1
|
Rolletschek H, Muszynska A, Schwender J, Radchuk V, Heinemann B, Hilo A, Plutenko I, Keil P, Ortleb S, Wagner S, Kalms L, Gündel A, Shi H, Fuchs J, Szymanski JJ, Braun HP, Borisjuk L. Mechanical forces orchestrate the metabolism of the developing oilseed rape embryo. THE NEW PHYTOLOGIST 2024. [PMID: 39044722 DOI: 10.1111/nph.19990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 06/18/2024] [Indexed: 07/25/2024]
Abstract
The initial free expansion of the embryo within a seed is at some point inhibited by its contact with the testa, resulting in its formation of folds and borders. Although less obvious, mechanical forces appear to trigger and accelerate seed maturation. However, the mechanistic basis for this effect remains unclear. Manipulation of the mechanical constraints affecting either the in vivo or in vitro growth of oilseed rape embryos was combined with analytical approaches, including magnetic resonance imaging and computer graphic reconstruction, immunolabelling, flow cytometry, transcriptomic, proteomic, lipidomic and metabolomic profiling. Our data implied that, in vivo, the imposition of mechanical restraints impeded the expansion of testa and endosperm, resulting in the embryo's deformation. An acceleration in embryonic development was implied by the cessation of cell proliferation and the stimulation of lipid and protein storage, characteristic of embryo maturation. The underlying molecular signature included elements of cell cycle control, reactive oxygen species metabolism and transcriptional reprogramming, along with allosteric control of glycolytic flux. Constricting the space allowed for the expansion of in vitro grown embryos induced a similar response. The conclusion is that the imposition of mechanical constraints over the growth of the developing oilseed rape embryo provides an important trigger for its maturation.
Collapse
Affiliation(s)
- Hardy Rolletschek
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Aleksandra Muszynska
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
- Amatera Biosciences, 4 rue Pierre Fontaine, Evry, 91000, France
| | - Jörg Schwender
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Volodymyr Radchuk
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Björn Heinemann
- Institut für Pflanzengenetik, Universität Hannover, Herrenhäuser Strasse, Hannover, 30419, Germany
| | - Alexander Hilo
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Iaroslav Plutenko
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Peter Keil
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Stefan Ortleb
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Steffen Wagner
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Laura Kalms
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - André Gündel
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
- Department of Ecology, Environment and Plant Sciences, University of Stockholm, Stockholm, 10691, Sweden
| | - Hai Shi
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jörg Fuchs
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| | - Jedrzej Jakub Szymanski
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
- Institute of Bio- and Geosciences, IBG-4: Bioinformatics, Forschungszentrum Jülich, Jülich, D-52428, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-Universität Düsseldorf, Düsseldorf, 40225, Germany
| | - Hans-Peter Braun
- Institut für Pflanzengenetik, Universität Hannover, Herrenhäuser Strasse, Hannover, 30419, Germany
| | - Ljudmilla Borisjuk
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Seeland, OT Gatersleben, 06466, Germany
| |
Collapse
|
2
|
Petrova A, Ageeva M, Kozlova L. Root growth of monocotyledons and dicotyledons is limited by different tissues. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1462-1476. [PMID: 37646760 DOI: 10.1111/tpj.16440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/16/2023] [Indexed: 09/01/2023]
Abstract
Plant growth and morphogenesis are determined by the mechanical properties of its cell walls. Using atomic force microscopy, we have characterized the dynamics of cell wall elasticity in different tissues in developing roots of several plant species. The elongation growth zone of roots of all species studied was distinguished by a reduced modulus of elasticity of most cell walls compared to the meristem or late elongation zone. Within the individual developmental zones of roots, there were also significant differences in the elasticity of the cell walls of the different tissues, thus identifying the tissues that limit root growth in the different species. In cereals, this is mainly the inner cortex, whereas in dicotyledons this function is performed by the outer tissues-rhizodermis and cortex. These differences result in a different behaviour of the roots of these species during longitudinal dissection. Modelling of longitudinal root dissection using measured properties confirmed the difference shown. Thus, the morphogenesis of monocotyledonous and dicotyledonous roots relies on different tissues as growth limiting, which should be taken into account when analyzing the localization of associated molecular events. At the same time, no matrix polysaccharide was found whose immunolabelling in type I or type II cell walls would predict their mechanical properties. However, assessment of the degree of anisotropy of cortical microtubules showed a striking correlation with the elasticity of the corresponding cell walls in all species studied.
Collapse
Affiliation(s)
- Anna Petrova
- Laboratory of Plant Cell Growth Mechanisms, Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia
| | - Marina Ageeva
- Microscopy Cabinet, Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia
| | - Liudmila Kozlova
- Laboratory of Plant Cell Growth Mechanisms, Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia
- Mechanics and Civil Engineering Laboratory, University of Montpellier, 860 Rue de St - Priest, 34090, Montpellier, France
| |
Collapse
|
3
|
Kim EJ, Kim JH, Hong WJ, Kim EY, Kim MH, Lee SK, Min CW, Kim ST, Park SK, Jung KH, Kim YJ. Rice pollen-specific OsRALF17 and OsRALF19 are essential for pollen tube growth. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:2218-2236. [PMID: 37195059 DOI: 10.1111/jipb.13508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/16/2023] [Indexed: 05/18/2023]
Abstract
Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors (RALFs) function as ligands for signal transduction during fertilization. However, functional studies on RALF in monocot plants are lacking. Herein, we functionally characterized two pollen-specific RALFs in rice (Oryza sativa) using multiple clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants, peptide treatment, expression analyses, and tag reporter lines. Among the 41 RALF members in rice, OsRALF17 was specifically expressed at the highest level in pollen and pollen tubes. Exogenously applied OsRALF17 or OsRALF19 peptide inhibited pollen tube germination and elongation at high concentrations but enhanced tube elongation at low concentrations, indicating growth regulation. Double mutants of OsRALF17 and OsRALF19 (ralf17/19) exhibited almost full male sterility with defects in pollen hydration, germination, and tube elongation, which was partially recovered by exogenous treatment with OsRALF17 peptide. This study revealed that two partially functionally redundant OsRALF17 and OsRALF19 bind to Oryza sativa male-gene transfer defective 2 (OsMTD2) and transmit reactive oxygen species signals for pollen tube germination and integrity maintenance in rice. Transcriptomic analysis confirmed their common downstream genes, in osmtd2 and ralf17/19. This study provides new insights into the role of RALF, expanding our knowledge of the biological role of RALF in regulating rice fertilization.
Collapse
Affiliation(s)
- Eui-Jung Kim
- Graduate School of Green Bio-Science & Crop Biotech Institute, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Ji-Hyun Kim
- Department of Life Science and Environmental Biochemistry, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
| | - Woo-Jong Hong
- Department of Smart Farm Science, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Eun Young Kim
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Myung-Hee Kim
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
- Genomics Division, Department of Agricultural Bio-Resources, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, Republic of Korea
| | - Su Kyoung Lee
- Graduate School of Green Bio-Science & Crop Biotech Institute, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Cheol Woo Min
- Department of Plant Bioscience, Pusan National University, Miryang, 50463, Republic of Korea
| | - Sun Tae Kim
- Department of Plant Bioscience, Pusan National University, Miryang, 50463, Republic of Korea
| | - Soon Ki Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Ki-Hong Jung
- Graduate School of Green Bio-Science & Crop Biotech Institute, Kyung Hee University, Yongin, 17104, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yu-Jin Kim
- Department of Life Science and Environmental Biochemistry, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
| |
Collapse
|
4
|
Marconi M, Wabnik K. Computer models of cell polarity establishment in plants. PLANT PHYSIOLOGY 2023; 193:42-53. [PMID: 37144853 PMCID: PMC10469401 DOI: 10.1093/plphys/kiad264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/30/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023]
Abstract
Plant development is a complex task, and many processes involve changes in the asymmetric subcellular distribution of cell components that strongly depend on cell polarity. Cell polarity regulates anisotropic growth and polar localization of membrane proteins and helps to identify the cell's position relative to its neighbors within an organ. Cell polarity is critical in a variety of plant developmental processes, including embryogenesis, cell division, and response to external stimuli. The most conspicuous downstream effect of cell polarity is the polar transport of the phytohormone auxin, which is the only known hormone transported in a polar fashion in and out of cells by specialized exporters and importers. The biological processes behind the establishment of cell polarity are still unknown, and researchers have proposed several models that have been tested using computer simulations. The evolution of computer models has progressed in tandem with scientific discoveries, which have highlighted the importance of genetic, chemical, and mechanical input in determining cell polarity and regulating polarity-dependent processes such as anisotropic growth, protein subcellular localization, and the development of organ shapes. The purpose of this review is to provide a comprehensive overview of the current understanding of computer models of cell polarity establishment in plants, focusing on the molecular and cellular mechanisms, the proteins involved, and the current state of the field.
Collapse
Affiliation(s)
- Marco Marconi
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| | - Krzysztof Wabnik
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| |
Collapse
|
5
|
Ušák D, Haluška S, Pleskot R. Callose synthesis at the center point of plant development-An evolutionary insight. PLANT PHYSIOLOGY 2023; 193:54-69. [PMID: 37165709 DOI: 10.1093/plphys/kiad274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/21/2023] [Accepted: 04/21/2023] [Indexed: 05/12/2023]
Abstract
Polar callose deposition into the extracellular matrix is tightly controlled in time and space. Its presence in the cell wall modifies the properties of the surrounding area, which is fundamental for the correct execution of numerous processes such as cell division, male gametophyte development, intercellular transport, or responses to biotic and abiotic stresses. Previous studies have been invaluable in characterizing specific callose synthases (CalSs) during individual cellular processes. However, the complex view of the relationships between a particular CalS and a specific process is still lacking. Here we review the recent proceedings on the role of callose and individual CalSs in cell wall remodelling from an evolutionary perspective and with a particular focus on cytokinesis. We provide a robust phylogenetic analysis of CalS across the plant kingdom, which implies a 3-subfamily distribution of CalS. We also discuss the possible linkage between the evolution of CalSs and their function in specific cell types and processes.
