Chemical reactions and interactions between molecules are commonly considered the basis of life, and thus the biochemical nature of cells and organisms is relatively well recognized. Research conducted in recent years, however, increasingly indicates that physical forces profoundly affect the functioning of life at all levels of its organization. To detect and to respond to such forces, plant cells and plants need to be structured mechanically. This volume focuses on mechanical aspects of plant life. It starts with a consideration of the mechanical integration of supracellular structures and mechanical properties of cellular building blocks to show how the structural integrity of plant cells is achieved and maintained during growth and development. The following chapters reveal how the functioning of integrated plant cells contributes to the mechanical integration of plants, and how the latter are able to detect physical stimuli and to reorganize their own cells in response to them. The mechanical aspects of plant responses to stresses are also presented. Finally, all these aspects are placed in an evolutionary context.
Plant cell walls are complex, dynamic cellular structures essential for plant growth, development, physiology and adaptation. Plant Cell Walls provides an in depth and diverse view of the microanatomy, biosynthesis and molecular physiology of these cellular structures, both in the life of the plant and in their use for bioproducts and biofuels. Plant Cell Walls is a textbook for upper-level undergraduates and graduate students, as well as a professional-level reference book. Over 400 drawings, micrographs, and photographs provide visual insight into the latest research, as well as the uses of plant cell walls in everyday life, and their applications in biotechnology. Illustrated panels concisely review research methods and tools; a list of key terms is given at the end of each chapter; and extensive references organized by concept headings provide readers with guidance for entry into plant cell wall literature. Cell wall material is of considerable importance to the biofuel, food, timber, and pulp and paper industries as well as being a major focus of research in plant growth and sustainability that are of central interest in present day agriculture and biotechnology. The production and use of plants for biofuel and bioproducts in a time of need for responsible global carbon use requires a deep understanding of the fundamental biology of plants and their cell walls. Such an understanding will lead to improved plant processes and materials, and help provide a sustainable resource for meeting the future bioenergy and bioproduct needs of humankind.
During the 1970s, renewed interest in plant mechanical signaling led to the discovery that plants subjected to mechanical stimulation develop shorter and thicker axes than undisturbed plants, a syndrome called thigmomorphogenesis. Currently, mechanosensing is being intensively studied because of its involvement in many physiological processes in plants and particularly in the control of plant morphogenesis. From an ecological point of view, the shaping of plant architecture has to be precisely organized in space to ensure light capture as well as mechanical stability. In natural environments terrestrial plants are subjected to mechanical stimulation mainly due to wind, but also due to precipitation, while aquatic and marine plants are subjected to current and wave energy. Plants acclimate to mechanically challenging environments by sensing mechanical stimulations and modifying their growth in length and diameter and their tissue properties to reduce potential for buckling or breakage. From a morphogenetic point of view, both external and internal mechanical cues play an important role in the control of cell division and meristem development likely by modulating microtubule orientation. How mechanical stimulations are being sensed by plants is an area of intense research. Different types of mechanosensors have been discovered or proposed, including ion channels gated by membrane tension (stretch activation) and plasma membrane receptor-like kinases that monitor the cell wall deformations. Electrophysiologists have measured the conductances of some stretch-activated channels and have showed that SAC of different structures can exhibit different conductances. The role of these differences in conductance has not yet been established. Once a mechanical stimulus has been perceived, it must be converted into a biological signal that can lead to variations of plant phenotype. Calcium has been shown to function as an early second messenger, tightly linked with changes in cytosolic and apoplastic pH. Transcriptional analyses of the effect of mechanical stimulation have revealed a considerable number of differentially expressed genes, some of which appear to be specific to mechanical signal transduction. These genes can thus serve as markers of mechanosensing, for example, in studies attempting to define signalling threshold, or variations of mechanosensitivity (accommodation). Quantitative biomechanical studies have lead to a model of mechanoperception which links mechanical state and plant responses, and provides an integrative tool to study the regulation of mechanosensing. This model includes parameters (sensitivity and threshold) that can be estimated experimentally. It has also been shown that plants are desensitized when exposed to multiple mechanical signals as a function of their mechanical history. Finally, mechanosensing is also involved in osmoregulation or cell expansion. The links between these different processes involving mechanical signalling need further investigation. This frontier research topic provides an overview of the different aspects of mechanical signaling in plants, spanning perception, effects on plant growth and morphogenesis, and broad ecological significance.
Plants use the Sun´s energy to synthesize the basic biomolecules that make up all the organic matter of all organisms of terrestrial ecosystems, including ourselves. Therefore, understanding their adaptive mechanisms to variations of environmental factors, both biotic and abiotic, is fundamental, and particularly relevant in the current context of rapid climate change. Some of the most important adaptive mechanisms of plants are the electrical and chemical signaling systems for the exchange of information between proximally and distally located cells. These signalling systems allow plants to dynamically coordinate the activities of all cells under a diversity of situations. In this Research Topic, we present eight articles that bring up new hypothesis and data to understand the mechanisms of systemic electrical signaling and the central role that it plays in adapting the whole plant to different stresses, as well as new findings on intracellular calcium and nitric oxide-based signaling pathways under stress, which could be extrapolated to non-plant research.
Endocytosis is a fundamental cellular process by means of which cells internalize extracellular and plasma membrane cargos for recycling or degradation. It is important for the establishment and maintenance of cell polarity, subcellular signaling and uptake of nutrients into specialized cells, but also for plant cell interactions with pathogenic and symbiotic microbes. Endocytosis starts by vesicle formation at the plasma membrane and progresses through early and late endosomal compartments. In these endosomes cargo is sorted and it is either recycled back to the plasma membrane, or degraded in the lytic vacuole. This book presents an overview of our current knowledge of endocytosis in plants with a main focus on the key molecules undergoing and regulating endocytosis. It also provides up to date methodological approaches as well as principles of protein, structural lipid, sugar and microbe internalization in plant cells. The individual chapters describe clathrin-mediated and fluid-phase endocytosis, as well as flotillin-mediated endocytosis and internalization of microbes. The book was written for a broad spectrum of readers including students, teachers and researchers.
This book outlines a unified theory of embryonic development, assuming morphogenesis to be a multi-level process including self-organizing steps while also obeying general laws. It is shown how molecular mechanisms generate mechanical forces, which in the long run lead to morphological changes. Questions such as how stress-mediated feedback acts at the cellular and supra-cellular levels and how executive and regulatory mechanisms are mutually dependent are addressed, while aspects of collective cell behavior and the morphogenesis of plants are also discussed. The morphomechanical approach employed in the book is based on the general principles of self-organization theory.
This book, written by the leading experts in the field of plant electrophysiology, provides a comprehensive and up-to-date overview of the current state of knowledge on electrical signaling and responses in plant physiology. It covers a significant interdisciplinary area for a broad range of researchers, emphasizing the physical, chemical, biological, and technological aspects of plant electrophysiology, while also demonstrating the role of electrochemical processes and ion channels in plant life cycles. Separate chapters describe the electrophysiology of the Venus flytrap, the Telegraph plant, Mimosa pudica, and other interesting plant species. Subsequent sections focus on mechanisms of plant movement, the role of ion channels, morphing structures, and the effects of electrical signal transduction on photosynthesis and respiration. Further topics include the electrophysiology of plant-insect interactions, how plants sense different environmental stresses and stimuli, and how phytoactuators respond to them. All chapters analyze the generation and transmission of electrical signals in plants.
With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences. The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.
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.
