had a different impact on metal homeostasis in the A. thaliana genetic background: AhHMA4 copies 2 and 3 were more highly expressed and provided higher Zn tolerance in roots and accumulation in shoots than copy 1, and AhHMA4 copy 3 also increased Cd tolerance in roots. These data suggest a certain extent of functional differentiation among the three A. halleri HMA4 copies, stemming from differences in expression levels rather than in expression profile. HMA4 is a key node of the Zn homeostasis network and small changes in expression level can have a major impact on Zn allocation to root or shoot tissues.
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Affiliation(s)
- Cécile Nouet
- Functional Genomics and Plant Molecular Imaging, Center for Protein Engineering (CIP), Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Jean-Benoit Charlier
- Functional Genomics and Plant Molecular Imaging, Center for Protein Engineering (CIP), Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Monique Carnol
- Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, B-4000 Liège, Belgium
| | - Bernard Bosman
- Laboratory of Plant and Microbial Ecology, Department of Biology, Ecology, Evolution, University of Liège, B-4000 Liège, Belgium
| | - Frédéric Farnir
- Biostatistics and Bioinformatics, FARAH, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - Patrick Motte
- Functional Genomics and Plant Molecular Imaging, Center for Protein Engineering (CIP), Department of Life Sciences, University of Liège, B-4000 Liège, Belgium PhytoSYSTEMS, University of Liège, B-4000 Liège, Belgium
| | - Marc Hanikenne
- Functional Genomics and Plant Molecular Imaging, Center for Protein Engineering (CIP), Department of Life Sciences, University of Liège, B-4000 Liège, Belgium PhytoSYSTEMS, University of Liège, B-4000 Liège, Belgium
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30
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Migocka M, Papierniak A, Maciaszczyk-Dziubinska E, Posyniak E, Kosieradzka A. Molecular and biochemical properties of two P1B2-ATPases, CsHMA3 and CsHMA4, from cucumber. PLANT, CELL & ENVIRONMENT 2015; 38:1127-41. [PMID: 25210955 DOI: 10.1111/pce.12447] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/27/2014] [Accepted: 08/29/2014] [Indexed: 05/18/2023]
Abstract
P1B-ATPases (heavy metal ATPases, HMAs) constitute a multigenic subfamily of P-ATPases involved in the transport of monovalent and divalent heavy metals in plant cells. Here, we present the organization of genes encoding the HMA family in the cucumber genome and report the function and biochemical properties of two cucumber proteins homologous to the HMA2-4-like plant HMAs. Eight genes encoding putative P1B -ATPases were identified in the cucumber genome. Among them, CsHMA3 was predominantly expressed in roots and up-regulated by Pb, Zn and Cd excess, whereas the CsHMA4 transcript was most abundant in roots and flowers of cucumber plants, and elevated under Pb and Zn excess. Expression of CsHMA3 in Saccharomyces cerevisiae enhanced yeast tolerance to Cd and Pb, whereas CsHMA4 conferred increased resistance of yeast cells to Cd and Zn. Immunostaining with specific antibodies raised against cucumber proteins revealed tonoplast localization of CsHMA3 and plasma membrane localization of CsHMA4 in cucumber root cells. Kinetic studies of CsHMA3 and CsHMA4 in yeast membranes indicated differing heavy metal cation affinities of these two proteins. Altogether, the results suggest an important role of CsHMA3 and CsHMA4 in Cd and Pb detoxification and Zn homeostasis in cucumber cells.