Collapse
Affiliation(s)
- David Ušák
- Czech Academy of Sciences, Institute of Experimental Botany, 165 02 Prague, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44 Prague, Czech Republic
| | - Samuel Haluška
- Czech Academy of Sciences, Institute of Experimental Botany, 165 02 Prague, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44 Prague, Czech Republic
| | - Roman Pleskot
- Czech Academy of Sciences, Institute of Experimental Botany, 165 02 Prague, Czech Republic
| |
Collapse
|
6
|
Municio-Diaz C, Muller E, Drevensek S, Fruleux A, Lorenzetti E, Boudaoud A, Minc N. Mechanobiology of the cell wall – insights from tip-growing plant and fungal cells. J Cell Sci 2022; 135:280540. [DOI: 10.1242/jcs.259208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ABSTRACT
The cell wall (CW) is a thin and rigid layer encasing the membrane of all plant and fungal cells. It ensures mechanical integrity by bearing mechanical stresses derived from large cytoplasmic turgor pressure, contacts with growing neighbors or growth within restricted spaces. The CW is made of polysaccharides and proteins, but is dynamic in nature, changing composition and geometry during growth, reproduction or infection. Such continuous and often rapid remodeling entails risks of enhanced stress and consequent damages or fractures, raising the question of how the CW detects and measures surface mechanical stress and how it strengthens to ensure surface integrity? Although early studies in model fungal and plant cells have identified homeostatic pathways required for CW integrity, recent methodologies are now allowing the measurement of pressure and local mechanical properties of CWs in live cells, as well as addressing how forces and stresses can be detected at the CW surface, fostering the emergence of the field of CW mechanobiology. Here, using tip-growing cells of plants and fungi as case study models, we review recent progress on CW mechanosensation and mechanical regulation, and their implications for the control of cell growth, morphogenesis and survival.
Collapse
Affiliation(s)
- Celia Municio-Diaz
- Université de Paris, CNRS, Institut Jacques Monod 1 , F-75006 Paris , France
- Equipe Labellisée LIGUE Contre le Cancer 2 , 75013 Paris , France
| | - Elise Muller
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Stéphanie Drevensek
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Antoine Fruleux
- LPTMS, CNRS, Université Paris-Saclay 4 , 91405 Orsay , France
| | - Enrico Lorenzetti
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Arezki Boudaoud
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Nicolas Minc
- Université de Paris, CNRS, Institut Jacques Monod 1 , F-75006 Paris , France
- Equipe Labellisée LIGUE Contre le Cancer 2 , 75013 Paris , France
| |
Collapse
|
7
|
Miller K, Strychalski W, Nickaeen M, Carlsson A, Haswell ES. In vitro experiments and kinetic models of Arabidopsis pollen hydration mechanics show that MSL8 is not a simple tension-gated osmoregulator. Curr Biol 2022; 32:2921-2934.e3. [PMID: 35660140 DOI: 10.1016/j.cub.2022.05.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 04/12/2022] [Accepted: 05/12/2022] [Indexed: 10/18/2022]
Abstract
Pollen, a neighbor-less cell containing the male gametes, undergoes mechanical challenges during plant sexual reproduction, including desiccation and rehydration. It was previously shown that the pollen-specific mechanosensitive ion channel MscS-like (MSL)8 is essential for pollen survival during hydration and proposed that it functions as a tension-gated osmoregulator. Here, we test this hypothesis with a combination of mathematical modeling and laboratory experiments. Time-lapse imaging revealed that wild-type pollen grains swell, and then they stabilize in volume rapidly during hydration. msl8 mutant pollen grains, however, continue to expand and eventually burst. We found that a mathematical model, wherein MSL8 acts as a simple-tension-gated osmoregulator, does not replicate this behavior. A better fit was obtained from variations of the model, wherein MSL8 inactivates independent of its membrane tension gating threshold or MSL8 strengthens the cell wall without osmotic regulation. Experimental and computational testing of several perturbations, including hydration in an osmolyte-rich solution, hyper-desiccation of the grains, and MSL8-YFP overexpression, indicated that the cell wall strengthening model best simulated experimental responses. Finally, the expression of a nonconducting MSL8 variant did not complement the msl8 overexpansion phenotype. These data indicate that contrary to our hypothesis and to the current understanding of MS ion channel function in bacteria, MSL8 does not act as a simple membrane tension-gated osmoregulator. Instead, they support a model wherein ion flux through MSL8 is required to alter pollen cell wall properties. These results demonstrate the utility of pollen as a cellular scale model system and illustrate how mathematical models can correct intuitive hypotheses.
Collapse
Affiliation(s)
- Kari Miller
- Department of Biology, Washington University, St. Louis, MO 63130, USA; NSF Center for Engineering Mechanobiology, Cleveland, OH, USA
| | - Wanda Strychalski
- Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Masoud Nickaeen
- University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | - Anders Carlsson
- NSF Center for Engineering Mechanobiology, Cleveland, OH, USA; Department of Physics, Washington University, St. Louis, MO 63130, USA
| | - Elizabeth S Haswell
- Department of Biology, Washington University, St. Louis, MO 63130, USA; NSF Center for Engineering Mechanobiology, Cleveland, OH, USA.
| |
Collapse
|
8
|
Liu S, Strauss S, Adibi M, Mosca G, Yoshida S, Dello Ioio R, Runions A, Andersen TG, Grossmann G, Huijser P, Smith RS, Tsiantis M. Cytokinin promotes growth cessation in the Arabidopsis root. Curr Biol 2022; 32:1974-1985.e3. [PMID: 35354067 DOI: 10.1016/j.cub.2022.03.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/21/2021] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
Abstract
The Arabidopsis root offers good opportunities to investigate how regulated cellular growth shapes different tissues and organs, a key question in developmental biology. Along the root's longitudinal axis, cells sequentially occupy different developmental states. Proliferative meristematic cells give rise to differentiating cells, which rapidly elongate in the elongation zone, then mature and stop growing in the differentiation zone. The phytohormone cytokinin contributes to this zonation by positioning the boundary between the meristem and the elongation zone, called the transition zone. However, the cellular growth profile underlying root zonation is not well understood, and the cellular mechanisms that mediate growth cessation remain unclear. By using time-lapse imaging, genetics, and computational analysis, we analyze the effect of cytokinin on root zonation and cellular growth. We found that cytokinin promotes growth cessation in the distal (shootward) elongation zone in conjunction with accelerating the transition from elongation to differentiation. We estimated cell-wall stiffness by using osmotic treatment experiments and found that cytokinin-mediated growth cessation is associated with cell-wall stiffening and requires the action of an auxin influx carrier, AUX1. Our measurement of growth and cell-wall mechanical properties at a cellular resolution reveal mechanisms via which cytokinin influences cell behavior to shape tissue patterns.
Collapse
Affiliation(s)
- Shanda Liu
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Sören Strauss
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Milad Adibi
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Gabriella Mosca
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany; Physics Department, Technical University Munich, James-Franck-Str. 1/I, 85748 Garching b. Munich, Germany
| | - Saiko Yoshida
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Raffaele Dello Ioio
- Dipartimento di Biologia e Biotecnologie, Laboratory of Functional Genomics and Proteomics of Model Systems, Università di Roma, Sapienza, via dei Sardi, 70, 00185 Rome, Italy
| | - Adam Runions
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Tonni Grube Andersen
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Guido Grossmann
- Institute for Cell and Interaction Biology, Heinrich-Heine Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Peter Huijser
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany; Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Miltos Tsiantis
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany.
| |
Collapse
|
9
|
Dumais J. Mechanics and hydraulics of pollen tube growth. THE NEW PHYTOLOGIST 2021; 232:1549-1565. [PMID: 34492127 DOI: 10.1111/nph.17722] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
All kingdoms of life have evolved tip-growing cells able to mine their environment or deliver cargo to remote targets. The basic cellular processes supporting these functions are understood in increasing detail, but the multiple interactions between them lead to complex responses that require quantitative models to be disentangled. Here, I review the equations that capture the fundamental interactions between wall mechanics and cell hydraulics starting with a detailed presentation of James Lockhart's seminal model. The homeostatic feedbacks needed to maintain a steady tip velocity are then shown to offer a credible explanation for the pulsatile growth observed in some tip-growing cells. Turgor pressure emerges as a central variable whose role in the morphogenetic process has been a source of controversy for more than 50 yr. I argue that recasting Lockhart's work as a process of chemical stress relaxation can clarify how cells control tip growth and help us internalise the important but passive role played by turgor pressure in the morphogenetic process.
Collapse
Affiliation(s)
- Jacques Dumais
- Faculty of Engineering and Sciences, Universidad Adolfo Ibáñez, Av. Padre Hurtado 750, Viña del Mar, Region of Valparaíso, Chile
| |
Collapse
|
10
|
Marconi M, Wabnik K. Shaping the Organ: A Biologist Guide to Quantitative Models of Plant Morphogenesis. FRONTIERS IN PLANT SCIENCE 2021; 12:746183. [PMID: 34675952 PMCID: PMC8523991 DOI: 10.3389/fpls.2021.746183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
Organ morphogenesis is the process of shape acquisition initiated with a small reservoir of undifferentiated cells. In plants, morphogenesis is a complex endeavor that comprises a large number of interacting elements, including mechanical stimuli, biochemical signaling, and genetic prerequisites. Because of the large body of data being produced by modern laboratories, solving this complexity requires the application of computational techniques and analyses. In the last two decades, computational models combined with wet-lab experiments have advanced our understanding of plant organ morphogenesis. Here, we provide a comprehensive review of the most important achievements in the field of computational plant morphodynamics. We present a brief history from the earliest attempts to describe plant forms using algorithmic pattern generation to the evolution of quantitative cell-based models fueled by increasing computational power. We then provide an overview of the most common types of "digital plant" paradigms, and demonstrate how models benefit from diverse techniques used to describe cell growth mechanics. Finally, we highlight the development of computational frameworks designed to resolve organ shape complexity through integration of mechanical, biochemical, and genetic cues into a quantitative standardized and user-friendly environment.
