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Long L, Persson DP, Duan F, Jørgensen K, Yuan L, Schjoerring JK, Pedas PR. The iron-regulated transporter 1 plays an essential role in uptake, translocation and grain-loading of manganese, but not iron, in barley. THE NEW PHYTOLOGIST 2018; 217:1640-1653. [PMID: 29206303 DOI: 10.1111/nph.14930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/29/2017] [Indexed: 05/05/2023]
Abstract
Transporters involved in manganese (Mn) uptake and intracellular Mn homeostasis in Arabidopsis and rice are well characterized, while much less is known for barley, which is particularly prone to Mn deficiency. In this study we have investigated the role of the iron-regulated transporter 1 (IRT1) for Mn uptake and translocation in barley plants. We employed an RNAi approach to reduce HvIRT1 expression to 5% of the wild-type level. This enabled characterization of the functional role of HvIRT1 by use of advanced imaging and phenotyping techniques applied to plants growing in hydroponics or soils with different Mn availability. Our results highlight the importance of HvIRT1 for the transport of Mn across the root endodermis into the stele. In the hvirt1-RNAi lines, a chlorotic phenotype with reduced shoot Mn concentration and impaired photosynthetic functionality was observed, especially under conditions with low Mn availability. We also document that HvIRT1 controlled the Mn distribution within the barley grain. Surprisingly, unlike other IRT1 orthologues, HvIRT1 played no significant role in iron uptake. We conclude that the barley IRT1 orthologue has a novel function with respect to ensuring sufficient shoot Mn concentrations. The preference of IRT1 for Mn instead of Fe is discussed in an evolutionary context.
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Affiliation(s)
- Lizhi Long
- Plant and Soil Science Section, Department of Plant and Environmental Sciences & Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK - 1871, Frederiksberg C, Denmark
- Key Lab of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Daniel P Persson
- Plant and Soil Science Section, Department of Plant and Environmental Sciences & Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK - 1871, Frederiksberg C, Denmark
| | - Fengying Duan
- Key Lab of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Kirsten Jørgensen
- Plant and Soil Science Section, Department of Plant and Environmental Sciences & Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK - 1871, Frederiksberg C, Denmark
| | - Lixing Yuan
- Key Lab of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Jan K Schjoerring
- Plant and Soil Science Section, Department of Plant and Environmental Sciences & Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK - 1871, Frederiksberg C, Denmark
| | - Pai R Pedas
- Plant and Soil Science Section, Department of Plant and Environmental Sciences & Copenhagen Plant Science Center, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK - 1871, Frederiksberg C, Denmark
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52
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Enrichment and Identification of the Most Abundant Zinc Binding Proteins in Developing Barley Grains by Zinc-IMAC Capture and Nano LC-MS/MS. Proteomes 2018; 6:proteomes6010003. [PMID: 29342075 PMCID: PMC5874762 DOI: 10.3390/proteomes6010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/07/2018] [Accepted: 01/11/2018] [Indexed: 01/02/2023] Open
Abstract
Background: Zinc accumulates in the embryo, aleurone, and subaleurone layers at different amounts in cereal grains. Our hypothesis is that zinc could be stored bound, not only to low MW metabolites/proteins, but also to high MW proteins as well. Methods: In order to identify the most abundant zinc binding proteins in different grain tissues, we microdissected barley grains into (1) seed coats; (2) aleurone/subaleurone; (3) embryo; and (4) endosperm. Initial screening for putative zinc binding proteins from the different tissue types was performed by fractionating proteins according to solubility (Osborne fractionation), and resolving those via Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) followed by polyvinylidene fluoride (PVDF) membrane blotting and dithizone staining. Selected protein fractions were subjected to Zn2+-immobilized metal ion affinity chromatography, and the captured proteins were identified using nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Results: In the endosperm, the most abundant zinc binding proteins were the storage protein B-hordeins, gamma-, and D-hordeins, while in the embryo, 7S globulins storage proteins exhibited zinc binding. In the aleurone/subaleurone, zinc affinity captured proteins were late abundant embryogenesis proteins, dehydrins, many isoforms of non-specific lipid transfer proteins, and alpha amylase trypsin inhibitor. Conclusions: We have shown evidence that abundant barley grain proteins have been captured by Zn-IMAC, and their zinc binding properties in relationship to the possibility of zinc storage is discussed.
