1
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Ghomi K, Rabiei B, Sabouri H, Gholamalipour Alamdari E. Association analysis, genetic diversity and population structure of barley (Hordeum vulgare L.) under heat stress conditions using SSR and ISSR markers linked to primary and secondary metabolites. Mol Biol Rep 2021; 48:6673-6694. [PMID: 34495461 DOI: 10.1007/s11033-021-06652-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/16/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Barley is one of the major cereal crops, which can provide a significant source of genes for stress tolerance due to its high diversity and adaptability. Metabolite traits are considered to be significant for adaptation of barley to heat stress. METHODS AND RESULTS In the present study, genetic relationships between 120 barley genotypes were determined with 50 simple sequence repeat (SSR) and 26 inter simple sequence repeat (ISSR) markers under heat stress and non-stress conditions. Moreover, genetic diversity of barley accessions was investigated using the studied markers covering 7 chromosomes of barley. RESULTS In general, 153 and 85 polymorphic alleles were detected for SSR and ISSR and number of the observed polymorphic allele varied between 2-9 and 2-6, with an average of 3.26 and 3.26 alleles per locus, respectively. Markers of Bmag0223, GBMS180/180, HVM7, ISSR22, ISSR25, and ISSR48 were the most informative due to their high polymorphism information content value demonstrating that putative techniques utilized in this research can be powerful and valuable tools in breeding program of barley. Association analysis was performed between 9 important traits and SSR and ISSR markers using four statistical models. The results revealed that the model containing both population structure (Q) and general similarity in genetic background arising from shared kinship (K) factors reduced false positive associations between markers and phenotypes. CONCLUSIONS According to the results, some of markers related to more than one trait under normal conditions (ISSR31-2, HVM62, and GBMS180/180) and heat stress conditions (ISSR20-5, EBmac635, HVM14, and ISSR37-3) were determined, which can be considered to be the most interesting candidates for further studies and simultaneously will provide a useful target for the future breeding programs, such as marker-assisted selection (MAS).
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Affiliation(s)
- Khadijeh Ghomi
- Department of Agronomy and Plant Breeding, Faculty of Agricultural Sciences, University of Guilan, Persian Gulf Highway, P.O. Box: 41635-1314, Rasht, Guilan, Iran
| | - Babak Rabiei
- Department of Agronomy and Plant Breeding, Faculty of Agricultural Sciences, University of Guilan, Persian Gulf Highway, P.O. Box: 41635-1314, Rasht, Guilan, Iran.
| | - Hossein Sabouri
- Department of Plant Production, Faculty of Agriculture and Natural Resources, Gonbad University, Shahid Fallahi Street, Gonbad-e Kāvūs, Golestan, Iran
| | - Ebrahim Gholamalipour Alamdari
- Department of Plant Production, Faculty of Agriculture and Natural Resources, Gonbad University, Shahid Fallahi Street, Gonbad-e Kāvūs, Golestan, Iran
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2
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Rosero A, Oulehlová D, Žárský V, Cvrčková F. Visualizing and Quantifying In Vivo Cortical Cytoskeleton Structure and Dynamics. Methods Mol Biol 2019; 1992:135-149. [PMID: 31148036 DOI: 10.1007/978-1-4939-9469-4_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The cortical microtubule and actin meshworks play a central role in the shaping of plant cells. Transgenic plants expressing fluorescent protein markers specifically tagging the two main cytoskeletal systems are available, allowing noninvasive in vivo studies. Advanced microscopy techniques, in particular confocal laser scanning microscopy (CLSM), spinning disk confocal microscopy (SDCM), and variable angle epifluorescence microscopy (VAEM), can be nowadays used for imaging the cortical cytoskeleton of living cells with unprecedented spatial and temporal resolution. With the aid of free computing tools based on the publicly available ImageJ software package, quantitative information can be extracted from microscopic images and video sequences, providing insight into both architecture and dynamics of the cortical cytoskeleton.
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Affiliation(s)
- Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.,Coordinación de Innovación Regional, C.I. Turipaná, Montería, Córdoba, Colombia
| | - Denisa Oulehlová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.,Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.,Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.
