Soft Matter in Plants: From Biophysics to Biomimetics

Description

Plants offer some of the most elegant applications of soft matter principles in Nature. Understanding the interplay between chemistry, physics, biology, and fluid mechanics is critical to forecast plant behaviour, which is necessary for agriculture and disease management. It also provides inspiration for novel engineering applications. Starting with fundamental concepts around plant biology, physics of soft matter and viscous fluids, readers of this book will be given a cross-disciplinary and expert grounding to the field. The book covers local scale aspects, such as cell and tissue mechanics, to regional scale matters covering movement, tropism, roots, through to global scale topics around fluid transport. Focussed chapters on water stress, networks, and biomimetics provide the user with a concise and complete introduction. Edited by internationally recognised leading experts in this field with contributions from key investigators worldwide, this book is the first introduction to the subject matter and will be suitable for both physical and life science readers. Cover Preface Contents Chapter 1 Basic Soft Matter for Plants 1.1 Fluids 1.1.1 Water Potential and Turgor Pressure 1.1.2 Pressure-driven Flows 1.1.3 Osmotic Flows and Solute Transport 1.1.4 Evaporation and Vapor Diffusion 1.2 Solids 1.2.1 The Wall Stress and the Force Balance 1.2.2 Elasticity 1.2.3 Poroelasticity: From Cell to Tissue 1.2.4 Growth 1.2.5 Mechanical Instabilities and Fast Movements Acknowledgements References Chapter 2 Fluid–Structure Interactions in Plant Vascular Flows 2.1 Introduction 2.2 From Bending a Branch to Increasing Cell Pressure 2.3 Xylem Flow Under Tension and the Effects of Conduit Collapse 2.4 Resistance to Collapse 2.5 Fluids and Elasticity in Intercellular Flows 2.6 Intracellular Flows and Cytoplasmic Streaming References Chapter 3 Theoretical Tools and Concepts for Modelling Growing Plant Tissues 3.1 An Introduction to the Mechanics of Multicellular Materials 3.2 Simple Constitutive Models and Lockhart's Equation 3.2.1 Simple Constitutive Laws in One Dimension 3.2.2 Lockhart's Model 3.3 One-dimensional Models for Elongation of Slender Tissues 3.3.1 A Continuous Model for Primary Root Growth 3.3.2 Growth Against an External Load 3.4 Quasi-1D Models for Bending of Slender Tissues 3.5 Constitutive Models for 3D Anisotropic Growing Materials 3.5.1 Anisotropy 3.5.2 Growth in Three Dimensions 3.6 Discrete Modelling Approaches for Multicellular Tissues 3.6.1 The Mechanical Energy of a Cell 3.6.2 Cell Topology and Geometry 3.6.3 Vertex Dynamics 3.6.4 Cell and Tissue Stress 3.7 Plant Cell Wall Mechanics and the Origins of the Lockhart Model 3.7.1 The Matrix 3.7.2 Fibres, Crosslinks and the Origins of the Lockhart Model 3.8 Outlook Acknowledgements References Chapter 4 Negative Pressure and Cavitation Dynamics in Plant-like Structures 4.1 Introduction 4.1.1 Negative Pressure 4.1.2 Cavitation 4.1.3 Negative Pressure and Cavitation in Plants 4.1.4 Chapter Contents 4.2 Water Properties 4.2.1 Cohesion and Surface Tension 4.2.2 Compressibility and Spinodal 4.2.3 Saturation Pressure, Phase Diagram 4.2.4 Metastable States 4.2.5 Chemical Potential, Water Potential 4.2.6 Evaporation vs. Cavitation 4.3 Origins of Negative Pressure 4.3.1 Dehydration: Mechanics 4.3.2 Dehydration: Thermodynamics 4.3.3 Dehydration: Discussion 4.3.4 Other Origins of Negative Pressure 4.4 Cavitation Mechanisms 4.4.1 Homogeneous Nucleation 4.4.2 Surface-aided Nucleation 4.4.3 Seeded Cavitation 4.4.4 Discussion 4.5 Confined Cavitation Theory 4.5.1 Critical Radius, Energy Barrier 4.5.2 Equilibrium Bubble 4.5.3 Inertial Oscillations 4.6 Cavitation Bubble Dynamics 4.6.1 Nucleation 4.6.2 Oscillations 4.6.3 Shape Evolution 4.6.4 Temporary Equilibrium 4.6.5 Emptying, Bubble Growth 4.6.6 Discussion 4.7 Propagation of Cavitation 4.7.1 Triggered Cavitation: Positive Interactions 4.7.2 Hindered Cavitation: Negative Interactions 4.7.3 Discussion 4.8 Conclusion Appendix A Effect of Air on the Saturation Vapor Pressure of Water Appendix B Free Energy of a Confined Bubble Acknowledgements References Chapter 5 Root–Soil Interaction 5.1 Introduction 5.2 The Single Root: An Interesting Material for Soft Matter Studies 5.2.1 How Does a Root Grow? 5.2.2 How Does a Root Behave Mechanically? 5.2.3 How do the Mechanical Stresses of the Soil Affect Root Growth? 5.3 The Impact of the Growing Root on the Physical Properties of Soil 5.3.1 The Mechanical Strength of Soil 5.3.2 How Does Root Growth Affect Soil at the Particle Scale? 5.3.3 How Does Root Mucilage Affect the Hydric Properties of the Soil? 5.4 The Complex Interplay of the Root System and Soil 5.4.1 Shear Strength of Rooted Soil 5.4.2 Laboratory Measurement of Root-reinforcement 5.4.3 Field Measurement of Root- reinforcement 5.4.4 Root-reinforcement Modelling Techniques 5.5 Concluding Remarks Acknowledgements References Chapter 6 Invasive Processes in the Life Cycle of Plants and Fungi 6.1 Introduction 6.2 Invasive Growth Serves a Diverse Range of Functions 6.2.1 Elongated Cells Can Confer Structural Stability 6.2.2 Invasion for Cargo Delivery Across Tissues 6.2.3 Spreading out for Procurement of Nutrients and Water 6.3 Cell Mechanics of Intrusive Growth 6.3.1 Highly Polarized Cell Extension Directs Force Generation 6.3.2 Turgor Pressure Generates the Invasive Force in Walled Cells 6.3.3 Cytoskeletal Elements Regulate Tip Growth and Invasion Through Cell Wall Assembly 6.4 Chemical and Enzymatic Tools Facilitating Invasion 6.5 Biomechanical Approaches to Quantify Invasive Forces 6.6 Conclusion and Perspective Acknowledgements References Chapter 7 Hygroresponsive Movements of Plants and Soft Actuators 7.1 Introduction 7.2 Physical Principles of Hygroresponsive Deformation of Plants 7.2.1 Hygroscopic Swelling in Plants 7.2.2 Deformation Modes Programmed by Structural Constraints 7.3 Hygroresponsive Soft Actuators 7.4 Conclusions Acknowledgements References Subject Index