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Deshpande P, Dapkekar A, Oak M, Paknikar K, Rajwade J. Nanocarrier-mediated foliar zinc fertilization influences expression of metal homeostasis related genes in flag leaves and enhances gluten content in durum wheat. PLoS One 2018; 13:e0191035. [PMID: 29342185 PMCID: PMC5771588 DOI: 10.1371/journal.pone.0191035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 12/27/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Wheat is the staple food for most of the world's population; however, it is a poor source of zinc. Foliar fertilization of zinc via zinc loaded chitosan nanocarriers (Zn-CNP) post-anthesis has proved to be a promising approach for grain zinc enhancement in durum wheat as evidenced in our earlier study. However, the molecular mechanism of uptake of zinc via Zn-CNP remains unclear. METHODS/PRINCIPLE FINDINGS Foliar application of Zn-CNP was performed at post anthesis stages in two durum wheat cultivars (MACS 3125 and UC1114, containing the Gpc-B1 gene), and expression levels of several metal-related genes were analyzed during early senescence. Zn-CNP application indeed caused changes in gene expression as revealed by qPCR data on representative genes involved in metal homeostasis, phloem transporters, and leaf senescence. Furthermore, zinc-regulated transporters and iron (Fe)-regulated transporter-like protein (ZIP) family [ZIP1, ZIP7, ZIP15], CA (carbonic anhydrase), and DMAS (2'-deoxymugineic acid synthase) in flag leaves exhibited significant correlation with zinc content in the seeds. The analysis of grain endosperm proteins showed enhancement of gamma gliadins while other gluten subunits decreased. Gene expression within ZIP family members varied with the type of cultivar mostly attributed to the Gpc-B1, concentration of external zinc ions as well as the type of tissue analyzed. Correlation analysis revealed the involvement of the selected genes in zinc enhancement. CONCLUSION At the molecular level, uptake of zinc via Zn-CNP nanocarrier was comparable to the uptake of zinc via common zinc fertilizers i.e. ZnSO4.
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Affiliation(s)
- Paresh Deshpande
- Nanobioscience group, Agharkar Research Institute, Pune, India
- Savitribai Phule Pune University, Ganeshkhind, Pune, India
| | - Ashwin Dapkekar
- Nanobioscience group, Agharkar Research Institute, Pune, India
- Savitribai Phule Pune University, Ganeshkhind, Pune, India
| | - Manoj Oak
- Savitribai Phule Pune University, Ganeshkhind, Pune, India
- Genetics and plant breeding, Agharkar Research Institute, Pune, India
| | - Kishore Paknikar
- Nanobioscience group, Agharkar Research Institute, Pune, India
- Savitribai Phule Pune University, Ganeshkhind, Pune, India
| | - Jyutika Rajwade
- Nanobioscience group, Agharkar Research Institute, Pune, India
- Savitribai Phule Pune University, Ganeshkhind, Pune, India
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54
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Ricachenevsky FK, Punshon T, Lee S, Oliveira BHN, Trenz TS, Maraschin FDS, Hindt MN, Danku J, Salt DE, Fett JP, Guerinot ML. Elemental Profiling of Rice FOX Lines Leads to Characterization of a New Zn Plasma Membrane Transporter, OsZIP7. FRONTIERS IN PLANT SCIENCE 2018; 9:865. [PMID: 30018622 PMCID: PMC6037872 DOI: 10.3389/fpls.2018.00865] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/04/2018] [Indexed: 05/07/2023]
Abstract
Iron (Fe) and zinc (Zn) are essential micronutrients required for proper development in both humans and plants. Rice (Oryza sativa L.) grains are the staple food for nearly half of the world's population, but a poor source of metals such as Fe and Zn. Populations that rely on milled cereals are especially prone to Fe and Zn deficiencies, the most prevalent nutritional deficiencies in humans. Biofortification is a cost-effective solution for improvement of the nutritional quality of crops. However, a better understanding of the mechanisms underlying grain accumulation of mineral nutrients is required before this approach can achieve its full potential. Characterization of gene function is more time-consuming in crops than in model species such as Arabidopsis thaliana. Aiming to more quickly characterize rice genes related to metal homeostasis, we applied the concept of high throughput elemental profiling (ionomics) to Arabidopsis lines heterologously expressing rice cDNAs driven by the 35S promoter, named FOX (Full Length Over-eXpressor) lines. We screened lines expressing candidate genes that could be used in the development of biofortified grain. Among the most promising candidates, we identified two lines ovexpressing the metal cation transporter OsZIP7. OsZIP7 expression in Arabidopsis resulted in a 25% increase in shoot Zn concentrations compared to non-transformed plants. We further characterized OsZIP7 and showed that it is localized to the plasma membrane and is able to complement Zn transport defective (but not Fe defective) yeast mutants. Interestingly, we showed that OsZIP7 does not transport Cd, which is commonly transported by ZIP proteins. Importantly, OsZIP7-expressing lines have increased Zn concentrations in their seeds. Our results indicate that OsZIP7 is a good candidate for developing Zn biofortified rice. Moreover, we showed the use of heterologous expression of genes from crops in A. thaliana as a fast method for characterization of crop genes related to the ionome and potentially useful in biofortification strategies.