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3
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Zhou X, Tamura K, Graumann K, Meier I. Exploring the Protein Composition of the Plant Nuclear Envelope. Methods Mol Biol 2016; 1411:45-65. [PMID: 27147033 DOI: 10.1007/978-1-4939-3530-7_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Due to rather limited sequence similarity, targeted identification of plant nuclear envelope and nuclear pore complex proteins has mainly followed two routes: (1) advanced computational identification followed by experimental verification and (2) immunoaffinity purification of complexes followed by mass spectrometry. Following candidate identification, fluorescence recovery after photobleaching (FRAP) and fluorescence resonance energy transfer (FRET) provide powerful tools to verify protein-protein interactions in situ at the NE. Here, we describe these methods for the example of Arabidopsis thaliana nuclear pore and nuclear envelope protein identification.
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Affiliation(s)
- Xiao Zhou
- Department of Molecular Genetics, The Ohio State University, 520 Aronoff Laboratory, 318 West 12th Ave., Columbus, OH, 43210, USA
| | | | - Katja Graumann
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Iris Meier
- Department of Molecular Genetics, The Ohio State University, 520 Aronoff Laboratory, 318 West 12th Ave., Columbus, OH, 43210, USA.
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4
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Takaoka Y, Shigenaga M, Imai M, Nukadzuka Y, Ishimaru Y, Saito K, Yokoyama R, Nishitani K, Ueda M. Protein ligand-tethered synthetic calcium indicator for localization control and spatiotemporal calcium imaging in plant cells. Bioorg Med Chem Lett 2016; 26:9-14. [PMID: 26602280 DOI: 10.1016/j.bmcl.2015.11.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 11/10/2015] [Accepted: 11/17/2015] [Indexed: 10/22/2022]
Abstract
In plant biology, calcium ions are involved in a variety of intriguing biological phenomena as a secondary messenger. However, most conventional calcium indicators are not applicable for plant cells because of the difficulty with their localization control in plant cells. We here introduce a method to monitor spatiotemporal Ca(2+) dynamics in living plant cells based on linking the synthetic calcium indicator Calcium Green-1 to a natural product-based protein ligand. In a proof-of-concept study using cultured BY-2 cells overexpressing the target protein for the ligand, the ligand-tethered probe accumulated in the cytosol and nucleus, and enabled real-time monitoring of the cytosolic and nucleus Ca(2+) dynamics under the physiological condition. The present strategy using ligand-tethered fluorescent sensors may be successfully applied to reveal the spatiotemporal dynamics of calcium ions in living plant cells.
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Affiliation(s)
- Yousuke Takaoka
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Miyuki Shigenaga
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Masaki Imai
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Yuuki Nukadzuka
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Yasuhiro Ishimaru
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Kei Saito
- Laboratory of Plant Cell Wall Biology, Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Ryusuke Yokoyama
- Laboratory of Plant Cell Wall Biology, Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Kazuhiko Nishitani
- Laboratory of Plant Cell Wall Biology, Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Minoru Ueda
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan.
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5
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Evans DE, Graumann K. Dynamics of the Plant Nuclear Envelope During Cell Division. Methods Mol Biol 2016; 1370:115-26. [PMID: 26659958 DOI: 10.1007/978-1-4939-3142-2_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The use of suspension cultures synchronised by aphidicolin provides a method to study cell division in living plant cells. This chapter describes the use of this technique in tobacco suspension cultures expressing nuclear and nuclear envelope proteins that have been fused to fluorescent proteins. The protocol provides advice on optimizing synchrony and on real-time imaging by confocal microscopy.
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Affiliation(s)
- David E Evans
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington Campus, Oxford, OX3 0BP, UK.
| | - Katja Graumann
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
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6
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Rosero A, Zárský V, Cvrčková F. Visualizing and quantifying the in vivo structure and dynamics of the Arabidopsis cortical cytoskeleton using CLSM and VAEM. Methods Mol Biol 2014; 1080:87-97. [PMID: 24132421 DOI: 10.1007/978-1-62703-643-6_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cortical microtubules, and to some extent also the actin meshwork, play a central role in the shaping of plant cells. Transgenic plants expressing fluorescent protein markers specifically tagging the two main cytoskeletal systems are available, allowing noninvasive in vivo studies. Advanced microscopy techniques, in particular confocal laser scanning microscopy (CLSM) and variable angle epifluorescence microscopy (VAEM), can be nowadays used for imaging the cortical cytoskeleton of living cells with unprecedented spatial and temporal resolution. With the aid of suitable computing techniques, quantitative information can be extracted from microscopic images and video sequences, providing insight into both architecture and dynamics of the cortical cytoskeleton.
