Plants are sessile and prone to multiple stresses in the changing environmental conditions. Of the several strategies adopted by plants to counteract the adverse effects of abiotic stress, phytohormones provide signals to allow plants to survive under stress conditions. They are one of the key systems integrating metabolic and developmental events in the whole plant and the response of plants to external factors and are essential for many processes throughout the life of a plant and influence the yield and quality of crops. The book 'Phytohormones and Abiotic Stress Tolerance in Plants' summarizes the current body of knowledge on crosstalk between plant stresses under the influence of phytohormones, and provides state-of-the-art knowledge of recent developments in understanding the role of phytohormones and abiotic stress tolerance in plants. This book presents information on how modulation in phytohormone levels affect regulation of biochemical and molecular mechanisms.

With the predicted increase of the human population and the subsequent need for larger food supplies, root health in crop plants could play a major role in providing sustainable highly productive crops that can cope with global climate changes. While the essentiality of roots and their relation to plant performance is broadly recognized, less is known about their role in plant growth and development. "Root Genomics" examines how various new genomic technologies are rapidly being applied to the study of roots, including high-throughput sequencing and genotyping, TILLING, transcription factor analysis, comparative genomics, gene discovery and transcriptional profiling, post-transcriptional events regulating microRNAs, proteome profiling and the use of molecular markers such as SSRs, DArTs, and SNPs for QTL analyses and the identification of superior genes/alleles. The book also covers topics such as the molecular breeding of crops in problematic soils and the responses of roots to a variety of stresses.

The Seventh International Symposium on the Structure and Function of Plant Lipids took place at the University of California, Davis, California July 27th to August 1st, 1986. This was the first time the Symposium was held in the United States. The list of previous host cities reads, Norwich, Karlsruhe, Goteborg, Paris, Groningen, Neuchatel. The addition of Davis to this distinguished list was made by the organizers with the doubts of people who give invitations to parties - will anybody come? In fact 155 participants registered and there were 21 spouses in attendance. The scientific program was composed of nine sessions: biochemistry of isoprenoids and sterols, function of isoprenoids and sterols, structure and function of lipids, biosynthesis of complex lipids, fatty acid oxygenases and desaturases, medium and long chain fatty acids, interaction of university, government and industrial research, algal lipids, and genetics and biotechnology. In addition to these sessions of plenary lectures, there were four poster sessions in which about 140 posters were presented. All of this was packed into four days, and there was some comment about the scarcity of time to ask questions of the speakers, discuss the posters and even to eat lunch. The compression of the program was a result of the continued desire of the organizing committees to avoid concurrent sessions. The congregation of participants into a single session increases interaction and generates a feeling of unity at these symposia.

The tomato is commercially important throughout the world both for the fresh fruit market and the processed food industries. It is grown in a wide range of climates in the field, under protection in plastic greenhouses and in heated glasshouses. Genetic, physiological and pathological investigations frequently adopt the tomato plant as a convenient subject. Hitherto, much of the information on tomatoes has been fragmented: tomatoes grown in the field and under protection have been considered separately and the more fundamental findings from research have often failed to reach those involved directly or indirectly in commercial crop production. Similarly, the research scientist is often unaware of the problems of commercial crop production and the possible relevance of his work to the crop. This book is an attempt to rectify that situation. By giving a thorough scientific review of all factors influencing tomato production systems, it is hoped that this book will prove useful to students, researchers and commercial producers alike. It gives the basis for the develop ment of improved cultivars, the formulation of strategies for managing pest, disease and disorder problems and the production of high yields of good quality fruit as well as suggesting important areas for scientific initiatives. The extensive bibliographies provide a comprehensive database for tomato researchers. Such a vast subject could not be covered with authority by anyone author."

The formation of roots is in some respects one of the least fundamentally understood of all plant functions. Propagation by cuttings is the aspect that will occur first to most gardeners and horticulturists, and it is certainly the most useful application. But any observant traveller in the tropics can notice that some trees have the habit of forming roots in the air. Climbers like Cissus bear long fine strings of roots hanging down. Pandanus trees tend to have stout aerial roots issuing from the bases of the long branches, while the tangle of roots around the trunk of many of the Ficus species is characteristic. In Ficus bengalensis, in particular, stout cylindrical roots firmly embedded in the ground from a height of 3 to 5 meters give support to the long horizontal branches, enabling them to spread still further. In the big old specimen at Adyar near Madras, the spread of these branches all around the tree, each with a strong root growing out every few meters, makes a shaded area under which meetings of almost 5000 people are sometimes held. The history of how the formation of roots on stem cuttings was found to be under hormonal control is worth repeating here.