Collapse
Affiliation(s)
| | - Krzysztof Wabnik
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón (Madrid), Spain
| |
Collapse
|
11
|
Althiab-Almasaud R, Chen Y, Maza E, Djari A, Frasse P, Mollet JC, Mazars C, Jamet E, Chervin C. Ethylene signaling modulates tomato pollen tube growth through modifications of cell wall remodeling and calcium gradient. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:893-908. [PMID: 34036648 DOI: 10.1111/tpj.15353] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
Ethylene modulates plant developmental processes including flower development. Previous studies have suggested ethylene participates in pollen tube (PT) elongation, and both ethylene production and perception seem critical at the time of fertilization. The full gene set regulated by ethylene during PT growth is unknown. To study this, we used various EThylene Receptor (ETR) tomato (Solanum lycopersicum) mutants: etr3-ko, a loss-of-function (LOF) mutant; and NR (NEVER RIPE), a gain-of-function (GOF) mutant. The etr3-ko PTs grew faster than wild-type (WT) PTs. Oppositely, NR PT elongation was slower than in WT, and PTs displayed larger diameters. ETR mutations result in feedback control of ethylene production. Furthermore, ethylene treatment of germinating pollen grains increased PT length in etr-ko mutants and WT, but not in NR. Treatment with the ethylene perception inhibitor 1-methylcyclopropene decreased PT length in etr-ko mutants and WT, but had no effect on NR. This confirmed that ethylene regulates PT growth. The comparison of PT transcriptomes in LOF and GOF mutants, etr3-ko and NR, both harboring mutations of the ETR3 gene, revealed that ethylene perception has major impacts on cell wall- and calcium-related genes as confirmed by microscopic observations showing a modified distribution of the methylesterified homogalacturonan pectic motif and of calcium load. Our results establish links between PT growth, ethylene, calcium, and cell wall metabolism, and also constitute a transcriptomic resource.
Collapse
Affiliation(s)
- Rasha Althiab-Almasaud
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
| | - Yi Chen
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Elie Maza
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
| | - Anis Djari
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
| | - Pierre Frasse
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
| | - Jean-Claude Mollet
- Laboratoire Glyco-MEV, SFR NORVEGE, Innovation Chimie Carnot, Normandie Univ, UniRouen, Rouen, France
| | - Christian Mazars
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, Auzeville-Tolosane, France
| | - Elisabeth Jamet
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, Auzeville-Tolosane, France
| | - Christian Chervin
- Laboratoire de Génomique et Biotechnologie des Fruits, Université de Toulouse, Toulouse INP-ENSAT, INRAE, Auzeville-Tolosane, France
| |
Collapse
|
12
|
Läubli NF, Burri JT, Marquard J, Vogler H, Mosca G, Vertti-Quintero N, Shamsudhin N, deMello A, Grossniklaus U, Ahmed D, Nelson BJ. 3D mechanical characterization of single cells and small organisms using acoustic manipulation and force microscopy. Nat Commun 2021; 12:2583. [PMID: 33972516 PMCID: PMC8110787 DOI: 10.1038/s41467-021-22718-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Quantitative micromechanical characterization of single cells and multicellular tissues or organisms is of fundamental importance to the study of cellular growth, morphogenesis, and cell-cell interactions. However, due to limited manipulation capabilities at the microscale, systems used for mechanical characterizations struggle to provide complete three-dimensional coverage of individual specimens. Here, we combine an acoustically driven manipulation device with a micro-force sensor to freely rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen. The versatility of this tool is demonstrated through the analysis of single Lilium longiflorum pollen grains, in combination with numerical simulations, and individual Caenorhabditis elegans nematodes. It reveals local variations in apparent stiffness for single specimens, providing previously inaccessible information and datasets on mechanical properties that serve as the basis for biophysical modelling and allow deeper insights into the biomechanics of these living systems.
Collapse
Affiliation(s)
- Nino F Läubli
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | - Jan T Burri
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | | | - Hannes Vogler
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Gabriella Mosca
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Nadia Vertti-Quintero
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | | | - Andrew deMello
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Daniel Ahmed
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
- Acoustic Robotics Systems Lab, ETH Zurich, Rüschlikon, Switzerland.
| | | |
Collapse
|
13
|
Abstract
Atomic force microscopy (AFM) is an indentation technique used to reconstruct the topography of various materials and organisms. AFM can also measure the mechanical properties of the sample. In plants, AFM is applied to image cell wall structural details and measure the elastic properties in the outer cell walls. Here, I describe the use of high-resolution AFM to measure the elasticity of resin-embedded ultrathin sections of leaf epidermal cell walls. This approach allows to access the fine details within the wall matrix and eliminate the influence of the topography or the turgor on mechanical measurements. In this chapter, the sample preparation, AFM image acquisition, and processing of force curves are described. Altogether, these methods allow to measure the wall stiffness and compare different cell wall regions.
Collapse
|
14
|
Cascallares M, Setzes N, Marchetti F, López GA, Distéfano AM, Cainzos M, Zabaleta E, Pagnussat GC. A Complex Journey: Cell Wall Remodeling, Interactions, and Integrity During Pollen Tube Growth. FRONTIERS IN PLANT SCIENCE 2020; 11:599247. [PMID: 33329663 PMCID: PMC7733995 DOI: 10.3389/fpls.2020.599247] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/02/2020] [Indexed: 05/05/2023]
Abstract
In flowering plants, pollen tubes undergo a journey that starts in the stigma and ends in the ovule with the delivery of the sperm cells to achieve double fertilization. The pollen cell wall plays an essential role to accomplish all the steps required for the successful delivery of the male gametes. This extended path involves female tissue recognition, rapid hydration and germination, polar growth, and a tight regulation of cell wall synthesis and modification, as its properties change not only along the pollen tube but also in response to guidance cues inside the pistil. In this review, we focus on the most recent advances in elucidating the molecular mechanisms involved in the regulation of cell wall synthesis and modification during pollen germination, pollen tube growth, and rupture.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Gabriela Carolina Pagnussat
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, CONICET, Mar del Plata, Argentina
| |
Collapse
|
15
|
Adhikari PB, Liu X, Kasahara RD. Mechanics of Pollen Tube Elongation: A Perspective. FRONTIERS IN PLANT SCIENCE 2020; 11:589712. [PMID: 33193543 PMCID: PMC7606272 DOI: 10.3389/fpls.2020.589712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/30/2020] [Indexed: 05/13/2023]
Abstract
Pollen tube (PT) serves as a vehicle that delivers male gametes (sperm cells) to a female gametophyte during double fertilization, which eventually leads to the seed formation. It is one of the fastest elongating structures in plants. Normally, PTs traverse through the extracellular matrix at the transmitting tract after penetrating the stigma. While the endeavor may appear simple, the molecular processes and mechanics of the PT elongation is yet to be fully resolved. Although it is the most studied "tip-growing" structure in plants, several features of the structure (e.g., Membrane dynamics, growth behavior, mechanosensing etc.) are only partially understood. In many aspects, PTs are still considered as a tissue rather than a "unique cell." In this review, we have attempted to discuss mainly on the mechanics behind PT-elongation and briefly on the molecular players involved in the process. Four aspects of PTs are particularly discussed: the PT as a cell, its membrane dynamics, mechanics of its elongation, and the potential mechanosensors involved in its elongation based on relevant findings in both plant and non-plant models.
Collapse
Affiliation(s)
- Prakash Babu Adhikari
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaoyan Liu
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ryushiro D. Kasahara
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
| |
Collapse
|
16
|
Vogler H, Burri JT, Nelson BJ, Grossniklaus U. Simultaneous measurement of turgor pressure and cell wall elasticity in growing pollen tubes. Methods Cell Biol 2020; 160:297-310. [PMID: 32896323 DOI: 10.1016/bs.mcb.2020.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Plant growth and morphogenesis are tightly controlled processes of division and expansion of individual cells. To fully describe the factors that influence cell expansion, it is necessary to quantify the counteracting forces of turgor pressure and cell wall stiffness, which together determine whether and how a cell expands. Several methods have been developed to measure these parameters, but most of them provide only values for one or the other, and thus require complex models to derive the missing quantity. Furthermore, available methods for turgor measurement are either accurate but invasive, like the pressure probe; or they lack accuracy, such as incipient plasmolysis or indentation-based methods that rely on information about the mechanical properties of the cell wall. Here, we describe a system that overcomes many of the above-mentioned disadvantages using growing pollen tubes of Lilium longiflorum as a model. By combining non-invasive microindentation and cell compression experiments, we separately measure turgor pressure and cell wall elasticity on the same pollen tube in parallel. Due to the modularity of the setup and the large range of the micro-positioning system, our method is not limited to pollen tubes but could be used to investigate the biomechanical properties of many other cell types or tissues.
Collapse
Affiliation(s)
- Hannes Vogler
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland.
| | - Jan T Burri
- Multi-Scale Robotics Lab, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Bradley J Nelson
- Multi-Scale Robotics Lab, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| |
Collapse
|
17
|
Williams JH, Oliveira PE. For things to stay the same, things must change: polyploidy and pollen tube growth rates. ANNALS OF BOTANY 2020; 125:925-935. [PMID: 31957784 PMCID: PMC7218811 DOI: 10.1093/aob/mcaa007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/17/2020] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Pollen tube growth rate (PTGR) is an important single-cell performance trait that may evolve rapidly under haploid selection. Angiosperms have experienced repeated cycles of polyploidy (whole genome duplication), and polyploidy has cell-level phenotypic consequences arising from increased bulk DNA amount and numbers of genes and their interactions. We sought to understand potential effects of polyploidy on several underlying determinants of PTGR - pollen tube dimensions and construction rates - by comparing diploid-polyploid near-relatives in Betula (Betulaceae) and Handroanthus (Bignoniaceae). METHODS We performed intraspecific, outcrossed hand-pollinations on pairs of flowers. In one flower, PTGR was calculated from the longest pollen tube per time of tube elongation. In the other, styles were embedded in glycol methacrylate, serial-sectioned in transverse orientation, stained and viewed at 1000× to measure tube wall thicknesses (W) and circumferences (C). Volumetric growth rate (VGR) and wall production rate (WPR) were then calculated for each tube by multiplying cross-sectional tube area (πr2) or wall area (W × C), by the mean PTGR of each maternal replicate respectively. KEY RESULTS In Betula and Handroanthus, the hexaploid species had significantly wider pollen tubes (13 and 25 %, respectively) and significantly higher WPRs (22 and 18 %, respectively) than their diploid congeners. PTGRs were not significantly different in both pairs, even though wider polyploid tubes were predicted to decrease PTGRs by 16 and 20 %, respectively. CONCLUSIONS The larger tube sizes of polyploids imposed a substantial materials cost on PTGR, but polyploids also exhibited higher VGRs and WPRs, probably reflecting the evolution of increased metabolic activity. Recurrent cycles of polyploidy followed by genome reorganization may have been important for the evolution of fast PTGRs in angiosperms, involving a complex interplay between correlated changes in ploidy level, genome size, cell size and pollen tube energetics.