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Affiliation(s)
- Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
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7
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Li X, Luu DT, Maurel C, Lin J. Probing plasma membrane dynamics at the single-molecule level. TRENDS IN PLANT SCIENCE 2013; 18:617-24. [PMID: 23911558 DOI: 10.1016/j.tplants.2013.07.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/22/2013] [Accepted: 07/01/2013] [Indexed: 05/21/2023]
Abstract
The plant plasma membrane is highly dynamic and changes multiple aspects of its organization in response to environmental and internal factors. A detailed understanding of membrane dynamics in living plant cells has remained obscure because of the limited spatial resolution of conventional optical microscopy. Recently, several single-molecule imaging approaches have been developed and used to provide valuable insights into the fundamental biochemical and biophysical properties of the plant plasma membrane, including the organization of membrane microdomains and the dynamics of single-molecule diffusion. Here we review single-molecule imaging methods, including total internal reflection fluorescence microscopy (TIRFM), fluorescence correlation spectroscopy (FCS), and super-resolution microscopy, and examine their contributions to recent progress in understanding protein dynamics and membrane organization in living plant cells.
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Affiliation(s)
- Xiaojuan Li
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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8
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Martins TV, Evans MJ, Woolfenden HC, Morris RJ. Towards the Physics of Calcium Signalling in Plants. PLANTS (BASEL, SWITZERLAND) 2013; 2:541-88. [PMID: 27137393 PMCID: PMC4844391 DOI: 10.3390/plants2040541] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 09/17/2013] [Accepted: 09/22/2013] [Indexed: 12/21/2022]
Abstract
Calcium is an abundant element with a wide variety of important roles within cells. Calcium ions are inter- and intra-cellular messengers that are involved in numerous signalling pathways. Fluctuating compartment-specific calcium ion concentrations can lead to localised and even plant-wide oscillations that can regulate downstream events. Understanding the mechanisms that give rise to these complex patterns that vary both in space and time can be challenging, even in cases for which individual components have been identified. Taking a systems biology approach, mathematical and computational techniques can be employed to produce models that recapitulate experimental observations and capture our current understanding of the system. Useful models make novel predictions that can be investigated and falsified experimentally. This review brings together recent work on the modelling of calcium signalling in plants, from the scale of ion channels through to plant-wide responses to external stimuli. Some in silico results that have informed later experiments are highlighted.
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Affiliation(s)
- Teresa Vaz Martins
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Matthew J Evans
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Hugh C Woolfenden
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard J Morris
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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9
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Rosero A, Žárský V, Cvrčková F. AtFH1 formin mutation affects actin filament and microtubule dynamics in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2013. [PMID: 23202131 PMCID: PMC3542049 DOI: 10.1093/jxb/ers351] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plant cell growth and morphogenesis depend on remodelling of both actin and microtubule cytoskeletons. AtFH1 (At5g25500), the main housekeeping Arabidopsis formin, is targeted to membranes and known to nucleate and bundle actin. The effect of mutations in AtFH1 on root development and cytoskeletal dynamics was examined. Consistent with primarily actin-related formin function, fh1 mutants showed increased sensitivity to the actin polymerization inhibitor latrunculin B (LatB). LatB-treated mutants had thicker, shorter roots than wild-type plants. Reduced cell elongation and morphological abnormalities were observed in both trichoblasts and atrichoblasts. Fluorescently tagged cytoskeletal markers were used to follow cytoskeletal dynamics in wild-type and mutant plants using confocal microscopy and VAEM (variable-angle epifluorescence microscopy). Mutants exhibited more abundant but less dynamic F-actin bundles and more dynamic microtubules than wild-type seedlings. Treatment of wild-type seedlings with a formin inhibitor, SMIFH2, mimicked the root growth and cell expansion phenotypes and cytoskeletal structure alterations observed in fh1 mutants. The results suggest that besides direct effects on actin organization, the in vivo role of AtFH1 also includes modulation of microtubule dynamics, possibly mediated by actin-microtubule cross-talk.
