1
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Yadav AS, Hong L, Klees PM, Kiss A, Petit M, He X, Barrios IM, Heeney M, Galang AMD, Smith RS, Boudaoud A, Roeder AH. Growth directions and stiffness across cell layers determine whether tissues stay smooth or buckle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.22.549953. [PMID: 37546730 PMCID: PMC10401922 DOI: 10.1101/2023.07.22.549953] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
From smooth to buckled, nature exhibits organs of various shapes and forms. How cellular growth patterns produce smooth organ shapes such as leaves and sepals remains unclear. Here we show that unidirectional growth and comparable stiffness across both epidermal layers of Arabidopsis sepals are essential for smoothness. We identified a mutant with ectopic ASYMMETRIC LEAVES 2 (AS2) expression on the outer epidermis. Our analysis reveals that ectopic AS2 expression causes outer epidermal buckling at early stages of sepal development, due to conflicting growth directions and unequal epidermal stiffnesses. Aligning growth direction and increasing stiffness of the outer epidermis restores smoothness. Furthermore, buckling influences auxin efflux transporter protein PIN-FORMED 1 polarity to generate outgrowth in the later stages, suggesting that buckling is sufficient to initiate outgrowths. Our findings suggest that in addition to molecular cues influencing tissue mechanics, tissue mechanics can also modulate molecular signals, giving rise to well-defined shapes.
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Affiliation(s)
- Avilash S. Yadav
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Lilan Hong
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Patrick M. Klees
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Annamaria Kiss
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRAE, INRIA, F-69342 Lyon, France
| | - Manuel Petit
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRAE, INRIA, F-69342 Lyon, France
| | - Xi He
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Iselle M. Barrios
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Michelle Heeney
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Anabella Maria D. Galang
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | | | - Arezki Boudaoud
- LadHyX, Ecole Polytechnique, CNRS, IP Paris, 91128 Palaiseau Cedex, France
| | - Adrienne H.K. Roeder
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
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2
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Al-Mosleh S, Mahadevan L. How to Grow a Flat Leaf. PHYSICAL REVIEW LETTERS 2023; 131:098401. [PMID: 37721834 DOI: 10.1103/physrevlett.131.098401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/08/2023] [Indexed: 09/20/2023]
Abstract
Growing a flat lamina such as a leaf is almost impossible without some feedback to stabilize long wavelength modes that are easy to trigger since they are energetically cheap. Here we combine the physics of thin elastic plates with feedback control theory to explore how a leaf can remain flat while growing. We investigate both in-plane (metric) and out-of-plane (curvature) growth variation and account for both local and nonlocal feedback laws. We show that a linearized feedback theory that accounts for both spatially nonlocal and temporally delayed effects suffices to suppress long wavelength fluctuations effectively and explains recently observed statistical features of growth in tobacco leaves. Our work provides a framework for understanding the regulation of the shape of leaves and other leaflike laminar objects.
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Affiliation(s)
- Salem Al-Mosleh
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - L Mahadevan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Departments of Physics, and Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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3
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Harline K, Roeder AHK. An optimized pipeline for live imaging whole Arabidopsis leaves at cellular resolution. PLANT METHODS 2023; 19:10. [PMID: 36726130 PMCID: PMC9890716 DOI: 10.1186/s13007-023-00987-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Live imaging is the gold standard for determining how cells give rise to organs. However, tracking many cells across whole organs over large developmental time windows is extremely challenging. In this work, we provide a comparably simple method for confocal live imaging entire Arabidopsis thaliana first leaves across early development. Our imaging method works for both wild-type leaves and the complex curved leaves of the jaw-1D mutant. RESULTS We find that dissecting the cotyledons, affixing a coverslip above the samples and mounting samples with perfluorodecalin yields optimal imaging series for robust cellular and organ level analysis. We provide details of our complementary image processing steps in MorphoGraphX software for segmenting, tracking lineages, and measuring a suite of cellular properties. We also provide MorphoGraphX image processing scripts we developed to automate analysis of segmented images and data presentation. CONCLUSIONS Our imaging techniques and processing steps combine into a robust imaging pipeline. With this pipeline we are able to examine important nuances in the cellular growth and differentiation of jaw-D versus WT leaves that have not been demonstrated before. Our pipeline is approachable and easy to use for leaf development live imaging.
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Affiliation(s)
- Kate Harline
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA
- Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY, 14853, USA
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA.
- Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY, 14853, USA.