Collapse
Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Paulo E Oliveira
- Instituto de Biologia, Universidade Federal de Uberlândia, Campus Umuarama, Uberlândia, Minas Gerais 38405-320 Brazil
| |
Collapse
|
18
|
Krenger R, Burri JT, Lehnert T, Nelson BJ, Gijs MAM. Force microscopy of the Caenorhabditis elegans embryonic eggshell. MICROSYSTEMS & NANOENGINEERING 2020; 6:29. [PMID: 32382445 PMCID: PMC7196560 DOI: 10.1038/s41378-020-0137-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 12/20/2019] [Accepted: 02/13/2020] [Indexed: 05/03/2023]
Abstract
Assays focusing on emerging biological phenomena in an animal's life can be performed during embryogenesis. While the embryo of Caenorhabditis elegans has been extensively studied, its biomechanical properties are largely unknown. Here, we demonstrate that cellular force microscopy (CFM), a recently developed technique that combines micro-indentation with high resolution force sensing approaching that of atomic force microscopy, can be successfully applied to C. elegans embryos. We performed, for the first time, a quantitative study of the mechanical properties of the eggshell of living C. elegans embryos and demonstrate the capability of the system to detect alterations of its mechanical parameters and shell defects upon chemical treatments. In addition to investigating natural eggshells, we applied different eggshell treatments, i.e., exposure to sodium hypochlorite and chitinase solutions, respectively, that selectively modified the multilayer eggshell structure, in order to evaluate the impact of the different layers on the mechanical integrity of the embryo. Finite element method simulations based on a simple embryo model were used to extract characteristic eggshell parameters from the experimental micro-indentation force-displacement curves. We found a strong correlation between the severity of the chemical treatment and the rigidity of the shell. Furthermore, our results showed, in contrast to previous assumptions, that short bleach treatments not only selectively remove the outermost vitelline layer of the eggshell, but also significantly degenerate the underlying chitin layer, which is primarily responsible for the mechanical stability of the egg.
Collapse
Affiliation(s)
- Roger Krenger
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jan T. Burri
- Multi-Scale Robotics Laboratory, ETH Zurich, Zürich, 8092 Switzerland
| | - Thomas Lehnert
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Bradley J. Nelson
- Multi-Scale Robotics Laboratory, ETH Zurich, Zürich, 8092 Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| |
Collapse
|
19
|
Quantification of Mechanical Forces and Physiological Processes Involved in Pollen Tube Growth Using Microfluidics and Microrobotics. Methods Mol Biol 2020; 2160:275-292. [PMID: 32529444 DOI: 10.1007/978-1-0716-0672-8_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pollen tubes face many obstacles on their way to the ovule. They have to decide whether to navigate around cells or penetrate the cell wall and grow through it or even within it. Besides chemical sensing, which directs the pollen tubes on their path to the ovule, this involves mechanosensing to determine the optimal strategy in specific situations. Mechanical cues then need to be translated into physiological signals, which eventually lead to changes in the growth behavior of the pollen tube. To study these events, we have developed a system to directly quantify the forces involved in pollen tube navigation. We combined a lab-on-a-chip device with a microelectromechanical systems-based force sensor to mimic the pollen tube's journey from stigma to ovary in vitro. A force-sensing plate creates a mechanical obstacle for the pollen tube to either circumvent or attempt to penetrate while measuring the involved forces in real time. The change of growth behavior and intracellular signaling activities can be observed with a fluorescence microscope.
Collapse
|
20
|
Grones P, Raggi S, Robert S. FORCE-ing the shape. CURRENT OPINION IN PLANT BIOLOGY 2019; 52:1-6. [PMID: 31234034 DOI: 10.1016/j.pbi.2019.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/10/2019] [Accepted: 05/22/2019] [Indexed: 05/27/2023]
Abstract
The plant cell wall is a dynamic structure that mediates cell and organ morphogenesis and provides structural support to the whole plant body. The primary load bearing components of the cell wall are a cellulose-xyloglucan network embedded in a pectin matrix. Plant morphogenesis is regulated by a constant adjustment of the chemical structure and thus mechanical properties of the cell wall components. These modifications are modulated by a variety of different remodeling agents that precisely control cell wall mechanical properties. Here, we briefly review the major recent updates on cell wall mechanics during growth and development.
Collapse
Affiliation(s)
- Peter Grones
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183 Umeå, Sweden
| | - Sara Raggi
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183 Umeå, Sweden
| | - Stéphanie Robert
- Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183 Umeå, Sweden.
| |
Collapse
|
21
|
Morisaku T, Onuki H, Hashimoto K, Kuchitsu K, Yui H. Development of a Near-infrared Laser-induced Surface Deformation Microscope and Its Application to the Dynamic Viscoelastic Measurements of Single Living Plant Cell Surfaces. ANAL SCI 2019; 35:1203-1207. [PMID: 31308300 DOI: 10.2116/analsci.19p227] [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: 11/23/2022]
Abstract
A near-infrared laser-induced surface deformation (NIR-LISD) microscope is developed and is applied to the dynamic viscoelastic measurements of the surface of a living plant cell. In the microscope, the deformation of the surface is induced by an NIR laser beam, and then the change in intensity of the probe beam reflected from the surface reflects its viscoelasticity. The application of the NIR laser beam has a great advantage for the prevention of damage to the plant cell compared to the irradiation of a visible laser beam in LISD measurements. The NIR-LISD microscope allows for discriminating the differences in power spectra between the subapical and lateral regions of single rhizoids. It is a useful method for the dynamic viscoelastic measurements of cells, such as plant cells, that are damaged due to the strong absorption of ultraviolet or visible light.
Collapse
Affiliation(s)
- Toshinori Morisaku
- Water Frontier Science & Technology Research Center, Research Institute for Science & Technology, Tokyo University of Science
| | - Hitomi Onuki
- Department of Chemistry, Faculty of Science, Tokyo University of Science
| | - Kenji Hashimoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Kazuyuki Kuchitsu
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science.,Imaging Frontier Center, Research Institute for Science & Technology, Tokyo University of Science
| | - Hiroharu Yui
- Water Frontier Science & Technology Research Center, Research Institute for Science & Technology, Tokyo University of Science.,Department of Chemistry, Faculty of Science, Tokyo University of Science
| |
Collapse
|
22
|
Bidhendi AJ, Geitmann A. Methods to quantify primary plant cell wall mechanics. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3615-3648. [PMID: 31301141 DOI: 10.1093/jxb/erz281] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 06/26/2019] [Indexed: 05/23/2023]
Abstract
The primary plant cell wall is a dynamically regulated composite material of multiple biopolymers that forms a scaffold enclosing the plant cells. The mechanochemical make-up of this polymer network regulates growth, morphogenesis, and stability at the cell and tissue scales. To understand the dynamics of cell wall mechanics, and how it correlates with cellular activities, several experimental frameworks have been deployed in recent years to quantify the mechanical properties of plant cells and tissues. Here we critically review the application of biomechanical tool sets pertinent to plant cell mechanics and outline some of their findings, relevance, and limitations. We also discuss methods that are less explored but hold great potential for the field, including multiscale in silico mechanical modeling that will enable a unified understanding of the mechanical behavior across the scales. Our overview reveals significant differences between the results of different mechanical testing techniques on plant material. Specifically, indentation techniques seem to consistently report lower values compared with tensile tests. Such differences may in part be due to inherent differences among the technical approaches and consequently the wall properties that they measure, and partly due to differences between experimental conditions.
Collapse
Affiliation(s)
- Amir J Bidhendi
- Department of Plant Science, McGill University, Macdonald Campus, Lakeshore, Ste-Anne-de-Bellevue, Québec, Canada
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, Montreal, Quebec, Canada
| | - Anja Geitmann
- Department of Plant Science, McGill University, Macdonald Campus, Lakeshore, Ste-Anne-de-Bellevue, Québec, Canada
| |
Collapse
|
23
|
Parrotta L, Faleri C, Guerriero G, Cai G. Cold stress affects cell wall deposition and growth pattern in tobacco pollen tubes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 283:329-342. [PMID: 31128704 DOI: 10.1016/j.plantsci.2019.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/29/2019] [Accepted: 03/15/2019] [Indexed: 05/08/2023]
Abstract
Cold is an abiotic stress seriously threatening crop productivity by decreasing biomass production. The pollen tube is a target of cold stress, but also a useful model to address questions on cell wall biosynthesis. We here provide (immuno)cytological data relative to the impact of cold on the pollen tube cell wall. We clearly show that the growth pattern is severely affected by the stress, since the typical pulsed-growth mechanism accompanied by the periodic deposition of pectin rings is absent/severely reduced. Additionally, pectins and cellulose accumulate in bulges provoked by the stress, while callose, which colocalizes with pectins in the periodic rings formed during pulsed growth, accumulates randomly in the stressed samples. The altered distribution of the cell wall components is accompanied by differences in the localization of glucan synthases: cellulose synthase shows a more diffuse localization, while callose synthase shows a more frequent cytoplasmic accumulation, thereby denoting a failure in plasma membrane insertion. The cell wall observations are complemented by the analysis of intracellular Ca2+, pH and reactive oxygen species (ROS): while in the case of pH no major differences are observed, a less focused Ca2+ and ROS gradients are present in the stressed samples. The standard oscillatory growth of pollen tubes is recovered by transient changes of turgor pressure induced by hypoosmotic media. Overall our data contribute to the understanding of the impact that cold stress has on the normal development of the pollen tube and unveil the cell wall-related aberrant features accompanying the observed alterations.