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Affiliation(s)
- Felipe K. Ricachenevsky
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Departamento de Biologia, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
- *Correspondence: Felipe K. Ricachenevsky,
| | - Tracy Punshon
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - Sichul Lee
- Center for Plant Aging Research, Institute for Basic Science (IBS), Daegu, South Korea
| | - Ben Hur N. Oliveira
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Thomaz S. Trenz
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Maria N. Hindt
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
| | - John Danku
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - David E. Salt
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Janette P. Fett
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Departamento de Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Mary Lou Guerinot
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
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55
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Menguer PK, Vincent T, Miller AJ, Brown JK, Vincze E, Borg S, Holm PB, Sanders D, Podar D. Improving zinc accumulation in cereal endosperm using HvMTP1, a transition metal transporter. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:63-71. [PMID: 28436146 PMCID: PMC5785336 DOI: 10.1111/pbi.12749] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/04/2017] [Accepted: 04/16/2017] [Indexed: 05/18/2023]
Abstract
Zinc (Zn) is essential for all life forms, including humans. It is estimated that around two billion people are deficient in their Zn intake. Human dietary Zn intake relies heavily on plants, which in many developing countries consists mainly of cereals. The inner part of cereal grain, the endosperm, is the part that is eaten after milling but contains only a quarter of the total grain Zn. Here, we present results demonstrating that endosperm Zn content can be enhanced through expression of a transporter responsible for vacuolar Zn accumulation in cereals. The barley (Hordeum vulgare) vacuolar Zn transporter HvMTP1 was expressed under the control of the endosperm-specific D-hordein promoter. Transformed plants exhibited no significant change in growth but had higher total grain Zn concentration, as measured by ICP-OES, compared to parental controls. Compared with Zn, transformants had smaller increases in concentrations of Cu and Mn but not Fe. Staining grain cross sections with the Zn-specific stain DTZ revealed a significant enhancement of Zn accumulation in the endosperm of two of three transformed lines, a result confirmed by ICP-OES in the endosperm of dissected grain. Synchrotron X-ray fluorescence analysis of longitudinal grain sections demonstrated a redistribution of grain Zn from aleurone to endosperm. We argue that this proof-of-principle study provides the basis of a strategy for biofortification of cereal endosperm with Zn.
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Affiliation(s)
| | | | | | | | - Eva Vincze
- Department of Molecular Biology and GeneticsFaculty of Science and TechnologyAarhus UniversitySlagelseDenmark
| | - Søren Borg
- Department of Molecular Biology and GeneticsFaculty of Science and TechnologyAarhus UniversitySlagelseDenmark
| | - Preben Bach Holm
- Department of Molecular Biology and GeneticsFaculty of Science and TechnologyAarhus UniversitySlagelseDenmark
| | - Dale Sanders
- The John Innes CentreNorwich Research ParkNorwichUK
- Department of BiologyUniversity of YorkYorkUK
| | - Dorina Podar
- Department of BiologyUniversity of YorkYorkUK
- Faculty of Biology and Geology and Institute of BionanotechnologyBabeș‐Bolyai UniversityCluj‐NapocaRomania
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56
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Koźmińska A, Wiszniewska A, Hanus-Fajerska E, Muszyńska E. Recent strategies of increasing metal tolerance and phytoremediation potential using genetic transformation of plants. PLANT BIOTECHNOLOGY REPORTS 2018; 12:1-14. [PMID: 29503668 PMCID: PMC5829118 DOI: 10.1007/s11816-017-0467-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/18/2017] [Indexed: 05/18/2023]
Abstract
Avoidance and reduction of soil contamination with heavy metals is one of the most serious global challenges. Nowadays, science offers us new opportunities of utilizing plants to extract toxic elements from the soil by means of phytoremediation. Plant abilities to uptake, translocate, and transform heavy metals, as well as to limit their toxicity, may be significantly enhanced via genetic engineering. This paper provides a comprehensive review of recent strategies aimed at the improvement of plant phytoremediation potential using plant transformation and employing current achievements in nuclear and cytoplasmic genome transformation. Strategies for obtaining plants suitable for effective soil clean-up and tolerant to excessive concentrations of heavy metals are critically assessed. Promising directions in genetic manipulations, such as gene silencing and cis- and intragenesis, are also discussed. Moreover, the ways of overcoming disadvantages of phytoremediation using genetic transformation approachare proposed. The knowledge gathered here could be useful for designing new research aimed at biotechnological improvement of phytoremediation efficiency.
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Affiliation(s)
- Aleksandra Koźmińska
- Institute of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Al. 29 Listopada 54, 31-425 Kraków, Poland
| | - Alina Wiszniewska
- Institute of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Al. 29 Listopada 54, 31-425 Kraków, Poland
| | - Ewa Hanus-Fajerska
- Institute of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Al. 29 Listopada 54, 31-425 Kraków, Poland
| | - Ewa Muszyńska
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, Building 37, 02-776 Warsaw, Poland
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57
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Evens NP, Buchner P, Williams LE, Hawkesford MJ. The role of ZIP transporters and group F bZIP transcription factors in the Zn-deficiency response of wheat (Triticum aestivum). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:291-304. [PMID: 28771859 PMCID: PMC5656842 DOI: 10.1111/tpj.13655] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 05/12/2023]
Abstract
Understanding the molecular basis of zinc (Zn) uptake and transport in staple cereal crops is critical for improving both Zn content and tolerance to low-Zn soils. This study demonstrates the importance of group F bZIP transcription factors and ZIP transporters in responses to Zn deficiency in wheat (Triticum aestivum). Seven group F TabZIP genes and 14 ZIPs with homeologs were identified in hexaploid wheat. Promoter analysis revealed the presence of Zn-deficiency-response elements (ZDREs) in a number of the ZIPs. Functional complementation of the zrt1/zrt2 yeast mutant by TaZIP3, -6, -7, -9 and -13 supported an ability to transport Zn. Group F TabZIPs contain the group-defining cysteine-histidine-rich motifs, which are the predicted binding site of Zn2+ in the Zn-deficiency response. Conservation of these motifs varied between the TabZIPs suggesting that individual TabZIPs may have specific roles in the wheat Zn-homeostatic network. Increased expression in response to low Zn levels was observed for several of the wheat ZIPs and bZIPs; this varied temporally and spatially suggesting specific functions in the response mechanism. The ability of the group F TabZIPs to bind to specific ZDREs in the promoters of TaZIPs indicates a conserved mechanism in monocots and dicots in responding to Zn deficiency. In support of this, TabZIPF1-7DL and TabZIPF4-7AL afforded a strong level of rescue to the Arabidopsis hypersensitive bzip19 bzip23 double mutant under Zn deficiency. These results provide a greater understanding of Zn-homeostatic mechanisms in wheat, demonstrating an expanded repertoire of group F bZIP transcription factors, adding to the complexity of Zn homeostasis.
