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Ahmed N, Zhang B, Bozdar B, Chachar S, Rai M, Li J, Li Y, Hayat F, Chachar Z, Tu P. The power of magnesium: unlocking the potential for increased yield, quality, and stress tolerance of horticultural crops. FRONTIERS IN PLANT SCIENCE 2023; 14:1285512. [PMID: 37941670 PMCID: PMC10628537 DOI: 10.3389/fpls.2023.1285512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023]
Abstract
Magnesium (Mg2+) is pivotal for the vitality, yield, and quality of horticultural crops. Central to plant physiology, Mg2+ powers photosynthesis as an integral component of chlorophyll, bolstering growth and biomass accumulation. Beyond basic growth, it critically affects crop quality factors, from chlorophyll synthesis to taste, texture, and shelf life. However, Mg2 + deficiency can cripple yields and impede plant development. Magnesium Transporters (MGTs) orchestrate Mg2+ dynamics, with notable variations observed in horticultural species such as Cucumis sativus, Citrullus lanatus, and Citrus sinensis. Furthermore, Mg2+ is key in fortifying plants against environmental stressors and diseases by reinforcing cell walls and spurring the synthesis of defense substances. A burgeoning area of research is the application of magnesium oxide nanoparticles (MgO-NPs), which, owing to their nanoscale size and high reactivity, optimize nutrient uptake, and enhance plant growth and stress resilience. Concurrently, modern breeding techniques provide insights into Mg2+ dynamics to develop crops with improved Mg2+ efficiency and resilience to deficiency. Effective Mg2+ management through soil tests, balanced fertilization, and pH adjustments holds promise for maximizing crop health, productivity, and sustainability. This review unravels the nuanced intricacies of Mg2+ in plant physiology and genetics, and its interplay with external factors, serving as a cornerstone for those keen on harnessing its potential for horticultural excellence.
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Affiliation(s)
- Nazir Ahmed
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Baige Zhang
- Key Laboratory for New Technology Research of Vegetable, Vegetable Research Institute, Guangdong Academy of Agricultural Science, Guangzhou, China
| | - Bilquees Bozdar
- Department of Crop Physiology, Faculty of Crop Production, Sindh Agriculture University, Tandojam, Pakistan
| | - Sadaruddin Chachar
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Mehtab Rai
- Department of Crop Physiology, Faculty of Crop Production, Sindh Agriculture University, Tandojam, Pakistan
| | - Juan Li
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Yongquan Li
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Faisal Hayat
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Zaid Chachar
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
| | - Panfeng Tu
- College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, China
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Kobayashi NI, Takagi H, Yang X, Nishizawa-Yokoi A, Segawa T, Hoshina T, Oonishi T, Suzuki H, Iwata R, Toki S, Nakanishi TM, Tanoi K. Mutations in RZF1, a zinc-finger protein, reduce magnesium uptake in roots and translocation to shoots in rice. PLANT PHYSIOLOGY 2023; 192:342-355. [PMID: 36718554 PMCID: PMC10152673 DOI: 10.1093/plphys/kiad051] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 05/03/2023]
Abstract
Magnesium (Mg) homeostasis is critical for maintaining many biological processes, but little information is available to comprehend the molecular mechanisms regulating Mg concentration in rice (Oryza sativa). To make up for the lack of information, we aimed to identify mutants defective in Mg homeostasis through a forward genetic approach. As a result of the screening of 2,825 M2 seedlings mutated by ion-beam irradiation, we found a rice mutant that showed reduced Mg content in leaves and slightly increased Mg content in roots. Radiotracer 28Mg experiments showed that this mutant, named low-magnesium content 1 (LMGC1), has decreased Mg2+ influx in the root and Mg2+ translocation from root to shoot. Consequently, LMGC1 is sensitive to the low Mg condition and prone to develop chlorosis in the young mature leaf. The MutMap method identified a 7.4-kbp deletion in the LMGC1 genome leading to a loss of two genes. Genome editing using CRISPR-Cas9 further revealed that one of the two lost genes, a gene belonging to the RanBP2-type zinc-finger family that we named RanBP2-TYPE ZINC FINGER1 (OsRZF1), was the causal gene of the low Mg phenotype. OsRZF1 is a nuclear protein and may have a fundamental role in maintaining Mg homeostasis in rice plants.