Collapse
Affiliation(s)
- Luigi Parrotta
- Università di Bologna, Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Via Irnerio 42, Bologna, Italy
| | - Claudia Faleri
- Università di Siena, Dipartimento di Scienze della Vita, via P.A. Mattioli 4, Siena, Italy
| | - Gea Guerriero
- Research and Innovation Department, Luxembourg Institute of Science and Technology, 5 avenue des Hauts-Fourneaux, L-4362, Esch/Alzette, Luxembourg
| | - Giampiero Cai
- Università di Siena, Dipartimento di Scienze della Vita, via P.A. Mattioli 4, Siena, Italy.
| |
Collapse
|
24
|
Vaz Dias F, Serrazina S, Vitorino M, Marchese D, Heilmann I, Godinho M, Rodrigues M, Malhó R. A role for diacylglycerol kinase 4 in signalling crosstalk during Arabidopsis pollen tube growth. THE NEW PHYTOLOGIST 2019; 222:1434-1446. [PMID: 30628082 DOI: 10.1111/nph.15674] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/28/2018] [Indexed: 05/29/2023]
Abstract
Diacylglycerol kinases (DGKs) play a major role in the production of phosphatidic acid (PtdOH) and were implicated in endomembrane trafficking and signalling cascades. In plants, the role of DGKs is less clear, as PtdOH seems to arise mostly from phospholipase D activity. Here, we investigated the function of the Arabidopsis gene encoding DGK4, which is highly expressed in pollen. In vitro, pollen tubes from homozygous dgk4 plants showed normal morphology, but reduced growth rate and altered stiffness and adhesion properties (revealed by atomic force microscopy). In vivo, dgk4 pollen was able to fertilize wild-type ovules, but self-pollination in dgk4 plants led to fewer seeds and shorter siliques. Phenotypic analysis revealed that the dgk4 mutation affects not only the male germ line but also the vegetative tissue. DGK4-green fluorescent protein fusion imaging revealed a cytosolic localization with a slightly higher signal in the subapical or apical region. dgk4 pollen tubes were found to exhibit perturbations in membrane recycling, and lipid analysis revealed a minor increase of PtdOH concomitant with decreased phosphatidylcholine, compared with wild-type. In vitro, DGK4 was found to exhibit kinase and guanylyl cyclase activity. Quantitative PCR data revealed downregulation of genes related to actin dynamics and phosphoinositide metabolism in mutant pollen, but upregulation of the DGK6 isoform. Altogether, these results are discussed considering a role of DGK4 in signalling cross-talk.
Collapse
Affiliation(s)
- Fernando Vaz Dias
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Susana Serrazina
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Miguel Vitorino
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Dario Marchese
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Ingo Heilmann
- Institute of Biochemistry and Biotechnology/Cellular Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Margarida Godinho
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Mário Rodrigues
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Rui Malhó
- Faculdade de Ciências de Lisboa, BioISI, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| |
Collapse
|
25
|
Burri JT, Vogler H, Munglani G, Laubli NF, Grossniklaus U, Nelson BJ. A Microrobotic System for Simultaneous Measurement of Turgor Pressure and Cell-Wall Elasticity of Individual Growing Plant Cells. IEEE Robot Autom Lett 2019. [DOI: 10.1109/lra.2019.2892582] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
26
|
Leszczuk A, Kozioł A, Szczuka E, Zdunek A. Analysis of AGP contribution to the dynamic assembly and mechanical properties of cell wall during pollen tube growth. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 281:9-18. [PMID: 30824065 DOI: 10.1016/j.plantsci.2019.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 05/22/2023]
Abstract
Arabinogalactan proteins as cell wall structural proteins are involved in fundamental processes during plant development and growth. The aim of this study was to evaluate AGP function in the distribution of pectin, cellulose and callose along Fragaria x ananassa pollen tube and to associate the cell wall structure with local mechanical properties. We used Yariv reagent which interacts with AGPs and allows the observation of the assembly of cell walls without AGPs performing their function. Cytochemical, immunofluorescence labelling and atomic force microscope have been used to characterize the changes in cell wall structure and stiffness. It was shown that disordering of the structure of AGP present in cell walls affects the localization of cellulose, pectins and the secretion of callose. Changes in cell wall assembly are relevant to pollen tube mechanical properties. The stiffness gradient lengthwise through the axis of the pollen tube has demonstrated a significantly higher Young's modulus of the shank region than the growth zone. It has been revealed that the apex of the pollen tube cultured in the presence of Yariv reagent is stiffer (1.68 MPa) than the corresponding region of the pollen tube grown under control conditions (0.13-0.27 MPa). AGP affects the structure of the cell wall by changing the distribution of other components and the modification of their localization, and hence it plays a significant role in the mechanical properties of the cell wall.
Collapse
Affiliation(s)
- Agata Leszczuk
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Arkadiusz Kozioł
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Ewa Szczuka
- Department of Plant Anatomy and Cytology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Artur Zdunek
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| |
Collapse
|
27
|
Majda M, Sapala A, Routier-Kierzkowska AL, Smith RS. Cellular Force Microscopy to Measure Mechanical Forces in Plant Cells. Methods Mol Biol 2019; 1992:215-230. [PMID: 31148041 DOI: 10.1007/978-1-4939-9469-4_14] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Cellular force microscopy (CFM) is a noninvasive microindentation method used to measure plant cell stiffness in vivo. CFM is a scanning probe microscopy technique similar in operation to atomic force microscopy (AFM); however, the scale of movement and range of forces are much larger, making it suitable for stiffness measurements on turgid plant cells in whole organs. CFM experiments can be performed on living samples over extended time periods, facilitating the exploration of the dynamics of processes involving mechanics. Different sensor technologies can be used, along with a variety of probe shapes and sizes that can be tailored to specific applications. Measurements can be made for specific indentation depths, forces and timing, allowing for very precise mechanical stimulation of cells with known forces. High forces with sharp tips can also be used for mechanical ablation of cells with force feedback.
Collapse
Affiliation(s)
- Mateusz Majda
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Aleksandra Sapala
- Max Planck Institute for Plant Breeding Research, Cologne, Germany.,Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Anne-Lise Routier-Kierzkowska
- Max Planck Institute for Plant Breeding Research, Cologne, Germany.,Institut de Recherche en Biologie Végétale, University of Montréal, Montreal, QC, Canada
| | - Richard S Smith
- Max Planck Institute for Plant Breeding Research, Cologne, Germany.
| |
Collapse
|
28
|
Dehors J, Mareck A, Kiefer-Meyer MC, Menu-Bouaouiche L, Lehner A, Mollet JC. Evolution of Cell Wall Polymers in Tip-Growing Land Plant Gametophytes: Composition, Distribution, Functional Aspects and Their Remodeling. FRONTIERS IN PLANT SCIENCE 2019; 10:441. [PMID: 31057570 PMCID: PMC6482432 DOI: 10.3389/fpls.2019.00441] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/22/2019] [Indexed: 05/22/2023]
Abstract
During evolution of land plants, the first colonizing species presented leafy-dominant gametophytes, found in non-vascular plants (bryophytes). Today, bryophytes include liverworts, mosses, and hornworts. In the first seedless vascular plants (lycophytes), the sporophytic stage of life started to be predominant. In the seed producing plants, gymnosperms and angiosperms , the gametophytic stage is restricted to reproduction. In mosses and ferns, the haploid spores germinate and form a protonema, which develops into a leafy gametophyte producing rhizoids for anchorage, water and nutrient uptakes. The basal gymnosperms (cycads and Ginkgo) reproduce by zooidogamy. Their pollen grains develop a multi-branched pollen tube that penetrates the nucellus and releases flagellated sperm cells that swim to the egg cell. The pollen grain of other gymnosperms (conifers and gnetophytes) as well as angiosperms germinates and produces a pollen tube that directly delivers the sperm cells to the ovule (siphonogamy). These different gametophytes, which are short or long-lived structures, share a common tip-growing mode of cell expansion. Tip-growth requires a massive cell wall deposition to promote cell elongation, but also a tight spatial and temporal control of the cell wall remodeling in order to modulate the mechanical properties of the cell wall. The growth rate of these cells is very variable depending on the structure and the species, ranging from very slow (protonemata, rhizoids, and some gymnosperm pollen tubes), to a slow to fast-growth in other gymnosperms and angiosperms. In addition, the structural diversity of the female counterparts in angiosperms (dry, semi-dry vs wet stigmas, short vs long, solid vs hollow styles) will impact the speed and efficiency of sperm delivery. As the evolution and diversity of the cell wall polysaccharides accompanied the diversification of cell wall structural proteins and remodeling enzymes, this review focuses on our current knowledge on the biochemistry, the distribution and remodeling of the main cell wall polymers (including cellulose, hemicelluloses, pectins, callose, arabinogalactan-proteins and extensins), during the tip-expansion of gametophytes from bryophytes, pteridophytes (lycophytes and monilophytes), gymnosperms and the monocot and eudicot angiosperms.
Collapse
|
29
|
Abstract
With the origin of pollination in ancient seed plants, the male gametophyte ("pollen") began to evolve a new and unique life history stage, the progamic phase, a post-pollination period in which pollen sexual maturation occurs in interaction with sporophyte-derived tissues. Pollen performance traits mediate the timing of the fertilization process, often in competition with other pollen, via the speed of pollen germination, sperm development, and pollen tube growth. Studies of pollen development rarely address the issue of performance or its evolution, which involves linking variation in developmental rates to relative fitness within populations or to adaptations on a macroevolutionary scale. Modifications to the pollen tube pathway and changes in the intensity of pollen competition affect the direction and strength of selection on pollen performance. Hence, pollen developmental evolution is always contextual-it involves both the population biology of pollen reaching stigmas and the co-evolution of sporophytic traits, such as the pollen tube pathway and mating system. For most species, performance evolution generally reflects a wandering history of periods of directional selection and relaxed selection, channeled by developmental limitations, a pattern that favors the accumulation of diversity and redundancy in developmental mechanisms and the genetic machinery. Developmental biologists are focused on finding universal mechanisms that underlie pollen function, and these are largely mechanisms that have evolved through their effects on performance. Here, we suggest ways in which studies of pollen performance or function could progress by cross-fertilization between the "evo" and "devo" fields.