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Affiliation(s)
- Magdalena Migocka
- Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wroclaw Kanonia 6/8, Wroclaw, 50-328, Poland
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31
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Siemianowski O, Barabasz A, Kendziorek M, Ruszczyńska A, Bulska E, Williams LE, Antosiewicz DM. HMA4 expression in tobacco reduces Cd accumulation due to the induction of the apoplastic barrier. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1125-39. [PMID: 24420575 PMCID: PMC3935570 DOI: 10.1093/jxb/ert471] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ectopic expression in tobacco (Nicotiana tabacum v. Xanthi) of the export protein AtHMA4 (responsible in Arabidopsis for the control of Zn/Cd root to shoot translocation) resulted in decreased Cd uptake/accumulation in roots and shoots. This study contributes to understanding the mechanisms underlying this Cd-dependent phenotype to help predict the consequences of transgene expression for potential phytoremediation/biofortification-based strategies. Microarray analysis was performed to identify metal homeostasis genes that were differentially expressed in roots of Cd-exposed AtHMA4-expressing tobacco relative to the wild type. It was established that down-regulation of genes known to mediate Cd uptake was not responsible for reduced Cd uptake/accumulation in AtHMA4 transformants. The transcript levels of NtIRT1 and NtZIP1 were higher in transgenic plants, indicating an induction of the Fe and Zn deficiency status due to AtHMA4 expression. Interestingly, upon exposure to Cd, genes involved in cell wall lignification (NtHCT, NtOMET, and NtPrx11a) were up-regulated in transformants. Microscopic analysis of roots demonstrated that expression of AtHMA4 caused an induction of cell wall lignification in the external cell layers that was accompanied by enhanced H2O2 accumulation. Further study showed that the concentration of other elements (B, Co, Cu, Ni, Mo, and Zn) was reduced in AtHMA4 transformants in the presence of Cd. In conclusion, due to ectopic expression of 35S::AtHMA4, the physical apoplastic barrier within the external cell layer developed, which is likely to be responsible for the reduction of Cd uptake/accumulation.
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Affiliation(s)
- Oskar Siemianowski
- University of Warsaw, Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, Miecznikowa str. 1, 02-096 Warszawa, Poland
| | - Anna Barabasz
- University of Warsaw, Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, Miecznikowa str. 1, 02-096 Warszawa, Poland
| | - Maria Kendziorek
- University of Warsaw, Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, Miecznikowa str. 1, 02-096 Warszawa, Poland
| | - Anna Ruszczyńska
- University of Warsaw, Faculty of Chemistry, Pasteura str. 1, 02-093 Warszawa, Poland
| | - Ewa Bulska
- University of Warsaw, Faculty of Chemistry, Pasteura str. 1, 02-093 Warszawa, Poland
| | | | - Danuta Maria Antosiewicz
- University of Warsaw, Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, Miecznikowa str. 1, 02-096 Warszawa, Poland
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32
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Functional analysis of the C-terminal region of the vacuolar cadmium-transporting rice OsHMA3. FEBS Lett 2014; 588:789-94. [PMID: 24492003 DOI: 10.1016/j.febslet.2014.01.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 01/09/2014] [Accepted: 01/17/2014] [Indexed: 11/21/2022]
Abstract
Rice OsHMA3 is a vacuolar cadmium (Cd) transporter belonging to the P1B-ATPase family and has a long (273aa) C-terminal region. We analyzed the function of the region related to Cd using the transgenic Arabidopsis Col-0 ecotype, which is sensitive to Cd. The OsHMA3 variant containing a truncated (58aa) C-terminal region did not confer Cd tolerance, whereas an OsHMA3 variant containing a longer truncated (105aa) C-terminal region conferred Cd tolerance to transgenic Arabidopsis. We conclude that the C-terminal region, particularly the region containing the first 105aa, has an important role in OsHMA3 activity.
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Cun P, Sarrobert C, Richaud P, Chevalier A, Soreau P, Auroy P, Gravot A, Baltz A, Leonhardt N, Vavasseur A. Modulation of Zn/Cd P1B2-ATPase activities in Arabidopsis impacts differently on Zn and Cd contents in shoots and seeds. Metallomics 2014; 6:2109-16. [DOI: 10.1039/c4mt00182f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Changes in the expression levels of P1B2-ATPases in Arabidopsis impacts Zn and Cd contents in shoots and seeds.