These proceedings bring together diverse disciplines that study nitrogen fixation and describe the most recent advances made in various fields: chemists are now studying FeMoco, the active site of nitrogenase in non-protein surroundings, and have refined the crystal structure of the enzyme to 1.6 angstroms.

Millions of trees live and grow all around us, and we all recognize the vital role they play in the world's ecosystems. Publicity campaigns exhort us to plant yet more. Yet until recently comparatively little was known about the root causes of the physical changes that attend their growth. Since trees typically increase in size by three to four orders of magnitude in their journey to maturity, this gap in our knowledge has been a crucial issue to address. Here at last is a synthesis of the current state of our knowledge about both the causes and consequences of ontogenetic changes in key features of tree structure and function. During their ontogeny, trees undergo numerous changes in their physiological function, the structure and mechanical properties of their wood, and overall architecture and allometry. This book examines the central interplay between these changes and tree size and age. It also explores the impact these changes can have, at the level of the individual tree, on the emerging characteristics of forest ecosystems at various stages of their development. The analysis offers an explanation for the importance of discriminating between the varied physical properties arising from the nexus of size and age, as well as highlighting the implications these ontogenetic changes have for commercial forestry and climate change. This important and timely summation of our knowledge base in this area, written by highly respected researchers, will be of huge interest, not only to researchers, but also to forest managers and silviculturists.

Plants cannot move away from their environments. As a result, all plants that have survived to date have evolved sophisticated signaling mechanisms that allow them to perceive, respond, and adapt to constantly changing environmental conditions. Among the many cellular processes that respond to environmental changes, elevation of calcium levels is by far the most universal messenger that matches primary signals to cellular responses. Yet it remains unclear how calcium, a simple cation, translates so many different signals into distinct responses - how is the "specificity" of signal-response coupling encoded within the calcium changes? This book will attempt to answer this question by describing the cellular and molecular mechanisms underlying the coding and decoding of calcium signals in plant cells.

The Molecular Biology ofChloroplasts and a genetic dissection ofphotosynthesis was first Mitochondria in Chlamydomonas is the seventh recognized by Paul Levine. Together with his volume to be published in the series Advances in coworkers, he initiated along-rangegenetic approach Photosynthesis of Kluwer Academic Publishers which proved to be highly successful. It provided (Series Editor: Govindjee). Volume 1 dealtwith The genetic support for the linear Z scheme of Molecular Biology of Cyanobacteria; Volume 2 with photosynthesis and led to the identification ofnew Anoxygenic PhotosyntheticBacteria; Volume 3 with components ofthe photosynthetic electron transfer BiophysicalTechniques in Photosynthesis; Volume 4 chain such astheRieskeproteinofthe cytochrome with Photosynthesis and the Environment; and complex. Volume 6 with Lipids in Photosynthesis: Structure, During the past 20 years, the powerful techniques of molecular biology and genetics, and the Function and Genetics. The main goal ofthis book is to provide a development ofmethods for efficient nuclear and comprehensive overview ofcurrent research with chloroplast transformation of C. reinhardtii have the green alga Chlamydomonas on chloroplast and greatly enhanced the potential ofthis organism as an mitochondrial biogenesis and function, with special experimental system for studying chloroplast emphasis on the assembly and structure-function biogenesis. This has led to impressive advances in relationships ofthe constituents ofthe photosynthetic our understanding of the regulation of chloroplast apparatus.

A shortage of water exists, not only in the arid regions of the world, but even in some moderately humid climates. This situation is a consequence of water require ments for agriculture and industry in amounts greater than the natural surplus. Even in Europe there is increased anxiety over the state of water reserves, and shortages are forecast for the near future if industry continues to expand. During the past 50 years in the United States, water use has increased about twice as fast as the rate of population growth, and shortages have already appeared in some places. The need to conserve declining water resources which has become apparent over the last few decades has led several investigators to conclude that plants with a high rate of transpiration endanger water resources, and the growth of such plants must not be encouraged. Some think that trees withdraw more water from the soil than other plant species and evaporate it excessively through the stomata of leaves. THORNTHWAITE and HARE (1955) explained transpiration on the same thermo dynamic basis as evaporation, and calculated its rate, using DALTON'S law or modifications thereof. In spite ofthe many past and present investigations into the problems of transpiration, the biological aspects of this essential process is still poorly understood."