Collapse
Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, United States.
| | - John B Reese
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, United States
| |
Collapse
|
30
|
Zhou LZ, Dresselhaus T. Friend or foe: Signaling mechanisms during double fertilization in flowering seed plants. Curr Top Dev Biol 2018; 131:453-496. [PMID: 30612627 DOI: 10.1016/bs.ctdb.2018.11.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the first description of double fertilization 120 years ago, the processes of pollen tube growth and guidance, sperm cell release inside the receptive synergid cell, as well as fusion of two sperm cells to the female gametes (egg and central cell) have been well documented in many flowering plants. Especially microscopic techniques, including live cell imaging, were used to visualize these processes. Molecular as well as genetic methods were applied to identify key players involved. However, compared to the first 11 decades since its discovery, the past decade has seen a tremendous advancement in our understanding of the molecular mechanisms regulating angiosperm fertilization. Whole signaling networks were elucidated including secreted ligands, corresponding receptors, intracellular interaction partners, and further downstream signaling events involved in the cross-talk between pollen tubes and their cargo with female reproductive cells. Biochemical and structural biological approaches are now increasingly contributing to our understanding of the different signaling processes required to distinguish between compatible and incompatible interaction partners. Here, we review the current knowledge about signaling mechanisms during above processes with a focus on the model plants Arabidopsis thaliana and Zea mays (maize). The analogy that many of the identified "reproductive signaling mechanisms" also act partly or fully in defense responses and/or cell death is also discussed.
Collapse
Affiliation(s)
- Liang-Zi Zhou
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
| |
Collapse
|
31
|
Marsollier AC, Ingram G. Getting physical: invasive growth events during plant development. CURRENT OPINION IN PLANT BIOLOGY 2018; 46:8-17. [PMID: 29981931 DOI: 10.1016/j.pbi.2018.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/04/2018] [Accepted: 06/07/2018] [Indexed: 05/10/2023]
Abstract
Plant cells are enclosed in cell walls that weld them together, meaning that cells rarely change neighbours. Nonetheless, invasive growth events play critical roles in plant development and are often key hubs for the integration of environmental and/or developmental signalling. Here we review cellular processes involved in three such events: lateral root emergence, pollen tube growth through stigma and style tissues, and embryo expansion through the endosperm (Figures 1-3). We consider processes such as regulation of water fluxes and cell turgor (driving growth), cell wall modifications (e.g. cell separation) and cell death (for creating space) within these three contexts with the aim of identifying key mechanisms implicated in providing a chemical and biophysical environments permitting invasive growth events.
Collapse
Affiliation(s)
- Anne-Charlotte Marsollier
- Université de Lyon, Laboratoire Reproduction et Développement des Plantes, ENS de lyon, CNRS, INRA, 46 Allée d'Italie, 69007 Lyon, France
| | - Gwyneth Ingram
- Université de Lyon, Laboratoire Reproduction et Développement des Plantes, ENS de lyon, CNRS, INRA, 46 Allée d'Italie, 69007 Lyon, France.
| |
Collapse
|
32
|
Burri JT, Vogler H, Läubli NF, Hu C, Grossniklaus U, Nelson BJ. Feeling the force: how pollen tubes deal with obstacles. THE NEW PHYTOLOGIST 2018; 220:187-195. [PMID: 29905972 DOI: 10.1111/nph.15260] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 05/08/2018] [Indexed: 05/06/2023]
Abstract
Physical forces are involved in the regulation of plant development and morphogenesis by translating mechanical stress into the modification of physiological processes, which, in turn, can affect cellular growth. Pollen tubes respond rapidly to external stimuli and provide an ideal system to study the effect of mechanical cues at the single-cell level. Here, pollen tubes were exposed to mechanical stress while monitoring the reconfiguration of their growth and recording the generated forces in real-time. We combined a lab-on-a-chip device with a microelectromechanical systems (MEMS)-based capacitive force sensor to mimic and quantify the forces that are involved in pollen tube navigation upon confronting mechanical obstacles. Several stages of obstacle avoidance were identified, including force perception, growth adjustment and penetration. We have experimentally determined the perceptive force threshold, which is the force threshold at which the pollen tube reacts to an obstacle, for Lilium longiflorum and Arabidopsis thaliana. In addition, the method we developed provides a way to calculate turgor pressure based on force and optical data. Pollen tubes sense physical barriers and actively adjust their growth behavior to overcome them. Furthermore, our system offers an ideal platform to investigate intracellular activity during force perception and growth adaption in tip growing cells.
Collapse
Affiliation(s)
- Jan T Burri
- Multi-Scale Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, 8092, Switzerland
| | - Hannes Vogler
- Department of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zürich, 8008, Switzerland
| | - Nino F Läubli
- Multi-Scale Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, 8092, Switzerland
| | - Chengzhi Hu
- Multi-Scale Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, 8092, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zürich, 8008, Switzerland
| | - Bradley J Nelson
- Multi-Scale Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, 8092, Switzerland
| |
Collapse
|
33
|
Yanagisawa N, Sugimoto N, Higashiyama T, Sato Y. Development of Microfluidic Devices to Study the Elongation Capability of Tip-growing Plant Cells in Extremely Small Spaces. J Vis Exp 2018. [PMID: 29889188 DOI: 10.3791/57262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In vivo, tip-growing plant cells need to overcome a series of physical barriers; however, researchers lack the methodology to visualize cellular behavior in such restrictive conditions. To address this issue, we have developed growth chambers for tip-growing plant cells that contain a series of narrow, micro-fabricated gaps (~1 µm) in a poly-dimethylsiloxane (PDMS) substrate. This transparent material allows the user to monitor tip elongation processes in individual cells during microgap penetration by time-lapse imaging. Using this experimental platform, we observed morphological changes in pollen tubes as they penetrated the microgap. We captured the dynamic changes in the shape of a fluorescently labeled vegetative nucleus and sperm cells in a pollen tube during this process. Furthermore, we demonstrated the capability of root hairs and moss protonemata to penetrate the 1 µm gap. This in vitro platform can be used to study how individual cells respond to physically constrained spaces and may provide insights into tip-growth mechanisms.
Collapse
Affiliation(s)
- Naoki Yanagisawa
- Division of Biological Science, Graduate School of Science, Nagoya University;
| | - Nagisa Sugimoto
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
| | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University; Institute of Transformative Bio-Molecules (ITbM), Nagoya University
| | - Yoshikatsu Sato
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University;
| |
Collapse
|
34
|
Abstract
In this introductory chapter, we describe male germline development in plants taking Arabidopsis thaliana as a reference species. We first describe the transition from sporophytic to germline development, then microsporogenesis including meiosis, followed by male gametophyte development prior to pollination, and finally the progamic phase culminating in double fertilization, which leads to the formation of the embryo and the endosperm. For detailed information on some of these processes or on the molecular underpinning of certain fate transitions, we refer the reader to recent reviews. An important but often neglected aspect of male gametophyte development is the formation of the unique pollen cell wall. In contrast to that of other plant cells, the pollen cell wall is composed of two principal layers, the intine and exine. While the intine, the inner pecto-cellulosic cell wall layer, is biochemically and structurally similar to a "classical" plant cell wall, the exine is a unique composite with sporopollenin as its main component. Biosynthesis of the cell wall is remarkably similar between the spores of mosses and ferns, and pollen of seed plants, although slight differences exist, even between closely related species (reviewed in Wallace et al., AoB Plants 2011:plr027, 2011). In the latter sections of this chapter, we will present a brief overview of cell wall development in Arabidopsis pollen, where this aspect has been intensively studied.
Collapse
|
35
|
Hong L, Dumond M, Zhu M, Tsugawa S, Li CB, Boudaoud A, Hamant O, Roeder AHK. Heterogeneity and Robustness in Plant Morphogenesis: From Cells to Organs. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:469-495. [PMID: 29505739 DOI: 10.1146/annurev-arplant-042817-040517] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Development is remarkably reproducible, producing organs with the same size, shape, and function repeatedly from individual to individual. For example, every flower on the Antirrhinum stalk has the same snapping dragon mouth. This reproducibility has allowed taxonomists to classify plants and animals according to their morphology. Yet these reproducible organs are composed of highly variable cells. For example, neighboring cells grow at different rates in Arabidopsis leaves, sepals, and shoot apical meristems. This cellular variability occurs in normal, wild-type organisms, indicating that cellular heterogeneity (or diversity in a characteristic such as growth rate) is either actively maintained or, at a minimum, not entirely suppressed. In fact, cellular heterogeneity can contribute to producing invariant organs. Here, we focus on how plant organs are reproducibly created during development from these highly variable cells.
Collapse
Affiliation(s)
- Lilan Hong
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
| | - Mathilde Dumond
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
- Current affiliation: Department for Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland;
| | - Mingyuan Zhu
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
| | - Satoru Tsugawa
- Theoretical Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan;
| | - Chun-Biu Li
- Department of Mathematics, Stockholm University, 106 91 Stockholm, Sweden;
| | - Arezki Boudaoud
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
| | - Olivier Hamant
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
| |
Collapse
|
36
|
Cameron C, Geitmann A. Cell mechanics of pollen tube growth. Curr Opin Genet Dev 2018; 51:11-17. [PMID: 29602058 DOI: 10.1016/j.gde.2018.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/03/2018] [Accepted: 03/09/2018] [Indexed: 12/13/2022]
Abstract
The pollen tube features particular traits that can only be understood when integrating cell biological with cell mechanical concepts. Firstly, regular temporal variations in the growth rate are governed by a feedback mechanism thought to involve mechanosensitive ion channels. Secondly, the tube uses invasive growth to penetrate the flower tissues with the aim to transport the male sperm cells to their target. Thirdly, the pollen tube is able to reorient its growth direction upon exposure to a guidance cue; the steering mechanism involves the sophisticated choreography of intracellular transport processes. Sophisticated imaging and micromanipulation techniques have been instrumental for the advancement in characterizing the biomechanical features of this crucial cell in the plant reproductive cycle.