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Affiliation(s)
- Pierre Cun
- IBEB-SBVME Laboratoire de Biologie du Développement des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Catherine Sarrobert
- IBEB-SBVME Groupe de Recherches Appliquées en Phytotechnologie
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Pierre Richaud
- IBEB-SBVME Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Anne Chevalier
- IBEB-SBVME Laboratoire d'Ecophysiologie Moléculaire des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Paul Soreau
- IBEB-SBVME Groupe de Recherches Appliquées en Phytotechnologie
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Pascaline Auroy
- IBEB-SBVME Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Antoine Gravot
- IBEB-SBVME Laboratoire de Biologie du Développement des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Anthony Baltz
- IBEB-SBVME Laboratoire de Biologie du Développement des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Nathalie Leonhardt
- IBEB-SBVME Laboratoire de Biologie du Développement des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
| | - Alain Vavasseur
- IBEB-SBVME Laboratoire de Biologie du Développement des Plantes
- UMR7265 CNRS-Commissariat à l'Energie Atomique et aux Energies Alternatives Cadarache
- Université Aix-Marseille
- F-13108 Saint-Paul-lez-Durance, France
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Barabasz A, Wilkowska A, Tracz K, Ruszczyńska A, Bulska E, Mills RF, Williams LE, Antosiewicz DM. Expression of HvHMA2 in tobacco modifies Zn-Fe-Cd homeostasis. JOURNAL OF PLANT PHYSIOLOGY 2013; 170:1176-86. [PMID: 23664582 DOI: 10.1016/j.jplph.2013.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/21/2013] [Accepted: 03/24/2013] [Indexed: 05/20/2023]
Abstract
HvHMA2 is a plasma membrane P1B-ATPase from barley that functions in Zn/Cd root-to-shoot transport. To assess the usefulness of HvHMA2 for modifying the metal content in aerial plant parts, it was expressed in tobacco under the CaMV35S promoter. Transformation with HvHMA2 did not produce one unique pattern of Zn and Cd accumulation; instead it depended on external metal supply. Thus Zn and Cd root-to-shoot translocation was facilitated, but not at all applied Zn/Cd concentrations. Metal uptake was restricted in HvHMA2-transformed plants and the level in the shoot was not enhanced. It was shown that HvHMA2 localizes to the plasma membrane of tobacco cells, and overloads the apoplast with Zn, which could explain the overall decrease in metal uptake observed. Despite the lower levels in the shoot, HvHMA2 transformants showed increased Zn sensitivity. Moreover, introduction of HvHMA2 into tobacco interfered with Fe metabolism and Fe accumulation was modified in HvHMA2-transformants in a Zn- and Cd-concentration dependent manner. The results indicate that ectopic expression of the export protein HvHMA2 in tobacco interferes with tobacco metal Zn-Cd-Fe cross-homeostasis, inducing internal mechanisms regulating metal uptake and tolerance.
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Affiliation(s)
- Anna Barabasz
- Institute of Experimental Plant Biology and Biotechnology, Faculty of Biology, University of Warsaw, Miecznikowa Street 1, 02-096 Warszawa, Poland
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Menguer PK, Farthing E, Peaston KA, Ricachenevsky FK, Fett JP, Williams LE. Functional analysis of the rice vacuolar zinc transporter OsMTP1. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2871-83. [PMID: 23761487 PMCID: PMC3697945 DOI: 10.1093/jxb/ert136] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Heavy metal homeostasis is maintained in plant cells by specialized transporters which compartmentalize or efflux metal ions, maintaining cytosolic concentrations within a narrow range. OsMTP1 is a member of the cation diffusion facilitator (CDF)/metal tolerance protein (MTP) family of metal cation transporters in Oryza sativa, which is closely related to Arabidopsis thaliana MTP1. Functional complementation of the Arabidopsis T-DNA insertion mutant mtp1-1 demonstrates that OsMTP1 transports Zn in planta and localizes at the tonoplast. When heterologously expressed in the yeast mutant zrc1 cot1, OsMTP1 complemented its Zn hypersensitivity and was also localized to the vacuole. OsMTP1 alleviated, to some extent, the Co sensitivity of this mutant, rescued the Fe hypersensitivity of the ccc1 mutant at low Fe concentrations, and restored growth of the Cd-hypersensitive mutant ycf1 at low Cd concentrations. These results suggest that OsMTP1 transports Zn but also Co, Fe, and Cd, possibly with lower affinity. Site-directed mutagenesis studies revealed two substitutions in OsMTP1 that alter the transport function of this protein. OsMTP1 harbouring a substitution of Leu82 to a phenylalanine can still transport low levels of Zn, with an enhanced affinity for Fe and Co, and a gain of function for Mn. A substitution of His90 with an aspartic acid completely abolishes Zn transport but improves Fe transport in OsMTP1. These amino acid residues are important in determining substrate specificity and may be a starting point for refining transporter activity in possible biotechnological applications, such as biofortification and phytoremediation.