The refinement of molecular techniques and the development of new probes of the phylogeny of diazotrophs has revealed an extreme biodiversity among the nitrogen fixers, which helps explain the role that nitrogen fixation plays in maintaining life on Earth. The most efficient ecosystems are those where the bacteria are associated with a plant in differentiated organs to benefit crop productivity. Most short-term benefit from fundamental research on nitrogen fixation is likely to result in the improvement of existing nitrogen-fixing symbiotic or associative systems. Longer-term efforts are aimed at extending the nitrogen-fixing capacity to other organisms, including transfer of the genetic information for efficient nitrogen fixation into the plant genome and using current knowledge of microbe-plant interactions to extend symbiosis to cereals and, in particular, to rice. Related challenges in sustainable agriculture and forestry include the creation of new nitrogen-fixing associations. All of these approaches were discussed at the 11th International Congress on Nitrogen Fixation, Paris, France, July 20-25, 1997 and covered in the present proceedings volume.

What are plant growth regulators? In the title, and throughout the text, we have adopted this expression to describe a population of endogenous molecules and synthetic compounds of similar structure that are be lieved to play important roles in the regulation of plant differentiation and development. For many years, plant scientists have endeavoured to understand the nature and action of plant growth regulators and, as a result, an awesome quantity of written material now exists describing these chemicals and their effects. In this book we have aimed to distil this wealth of information into a more digestible form, and in particular we have focused our attention on a critical appraisal of the literature. The past few years have witnessed a change of emphasis in plant growth regulator research, which has been fuelled by powerful new techniques in molecular and cell biology. Today we can do more than just apply a plant growth regulator and quantify its effects; we have reached an exciting crossroads where plant scientists, molecular bio logists and chemists can pool their expertise and apply it to the out standing problems in this area. The combination of these three disciplines within the book is clear evidence of this. In keeping with a volume of this size, we have assumed that the reader has a sound knowledge of plant physiology and biochemistry. However, wherever possible, we have highlighted useful reviews which provide background information, along with recent publications that have contributed significantly to the literature."

The progress in photosynthesis research has been transduction and expression of photosynthetic genes quite dramatic during the last two decades. The which occur both in the nuclear/cytosol compartment Nobel prizes awarded to Peter Mitchel (1978), to and in the chloroplast. Several chapters are devoted Johannes Deisenhofer, Hartmut Michel and Robert to the transcription machinery and the two plastid Huber (1988), to Rudolf Marcus (1992) and to Paul RNA-polymerase complexes, to the regulation of Boyer and John Walker (1997) have recognized photosynthesis genes by redox signaling both in directly or indirectly the structural or mechanistic chloroplasts and in the prokaryotic systems, as well discoveries related to the photosynthetic energy as to the sugar sensing mechanisms. Chapters also conversion. Actually, photosynthesis may be the first cover important regulatory aspects imposed by po- biological process described, not only in molecular transcriptional modifications and degradation of terms, but even in atomic terms. mRNA molecules, and the translational regulation Much of the excitement around photosynthesis is mechanisms operating in chloroplasts. based upon the connection between light and life. Part III Biogenesis, turnover and senescence is closely connected to the question of regulation. Light is an elusive substrate that cannot be handled The chapters included emphasize how the c- in the same way as conventional chemical substrates plicated membrane structures, composed of both in biological metabolic reactions."

Desiccation tolerance was essential when plants first began to conquer land, roughly 400 million years ago. While most desiccation-tolerant plants belong to basal phylogenetic taxa, this capacity has also evolved among some vascular plant species.

In this volume renowned experts treat plant desiccation tolerance at the organismic as well as at the cellular level. The diversity of ecophysiological adaptations and acclimations of cyanobacteria, eukaryotic algae, mosses, and lichens is addressed in several chapters. The particular problems of vascular plants during dehydration/rehydration cycles resulting not only from their hydraulic architectures, but also from severe secondary stresses associated with the desiccated state are discussed. Based on the treatment of desiccation tolerance at the organismic level, a second section of the book is devoted to the cell biological level. It delineates the general concepts of functional genomics, epigenetics, genetics, molecular biology and the sensing and signalling networks of systems biology involved in dehydration/rehydration cycles.

This book provides an invaluable compilation of current knowledge, which is a prerequisite for a better understanding of plant desiccation tolerance in natural as well as agro- and forest ecosystems where water is one of the most essential resources.