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Affiliation(s)
- Natsuko I Kobayashi
- Graduate School of Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroki Takagi
- Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa 921-8836, Japan
| | - Xiaoyu Yang
- Graduate School of Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ayako Nishizawa-Yokoi
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3 Kannondai, Tsukuba 305-8604, Japan
| | - Tenta Segawa
- Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa 921-8836, Japan
| | - Tatsuaki Hoshina
- Graduate School of Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takayuki Oonishi
- Center for Education and Research of Community Collaboration, Utsunomiya University, Utsunomiya 321-8505, Japan
| | - Hisashi Suzuki
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Ren Iwata
- Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Seiichi Toki
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3 Kannondai, Tsukuba 305-8604, Japan
- Faculty of Agriculture, Ryukoku University, 1-5 Yokotani, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Yokohama, Kanagawa 236-0027, Japan
| | - Tomoko M Nakanishi
- Graduate School of Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Hoshi University, 2-4-41 Ebara, Shinagawa-Ku, Tokyo 142-8501, Japan
| | - Keitaro Tanoi
- Graduate School of Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Hardy S, Zolotarov Y, Coleman J, Roitman S, Khursheed H, Aubry I, Uetani N, Tremblay M. PRL-1/2 phosphatases control TRPM7 magnesium-dependent function to regulate cellular bioenergetics. Proc Natl Acad Sci U S A 2023; 120:e2221083120. [PMID: 36972446 PMCID: PMC10083557 DOI: 10.1073/pnas.2221083120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/03/2023] [Indexed: 03/29/2023] Open
Abstract
Phosphatases of regenerating liver (PRL-1, PRL-2, PRL-3; also known as PTP4A1, PTP4A2, PTP4A3, respectively) control intracellular magnesium levels by interacting with the CNNM magnesium transport regulators. Still, the exact mechanism governing magnesium transport by this protein complex is not well understood. Herein, we have developed a genetically encoded intracellular magnesium-specific reporter and demonstrate that the CNNM family inhibits the function of the TRPM7 magnesium channel. We show that the small GTPase ARL15 increases CNNM3/TRPM7 protein complex formation to reduce TRPM7 activity. Conversely, PRL-2 overexpression counteracts ARL15 binding to CNNM3 and enhances the function of TRPM7 by preventing the interaction between CNNM3 and TRPM7. Moreover, while TRPM7-induced cell signaling is promoted by PRL-1/2, it is reduced when CNNM3 is overexpressed. Lowering cellular magnesium levels reduces the interaction of CNNM3 with TRPM7 in a PRL-dependent manner, whereby knockdown of PRL-1/2 restores the protein complex formation. Cotargeting of TRPM7 and PRL-1/2 alters mitochondrial function and sensitizes cells to metabolic stress induced by magnesium depletion. These findings reveal the dynamic regulation of TRPM7 function in response to PRL-1/2 levels, to coordinate magnesium transport and reprogram cellular metabolism.
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Affiliation(s)
- Serge Hardy
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Yevgen Zolotarov
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Jacob Coleman
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Simon Roitman
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Hira Khursheed
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Isabelle Aubry
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Noriko Uetani
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
| | - Michel L. Tremblay
- Goodman Cancer Institute, McGill University, Montreal, QCH3A1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QCH3A1A3, Canada
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Sun L, Zhang P, Xing M, Li R, Yu H, Ju Q, Yang J, Xu J. NAC32 alleviates magnesium toxicity-induced cell death through positive regulation of XIPOTL1 expression. PLANT PHYSIOLOGY 2023; 191:849-853. [PMID: 36477811 PMCID: PMC9922428 DOI: 10.1093/plphys/kiac562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Abscisic acid–inducible NAC32 alleviates magnesium toxicity-mediated cell death in roots through direct regulation of XIPOTL1 expression in Arabidopsis.