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Affiliation(s)
- Nicholas P. Evens
- Rothamsted ResearchWest CommonHarpenden, HertfordshireAL5 2JQUK
- Biological ScienceUniversity of SouthamptonLife Sciences Building 85, Highfield CampusSouthamptonSO17 1BJUK
| | - Peter Buchner
- Rothamsted ResearchWest CommonHarpenden, HertfordshireAL5 2JQUK
| | - Lorraine E. Williams
- Biological ScienceUniversity of SouthamptonLife Sciences Building 85, Highfield CampusSouthamptonSO17 1BJUK
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58
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Zeng Z, Huang H, Han N, Huang CY, Langridge P, Bian H, Zhu M. Endopolyploidy levels in barley vary in different root types and significantly decrease under phosphorus deficiency. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 118:11-21. [PMID: 28601019 DOI: 10.1016/j.plaphy.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
Increased endopolyploidy is important for plant growth and development as well as for adaptation to environmental stresses. However, little is known about the role of reduced endopolyploidy, especially in root systems. In this report, endopolyploidy variations were examined in different types of barley (Hordeum vulgare L.) roots, and the effects of phosphorus (P) deficiency and salinity (NaCl) stress on root endopolyploidy were also studied. The results showed that the endopolyploidy levels were lower in lateral roots than in either primary or nodal roots. The lower endopolyploidy in lateral roots was attributed to cortical cells. P deficiency reduced the endopolyploidy levels in lateral roots and mature zone of primary roots. By contrast, salinity had no effects on the endopolyploidy levels in either lateral or primary roots, but had a minor effect on nodal roots. Transcript analysis of cell cycle-related genes showed that multiple cell cycle-related genes were more highly expressed in lateral roots than in primary roots, suggesting their roles in lowering endopolyploidy. P deficiency reduced HvCCS52A1 transcripts in the mature zone of primary roots, but had little effect on the transcripts of 12 cell cycle-related genes in lateral roots, suggesting that endopolyploidy regulation differs between lateral roots and primary roots. Our results revealed that endopolyploidy reduction in root systems could be an integrated part of endopolyploidy plasticity in barley growth and development as well as in adaptation to a low P environment.
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Affiliation(s)
- Zhanghui Zeng
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Huahong Huang
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang, 311300, China
| | - Ning Han
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Chun Y Huang
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Peter Langridge
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Hongwu Bian
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Muyuan Zhu
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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59
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Breeding for increased grain protein and micronutrient content in wheat: Ten years of the GPC-B1 gene. J Cereal Sci 2017. [DOI: 10.1016/j.jcs.2017.01.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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60
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Singh RK, Prasad M. Advances in Agrobacterium tumefaciens-mediated genetic transformation of graminaceous crops. PROTOPLASMA 2016; 253:691-707. [PMID: 26660352 DOI: 10.1007/s00709-015-0905-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/27/2015] [Indexed: 05/05/2023]
Abstract
Steady increase in global population poses several challenges to plant science research, including demand for increased crop productivity, grain yield, nutritional quality and improved tolerance to different environmental factors. Transgene-based approaches are promising to address these challenges by transferring potential candidate genes to host organisms through different strategies. Agrobacterium-mediated gene transfer is one such strategy which is well known for enabling efficient gene transfer in both monocot and dicots. Due to its versatility, this technique underwent several advancements including development of improved in vitro plant regeneration system, co-cultivation and selection methods, and use of hyper-virulent strains of Agrobacterium tumefaciens harbouring super-binary vectors. The efficiency of this method has also been enhanced by the use of acetosyringone to induce the activity of vir genes, silver nitrate to reduce the Agrobacterium-induced necrosis and cysteine to avoid callus browning during co-cultivation. In the last two decades, extensive efforts have been invested towards achieving efficient Agrobacterium-mediated transformation in cereals. Though high-efficiency transformation systems have been developed for rice and maize, comparatively lesser progress has been reported in other graminaceous crops. In this context, the present review discusses the progress made in Agrobacterium-mediated transformation system in rice, maize, wheat, barley, sorghum, sugarcane, Brachypodium, millets, bioenergy and forage and turf grasses. In addition, it also provides an overview of the genes that have been recently transferred to these graminaceous crops using Agrobacterium, bottlenecks in this technique and future possibilities for crop improvement.