The motivation for us to conceive this series of volumes on regulation was mainly our belief that it would be fun, and at the same time productive, to approach the subject in a way that differs from that of other treatises. We thought it might be interesting and instructive for both author and reader-to examine a particular area of investigation in a framework of many different problems. Cutting across the traditional boundaries that have separated the subjects in past volumes on regulation is not an easy thing to do-not because it is difficult to think of what interesting topics should replace the old ones, but because it is difficult to find authors who are willing to write about areas outside those pursued in their own laboratories. Anyone who takes on the task of reviewing a broad area of interest must weave together its various parts by picking up the threads from many different laboratories, and attempt to produce a fabric with a meaningful design. Finding persons who are likely to succeed in such a task was the most difficult part of our job. In the first volume of this treatise, most of the chapters dealt with the mechanisms of The second volume involved a somewhat regulation of gene expression in microorganisms. broader area, spanning the prokaryotic-eukaryotic border. Topics ranged from phage mor phogenesis to the role of gradients in development. The last volume-Volume 3A-con cerned hormones, as does this volume-Volume 3B.

Our view of plants is changing dramatically. Rather than being only slowly responding organisms, their signaling is often very fast and signals, both of endogenous and exogenous origin, spread throughout plant bodies rapidly. Higher plants coordinate and integrate their tissues and organs via sophisticated sensory systems, which sensitively screen both internal and external factors, feeding them information through both chemical and electrical systemic long-distance communication channels. This revolution in our understanding of higher plants started some twenty years ago with the discovery of systemin and rapid advances continue to be made. This volume captures the current 'state of the art' of this exciting topic in plant sciences.

Scientists are continually making exciting discoveries concerning the interactions between microbes and plants, interactions which may be damaging, in the case of plant pathogens, or beneficial, as in the case of nitrogen fixation. This new volume in the successful and well received Chapman & Hall Plant-Microbe Interaction series is an exciting and broad-ranging view of the outstanding work being done in this area.

This book covers the hot topics of angiosperm structure and evolution in several chapters discussing vegetative and reproductive characters. It also looks at the implications of ancestral angiosperm characters for an herbaceous origin and the phylogeny of angiosperms from a structure and molecular perspective.

The Genetics and Genomics of the Brassicaceae provides a review of this important family (commonly termed the mustard family, or Cruciferae). The family contains several cultivated species, including radish, rocket, watercress, wasabi and horseradish, in addition to the vegetable and oil crops of the Brassica genus. There are numerous further species with great potential for exploitation in 21st century agriculture, particularly as sources of bioactive chemicals. These opportunities are reviewed, in the context of the Brassicaceae in agriculture. More detailed descriptions are provided of the genetics of the cultivated Brassica crops, including both the species producing most of the brassica vegetable crops (B. rapa and B. oleracea) and the principal species producing oilseed crops (B. napus and B. juncea). The Brassicaceae also include important "model" plant species. Most prominent is Arabidopsis thaliana, the first plant species to have its genome sequenced. Natural genetic variation is reviewed for A. thaliana, as are the genetics of the closely related A. lyrata and of the genus Capsella. Self incompatibility is widespread in the Brassicaceae, and this subject is reviewed. Interest arising from both the commercial value of crop species of the Brassicaceae and the importance of Arabidopsis thaliana as a model species, has led to the development of numerous resources to support research. These are reviewed, including germplasm and genomic library resources, and resources for reverse genetics, metabolomics, bioinformatics and transformation. Molecular studies of the genomes of species of the Brassicaceae revealed extensive genome duplication, indicative of multiple polyploidy events during evolution. In some species, such as Brassica napus, there is evidence of multiple rounds of polyploidy during its relatively recent evolution, thus the Brassicaceae represent an excellent model system for the study of the impacts of polyploidy and the subsequent process of diploidisation, whereby the genome stabilises. Sequence-level characterization of the genomes of Arabidopsis thaliana and Brassica rapa are presented, along with summaries of comparative studies conducted at both linkage map and sequence level, and analysis of the structural and functional evolution of resynthesised polyploids, along with a description of the phylogeny and karyotype evolution of the Brassicaceae. Finally, some perspectives of the editors are presented. These focus upon the Brassicaceae species as models for studying genome evolution following polyploidy, the impact of advances in genome sequencing technology, prospects for future transcriptome analysis and upcoming model systems.

Photosynthesis--the capture of light energy by living organisms -is a simple enough concept, but its investigation draws on the resources of disciplines from all fields of science. The aim of this text is to provide a clear, stimulating and essentially affordable coverage for undergraduate students of biology. The activity of science is debate and practical experiment; its product is a body of propositions which at any given time reflects the judgment and prejudices of those taking part. The value of a proposition is related to the conceivable alternatives, and writing it down without its context creates the false impression that science progresses by compilation of an increasing list of absolute truths. It does not; the facts and figures pres ented in the following pages have no intrinsic value unless they can be used by the reader to support an argument or point of view. In short, the reader is urged to respond 'So what?' to every item. Secondly, ideas-like other foods-should be date-stamped; science is inseparable from its history. I have set out time-charts to represent the evolution of our understanding in certain areas. I have assumed that the reader is pursuing a course with a content of biochemistry, microbiology and plant science, or has access to basic texts. I have assumed also that common methods such as spectrophotometry, chromatography and electrophoresis, as well as the techniques of mol ecular biology, will be either part of the same course or in active use nearby."