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Affiliation(s)
| | | | | | | | | | | | | | - Jin Xu
- Author for correspondence:
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Homologs of Ancestral CNNM Proteins Affect Magnesium Homeostasis and Circadian Rhythmicity in a Model Eukaryotic Cell. Int J Mol Sci 2023; 24:ijms24032273. [PMID: 36768595 PMCID: PMC9916543 DOI: 10.3390/ijms24032273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/18/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Biological rhythms are ubiquitous across organisms and coordinate key cellular processes. Oscillations of Mg2+ levels in cells are now well-established, and due to the critical roles of Mg2+ in cell metabolism, they are potentially fundamental for the circadian control of cellular activity. The identity of the transport proteins responsible for sustaining Mg2+ levels in eukaryotic cells remains hotly debated, and several are restricted to specific groups of higher eukaryotes. Here, using the eukaryotic minimal model cells of Ostreococcus tauri, we report two homologs of common descents of the Cyclin M (CNNM)/CorC protein family. Overexpression of these proteins leads to a reduction in the overall magnesium content of cells and a lengthening of the period of circadian gene expression rhythms. However, we observed a paradoxical increase in the magnesium content of the organelle fraction. The chemical inhibition of Mg2+ transport has a synergistic effect on circadian period lengthening upon the overexpression of one CNNM homolog, but not the other. Finally, both homologs rescue the deleterious effect of low extracellular magnesium on cell proliferation rates. Overall, we identified two CNNM proteins that directly affect Mg2+ homeostasis and cellular rhythms.
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Yan J, Ye X, Song Y, Ren T, Wang C, Li X, Cong R, Lu Z, Lu J. Sufficient potassium improves inorganic phosphate-limited photosynthesis in Brassica napus by enhancing metabolic phosphorus fractions and Rubisco activity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:416-429. [PMID: 36479950 DOI: 10.1111/tpj.16057] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/22/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Crop photosynthesis (A) and productivity are often limited by a combination of nutrient stresses, such that changes in the availability of one nutrient may affect the availability of another nutrient, in turn influencing A. In this study, we examined the synergistic effects of phosphorus (P) and potassium (K) on leaf A in a nutrient amendment experiment, in which P and K were added individually or in combination to Brassica napus grown under P and K co-limitation. The data revealed that the addition of P gradually removed the dominant limiting factor (i.e. the limited availability of P) and improved leaf A. Strikingly, the addition of K synergistically improved the overall uptake of P, mainly by boosting plant growth, and compensated for the physiological demand for P by prioritizing investment in metabolic pools of P (P-containing metabolites and inorganic phosphate, Pi). The enlarged pool of metabolically active P was partially associated with the upregulation of Pi regeneration through release from triose phosphates rather than replacement of P-containing lipids. This process mitigated P restrictions on A by maintaining the ATP/NADPH and NADPH/NADP+ ratios and increasing the content and activity of Rubisco. Our findings demonstrate that sufficient K increased Pi-limited A by enhancing metabolic P fractions and Rubisco activity. Thus, ionic synergism may be exploited to mitigate nutrient-limiting factors to improve crop productivity.
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Affiliation(s)
- Jinyao Yan
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaolei Ye
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Yi Song
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Tao Ren
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Chongming Wang
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaokun Li
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Rihuan Cong
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Zhifeng Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Jianwei Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
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Inoue S, Hayashi M, Huang S, Yokosho K, Gotoh E, Ikematsu S, Okumura M, Suzuki T, Kamura T, Kinoshita T, Ma JF. A tonoplast-localized magnesium transporter is crucial for stomatal opening in Arabidopsis under high Mg 2+ conditions. THE NEW PHYTOLOGIST 2022; 236:864-877. [PMID: 35976788 PMCID: PMC9804957 DOI: 10.1111/nph.18410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Plant stomata play an important role in CO2 uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing under changing environmental conditions are still not completely understood. Through large-scale genetic screening, we isolated an Arabidopsis mutant (closed stomata2 (cst2)) that is defective in stomatal opening. We cloned the causal gene (MGR1/CST2) and functionally characterized this gene. The mutant phenotype was caused by a mutation in a gene encoding an unknown protein with similarities to the human magnesium (Mg2+ ) efflux transporter ACDP/CNNM. MGR1/CST2 was localized to the tonoplast and showed transport activity for Mg2+ . This protein was constitutively and highly expressed in guard cells. Knockout of this gene resulted in stomatal closing, decreased photosynthesis and growth retardation, especially under high Mg2+ conditions, while overexpression of this gene increased stomatal opening and tolerance to high Mg2+ concentrations. Furthermore, guard cell-specific expression of MGR1/CST2 in the mutant partially restored its stomatal opening. Our results indicate that MGR1/CST2 expression in the leaf guard cells plays an important role in maintaining cytosolic Mg2+ concentrations through sequestering Mg2+ into vacuoles, which is required for stomatal opening, especially under high Mg2+ conditions.