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4
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Nakayama H, Koga H, Long Y, Hamant O, Ferjani A. Looking beyond the gene network - metabolic and mechanical cell drivers of leaf morphogenesis. J Cell Sci 2022; 135:275072. [PMID: 35438169 DOI: 10.1242/jcs.259611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The above-ground organs in plants display a rich diversity, yet they grow to characteristic sizes and shapes. Organ morphogenesis progresses through a sequence of key events, which are robustly executed spatiotemporally as an emerging property of intrinsic molecular networks while adapting to various environmental cues. This Review focuses on the multiscale control of leaf morphogenesis. Beyond the list of known genetic determinants underlying leaf growth and shape, we focus instead on the emerging novel mechanisms of metabolic and biomechanical regulations that coordinate plant cell growth non-cell-autonomously. This reveals how metabolism and mechanics are not solely passive outcomes of genetic regulation but play instructive roles in leaf morphogenesis. Such an integrative view also extends to fluctuating environmental cues and evolutionary adaptation. This synthesis calls for a more balanced view on morphogenesis, where shapes are considered from the standpoints of geometry, genetics, energy and mechanics, and as emerging properties of the cellular expression of these different properties.
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Affiliation(s)
- Hokuto Nakayama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 113-0033 Tokyo, Japan
| | - Hiroyuki Koga
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 113-0033 Tokyo, Japan
| | - Yuchen Long
- Department of Biological Sciences, The National University of Singapore, Singapore 117543, Singapore
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, 69007 Lyon, France
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, 184-8501 Tokyo, Japan
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5
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Autran D, Bassel GW, Chae E, Ezer D, Ferjani A, Fleck C, Hamant O, Hartmann FP, Jiao Y, Johnston IG, Kwiatkowska D, Lim BL, Mahönen AP, Morris RJ, Mulder BM, Nakayama N, Sozzani R, Strader LC, ten Tusscher K, Ueda M, Wolf S. What is quantitative plant biology? QUANTITATIVE PLANT BIOLOGY 2021; 2:e10. [PMID: 37077212 PMCID: PMC10095877 DOI: 10.1017/qpb.2021.8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 05/03/2023]
Abstract
Quantitative plant biology is an interdisciplinary field that builds on a long history of biomathematics and biophysics. Today, thanks to high spatiotemporal resolution tools and computational modelling, it sets a new standard in plant science. Acquired data, whether molecular, geometric or mechanical, are quantified, statistically assessed and integrated at multiple scales and across fields. They feed testable predictions that, in turn, guide further experimental tests. Quantitative features such as variability, noise, robustness, delays or feedback loops are included to account for the inner dynamics of plants and their interactions with the environment. Here, we present the main features of this ongoing revolution, through new questions around signalling networks, tissue topology, shape plasticity, biomechanics, bioenergetics, ecology and engineering. In the end, quantitative plant biology allows us to question and better understand our interactions with plants. In turn, this field opens the door to transdisciplinary projects with the society, notably through citizen science.
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Affiliation(s)
- Daphné Autran
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
| | - George W. Bassel
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Eunyoung Chae
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Daphne Ezer
- The Alan Turing Institute, London, United Kingdom
- Department of Statistics, University of Warwick, Coventry, United Kingdom
- Department of Biology, University of York, York, United Kingdom
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Christian Fleck
- Freiburg Center for Data Analysis and Modeling (FDM), University of Freiburg, Breisgau, Germany
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, École normale supérieure (ENS) de Lyon, Université Claude Bernard Lyon (UCBL), Lyon, France
- Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE), CNRS, Université de Lyon, Lyon, France
| | | | - Yuling Jiao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | | | - Dorota Kwiatkowska
- Institute of Biology, Biotechnology and Environment Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice, Poland
| | - Boon L. Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Ari Pekka Mahönen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Richard J. Morris
- Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom
| | - Bela M. Mulder
- Department of Living Matter, Institute AMOLF, Amsterdam, The Netherlands
| | - Naomi Nakayama
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ross Sozzani
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North CarolinaUSA
| | - Lucia C. Strader
- Department of Biology, Duke University, Durham, North Carolina, USA
- NSF Science and Technology Center for Engineering Mechanobiology, Department of Biology, Washington University in St. Louis, St. Louis, MissouriUSA
| | - Kirsten ten Tusscher
- Theoretical Biology, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Minako Ueda
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Sebastian Wolf
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, Heidelberg, Germany
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6
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Moulia B, Douady S, Hamant O. Fluctuations shape plants through proprioception. Science 2021; 372:372/6540/eabc6868. [PMID: 33888615 DOI: 10.1126/science.abc6868] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Plants constantly experience fluctuating internal and external mechanical cues, ranging from nanoscale deformation of wall components, cell growth variability, nutating stems, and fluttering leaves to stem flexion under tree weight and wind drag. Developing plants use such fluctuations to monitor and channel their own shape and growth through a form of proprioception. Fluctuations in mechanical cues may also be actively enhanced, producing oscillating behaviors in tissues. For example, proprioception through leaf nastic movements may promote organ flattening. We propose that fluctuation-enhanced proprioception allows plant organs to sense their own shapes and behave like active materials with adaptable outputs to face variable environments, whether internal or external. Because certain shapes are more amenable to fluctuations, proprioception may also help plant shapes to reach self-organized criticality to support such adaptability.