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Affiliation(s)
- Paloma K. Menguer
- Centre for Biological Science, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1B, UK
- Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, 91501–970, Brazil
| | - Emily Farthing
- Centre for Biological Science, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1B, UK
| | - Kerry A. Peaston
- Centre for Biological Science, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1B, UK
| | - Felipe Klein Ricachenevsky
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, PO Box 15005, Porto Alegre, 91501–970, Brazil
| | - Janette Palma Fett
- Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, 91501–970, Brazil
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, PO Box 15005, Porto Alegre, 91501–970, Brazil
| | - Lorraine E. Williams
- Centre for Biological Science, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1B, UK
- *To whom correspondence should be addressed. E-mail:
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Siemianowski O, Barabasz A, Weremczuk A, Ruszczyńska A, Bulska E, Williams LE, Antosiewicz DM. Development of Zn-related necrosis in tobacco is enhanced by expressing AtHMA4 and depends on the apoplastic Zn levels. PLANT, CELL & ENVIRONMENT 2013; 36:1093-104. [PMID: 23170996 DOI: 10.1111/pce.12041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 10/18/2012] [Accepted: 11/10/2012] [Indexed: 05/20/2023]
Abstract
AtHMA4 was previously shown to contribute to the control of Zn root-to-shoot translocation and tolerance to high Zn. However, heterologous expression of 35S::AtHMA4 in tobacco (Nicotiana tabacum cv. Xanthi) results in enhanced Zn sensitivity. This study provides a better understanding of the development of this Zn-sensitive phenotype and demonstrates that substantial modifications of Zn homeostasis occur due to AtHMA4 expression. We show that ectopically expressing AtHMA4 in tobacco results in overloading the root and leaf apoplast with Zn. The tissue and cellular distribution of Zn, monitored using Zinpyr-1, was altered in the AtHMA4-expressing plants compared with wild type. Increased loading of the leaf apoplast with Zn in AtHMA4 transformants induced necrosis; this appeared at lower levels of Zn supply in the transgenics compared with wild type. This study suggests that Zn concentration may be sensed in the apoplast of leaves, and if concentrations are above a certain threshold then particular groups of cells accumulate Zn and necrosis is initiated. Therefore, this could be considered as a mechanism for protecting the other parts of the photosynthetically active leaf from Zn toxicity.
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Affiliation(s)
- Oskar Siemianowski
- Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, University of Warsaw, Miecznikowa str. 1, 02-096, Warszawa, Poland
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Rouached H. Recent developments in plant zinc homeostasis and the path toward improved biofortification and phytoremediation programs. PLANT SIGNALING & BEHAVIOR 2013; 8:e22681. [PMID: 23221755 PMCID: PMC3745571 DOI: 10.4161/psb.22681] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 05/20/2023]
Abstract
Zinc (Zn) is an essential micronutrient for all living organisms. Plants serve as a major entry point for this element into the food chain. Zn deficiency has become a widespread nutritional condition, which mirror the inadequate Zn reserves in significant proportion of the earth's arable land. A recent assessment by the World Health Organization revealed that one third of the world's population is at risk of Zn deficiency. To counter this alarming situation, substantial efforts have been made to increase Zn content and availability in staple crops and grains. Nevertheless, the absence of fundamental information has held back progress in this field. Developing a better understanding of how Zn homeostasis is regulated in plants, such as Zn transporters at loading bottlenecks, is of primary interest to biofortification and phytoremediation programs. Many reviews have been published on this subject, and here we briefly summarize the regulation of one limiting step in Zn distribution within plants - the loading of Zn into root xylem.
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Takahashi R, Bashir K, Ishimaru Y, Nishizawa NK, Nakanishi H. The role of heavy-metal ATPases, HMAs, in zinc and cadmium transport in rice. PLANT SIGNALING & BEHAVIOR 2012; 7:1605-7. [PMID: 23072989 PMCID: PMC3578901 DOI: 10.4161/psb.22454] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The P(1B)-type heavy metal ATPases (HMAs) are diverse in terms of tissue distribution, subcellular localization, and metal specificity. Functional studies of HMAs have shown that these transporters can be divided into two subgroups based on their metal-substrate specificity: a copper (Cu)/silver (Ag) group and a zinc (Zn)/cobalt (Co)/cadmium (Cd)/lead (Pb) group. Studies on Arabidopsis thaliana and metal hyperaccumulator plants indicate that HMAs play an important role in the translocation or detoxification of Zn and Cd in plants. Rice possesses nine HMA genes, of which OsHMA1-OsHMA3 belong to the Zn/Co/Cd/Pb subgroup. OsHMA2 plays an important role in root-to-shoot translocation of Zn and Cd, and participates in Zn and Cd transport to developing seeds in rice. OsHMA3 transports Cd and plays a role in the sequestration of Cd into vacuoles in root cells. Modification of the expression of these genes might be an effective approach for reducing the Cd concentration in rice grains.