Collapse
Affiliation(s)
- Christine Cameron
- Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Québec H9X 3V9, Canada
| | - Anja Geitmann
- Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Québec H9X 3V9, Canada.
| |
Collapse
|
37
|
Li HJ, Meng JG, Yang WC. Multilayered signaling pathways for pollen tube growth and guidance. PLANT REPRODUCTION 2018; 31:31-41. [PMID: 29441420 DOI: 10.1007/s00497-018-0324-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/24/2018] [Indexed: 05/22/2023]
Abstract
Sexual reproductive success is essential for the survival of all higher organisms. As the most prosperous and diverse group of land plants on earth, flowering plants evolved highly sophisticated fertilization mechanisms. To adapt to the terrestrial environment, a tubular structure pollen tube has been evolved to deliver the immobile sperm cells to the egg and central cell enclosed within the ovule. The pollen tube is generated from the vegetative cell of the pollen (male gametophyte), where two sperm cells are hosted. Pollen tube elongation in the maternal tissue and navigation to the ovule require intimate cell-cell interactions between the tube and female tissues. Questions on how the single-celled pollen tube accomplishes such task and how the female tissues accommodate the tube have attracted many plant biologists. Here, we review recent progresses and concepts in understanding the molecular mechanisms governing pollen tube growth and its interactions with the female tissues. We will also discuss the future perspective in this field.
Collapse
Affiliation(s)
- Hong-Ju Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China.
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China.
| | - Jiang-Guo Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China.
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China.
| |
Collapse
|
38
|
Affiliation(s)
- Martin Stegmann
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Cyril Zipfel
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK.
| |
Collapse
|
39
|
Ndinyanka Fabrice T, Kaech A, Barmettler G, Eichenberger C, Knox JP, Grossniklaus U, Ringli C. Efficient preparation of Arabidopsis pollen tubes for ultrastructural analysis using chemical and cryo-fixation. BMC PLANT BIOLOGY 2017; 17:176. [PMID: 29078752 PMCID: PMC5658917 DOI: 10.1186/s12870-017-1136-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/18/2017] [Indexed: 05/19/2023]
Abstract
BACKGROUND The pollen tube (PT) serves as a model system for investigating plant cell growth and morphogenesis. Ultrastructural studies are indispensable to complement data from physiological and genetic analyses, yet an effective method is lacking for PTs of the model plant Arabidopsis thaliana. METHODS Here, we present reliable approaches for ultrastructural studies of Arabidopsis PTs, as well as an efficient technique for immunogold detection of cell wall epitopes. Using different fixation and embedding strategies, we show the amount of PT ultrastructural details that can be obtained by the different methods. RESULTS Dozens of cross-sections can be obtained simultaneously by the approach, which facilitates and shortens the time for evaluation. In addition to in vitro-grown PTs, our study follows the route of PTs from germination, growth along the pistil, to the penetration of the dense stylar tissue, which requires considerable mechanical forces. To this end, PTs have different strategies from growing between cells but also between the protoplast and the cell wall and even within each other, where they share a partly common cell wall. The separation of PT cell walls in an outer and an inner layer reported for many plant species is less clear in Arabidopsis PTs, where these cell wall substructures are connected by a distinct transition zone. CONCLUSIONS The major advancement of this method is the effective production of a large number of longitudinal and cross-sections that permits obtaining a detailed and representative picture of pollen tube structures in an unprecedented way. This is particularly important when comparing PTs of wild type and mutants to identify even subtle alterations in cytoarchitecture. Arabidopsis is an excellent plant for genetic manipulation, yet the PTs, several-times smaller compared to tobacco or lily, represent a technical challenge. This study reveals a method to overcome this problem and make Arabidopsis PTs more amenable to a combination of genetic and ultrastructural analyses.
Collapse
Affiliation(s)
- Tohnyui Ndinyanka Fabrice
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - Andres Kaech
- Center for Microscopy and Image Analysis, University of Zurich, 8057 Zurich, Switzerland
| | - Gery Barmettler
- Center for Microscopy and Image Analysis, University of Zurich, 8057 Zurich, Switzerland
| | - Christof Eichenberger
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - J. Paul Knox
- University of Leeds, Center for Plant Sciences, Leeds, LS2 9JT UK
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - Christoph Ringli
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| |
Collapse
|
40
|
Shamsudhin N, Atakan HB, Laubli N, Vogler H, Sebastian A, Grossniklaus U, Nelson BJ. Probing the micromechanics of the fastest growing plant cell - the pollen tube. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:461-464. [PMID: 28268371 DOI: 10.1109/embc.2016.7590739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The pollen tube is a fast growing cellular protrusion that plays a key role in the reproductive process of flowering plants. It serves as an important model for studying cellular morphogenesis, anisotropic growth mechanisms, and cellular signaling in the plant sciences. The anisotropic growth of pollen tubes is driven by a finely tuned control of the intracellular turgor pressure and the extensibility of the cell wall. To decipher this internal feedback loop and mathematically model the growth process, a quantitative understanding of the mechanical properties of the cell wall is crucial, in addition to biochemical investigations. We report an integrated microfluidic-MEMS force sensor system that allows for high-throughput optical and mechanical investigations of pollen tubes. The system permits large-scale germination, growth, and optical phenotyping of pollen tubes empowering rapid micro-indentation measurements on these cells.
Collapse
|
41
|
Capability of tip-growing plant cells to penetrate into extremely narrow gaps. Sci Rep 2017; 7:1403. [PMID: 28469280 PMCID: PMC5431147 DOI: 10.1038/s41598-017-01610-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/31/2017] [Indexed: 11/08/2022] Open
Abstract
Plant cells are covered with rigid cell walls, yet tip-growing cells can elongate by providing new cell wall material to their apical regions. Studies of the mechanical properties of tip-growing plant cells typically involve measurement of the turgor pressure and stiffness of the cells’ apical regions. These experiments, however, do not address how living tip-growing cells react when they encounter physical obstacles that are not substantially altered by turgor pressure. To investigate this issue, we constructed microfabricated platforms with a series of artificial gaps as small as 1 μm, and examined the capability of tip-growing plant cells, including pollen tubes, root hairs, and moss protonemata, to penetrate into these gaps. The cells were grown inside microfluidic chambers and guided towards the gaps using microdevices customized for each cell type. All types of tip-growing cells could grow through the microgaps with their organelles intact, even though the gaps were much smaller than the cylindrical cell diameter. Our findings reveal the dramatic physiological and developmental flexibility of tip-growing plant cells. The microfluidic platforms designed in this study provide novel tools for the elucidation of the mechanical properties of tip-growing plant cells in extremely small spaces.
Collapse
|
42
|
Hu C, Vogler H, Aellen M, Shamsudhin N, Jang B, Burri JT, Läubli N, Grossniklaus U, Pané S, Nelson BJ. High precision, localized proton gradients and fluxes generated by a microelectrode device induce differential growth behaviors of pollen tubes. LAB ON A CHIP 2017; 17:671-680. [PMID: 28098283 DOI: 10.1039/c6lc01307d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Pollen tubes are tip-growing plant cells that deliver the sperm cells to the ovules for double fertilization of the egg cell and the endosperm. Various directional cues can trigger the reorientation of pollen tube growth direction on their passage through the female tissues. Among the external stimuli, protons serve an important, regulatory role in the control of pollen tube growth. The generation of local guidance cues has been challenging when investigating the mechanisms of perception and processing of such directional triggers in pollen tubes. Here, we developed and characterized a microelectrode device to generate a local proton gradient and proton flux through water electrolysis. We confirmed that the cytoplasmic pH of pollen tubes varied with environmental pH change. Depending on the position of the pollen tube tip relative to the proton gradient, we observed alterations in the growth behavior, such as bursting at the tip, change in growth direction, or complete growth arrest. Bursting and growth arrest support the hypothesis that changes in the extracellular H+ concentration may interfere with cell wall integrity and actin polymerization at the growing tip. A change in growth direction for some pollen tubes implies that they can perceive the local proton gradient and respond to it. We also showed that the growth rate is directly correlated with the extracellular pH in the tip region. Our microelectrode approach provides a simple method to generate protons and investigate their effect on plant cell growth.
Collapse
Affiliation(s)
- Chengzhi Hu
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Hannes Vogler
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Marianne Aellen
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Naveen Shamsudhin
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Bumjin Jang
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Jan T Burri
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Nino Läubli
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Salvador Pané
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Bradley J Nelson
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| |
Collapse
|
43
|
Mosca G, Sapala A, Strauss S, Routier-Kierzkowska AL, Smith RS. On the micro-indentation of plant cells in a tissue context. Phys Biol 2017; 14:015003. [DOI: 10.1088/1478-3975/aa5698] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
44
|
Hu C, Munglani G, Vogler H, Ndinyanka Fabrice T, Shamsudhin N, Wittel FK, Ringli C, Grossniklaus U, Herrmann HJ, Nelson BJ. Characterization of size-dependent mechanical properties of tip-growing cells using a lab-on-chip device. LAB ON A CHIP 2016; 17:82-90. [PMID: 27883138 DOI: 10.1039/c6lc01145d] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Quantification of mechanical properties of tissues, living cells, and cellular components is crucial for the modeling of plant developmental processes such as mechanotransduction. Pollen tubes are tip-growing cells that provide an ideal system to study the mechanical properties at the single cell level. In this article, a lab-on-a-chip (LOC) device is developed to quantitatively measure the biomechanical properties of lily (Lilium longiflorum) pollen tubes. A single pollen tube is fixed inside the microfluidic chip at a specific orientation and subjected to compression by a soft membrane. By comparing the deformation of the pollen tube at a given external load (compressibility) and the effect of turgor pressure on the tube diameter (stretch ratio) with finite element modeling, its mechanical properties are determined. The turgor pressure and wall stiffness of the pollen tubes are found to decrease considerably with increasing initial diameter of the pollen tubes. This observation supports the hypothesis that tip-growth is regulated by a delicate balance between turgor pressure and wall stiffness. The LOC device is modular and adaptable to a variety of cells that exhibit tip-growth, allowing for the straightforward measurement of mechanical properties.
