Dormancy and Developmental Arrest: Experimental Analysis in Plants and Animals discusses the experimentation on states of suspended animation of living organisms. The book presents the range and complexity of interconnected processes involving structural, physiological, and molecular alterations in the organism. The text describes the physiological responses of animals and plants to environmental signals. It discusses the activities of nucleic acid and protein synthesis prior to dormancy state. The text also describes plant embryo development and the regulation of body temperature in dormant states. The book will provide valuable insights for biologists, zoologists, botanists, students, and researchers in the field of biology.
The formation, dispersal and germination of seeds are crucial stages in the life cycles of gymnosperm and angiosperm plants. The unique properties of seeds, particularly their tolerance to desiccation, their mobility, and their ability to schedule their germination to coincide with times when environmental conditions are favorable to their survival as seedlings, have no doubt contributed significantly to the success of seed-bearing plants. Humans are also dependent upon seeds, which constitute the majority of the world’s staple foods (e.g., cereals and legumes). Seeds are an excellent system for studying fundamental developmental processes in plant biology, as they develop from a single fertilized zygote into an embryo and endosperm, in association with the surrounding maternal tissues. As genetic and molecular approaches have become increasingly powerful tools for biological research, seeds have become an attractive system in which to study a wide array of metabolic processes and regulatory systems. Seed Development, Dormancy and Germination provides a comprehensive overview of seed biology from the point of view of the developmental and regulatory processes that are involved in the transition from a developing seed through dormancy and into germination and seedling growth. It examines the complexity of the environmental, physiological, molecular and genetic interactions that occur through the life cycle of seeds, along with the concepts and approaches used to analyze seed dormancy and germination behavior. It also identifies the current challenges and remaining questions for future research. The book is directed at plant developmental biologists, geneticists, plant breeders, seed biologists and graduate students.
Life evolves in a cyclic environment, and to be successful, organisms must adapt not only to their spatial habitat, but also to their temporal habitat. How do plants and animals determine the time of year so they can anticipate seasonal changes in their habitats? In most cases, day length, or photoperiod, acts as the principal external cue for determining seasonal activity. For organisms not living at the bottom of the ocean or deep in a cave, day follows night, and the length of the day changes predictably throughout the year. These changes in photoperiod provide the most accurate signal for predicting upcoming seasonal conditions. Measuring day length allows plants and animals to anticipate and adapt to seasonal changes in their environments in order to optimally time key developmental events including seasonal growth and flowering of plants, annual bouts of reproduction, dormancy and migration in insects, and the collapse and regrowth of the reproductive system that drives breeding seasons in mammals and birds.Although research on photoperiodic time measurement originally integrated work on plants and animals, recent work has focused more narrowly and separately on plants, invertebrates, or vertebrates. As the fields have become more specialized there has been less interaction across the broader field of photoperiodism. As a result, researchers in each area often needlessly repeat both theoretical and experimental work. For example, understanding that there are genetically distinct morphs among species that, depending on latitude, respond to different critical photoperiods was discovered separately in plants, invertebrates, and vertebrates over the course of 20 years. However, over the past decade, intense work on daily and seasonal rhythms in fruit flies, mustard plants, and hamsters and mice, has led to remarkable progress in understanding the phenomenology, as well as the molecular and genetic mechanisms underlying circadian rhythms and clocks. This book was developed to further this type of cooperation among scientists from all related disciplines. It brings together leading researchers working on photoperiodic timing of seasonal adaptations in plants, invertebrates, and vertebrates. Each of its three sections begins with an introduction by the section editor, and at the end of the book, the section editors present a synthesis of common themes in photoperiodism, as well as discuss similarities and differences in approaches to the study of photoperiodism, and future directions for research on photoperiodic time measurement.
Freshwater turtles and goldfish can survive for several days without oxygen, some diving turtles for several months; hibernating animals can exist without food for long periods; others can survive extreme conditions such as desiccation, freezing, and thawing. These creatures are, in effect, self-sustaining life-support systems, with a mysterious ability to regulate their own metabolisms. These capabilities raise important questions, which Hochachka and Guppy explore in this seminal new book. What mechanisms turn down (or off) cell metabolism and other cell functions? How does an animal such as an opossum know when to activate mechanisms for slowing or stopping tissue and organ functions? How does it know when to turn them on again? How extensive is metabolic arrest as a defense against harsh environmental conditions? Can we decipher universal principles of metabolic arrest from available data? The lessons to be learned are of potentially great interest to clinicians, because the authors provide a theoretical framework in which to organize an attack on the all-too-practical problem of protecting tissues against hypoxia. Areas that may be influenced include research on cardiac arrest, strokes, acute renal failure, liver ischemia, lung injury, respiratory defense syndrome, claudication, shock, and organ transplant. Investigation of other metabolic arrest mechanisms may be similarly useful in both clinical and agricultural fields. This is a pioneering book of great use to biomedical/clinical researchers and to biologists, biochemists, and physiologists generally.
This is the first scholarly reference work to cover all the major scientific themes and facets of the subject of seeds. It outlines the latest fundamental biological knowledge about seeds, together with the principles of agricultural seed processing, storage and sowing, the food and industrial uses of seeds, and the roles of seeds in history, economies and cultures. With contributions from 110 expert authors worldwide, the editors have created 560 authoritative articles, illustrated with plentiful tables, figures, black-and-white and color photographs, suggested further reading matter and 670 supplementary definitions. The contents are alphabetically arranged and cross-referenced to connect related entries.