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Affiliation(s)
- Roshan Kumar Singh
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110 067, India
| | - Manoj Prasad
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110 067, India.
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61
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P G K, Kuruvilla S, Mathew MK. Functional characterization of a transition metal ion transporter, OsZIP6 from rice (Oryza sativa L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 97:165-74. [PMID: 26476396 DOI: 10.1016/j.plaphy.2015.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/03/2015] [Accepted: 10/03/2015] [Indexed: 05/07/2023]
Abstract
Micronutrients are important for the growth and development of plants, which deploy families of transporters for their uptake and distribution. We have functionally characterized a novel transition metal ion transporter from rice, OsZIP6 (Oryza sativa zinc regulated transporter, iron regulated transporter-like protein 6). The transporter was found to be transcriptionally activated in shoot and root tissues in response to deficiency in Fe(2+), Zn(2+) and Mn(2+). OsZIP6 was expressed in Xenopus laevis oocytes, where currents were observed on addition of Co(2+), Fe(2+) and Cd(2+) but not Zn(2+), Mn(2+) and Ni(2+). This substrate range for OsZIP6, identified using two-electrode voltage clamp electrophysiology was confirmed by atomic absorption spectroscopy. Ion transport by OsZIP6 was found to be pH dependent and enhanced transport was observed at acidic pH. Radioisotope uptake suggested that Co(2+) competitively inhibits Fe(2+) uptake by OsZIP6. Identification and characterization of ZIP family members from crop plants will contribute to an understanding of nutrient mineral homeostasis in these plants.
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Affiliation(s)
- Kavitha P G
- Membrane Physiology Lab, National Centre for Biological Sciences (NCBS), GKVK Campus, Bellary Road, Bangalore 560 065, India
| | - Sam Kuruvilla
- Membrane Physiology Lab, National Centre for Biological Sciences (NCBS), GKVK Campus, Bellary Road, Bangalore 560 065, India
| | - M K Mathew
- Membrane Physiology Lab, National Centre for Biological Sciences (NCBS), GKVK Campus, Bellary Road, Bangalore 560 065, India.
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62
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Deciphering Mineral Homeostasis in Barley Seed Transfer Cells at Transcriptional Level. PLoS One 2015; 10:e0141398. [PMID: 26536247 PMCID: PMC4633283 DOI: 10.1371/journal.pone.0141398] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/06/2015] [Indexed: 12/13/2022] Open
Abstract
In addition to the micronutrient inadequacy of staple crops for optimal human nutrition, a global downtrend in crop-quality has emerged from intensive breeding for yield. This trend will be aggravated by elevated levels of the greenhouse gas carbon dioxide. Therefore, crop biofortification is inevitable to ensure a sustainable supply of minerals to the large part of human population who is dietary dependent on staple crops. This requires a thorough understanding of plant-mineral interactions due to the complexity of mineral homeostasis. Employing RNA sequencing, we here communicate transfer cell specific effects of excess iron and zinc during grain filling in our model crop plant barley. Responding to alterations in mineral contents, we found a long range of different genes and transcripts. Among them, it is worth to highlight the auxin and ethylene signaling factors Arfs, Abcbs, Cand1, Hps4, Hac1, Ecr1, and Ctr1, diurnal fluctuation components Sdg2, Imb1, Lip1, and PhyC, retroelements, sulfur homeostasis components Amp1, Hmt3, Eil3, and Vip1, mineral trafficking components Med16, Cnnm4, Aha2, Clpc1, and Pcbps, and vacuole organization factors Ymr155W, RabG3F, Vps4, and Cbl3. Our analysis introduces new interactors and signifies a broad spectrum of regulatory levels from chromatin remodeling to intracellular protein sorting mechanisms active in the plant mineral homeostasis. The results highlight the importance of storage proteins in metal ion toxicity-resistance and chelation. Interestingly, the protein sorting and recycling factors Exoc7, Cdc1, Sec23A, and Rab11A contributed to the response as well as the polar distributors of metal-transporters ensuring the directional flow of minerals. Alternative isoform switching was found important for plant adaptation and occurred among transcripts coding for identical proteins as well as transcripts coding for protein isoforms. We also identified differences in the alternative-isoform preference between the treatments, indicating metal-affinity shifts among isoforms of metal transporters. Most important, we found the zinc treatment to impair both photosynthesis and respiration. A wide range of transcriptional changes including stress-related genes and negative feedback loops emphasize the importance to withhold mineral contents below certain cellular levels which otherwise might lead to agronomical impeding side-effects. By illustrating new mechanisms, genes, and transcripts, this report provides a solid platform towards understanding the complex network of plant mineral homeostasis.