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Affiliation(s)
- Bruno Moulia
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France.
| | - Stéphane Douady
- Laboratoire Matières et Systèmes Complexes (MSC), Université de Paris, CNRS, 75205 Paris Cedex 13, France.
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, 69007 Lyon, France.
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7
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Trinh DC, Alonso-Serra J, Asaoka M, Colin L, Cortes M, Malivert A, Takatani S, Zhao F, Traas J, Trehin C, Hamant O. How Mechanical Forces Shape Plant Organs. Curr Biol 2021; 31:R143-R159. [PMID: 33561417 DOI: 10.1016/j.cub.2020.12.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Plants produce organs of various shapes and sizes. While much has been learned about genetic regulation of organogenesis, the integration of mechanics in the process is also gaining attention. Here, we consider the role of forces as instructive signals in organ morphogenesis. Turgor pressure is the primary cause of mechanical signals in developing organs. Because plant cells are glued to each other, mechanical signals act, in essence, at multiple scales, through cell wall contiguity and water flux. In turn, cells use such signals to resist mechanical stress, for instance, by reinforcing their cell walls. We show that the three elemental shapes behind plant organs - spheres, cylinders and lamina - can be actively maintained by such a mechanical feedback. Combinations of this 3-letter alphabet can generate more complex shapes. Furthermore, mechanical conflicts emerge at the boundary between domains exhibiting different growth rates or directions. These secondary mechanical signals contribute to three other organ shape features - folds, shape reproducibility and growth arrest. The further integration of mechanical signals with the molecular network offers many fruitful prospects for the scientific community, including the role of proprioception in organ shape robustness or the definition of cell and organ identities as a result of an interplay between biochemical and mechanical signals.
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Affiliation(s)
- Duy-Chi Trinh
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France; Department of Pharmacological, Medical and Agronomical Biotechnology, University of Science and Technology of Hanoi, Cau Giay District, Hanoi, Vietnam
| | - Juan Alonso-Serra
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Mariko Asaoka
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Leia Colin
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Matthieu Cortes
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Alice Malivert
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Shogo Takatani
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Feng Zhao
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Jan Traas
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Christophe Trehin
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
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8
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Cortical tension overrides geometrical cues to orient microtubules in confined protoplasts. Proc Natl Acad Sci U S A 2020; 117:32731-32738. [PMID: 33288703 PMCID: PMC7768696 DOI: 10.1073/pnas.2008895117] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In plants, microtubules largely determine the direction of cell expansion and the orientation of cell division planes. However, what processes orient the microtubules has remained debated. Here, we used microfabricated wells to confine and deform wallless plant cells in a controlled way to analyze the response of microtubules to cell geometry and surface tension. We demonstrate that microtubules align with cell geometry by default, whereas when surface tension increases (e.g. when turgor pressure increases), they align with the direction of maximal tension. Not only does this explain many observations in plant tissues, but it also provides a simple mechanism at the core of plant morphogenesis, in which microtubules can spontaneously align with tension, in a typical self-organized system. In plant cells, cortical microtubules (CMTs) generally control morphogenesis by guiding cellulose synthesis. CMT alignment has been proposed to depend on geometrical cues, with microtubules aligning with the cell long axis in silico and in vitro. Yet, CMTs are usually transverse in vivo, i.e., along predicted maximal tension, which is transverse for cylindrical pressurized vessels. Here, we adapted a microwell setup to test these predictions in a single-cell system. We confined protoplasts laterally to impose a curvature ratio and modulated pressurization through osmotic changes. We find that CMTs can be longitudinal or transverse in wallless protoplasts and that the switch in CMT orientation depends on pressurization. In particular, longitudinal CMTs become transverse when cortical tension increases. This explains the dual behavior of CMTs in planta: CMTs become longitudinal when stress levels become low, while stable transverse CMT alignments in tissues result from their autonomous response to tensile stress fluctuations.
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9
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Rivière M, Corre Y, Peaucelle A, Derr J, Douady S. The hook shape of growing leaves results from an active regulatory process. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6408-6417. [PMID: 32816036 DOI: 10.1093/jxb/eraa378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
The rachis of most growing compound leaves observed in nature exhibits a stereotypical hook shape. In this study, we focus on the canonical case of Averrhoa carambola. Combining kinematics and mechanical investigation, we characterize this hook shape and shed light on its establishment and maintenance. We show quantitatively that the hook shape is a conserved bent zone propagating at constant velocity and constant distance from the apex throughout development. A simple mechanical test reveals non-zero intrinsic curvature profiles for the rachis during its growth, indicating that the hook shape is actively regulated. We show a robust spatial organization of growth, curvature, rigidity, and lignification, and their interplay. Regulatory processes appear to be specifically localized: in particular, differential growth occurs where the elongation rate drops. Finally, impairing the graviception of the leaf on a clinostat led to reduced hook curvature but not to its loss. Altogether, our results suggest a role for proprioception in the regulation of the leaf hook shape, likely mediated via mechanical strain.