The study of thermoregulation in endotherms has contributed much to the emergence of the concept of control theory in biology. By the same token, the study of tempera ture adjustment in ectotherms is likely to have a far-reaching influence on ideas on the regulation of metabolism in general. The reason for this is that ectotherms, in adapting to the vagaries of a thermally unstable environment, deploy a range of subtle molecular and organismic strategies. Thus the experimenter, using temperature changes as a tool, is well equipped to analyze some of these strategies. This approach has enabled some important mechanisms of temperature-induced adaptation to be elucidated; the most striking of these are the effects on metabolism of changes in the conformation of enzymes and the transfer properties of membranes. Furthermore, there is a vague but persistent feeling among those working in this field that changes in the nervous system will ultimately prove to be the agency by which many of the molecular mechanisms of temperature adaptation are controlled. Should this indeed be the case, a new phase would soon begin in our understanding of the interactions between the systemic and the cellular levels of organization. However, it is not only questions about the causes of temperature adaptation that can provide answers of potential importance to the general biologist; of equal significance are questions as to the meaning of temperature adaptation in a particular organism.
All cellular life-forms can exist in replicating and non-replicating states. Organisms replicate only when the conditions are beneficial, and when not replicating they concentrate on survival of these environmental stresses. Many bacteria, harmful to humans, survive the period of infection in a low growth state. This 2003 book addresses the basic science of microbial dormancy and low growth states, putting this in the context of human medicine. Such fundamental topics as bacterial growth and non-growth, culturability and viability are covered, as well as survival of the host's immune response, and inter-bacterial signalling. Following this introduction, more medically focused topics are discussed, namely antibiotic resistance arising during stationary phase, biofilms, the bacteria which cause gastric ulcers and tuberculosis as the classic persistent bacterial infection. This book will interest graduate students and researchers in medical microbiology, immunology and infectious disease medicine who are interested in bacterial dormancy in relation to disease.
Biologists ask how the growth, development and behaviour of organisms happen, how these processes are co-ordinated and how they are regulated by the environment. Today the questions are phrased in terms of the genes involved, their structure and the control of their expression. Mutations (recognised by a change in phenotype) label genes and can be used to study gene structure, gene function and the organisation of the genome. This is "Genetics". Study of phenotypes down to the level of the enzymes and structural proteins coded for by genes is "Biochemistry". It is self evident that only by studying phenotype ("Biochemistry") can we do "Ge netics" and that "Genetics" (perturbation of the phenotype) is the key to understanding the "Biochemistry". There can surely be no better argu ments for a more holistic approach to biology than the massive output of knowledge from microbial "Biochemical Genetics" and the more recent revelations from "Molecular Genetic" studies of development in Droso phila.
The brine shrimp Artemia has become an important experimental system for studies of the developmental process. In recent years the shrimp has yielded considerable information on the pattern of development, bio chemistry, and gene structure and expression of crustaceans. This book is a compilation of research activity from twenty five of the most active re search laboratories working with brine shrimp in the above areas. It also represents the proceedings of a NATO Advanced Research Workshop held in Montreal, Canada, August 11-13, 1988. The book contains twenty nine full papers covering the major areas discussed at the workshop. In addition, one page abstracts representing seventeen poster presentations which were given at the workshop, and which were deemed to be most relevant to the theme of the book, are included. These are designated with an [al in the Table of Contents following the title of each paper. A considerable amount of discussion which took place during the workshop has not been included in the book because of space limitations. However, the editors will endeavour to make some of this in formation available at a later date through the Artemia Newsletter. In addition to the high percentage of invited speakers who attended and contributed to the workshop, the organizers would like to thank a number of participants who made valuable contributions to the major dis cussion sessions. These include: John Freeman, Michael Horst, Herman Slegers, Jack Vaughn, Frank Conte, Sandy McLennan, Clive Trotman and Patrick Sorgeloos.
Plant hormones play a crucial role in controlling the way in which plants grow and develop. While metabolism provides the power and building blocks for plant life, it is the hormones that regulate the speed of growth of the individual parts and integrate them to produce the form that we recognize as a plant. This book is a description of these natural chemicals: how they are synthesized and metabolized, how they act at both the organismal and molecular levels, how we measure them, a description of some of the roles they play in regulating plant growth and development, and the prospects for the genetic engineering of hormone levels or responses in crop plants. This is an updated revision of the third edition of the highly acclaimed text. Thirty-three chapters, including two totally new chapters plus four chapter updates, written by a group of fifty-five international experts, provide the latest information on Plant Hormones, particularly with reference to such new topics as signal transduction, brassinosteroids, responses to disease, and expansins. The book is not a conference proceedings but a selected collection of carefully integrated and illustrated reviews describing our knowledge of plant hormones and the experimental work that is the foundation of this information. The Revised 3rd Edition adds important information that has emerged since the original publication of the 3rd edition. This includes information on the receptors for auxin, gibberellin, abscisic acid and jasmonates, in addition to new chapters on strigolactones, the branching hormones, and florigen, the flowering hormone.