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Tiong J, McDonald G, Genc Y, Shirley N, Langridge P, Huang CY. Increased expression of six ZIP family genes by zinc (Zn) deficiency is associated with enhanced uptake and root-to-shoot translocation of Zn in barley (Hordeum vulgare). THE NEW PHYTOLOGIST 2015; 207:1097-109. [PMID: 25904503 DOI: 10.1111/nph.13413] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/17/2015] [Indexed: 05/20/2023]
Abstract
Low zinc (Zn) in soils reduces yield and grain Zn content. Regulation of ZRT/IRT-like protein (ZIP) family genes is a major mechanism in plant adaptation to low and fluctuating Zn in soil. Although several Zn deficiency-inducible ZIP genes are identified in cereals, there has been no systematic study on the association of Zn deficiency-induced uptake and root-to-shoot translocation with expression of ZIP family genes. We measured Zn deficiency-induced uptake and root-to-shoot translocation of Zn in barley (Hordeum vulgare) plants by resupplying 0.5 μM Zn, and quantified the transcripts of thirteen HvZIP genes. Subcellular localization and tissue-specific expression were also determined for Zn deficiency-inducible HvZIP genes. Zn deficiency enhanced the capacity of uptake and root-to-shoot translocation of Zn, and sustained the enhanced capacity for 6 d after Zn resupply. Six HvZIP genes were highly induced in roots of Zn-deficient plants, and their proteins were localized in the plasma membrane. Tissue-specific expression in roots supports their roles in uptake and root-to-shoot translocation of Zn under low Zn conditions. Our results provide a comprehensive view on the physiological roles of ZIP genes in plant adaptation to low and fluctuating Zn in soil, and pave the way for development of new strategies to improve Zn-deficiency tolerance and biofortification in cereals.
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Affiliation(s)
- Jingwen Tiong
- Australian Centre for Plant Functional Genomics, School of Agriculture Food and Wine, the University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia
| | - Glenn McDonald
- School of Agriculture, Food and Wine, the University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Yusuf Genc
- School of Agriculture, Food and Wine, the University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Neil Shirley
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, the University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Peter Langridge
- Australian Centre for Plant Functional Genomics, School of Agriculture Food and Wine, the University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia
| | - Chun Y Huang
- Australian Centre for Plant Functional Genomics, School of Agriculture Food and Wine, the University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia
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Ricachenevsky FK, Menguer PK, Sperotto RA, Fett JP. Got to hide your Zn away: Molecular control of Zn accumulation and biotechnological applications. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 236:1-17. [PMID: 26025516 DOI: 10.1016/j.plantsci.2015.03.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 03/12/2015] [Accepted: 03/13/2015] [Indexed: 05/20/2023]
Abstract
Zinc (Zn) is an essential micronutrient for all organisms, with key catalytic and structural functions. Zn deficiency in plants, common in alkaline soils, results in growth arrest and sterility. On the other hand, Zn can become toxic at elevated concentrations. Several studies revealed molecules involved with metal acquisition in roots, distribution within the plant and translocation to seeds. Transmembrane Zn transport proteins and Zn chelators are involved in avoiding its toxic effects. Plant species with the capacity to hyperaccumulate and hypertolerate Zn have been characterized. Plants that accumulate and tolerate high amounts of Zn and produce abundant biomass may be useful for phytoremediation, allowing cleaning of metal-contaminated soils. The study of Zn hyperaccumulators may provide indications of genes and processes useful for biofortification, for developing crops with high amounts of nutrients in edible tissues. Future research needs to focus on functional characterization of Zn transporters in planta, elucidation of Zn uptake and sensing mechanisms, and on understanding the cross-talk between Zn homeostasis and other physiological processes. For this, new research should use multidisciplinary approaches, combining traditional and emerging techniques, such as genome-encoded metal sensors and multi-element imaging, quantification and speciation using synchrotron-based methods.
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Affiliation(s)
- Felipe Klein Ricachenevsky
- Centro de Biotecnologia & Programa de Pós-Graduação em Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | - Paloma Koprovski Menguer
- Centro de Biotecnologia & Programa de Pós-Graduação em Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; John Innes Centre, Norwich, United Kingdom.
| | - Raul Antonio Sperotto
- Centro de Ciências Biológicas e da Saúde & Programa de Pós-Graduação em Biotecnologia, Centro Universitário UNIVATES, Lajeado, RS, Brazil.
| | - Janette Palma Fett
- Centro de Biotecnologia & Programa de Pós-Graduação em Botânica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Wang YY, Wei YY, Dong LX, Lu LL, Feng Y, Zhang J, Pan FS, Yang XE. Improved yield and Zn accumulation for rice grain by Zn fertilization and optimized water management. J Zhejiang Univ Sci B 2015; 15:365-74. [PMID: 24711357 DOI: 10.1631/jzus.b1300263] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Zinc (Zn) deficiency and water scarcity are major challenges in rice (Oryza sativa L.) under an intensive rice production system. This study aims to investigate the impact of water-saving management and different Zn fertilization source (ZnSO4 and Zn-EDTA) regimes on grain yield and Zn accumulation in rice grain. Different water managements, continuous flooding (CF), and alternate wetting and drying (AWD) were applied during the rice growing season. Compared with CF, the AWD regime significantly increased grain yield and Zn concentrations in both brown rice and polished rice. Grain yield of genotypes (Nipponbare and Jiaxing27), on the average, was increased by 11.4%, and grain Zn concentration by 3.9% when compared with those under a CF regime. Zn fertilization significantly increased Zn density in polished rice, with a more pronounced effect of ZnSO4 being observed as compared with Zn-EDTA, especially under an AWD regime. Decreased phytic acid content and molar ratio of phytic acid to Zn were also noted in rice grains with Zn fertilization. The above results demonstrated that water management of AWD combined with ZnSO4 fertilization was an effective agricultural practice to elevate grain yield and increase Zn accumulation and bioavailability in rice grains.