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Affiliation(s)
- Ryuichi Takahashi
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo, Japan
| | - Khurram Bashir
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo, Japan
| | - Yasuhiro Ishimaru
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo, Japan
- Graduate School of Science; Tohoku University; Sendai, Miyagi, Japan
| | - Naoko K. Nishizawa
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo, Japan
- Research Institute for Bioresources and Biotechnology; Ishikawa Prefectural University; Ishikawa, Japan
| | - Hiromi Nakanishi
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo, Japan
- * Correspondence to: Hiromi Nakanisihi;
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Mikkelsen MD, Pedas P, Schiller M, Vincze E, Mills RF, Borg S, Møller A, Schjoerring JK, Williams LE, Baekgaard L, Holm PB, Palmgren MG. Barley HvHMA1 is a heavy metal pump involved in mobilizing organellar Zn and Cu and plays a role in metal loading into grains. PLoS One 2012; 7:e49027. [PMID: 23155447 PMCID: PMC3498361 DOI: 10.1371/journal.pone.0049027] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 10/03/2012] [Indexed: 12/11/2022] Open
Abstract
Heavy metal transporters belonging to the P(1B)-ATPase subfamily of P-type ATPases are key players in cellular heavy metal homeostasis. Heavy metal transporters belonging to the P(1B)-ATPase subfamily of P-type ATPases are key players in cellular heavy metal homeostasis. In this study we investigated the properties of HvHMA1, which is a barley orthologue of Arabidopsis thaliana AtHMA1 localized to the chloroplast envelope. HvHMA1 was localized to the periphery of chloroplast of leaves and in intracellular compartments of grain aleurone cells. HvHMA1 expression was significantly higher in grains compared to leaves. In leaves, HvHMA1 expression was moderately induced by Zn deficiency, but reduced by toxic levels of Zn, Cu and Cd. Isolated barley chloroplasts exported Zn and Cu when supplied with Mg-ATP and this transport was inhibited by the AtHMA1 inhibitor thapsigargin. Down-regulation of HvHMA1 by RNA interference did not have an effect on foliar Zn and Cu contents but resulted in a significant increase in grain Zn and Cu content. Heterologous expression of HvHMA1 in heavy metal-sensitive yeast strains increased their sensitivity to Zn, but also to Cu, Co, Cd, Ca, Mn, and Fe. Based on these results, we suggest that HvHMA1 is a broad-specificity exporter of metals from chloroplasts and serve as a scavenging mechanism for mobilizing plastid Zn and Cu when cells become deficient in these elements. In grains, HvHMA1 might be involved in mobilizing Zn and Cu from the aleurone cells during grain filling and germination.
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Affiliation(s)
- Maria Dalgaard Mikkelsen
- Centre for Membrane Pumps in Cells and Disease (PUMPKIN), Danish National Research Foundation, Frederiksberg, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Pai Pedas
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Michaela Schiller
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Eva Vincze
- Department of Molecular Biology and Genetics, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | - Rebecca F. Mills
- Centre for Biological Sciences, University of Southampton, Southampton, Hampshire, United Kingdom
| | - Søren Borg
- Department of Molecular Biology and Genetics, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | - Annette Møller
- Centre for Membrane Pumps in Cells and Disease (PUMPKIN), Danish National Research Foundation, Frederiksberg, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Jan K. Schjoerring
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lorraine E. Williams
- Centre for Biological Sciences, University of Southampton, Southampton, Hampshire, United Kingdom
| | - Lone Baekgaard
- Centre for Membrane Pumps in Cells and Disease (PUMPKIN), Danish National Research Foundation, Frederiksberg, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Preben Bach Holm
- Department of Molecular Biology and Genetics, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | - Michael G. Palmgren