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.

Natural and agro-ecosystems are frequently exposed to natural or synthetic substances, which, while they have no direct nutritional value or significance in metabolism, may negatively affect plant functioning. These, xenobiotics, may originate from both natural (fires, volcano eruptions, soil or rock erosion, biodegradation) and anthropogenic (air and soil pollution, herbicides) sources. And, while affected plants have only a limited number of possibilities for avoiding accumulation of these compounds, they do exhibit several enzymatic reactions for detoxification including oxidation, reduction, hydrolysis and conjugation reactions. In agro-ecosystems in particular these mechanisms have great significance in relation to herbicide detoxification and tolerance. In this volume an international group of experts present an overview of the nature and distribution of organic xenobiotics, including their uptake, effects on plant functioning and detoxification mechanisms. The particular significance of glutathione S-transferases in bio-indication and bio-monitoring, and in the detoxification of volatile organic air pollutants and herbicides is evaluated, and their potential significance in phytoremediation and bioaccumulation will be discussed. This volume will be of interest to a wide audience, from graduate students to senior researchers in a wide range of disciplines including plant ecology, plant biochemistry, agriculture and environmental management. It will also be of practical interest to environmentalists, policy makers and resource managers.

Phosphorus (P) is a finite resource which is essential for life. It is a limiting nutrient in many ecosystems but also a pollutant which can affect biodiversity in terrestrial ecosystems and change the ecology of water bodies. This book collects the latest information on biological processes in soil P cycling, which to date have remained much less understood than physico-chemical processes. The methods section presents spectroscopic techniques and the characterization of microbial P forms, as well as the use of tracers, molecular approaches and modeling of soil-plant systems. The section on processes deals with mycorrhizal symbioses, microbial P solubilization, soil macrofauna, phosphatase enzymes and rhizosphere processes. On the system level, P cycling is examined for grasslands, arctic and alpine soils, forest plantations, tropical forests, and dryland regions. Further, P management with respect to animal production and cropping, and the interactions between global change and P cycling, are treated.

In a field of mature bananas, plants can be seen at all stages of vegetative growth and fruit maturity, providing a fascination for anyone who has an interest in growing crops. Banana farmers in the tropics can harvest fruit every day of the year. The absence of seasonality in production is an advantage, in that it provides a continuity of carbohydrate to meet dietary needs as well as a regular source of income, a feature that perhaps has been under-estimated by rural planners and agricultural strategists. The burgeoning interest in bananas in the last 20 years results from the belated realization that Musa is an under-exploited genus, notwithstanding the fact that one genetically narrow group, the Cavendish cultivars, supply a major export commodity second only to citrus in terms of the world fruit trade. International research interest in the diversity of fruit types has been slow to develop, presumably because bananas and plantains have hitherto been regarded as a reliable backyard source of dessert fruit or starch supplying the needs of the household, and in this situation relatively untroubled by pests, diseases or agronomic problems.

Rapid advances have taken place in various aspects of reproductive biology during the last decade. These advances have centered around several organ systems that comprise the reproductive system and encompass molecular events and structure-function relationships. It becomes important to review these advances in knowledge, at periodic intervals, with respect to feedback systems and regulatory loops that control reproductive processes in vivo. Towards this end, a workshop entitled "Functional Correlates of Hormone Receptors in Reproduction" sponsored by the National Institute of Child Health and Human Development and the Reproductive Biology Study Section of the Division of Research Grants, National Institutes of Health was held in October 1980. The proceedings of the workshop were published by Elsevier Biomedical/New York. This workshop was followed by two workshops sponsored by the Reproductive Biology Study Section of the Division of Research Grants, National Institutes of Health entitled "Role of Peptides and Proteins in Control of Reproduction" in February 1982 and published by Elsevier Biomedical and "Molecular and Cellular Aspects of Reproduction" in October 1985 and published by Plenum Press. It was, therefore, timely to review the current state of knowledge regarding the regulation of ovarian and testicular function by bringing together scientists working in separate and discrete aspects of reproduction to review the functional implications of their research on the regulation of function within the same tissue and also in relationship to feedback systems and regulatory loops with other tissues.