Collapse
Affiliation(s)
- Chengzhi Hu
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Gautam Munglani
- Computational Physics for Engineering Materials, Institute for Building Materials, ETH Zurich, Stefano-Franscini-Platz 3, CH-8093 Zurich, Switzerland
| | - Hannes Vogler
- Institute of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Tohnyui Ndinyanka Fabrice
- Institute of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Naveen Shamsudhin
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| | - Falk K Wittel
- Computational Physics for Engineering Materials, Institute for Building Materials, ETH Zurich, Stefano-Franscini-Platz 3, CH-8093 Zurich, Switzerland
| | - Christoph Ringli
- Institute of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Ueli Grossniklaus
- Institute of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Hans J Herrmann
- Computational Physics for Engineering Materials, Institute for Building Materials, ETH Zurich, Stefano-Franscini-Platz 3, CH-8093 Zurich, Switzerland
| | - Bradley J Nelson
- Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich, Switzerland.
| |
Collapse
|
45
|
Shamsudhin N, Laeubli N, Atakan HB, Vogler H, Hu C, Haeberle W, Sebastian A, Grossniklaus U, Nelson BJ. Massively Parallelized Pollen Tube Guidance and Mechanical Measurements on a Lab-on-a-Chip Platform. PLoS One 2016; 11:e0168138. [PMID: 27977748 PMCID: PMC5158026 DOI: 10.1371/journal.pone.0168138] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/27/2016] [Indexed: 11/19/2022] Open
Abstract
Pollen tubes are used as a model in the study of plant morphogenesis, cellular differentiation, cell wall biochemistry, biomechanics, and intra- and intercellular signaling. For a "systems-understanding" of the bio-chemo-mechanics of tip-polarized growth in pollen tubes, the need for a versatile, experimental assay platform for quantitative data collection and analysis is critical. We introduce a Lab-on-a-Chip (LoC) concept for high-throughput pollen germination and pollen tube guidance for parallelized optical and mechanical measurements. The LoC localizes a large number of growing pollen tubes on a single plane of focus with unidirectional tip-growth, enabling high-resolution quantitative microscopy. This species-independent LoC platform can be integrated with micro-/nano-indentation systems, such as the cellular force microscope (CFM) or the atomic force microscope (AFM), allowing for rapid measurements of cell wall stiffness of growing tubes. As a demonstrative example, we show the growth and directional guidance of hundreds of lily (Lilium longiflorum) and Arabidopsis (Arabidopsis thaliana) pollen tubes on a single LoC microscopy slide. Combining the LoC with the CFM, we characterized the cell wall stiffness of lily pollen tubes. Using the stiffness statistics and finite-element-method (FEM)-based approaches, we computed an effective range of the linear elastic moduli of the cell wall spanning the variability space of physiological parameters including internal turgor, cell wall thickness, and tube diameter. We propose the LoC device as a versatile and high-throughput phenomics platform for plant reproductive and development biology using the pollen tube as a model.
Collapse
Affiliation(s)
| | - Nino Laeubli
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | | | - Hannes Vogler
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Chengzhi Hu
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | | | | | - Ueli Grossniklaus
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- Zurich-Basel Plant Science Center, Zurich, Switzerland
| | | |
Collapse
|
46
|
Yakubov GE, Bonilla MR, Chen H, Doblin MS, Bacic A, Gidley MJ, Stokes JR. Mapping nano-scale mechanical heterogeneity of primary plant cell walls. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2799-816. [PMID: 26988718 PMCID: PMC4861025 DOI: 10.1093/jxb/erw117] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nanoindentation experiments are performed using an atomic force microscope (AFM) to quantify the spatial distribution of mechanical properties of plant cell walls at nanometre length scales. At any specific location on the cell wall, a complex (non-linear) force-indentation response occurs that can be deconvoluted using a unique multiregime analysis (MRA). This allows an unambiguous evaluation of the local transverse elastic modulus of the wall. Nanomechanical measurements on suspension-cultured cells (SCCs), derived from Italian ryegrass (Lolium multiflorum) starchy endosperm, show three characteristic modes of deformation and a spatial distribution of elastic moduli across the surface. 'Soft' and 'hard' domains are found across length scales between 0.1 µm and 3 µm, which is well above a typical pore size of the polysaccharide mesh. The generality and wider applicability of this mechanical heterogeneity is verified through in planta characterization on leaf epidermal cells of Arabidopsis thaliana and L. multiflorum The outcomes of this research provide a basis for uncovering and quantifying the relationships between local wall composition, architecture, cell growth, and/or morphogenesis.
Collapse
Affiliation(s)
- Gleb E Yakubov
- Australian Research Council Centre of Excellence in Plant Cell Walls School of Chemical Engineering, The University of Queensland, Queensland, Australia
| | - Mauricio R Bonilla
- Australian Research Council Centre of Excellence in Plant Cell Walls School of Chemical Engineering, The University of Queensland, Queensland, Australia
| | - Huaying Chen
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Queensland, Australia
| | - Monika S Doblin
- Australian Research Council Centre of Excellence in Plant Cell Walls School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony Bacic
- Australian Research Council Centre of Excellence in Plant Cell Walls School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael J Gidley
- Australian Research Council Centre of Excellence in Plant Cell Walls Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Queensland, Australia
| | - Jason R Stokes
- Australian Research Council Centre of Excellence in Plant Cell Walls School of Chemical Engineering, The University of Queensland, Queensland, Australia
| |
Collapse
|
47
|
Voxeur A, Höfte H. Cell wall integrity signaling in plants: “To grow or not to grow that's the question”. Glycobiology 2016; 26:950-960. [DOI: 10.1093/glycob/cww029] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/27/2016] [Indexed: 11/12/2022] Open
|
48
|
Williams JH, Edwards JA, Ramsey AJ. Economy, efficiency, and the evolution of pollen tube growth rates. AMERICAN JOURNAL OF BOTANY 2016; 103:471-483. [PMID: 26936897 DOI: 10.3732/ajb.1500264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
PREMISE Pollen tube growth rate (PTGR) is an important aspect of male gametophyte performance because of its central role in the fertilization process. Theory suggests that under intense competition, PTGRs should evolve to be faster, especially if PTGR accurately reflects gametophyte quality. Oddly, we know remarkably little about how effectively the work of tube construction is translated to elongation (growth and growth rate). Here we test the prediction that pollen tubes grow equally efficiently by comparing the scaling of wall production rate (WPR) to PTGR in three water lilies that flower concurrently: Nymphaea odorata, Nuphar advena and Brasenia schreberi. METHODS Single-donor pollinations on flower or carpel pairs were fixed just after pollen germination (time A) and 45 min later (time B). Mean PTGR was calculated as the average increase in tube length over that growth period. Tube circumferences (C) and wall thicknesses (W) were measured at time B. For each donor, WPR = mean (C × W) × mean PTGR. KEY RESULTS Within species, pollen tubes maintained a constant WPR to PTGR ratio, but species had significantly different ratios. N. odorata and N. advena had similar PTGRs, but for any given PTGR, they had the lowest and highest WPRs, respectively. CONCLUSIONS We showed that growth rate efficiencies evolved by changes in the volume of wall material used for growth and in how that material was partitioned between lateral and length dimensions. The economics of pollen tube growth are determined by tube design, which is consequent on trade-offs between efficient growth and other pollen tube functions.
Collapse
Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996 USA
| | - Jacob A Edwards
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996 USA
| | - Adam J Ramsey
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996 USA
| |
Collapse
|
49
|
Williams JH, Mazer SJ. Pollen--tiny and ephemeral but not forgotten: New ideas on their ecology and evolution. AMERICAN JOURNAL OF BOTANY 2016; 103:365-74. [PMID: 26980838 DOI: 10.3732/ajb.1600074] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 02/29/2016] [Indexed: 05/08/2023]
Abstract
Ecologists and evolutionary biologists have been interested in the functional biology of pollen since the discovery in the 1800s that pollen grains encompass tiny plants (male gametophytes) that develop and produce sperm cells. After the discovery of double fertilization in flowering plants, botanists in the early 1900s were quick to explore the effects of temperature and maternal nutrients on pollen performance, while evolutionary biologists began studying the nature of haploid selection and pollen competition. A series of technical and theoretic developments have subsequently, but usually separately, expanded our knowledge of the nature of pollen performance and how it evolves. Today, there is a tremendous diversity of interests that touch on pollen performance, ranging from the ecological setting on the stigma, structural and physiological aspects of pollen germination and tube growth, the form of pollen competition and its role in sexual selection in plants, virus transmission, mating system evolution, and inbreeding depression. Given the explosion of technical knowledge of pollen cell biology, computer modeling, and new methods to deal with diversity in a phylogenetic context, we are now more than ever poised for a new era of research that includes complex functional traits that limit or enhance the evolution of these deceptively simple organisms.
Collapse
Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996 USA
| | - Susan J Mazer
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California 93105 USA
| |
Collapse
|
50
|
Bidhendi AJ, Geitmann A. Relating the mechanics of the primary plant cell wall to morphogenesis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:449-61. [PMID: 26689854 DOI: 10.1093/jxb/erv535] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Regulation of the mechanical properties of the cell wall is a key parameter used by plants to control the growth behavior of individual cells and tissues. Modulation of the mechanical properties occurs through the control of the biochemical composition and the degree and nature of interlinking between cell wall polysaccharides. Preferentially oriented cellulose microfibrils restrict cellular expansive growth, but recent evidence suggests that this may not be the trigger for anisotropic growth. Instead, non-uniform softening through the modulation of pectin chemistry may be an initial step that precedes stress-induced stiffening of the wall through cellulose. Here we briefly review the major cell wall polysaccharides and their implication for plant cell wall mechanics that need to be considered in order to study the growth behavior of the primary plant cell wall.
Collapse
Affiliation(s)
- Amir J Bidhendi
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, Montreal, Quebec H1X 2B2, Canada
| | - Anja Geitmann
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, Montreal, Quebec H1X 2B2, Canada
| |
Collapse
|