- Centre for Membrane Pumps in Cells and Disease (PUMPKIN), Danish National Research Foundation, Frederiksberg, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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Genome-wide association studies identify heavy metal ATPase3 as the primary determinant of natural variation in leaf cadmium in Arabidopsis thaliana. PLoS Genet 2012; 8:e1002923. [PMID: 22969436 PMCID: PMC3435251 DOI: 10.1371/journal.pgen.1002923] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/13/2012] [Indexed: 11/19/2022] Open
Abstract
Understanding the mechanism of cadmium (Cd) accumulation in plants is important to help reduce its potential toxicity to both plants and humans through dietary and environmental exposure. Here, we report on a study to uncover the genetic basis underlying natural variation in Cd accumulation in a world-wide collection of 349 wild collected Arabidopsis thaliana accessions. We identified a 4-fold variation (0.5–2 µg Cd g−1 dry weight) in leaf Cd accumulation when these accessions were grown in a controlled common garden. By combining genome-wide association mapping, linkage mapping in an experimental F2 population, and transgenic complementation, we reveal that HMA3 is the sole major locus responsible for the variation in leaf Cd accumulation we observe in this diverse population of A. thaliana accessions. Analysis of the predicted amino acid sequence of HMA3 from 149 A. thaliana accessions reveals the existence of 10 major natural protein haplotypes. Association of these haplotypes with leaf Cd accumulation and genetics complementation experiments indicate that 5 of these haplotypes are active and 5 are inactive, and that elevated leaf Cd accumulation is associated with the reduced function of HMA3 caused by a nonsense mutation and polymorphisms that change two specific amino acids. Cadmium (Cd) is a potentially toxic metal pollutant that threatens food quality and human health in many regions of the world. Plants have evolved mechanisms for the acquisition of essential metals such as zinc and iron from the soil. Though often quite specific, such mechanisms can also lead to the accumulation of Cd by plants. Understanding natural variation in the processes that contribute to Cd accumulation in food crops could help minimize the human health risk posed. We have discovered that DNA sequence changes at a single gene, which encodes the Heavy Metal ATPase 3 (HMA3), drives the variation in Cd accumulation we observe in a world-wide sample of Arabidopsis thaliana. We identified 10 major HMA3 protein variants, of which five contribute to reduce Cd accumulation in leaves of A. thaliana.
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Jaffé FW, Freschet GEC, Valdes BM, Runions J, Terry MJ, Williams LE. G protein-coupled receptor-type G proteins are required for light-dependent seedling growth and fertility in Arabidopsis. THE PLANT CELL 2012; 24:3649-68. [PMID: 23001037 PMCID: PMC3480293 DOI: 10.1105/tpc.112.098681] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 07/13/2012] [Accepted: 08/28/2012] [Indexed: 05/20/2023]
Abstract
G protein-coupled receptor-type G proteins (GTGs) are highly conserved membrane proteins in plants, animals, and fungi that have eight to nine predicted transmembrane domains. They have been classified as G protein-coupled receptor-type G proteins that function as abscisic acid (ABA) receptors in Arabidopsis thaliana. We cloned Arabidopsis GTG1 and GTG2 and isolated new T-DNA insertion alleles of GTG1 and GTG2 in both Wassilewskija and Columbia backgrounds. These gtg1 gtg2 double mutants show defects in fertility, hypocotyl and root growth, and responses to light and sugars. Histological studies of shoot tissue reveal cellular distortions that are particularly evident in the epidermal layer. Stable expression of GTG1(pro):GTG1-GFP (for green fluorescent protein) in Arabidopsis and transient expression in tobacco (Nicotiana tabacum) indicate that GTG1 is localized primarily to Golgi bodies and to the endoplasmic reticulum. Microarray analysis comparing gene expression profiles in the wild type and double mutant revealed differences in expression of genes important for cell wall function, hormone response, and amino acid metabolism. The double mutants isolated here respond normally to ABA in seed germination assays, root growth inhibition, and gene expression analysis. These results are inconsistent with their proposed role as ABA receptors but demonstrate that GTGs are fundamentally important for plant growth and development.