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Affiliation(s)
- Yu-yan Wang
- Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; College of Agriculture, Guangxi University, Nanning 530005, China
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Gaitán-Solís E, Taylor NJ, Siritunga D, Stevens W, Schachtman DP. Overexpression of the transporters AtZIP1 and AtMTP1 in cassava changes zinc accumulation and partitioning. FRONTIERS IN PLANT SCIENCE 2015; 6:492. [PMID: 26217349 PMCID: PMC4496839 DOI: 10.3389/fpls.2015.00492] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Zinc deficiency in humans is a serious problem worldwide with an estimated one third of populations at risk for insufficient zinc in diet, which leads to impairment of cognitive abilities and immune system function. The goal of this research was to increase the bioavailable zinc in the edible portion of cassava roots to improve the overall zinc nutrition of populations that rely on cassava as a dietary staple. To increase zinc concentrations, two Arabidopsis thaliana genes coding for ZIP1 and MTP1 were overexpressed with a tuber-specific or constitutive promoter. Eighteen transgenic events from four constructs, out of a total of 73 events generated, showed significantly higher zinc concentrations in the edible portion of the storage root compared to the non-transgenic controls. The zinc content in the transgenic lines ranged from 4 to 73 mg/kg dry weight (DW) as compared to the non-transgenic control which contained 8 mg/kg. Striking changes in whole plant phenotype such as smaller plant size and chlorotic leaves were observed in transgenic lines that over accumulated zinc. In a confined field trial five transgenic events grown for 12 months showed a range of zinc concentrations from 18 to 217 mg/kg DW. Although the overexpression of zinc transporters was successful in increasing the zinc concentrations in 25% of the transgenic lines generated, it also resulted in a decrease in plant and tuber size and overall yield due to what appears to be zinc deficiency in the aerial parts of the plant.
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Affiliation(s)
| | | | | | | | - Daniel P. Schachtman
- Department of Agronomy and Horticulture, University of Nebraska LincolnLincoln, NE, USA
- *Correspondence: Daniel P. Schachtman, Department of Agronomy and Horticulture, University of Nebraska Lincoln, Beadle E243, Lincoln, NE 68588, USA,
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Pearce S, Tabbita F, Cantu D, Buffalo V, Avni R, Vazquez-Gross H, Zhao R, Conley CJ, Distelfeld A, Dubcovksy J. Regulation of Zn and Fe transporters by the GPC1 gene during early wheat monocarpic senescence. BMC PLANT BIOLOGY 2014; 14:368. [PMID: 25524236 PMCID: PMC4302714 DOI: 10.1186/s12870-014-0368-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 12/05/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND During wheat senescence, leaf components are degraded in a coordinated manner, releasing amino acids and micronutrients which are subsequently transported to the developing grain. We have previously shown that the simultaneous downregulation of Grain Protein Content (GPC) transcription factors, GPC1 and GPC2, greatly delays senescence and disrupts nutrient remobilization, and therefore provide a valuable entry point to identify genes involved in micronutrient transport to the wheat grain. RESULTS We generated loss-of-function mutations for GPC1 and GPC2 in tetraploid wheat and showed in field trials that gpc1 mutants exhibit significant delays in senescence and reductions in grain Zn and Fe content, but that mutations in GPC2 had no significant effect on these traits. An RNA-seq study of these mutants at different time points showed a larger proportion of senescence-regulated genes among the GPC1 (64%) than among the GPC2 (37%) regulated genes. Combined, the two GPC genes regulate a subset (21.2%) of the senescence-regulated genes, 76.1% of which are upregulated at 12 days after anthesis, before the appearance of any visible signs of senescence. Taken together, these results demonstrate that GPC1 is a key regulator of nutrient remobilization which acts predominantly during the early stages of senescence. Genes upregulated at this stage include transporters from the ZIP and YSL gene families, which facilitate Zn and Fe export from the cytoplasm to the phloem, and genes involved in the biosynthesis of chelators that facilitate the phloem-based transport of these nutrients to the grains. CONCLUSIONS This study provides an overview of the transport mechanisms activated in the wheat flag leaf during monocarpic senescence. It also identifies promising targets to improve nutrient remobilization to the wheat grain, which can help mitigate Zn and Fe deficiencies that afflict many regions of the developing world.