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Affiliation(s)
- Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
- * To whom correspondence should be addressed. E-mail:
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10
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Abstract
Leaf epidermal cells make ideal specimens for the investigation of the plant secretory pathway in that it is relatively easy to tag with fluorescent proteins and visualize in vivo the various organelles of the pathway. A number of techniques can be employed to identify and study proteins within the endomembrane organelles and to study their dynamics and interactions. Here, we discuss the most commonly used approaches to express proteins within arabidopsis and tobacco leaves, the use of mutant screens to identify trafficking proteins, and the use of two in vivo techniques, Fluorescence recovery after photobleaching and Förster resonance energy transfer, to study protein dynamics in plant cells.
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Affiliation(s)
- Giovanni Stefano
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA; Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
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11
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Liebminger E, Grass J, Jez J, Neumann L, Altmann F, Strasser R. Myrosinases TGG1 and TGG2 from Arabidopsis thaliana contain exclusively oligomannosidic N-glycans. PHYTOCHEMISTRY 2012; 84:24-30. [PMID: 23009876 PMCID: PMC3494833 DOI: 10.1016/j.phytochem.2012.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/27/2012] [Accepted: 08/29/2012] [Indexed: 05/08/2023]
Abstract
In all eukaryotes N-glycosylation is the most prevalent protein modification of secretory and membrane proteins. Although the N-glycosylation capacity and the individual steps of the N-glycan processing pathway have been well studied in the model plant Arabidopsis thaliana, little attention has been paid to the characterization of the glycosylation status of individual proteins. We report here the structural analysis of all N-glycans present on the endogenous thioglucoside glucohydrolases (myrosinases) TGG1 and TGG2 from A. thaliana. All nine glycosylation sites of TGG1 and all four glycosylation sites of TGG2 are occupied by oligomannosidic structures with Man₅GlcNAc₂ as the major glycoform. Analysis of the oligomannosidic isomers from wild-type plants and mannose trimming deficient mutants by liquid chromatography with porous graphitic carbon and mass spectrometry revealed that the N-glycans from both myrosinases are processed by Golgi-located α-mannosidases.
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Affiliation(s)
- Eva Liebminger
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Josephine Grass
- Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Jakub Jez
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Laura Neumann
- Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Friedrich Altmann
- Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
- Corresponding author. Tel.: +43 1 47654 6705; fax: +43 1 47654 6392.
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12
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Domozych DS. The quest for four-dimensional imaging in plant cell biology: it's just a matter of time. ANNALS OF BOTANY 2012; 110:461-74. [PMID: 22628381 PMCID: PMC3394652 DOI: 10.1093/aob/mcs107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/04/2012] [Indexed: 05/22/2023]
Abstract
BACKGROUND Analysis of plant cell dynamics over time, or four-dimensional imaging (4-DI), represents a major goal of plant science. The ability to resolve structures in the third dimension within the cell or tissue during developmental events or in response to environmental or experimental stresses (i.e. 4-DI) is critical to our understanding of gene expression, post-expression modulations of macromolecules and sub-cellular system interactions. SCOPE Microscopy-based technologies have been profoundly integral to this type of investigation, and new and refined microscopy technologies now allow for the visualization of cell dynamics with unprecedented resolution, contrast and experimental versatility. However, certain realities of light and electron microscopy, choice of specimen and specimen preparation techniques limit the scope of readily attaining 4-DI. Today, the plant microscopist must use a combinatorial strategy whereby multiple microscopy-based investigations are used. Modern fluorescence, confocal laser scanning, transmission electron and scanning electron microscopy provide effective conduits for synthesizing data detailing live cell dynamics and highly resolved snapshots of specific cell structures that will ultimately lead to 4-DI. This review provides a synopsis of such technologies available.
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Affiliation(s)
- David S Domozych
- Department of Biology and Skidmore Microscopy Imaging Center, Skidmore College, Saratoga Springs, NY 12866, USA.