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Affiliation(s)
- Mathieu Rivière
- Laboratoire Matière & Systèmes Complexes UMR 7057, Université Paris Diderot, Sorbonne Paris Cité, CNRS, Paris Cedex, France
| | - Yoann Corre
- Laboratoire Matière & Systèmes Complexes UMR 7057, Université Paris Diderot, Sorbonne Paris Cité, CNRS, Paris Cedex, France
| | - Alexis Peaucelle
- Laboratoire Matière & Systèmes Complexes UMR 7057, Université Paris Diderot, Sorbonne Paris Cité, CNRS, Paris Cedex, France
- Institut Jean-Pierre Bourgin, INRAE, CNRS, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Julien Derr
- Laboratoire Matière & Systèmes Complexes UMR 7057, Université Paris Diderot, Sorbonne Paris Cité, CNRS, Paris Cedex, France
| | - Stéphane Douady
- Laboratoire Matière & Systèmes Complexes UMR 7057, Université Paris Diderot, Sorbonne Paris Cité, CNRS, Paris Cedex, France
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10
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Müller UK, Poppinga S. Form, Structure, and Function: How Plants vs. Animals Solve Physical Problems. Integr Comp Biol 2020; 60:815-819. [PMID: 33141898 DOI: 10.1093/icb/icaa118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plants and animals have evolved solutions for a wide range of mechanical problems, such as adhesion and dispersal. Several of these solutions have been sources for bio-inspiration, like the Lotus Effect for self-cleaning surfaces or Velcro for adhesion. This symposium brought together plant and animal biomechanics researchers who tackle similar problems in different systems under the unifying theme of structure-function relations with relevance to bio-inspiration. For both communities it holds true that the structural systems, which have evolved in the respective organisms to address the mechanical challenges mentioned above, are often highly complex. This requires interdisciplinary research involving "classical" experimental biology approaches in combination with advanced imaging methods and computational modeling. The transfer of such systems into biomimetic technical materials and structures comes with even more challenges, like scalability issues and applicability. Having brought all these topics under one umbrella, this symposium presented the forefront of biophysical basic and application-oriented international research with the goal of facilitation knowledge transfer across systems and disciplines.
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Affiliation(s)
- Ulrike K Müller
- Department of Biology, California State University Fresno, Fresno, California USA
| | - Simon Poppinga
- Plant Biomechanics Group, Botanic Garden, University of Freiburg, Freiburg im Breisgau, Germany.,Freiburg Materials Research Center (FMF), University of Freiburg, Freiburg im Breisgau, Germany
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11
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Wang H, Nilsen ET, Upmanyu M. Mechanical basis for thermonastic movements of cold-hardy Rhododendron leaves. J R Soc Interface 2020; 17:20190751. [PMID: 32156184 PMCID: PMC7115238 DOI: 10.1098/rsif.2019.0751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 02/13/2020] [Indexed: 11/12/2022] Open
Abstract
The profusion of rhododendrons in cold climates is as remarkable as the beauty of their blooms. The cold-hardiness of some of the montane species is in part due to reversible leaf movements triggered under frigid conditions wherein the leaves droop at the leaf stalks (petioles) and their margins roll up around the midrib. We probe the mechanics of these movements using leaf dissection studies that reveal that the through-thickness differential expansion necessary for leaf rolling is anisotropically distributed transverse to and along the midrib. Numerical simulations and theoretical analyses of bilayer laminae show that the longitudinal expansion amplifies the transverse rolling extent. The curvature diversion scales with the in-plane Poisson's ratio, suitably aided by the stiff midrib that serves as a symmetry breaking constraint that controls the competition between the longitudinal and transverse rolling. Comparison of leaf rolling with and without the petiole indicates that the petiole flexibility and leaf rolling are in part mechanically coupled responses, implicating the hydraulic pathways that maintain the critical level of midrib stiffness necessary to support the longitudinal expansion. The study highlights the importance of curvature diversion for efficient nastic and tropic leaf movements that enhance cold-hardiness and drought resistance, and for morphing more general hinged laminae.
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Affiliation(s)
- Hailong Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, People’s Republic of China
| | - Erik T. Nilsen
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Moneesh Upmanyu
- Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP), Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA
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