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Affiliation(s)
- Felix W. Jaffé
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Gian-Enrico C. Freschet
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Billy M. Valdes
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - John Runions
- Oxford Brookes University, Department of Biological and Medical Sciences, Oxford OX3 0BP, United Kingdom
| | - Matthew J. Terry
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Lorraine E. Williams
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Mills RF, Peaston KA, Runions J, Williams LE. HvHMA2, a P(1B)-ATPase from barley, is highly conserved among cereals and functions in Zn and Cd transport. PLoS One 2012; 7:e42640. [PMID: 22880063 PMCID: PMC3411818 DOI: 10.1371/journal.pone.0042640] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/11/2012] [Indexed: 11/21/2022] Open
Abstract
Manipulation of crops to improve their nutritional value (biofortification) and optimisation of plants for removal of toxic metals from contaminated soils (phytoremediation) are major goals. Identification of membrane transporters with roles in zinc and cadmium transport would be useful for both aspects. The P1B-ATPases play important roles in heavy metal allocation and detoxification in Arabidopsis and it is now important to elucidate their roles in monocots. We identified nine P1B-ATPases in barley and this study focuses on the functional characterization of HvHMA2, providing evidence for its role in heavy metal transport. HvHMA2 was cloned using information from EST analysis and 5′ RACE. It possesses the conserved aspartate that is phosphorylated during the reaction cycle of P-type pumps and has motifs and key residues characteristic of P1B-ATPases, falling into the P1B-2 subclass. Homologous sequences occur in three major sub-families of the Poaceae (Gramineae). Heterologous expression in Saccharomyces cerevisiae demonstrates that HvHMA2 functions as a Zn and Cd pump. Mutagenesis studies show that proposed cation coordination sites of the P1B-2 pumps are crucial for the metal responses conferred by HvHMA2 in yeast. HvHMA2 expression suppresses the Zn-deficient phenotype of the Arabidopsis hma2hma4 mutant indicating that HvHMA2 functions as a Zn pump in planta and could play a role in root to shoot Zn transport. When expressed in Arabidopsis, HvHMA2 localises predominantly to the plasma membrane.
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Affiliation(s)
- Rebecca F. Mills
- Centre for Biological Sciences, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Kerry A. Peaston
- Centre for Biological Sciences, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - John Runions
- Oxford Brookes University, School of Life Sciences, Oxford, United Kingdom
| | - Lorraine E. Williams
- Centre for Biological Sciences, University of Southampton, Highfield Campus, Southampton, United Kingdom
- * E-mail:
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Craciun AR, Meyer CL, Chen J, Roosens N, De Groodt R, Hilson P, Verbruggen N. Variation in HMA4 gene copy number and expression among Noccaea caerulescens populations presenting different levels of Cd tolerance and accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:4179-89. [PMID: 22581842 DOI: 10.1093/jxb/ers104] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
There is huge variability among populations of the hyperaccumulator Noccaea caerulescens (formerly Thlaspi caerulescens) in their capacity to tolerate and accumulate cadmium. To gain new insights into the mechanisms underlying this variability, we estimated cadmium fluxes and further characterized the N. caerulescens heavy metal ATPase 4 (NcHMA4) gene in three populations (two calamine, Saint-Félix-de-Pallières, France and Prayon, Belgium; one serpentine, Puente Basadre, Spain) presenting contrasting levels of tolerance and accumulation. Cadmium uptake and translocation varied among populations in the same way as accumulation; the population with the highest cadmium concentration in shoots (Saint Félix-de-Pallières) presented the highest capacity for uptake and translocation. We demonstrated that the four NcHMA4 copies identified in a previous study are not fixed at the species level, and that the copy truncated in the C-terminal part encodes a functional protein. NcHMA4 expression and gene copy number was lower in the serpentine population, which was the least efficient in cadmium translocation compared to the calamine populations. NcHMA4 expression was associated with the vascular tissue in all organs, with a maximum at the crown. Overall, our results indicate that differences in cadmium translocation ability of the studied populations appear to be controlled, at least partially, by NcHMA4, while the overexpression of NcHMA4 in the two calamine populations may result from convergent evolution.
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Affiliation(s)
- Adrian R Craciun
- Laboratoire de Physiologie et Génétique Moléculaire des Plantes, Université Libre de Bruxelles, Campus de la Plaine, CP242, Bd du Triomphe, 1050 Brussels, Belgium
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Satoh-Nagasawa N, Mori M, Nakazawa N, Kawamoto T, Nagato Y, Sakurai K, Takahashi H, Watanabe A, Akagi H. Mutations in rice (Oryza sativa) heavy metal ATPase 2 (OsHMA2) restrict the translocation of zinc and cadmium. PLANT & CELL PHYSIOLOGY 2012; 53:213-24. [PMID: 22123790 DOI: 10.1093/pcp/pcr166] [Citation(s) in RCA: 237] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Widespread soil contamination with heavy metals has fostered the need for plant breeders to develop new crops that do not accumulate heavy metals. Metal-transporting transmembrane proteins that transport heavy metals across the plant plasma membrane are key targets for developing these new crops. Oryza sativa heavy metal ATPase 3 (OsHMA3) is known to be a useful gene for limiting cadmium (Cd) accumulation in rice. OsHMA2 is a close homolog of OsHMA3, but the function of OsHMA2 is unknown. To gain insight into the function of OsHMA2, we analyzed three Tos17 insertion mutants. The translocation ratios of zinc (Zn) and Cd were clearly lower in all mutants than in the wild type, suggesting that OsHMA2 is a major transporter of Zn and Cd from roots to shoots. By comparing each allele in the OsHMA2 protein structure and measuring the Cd translocation ratio, we identified the C-terminal region as essential for Cd translocation into shoots. Two alleles were identified as good material for breeding rice that does not contain Cd in the grain but does contain some Zn, and that grows normally.