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13
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Spira F, Dominguez-Escobar J, Müller N, Wedlich-Söldner R. Visualization of cortex organization and dynamics in microorganisms, using total internal reflection fluorescence microscopy. J Vis Exp 2012:e3982. [PMID: 22588431 DOI: 10.3791/3982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
TIRF microscopy has emerged as a powerful imaging technology to study spatio-temporal dynamics of fluorescent molecules in vitro and in living cells. The optical phenomenon of total internal reflection occurs when light passes from a medium with high refractive index into a medium with low refractive index at an angle larger than a characteristic critical angle (i.e. closer to being parallel with the boundary). Although all light is reflected back under such conditions, an evanescent wave is created that propagates across and along the boundary, which decays exponentially with distance, and only penetrates sample areas that are 100-200 nm near the interface. In addition to providing superior axial resolution, the reduced excitation of out of focus fluorophores creates a very high signal to noise ratios and minimizes damaging effects of photobleaching. Being a widefield technique, TIRF also allows faster image acquisition than most scanning based confocal setups. At first glance, the low penetration depth of TIRF seems to be incompatible with imaging of bacterial and fungal cells, which are often surrounded by thick cell walls. On the contrary, we have found that the cell walls of yeast and bacterial cells actually improve the usability of TIRF and increase the range of observable structures. Many cellular processes can therefore be directly accessed by TIRF in small, single-cell microorganisms, which often offer powerful genetic manipulation techniques. This allows us to perform in vivo biochemistry experiments, where kinetics of protein interactions and activities can be directly assessed in living cells. We describe here the individual steps required to obtain high quality TIRF images for Saccharomyces cerevisiae or Bacillus subtilis cells. We point out various problems that can affect TIRF visualization of fluorescent probes in cells and illustrate the procedure with several application examples. Finally, we demonstrate how TIRF images can be further improved using established image restoration techniques.
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Affiliation(s)
- Felix Spira
- AG Cellular Dynamics and Cell Patterning, Max Planck Institute of Biochemistry
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Sparkes I, Brandizzi F. Fluorescent protein-based technologies: shedding new light on the plant endomembrane system. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:96-107. [PMID: 22449045 DOI: 10.1111/j.1365-313x.2011.04884.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Without doubt, GFP and spectral derivatives have revolutionized the way biologists approach their journey toward the discovery of how plant cells function. It is fascinating that in its early days GFP was used merely for localization studies, but as time progressed researchers successfully explored new avenues to push the power of GFP technology to reach new and exciting research frontiers. This has had a profound impact on the way we can now study complex and dynamic systems such as plant endomembranes. Here we briefly describe some of the approaches where GFP has revolutionized in vivo studies of protein distribution and dynamics and focus on two emerging approaches for the application of GFP technology in plant endomembranes, namely optical tweezers and forward genetics approaches, which are based either on the light or on genetic manipulation of secretory organelles to gain insights on the factors that control their activities and integrity.
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Affiliation(s)
- Imogen Sparkes
- Biosciences,College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter, UK
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15
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Hohenberger P, Eing C, Straessner R, Durst S, Frey W, Nick P. Plant actin controls membrane permeability. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1808:2304-12. [PMID: 21669183 DOI: 10.1016/j.bbamem.2011.05.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/26/2011] [Accepted: 05/27/2011] [Indexed: 10/18/2022]
Abstract
The biological effects of electric pulses with low rise time, high field strength, and durations in the nanosecond range (nsPEFs) have attracted considerable biotechnological and medical interest. However, the cellular mechanisms causing membrane permeabilization by nanosecond pulsed electric fields are still far from being understood. We investigated the role of actin filaments for membrane permeability in plant cells using cell lines where different degrees of actin bundling had been introduced by genetic engineering. We demonstrate that stabilization of actin increases the stability of the plasma membrane against electric permeabilization recorded by penetration of Trypan Blue into the cytoplasm. By use of a cell line expressing the actin bundling WLIM domain under control of an inducible promotor we can activate membrane stabilization by the glucocorticoid analog dexamethasone. By total internal reflection fluorescence microscopy we can visualize a subset of the cytoskeleton that is directly adjacent to the plasma membrane. We conclude that this submembrane cytoskeleton stabilizes the plasma membrane against permeabilization through electric pulses.
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Affiliation(s)
- Petra Hohenberger
- Botanical Institute, Karlsruhe Institute of Technology, Kaiserstr. 2, 76128 Karlsruhe, Germany
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