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Affiliation(s)
- Shin‐ichiro Inoue
- Division of Biological Science, Graduate School of ScienceNagoya UniversityFuro‐cho, Chikusa‐kuNagoyaAichi464‐8602Japan
| | - Maki Hayashi
- Division of Biological Science, Graduate School of ScienceNagoya UniversityFuro‐cho, Chikusa‐kuNagoyaAichi464‐8602Japan
| | - Sheng Huang
- Institute of Plant Science and ResourcesOkayama UniversityChuo 2‐20‐1Kurashiki710‐0046Japan
| | - Kengo Yokosho
- Institute of Plant Science and ResourcesOkayama UniversityChuo 2‐20‐1Kurashiki710‐0046Japan
| | - Eiji Gotoh
- Department of Forest Environmental Sciences, Faculty of AgricultureKyushu University744 MotookaFukuoka819‐0395Japan
| | - Shuka Ikematsu
- Institute of Transformative Bio‐Molecules (WPI‐ITbM)Nagoya UniversityFuro‐cho, ChikusaNagoya464‐8602Japan
| | - Masaki Okumura
- Division of Biological Science, Graduate School of ScienceNagoya UniversityFuro‐cho, Chikusa‐kuNagoyaAichi464‐8602Japan
| | - Takamasa Suzuki
- Department of Biological Chemistry, College of Bioscience and BiotechnologyChubu UniversityKasugai‐shiAichi487‐8501Japan
| | - Takumi Kamura
- Division of Biological Science, Graduate School of ScienceNagoya UniversityFuro‐cho, Chikusa‐kuNagoyaAichi464‐8602Japan
| | - Toshinori Kinoshita
- Division of Biological Science, Graduate School of ScienceNagoya UniversityFuro‐cho, Chikusa‐kuNagoyaAichi464‐8602Japan
- Institute of Transformative Bio‐Molecules (WPI‐ITbM)Nagoya UniversityFuro‐cho, ChikusaNagoya464‐8602Japan
| | - Jian Feng Ma
- Institute of Plant Science and ResourcesOkayama UniversityChuo 2‐20‐1Kurashiki710‐0046Japan
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Zhang B, Zhang C, Tang R, Zheng X, Zhao F, Fu A, Lan W, Luan S. Two magnesium transporters in the chloroplast inner envelope essential for thylakoid biogenesis in Arabidopsis. THE NEW PHYTOLOGIST 2022; 236:464-478. [PMID: 35776059 DOI: 10.1111/nph.18349] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 06/25/2022] [Indexed: 06/15/2023]
Abstract
Magnesium (Mg2+ ) serves as a cofactor for a number of photosynthetic enzymes in the chloroplast, and is the central atom of the Chl molecule. However, little is known about the molecular mechanism of Mg2+ transport across the chloroplast envelope. Here, we report the functional characterization of two transport proteins in Arabidopsis: Magnesium Release 8 (MGR8) and MGR9, of the ACDP/CNNM family, which is evolutionarily conserved across all lineages of living organisms. Both MGR8 and MGR9 genes were expressed ubiquitously, and their encoded proteins were localized in the inner envelope of chloroplasts. Mutations of MGR8 and MGR9 together, but neither of them alone, resulted in albino ovules and chlorotic seedlings. Further analysis revealed severe defects in thylakoid biogenesis and assembly of photosynthetic complexes in the double mutant. Both MGR8 and MGR9 functionally complemented the growth of the Salmonella typhimurium mutant strain MM281, which lacks Mg2+ uptake capacity. The embryonic and early seedling defects of the mgr8/mgr9 double mutant were rescued by the expression of MGR9 under the embryo-specific ABI3 promoter. The partially rescued mutant plants were hypersensitive to Mg2+ deficient conditions and contained less Mg2+ in their chloroplasts than wild-type plants. Taken together, we conclude that MGR8 and MGR9 serve as Mg2+ transporters and are responsible for chloroplast Mg2+ uptake.