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Affiliation(s)
- Namiko Satoh-Nagasawa
- Department of Biological Production, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjyo-Nakano, Akita, Japan.
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Shanmugam V, Lo JC, Wu CL, Wang SL, Lai CC, Connolly EL, Huang JL, Yeh KC. Differential expression and regulation of iron-regulated metal transporters in Arabidopsis halleri and Arabidopsis thaliana--the role in zinc tolerance. THE NEW PHYTOLOGIST 2011; 190:125-137. [PMID: 21219335 DOI: 10.1111/j.1469-8137.2010.03606.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
To avoid zinc (Zn) toxicity, plants have developed a Zn homeostasis mechanism to cope with Zn excess in the surrounding soil. In this report, we uncovered the difference of a cross-homeostasis system between iron (Fe) and Zn in dealing with Zn excess in the Zn hyperaccumulator Arabidopsis halleri ssp. gemmifera and nonhyperaccumulator Arabidopsis thaliana. Arabidopsis halleri shows low expression of the Fe acquisition and deficiency response-related genes IRT1 and IRT2 compared with A. thaliana. In A. thaliana, lowering the expression of IRT1 and IRT2 through the addition of excess Fe to the medium increases Zn tolerance. Excess Zn induces significant Fe deficiency in A. thaliana and reduces Fe accumulation in shoots. By contrast, the accumulation of Fe in shoots of A. halleri was stable under various Zn treatments. Root ferric chelate reductase (FRO) activity and expression of FIT are low in A. halleri compared with A. thaliana. Overexpressing a ZIP family member IRT3 in irt1-1, rescues the Fe-deficient phenotype. A fine-tuned Fe homeostasis mechanism in A. halleri maintains optimum Fe level by Zn-regulated ZIP transporters and prevents high Zn uptake through Fe-regulated metal transporters, and in part be responsible for Zn tolerance.
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Affiliation(s)
- Varanavasiappan Shanmugam
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
- Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan, 11529
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan, 402
| | - Jing-Chi Lo
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan 10617
| | - Chia-Lin Wu
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
| | - Shan-Li Wang
- Department of Soil and Environmental Sciences, National Chung-Hsing University, Taichung, Taiwan 402
| | - Chong-Cheong Lai
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
| | - Erin L Connolly
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Jing-Ling Huang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
| | - Kuo-Chen Yeh
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, 11529
- Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan, 11529
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan, 402
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Ó Lochlainn S, Bowen HC, Fray RG, Hammond JP, King GJ, White PJ, Graham NS, Broadley MR. Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator Noccaea caerulescens. PLoS One 2011; 6:e17814. [PMID: 21423774 PMCID: PMC3053397 DOI: 10.1371/journal.pone.0017814] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 02/10/2011] [Indexed: 11/19/2022] Open
Abstract
Zinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea.A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOS™ clones with insert sizes ∼20-40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs.Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter β-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue.This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae.
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Affiliation(s)
- Seosamh Ó Lochlainn
- Plant and Crop Sciences Division, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - Helen C. Bowen
- Warwick HRI, University of Warwick, Wellesbourne, Warwick, United Kingdom
| | - Rupert G. Fray
- Plant and Crop Sciences Division, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - John P. Hammond
- Plant and Crop Sciences Division, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - Graham J. King
- Rothamsted Research, Harpenden, United Kingdom
- Southern Cross Plant Science, Southern Cross University, Lismore, Australia
| | - Philip J. White
- Scottish Crop Research Institute, Invergowrie, Dundee, United Kingdom
| | - Neil S. Graham
- Plant and Crop Sciences Division, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - Martin R. Broadley
- Plant and Crop Sciences Division, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
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