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Affiliation(s)
- Stephen Pearce
- />Department of Plant Sciences, University of California, Davis, CA 95616 USA
| | - Facundo Tabbita
- />Consejo Nacional de Investigaciones Científicas y Técnicas and Instituto de Recursos Biológicos, CIRN, INTA, N. Repetto y Los Reseros s/n (1686), Hurlingham, Argentina
| | - Dario Cantu
- />Department of Viticulture and Enology, University of California, Davis, CA 95616 USA
| | - Vince Buffalo
- />Department of Plant Sciences, University of California, Davis, CA 95616 USA
| | - Raz Avni
- />Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978 Israel
| | - Hans Vazquez-Gross
- />Department of Plant Sciences, University of California, Davis, CA 95616 USA
| | - Rongrong Zhao
- />Department of Plant Nutrition, College of Resources and Environmental Science, China Agricultural University, Beijing, 100193 People’s Republic of China
| | | | - Assaf Distelfeld
- />Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978 Israel
| | - Jorge Dubcovksy
- />Department of Plant Sciences, University of California, Davis, CA 95616 USA
- />Howard Hughes Medical Institute and Gordon & Betty Moore Foundation Investigator, Davis, CA 95616 USA
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68
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Olsen LI, Palmgren MG. Many rivers to cross: the journey of zinc from soil to seed. FRONTIERS IN PLANT SCIENCE 2014; 5:30. [PMID: 24575104 PMCID: PMC3921580 DOI: 10.3389/fpls.2014.00030] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/23/2014] [Indexed: 05/18/2023]
Abstract
An important goal of micronutrient biofortification is to enhance the amount of bioavailable zinc in the edible seed of cereals and more specifically in the endosperm. The picture is starting to emerge for how zinc is translocated from the soil through the mother plant to the developing seed. On this journey, zinc is transported from symplast to symplast via multiple apoplastic spaces. During each step, zinc is imported into a symplast before it is exported again. Cellular import and export of zinc requires passage through biological membranes, which makes membrane-bound transporters of zinc especially interesting as potential transport bottlenecks. Inside the cell, zinc can be imported into or exported out of organelles by other transporters. The function of several membrane proteins involved in the transport of zinc across the tonoplast, chloroplast or plasma membranes are currently known. These include members of the ZIP (ZRT-IRT-like Protein), and MTP (Metal Tolerance Protein) and heavy metal ATPase (HMA) families. An important player in the transport process is the ligand nicotianamine that binds zinc to increase its solubility in living cells and in this way buffers the intracellular zinc concentration.
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Affiliation(s)
- Lene I. Olsen
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research FoundationFrederiksberg, Denmark
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
| | - Michael G. Palmgren
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research FoundationFrederiksberg, Denmark
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- *Correspondence: Michael G. Palmgren, Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark e-mail:
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Athman A, Tanz SK, Conn VM, Jordans C, Mayo GM, Ng WW, Burton RA, Conn SJ, Gilliham M. Protocol: a fast and simple in situ PCR method for localising gene expression in plant tissue. PLANT METHODS 2014; 10:29. [PMID: 25250056 PMCID: PMC4171716 DOI: 10.1186/1746-4811-10-29] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/10/2014] [Indexed: 05/03/2023]
Abstract
BACKGROUND An important step in characterising the function of a gene is identifying the cells in which it is expressed. Traditional methods to determine this include in situ hybridisation, gene promoter-reporter fusions or cell isolation/purification techniques followed by quantitative PCR. These methods, although frequently used, can have limitations including their time-consuming nature, limited specificity, reliance upon well-annotated promoters, high cost, and the need for specialized equipment. In situ PCR is a relatively simple and rapid method that involves the amplification of specific mRNA directly within plant tissue whilst incorporating labelled nucleotides that are subsequently detected by immunohistochemistry. Another notable advantage of this technique is that it can be used on plants that are not easily genetically transformed. RESULTS An optimised workflow for in-tube and on-slide in situ PCR is presented that has been evaluated using multiple plant species and tissue types. The protocol includes optimised methods for: (i) fixing, embedding, and sectioning of plant tissue; (ii) DNase treatment; (iii) in situ RT-PCR with the incorporation of DIG-labelled nucleotides; (iv) signal detection using colourimetric alkaline phosphatase substrates; and (v) mounting and microscopy. We also provide advice on troubleshooting and the limitations of using fluorescence as an alternative detection method. Using our protocol, reliable results can be obtained within two days from harvesting plant material. This method requires limited specialized equipment and can be adopted by any laboratory with a vibratome (vibrating blade microtome), a standard thermocycler, and a microscope. We show that the technique can be used to localise gene expression with cell-specific resolution. CONCLUSIONS The in situ PCR method presented here is highly sensitive and specific. It reliably identifies the cellular expression pattern of even highly homologous and low abundance transcripts within target tissues, and can be completed within two days of harvesting tissue. As such, it has considerable advantages over other methods, especially in terms of time and cost. We recommend its adoption as the standard laboratory technique of choice for demonstrating the cellular expression pattern of a gene of interest.
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Affiliation(s)
- Asmini Athman
- ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, SA, Australia
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Sandra K Tanz
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, WA, Australia
| | - Vanessa M Conn
- ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, SA, Australia
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Charlotte Jordans
- ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, SA, Australia
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Gwenda M Mayo
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
- Adelaide Microscopy Waite Facility, University of Adelaide, Glen Osmond, SA, Australia
| | - Weng W Ng
- ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, SA, Australia
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Rachel A Burton
- ARC Centre of Excellence in Plant Cell Walls, University of Adelaide, Glen Osmond, SA, Australia
| | - Simon J Conn
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
- Centre for Cancer Biology, Division Immunology, Level 3, Frome Road, Adelaide, SA, Australia
| | - Matthew Gilliham
- ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, Glen Osmond, SA, Australia
- Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
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