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Affiliation(s)
- Bin Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and Institute of Future Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- College of Life Sciences, Northwest University, Xi'an, 710069, China
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, China
| | - Chi Zhang
- College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Renjie Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Xiaojiang Zheng
- College of Life Sciences, Northwest University, Xi'an, 710069, China
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Fugeng Zhao
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, China
| | - Aigen Fu
- College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Wenzhi Lan
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, China
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
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Tang RJ, Yang Y, Yan YW, Mao DD, Yuan HM, Wang C, Zhao FG, Luan S. Two transporters mobilize magnesium from vacuolar stores to enable plant acclimation to magnesium deficiency. PLANT PHYSIOLOGY 2022; 190:1307-1320. [PMID: 35809075 PMCID: PMC9516776 DOI: 10.1093/plphys/kiac330] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 06/22/2022] [Indexed: 05/19/2023]
Abstract
Magnesium (Mg) is an essential metal for chlorophyll biosynthesis and other metabolic processes in plant cells. Mg is largely stored in the vacuole of various cell types and remobilized to meet cytoplasmic demand. However, the transport proteins responsible for mobilizing vacuolar Mg2+ remain unknown. Here, we identified two Arabidopsis (Arabidopsis thaliana) Mg2+ transporters (MAGNESIUM TRANSPORTER 1 and 2; MGT1 and MGT2) that facilitate Mg2+ mobilization from the vacuole, especially when external Mg supply is limited. In addition to a high degree of sequence similarity, MGT1 and MGT2 exhibited overlapping expression patterns in Arabidopsis tissues, implying functional redundancy. Indeed, the mgt1 mgt2 double mutant, but not mgt1 and mgt2 single mutants, showed exaggerated growth defects as compared to the wild type under low-Mg conditions, in accord with higher expression levels of Mg-starvation gene markers in the double mutant. However, overall Mg level was also higher in mgt1 mgt2, suggesting a defect in Mg2+ remobilization in response to Mg deficiency. Consistently, MGT1 and MGT2 localized to the tonoplast and rescued the yeast (Saccharomyces cerevisiae) mnr2Δ (manganese resistance 2) mutant strain lacking the vacuolar Mg2+ efflux transporter. In addition, disruption of MGT1 and MGT2 suppressed high-Mg sensitivity of calcineurin B-like 2 and 3 (cbl2 cbl3), a mutant defective in vacuolar Mg2+ sequestration, suggesting that vacuolar Mg2+ influx and efflux processes are antagonistic in a physiological context. We further crossed mgt1 mgt2 with mgt6, which lacks a plasma membrane MGT member involved in Mg2+ uptake, and found that the triple mutant was more sensitive to low-Mg conditions than either mgt1 mgt2 or mgt6. Hence, Mg2+ uptake (via MGT6) and vacuolar remobilization (through MGT1 and MGT2) work synergistically to achieve Mg2+ homeostasis in plants, especially under low-Mg supply in the environment.
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Affiliation(s)
- Ren-Jie Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
| | - Yang Yang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Yu-Wei Yan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute of Sichuan Agricultural University, Chengdu, Sichuan Province, China
| | - Dan-Dan Mao
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Hong-Mei Yuan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Chao Wang
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
| | - Fu-Geng Zhao
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing 210093, China
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10
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Bakshi A, Gilroy S. Moving magnesium. MOLECULAR PLANT 2022; 15:796-798. [PMID: 35422405 DOI: 10.1016/j.molp.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Arkadipta Bakshi
- Department of Botany, University of Wisconsin-Madison, Birge Hall, 430 Lincoln Drive, Madison, WI 53076, USA
| | - Simon Gilroy
- Department of Botany, University of Wisconsin-Madison, Birge Hall, 430 Lincoln Drive, Madison, WI 53076, USA.
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