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 study of water stress is one of the most interesting subjects in. the investigation of water relations in plants. From the theoretical point of view it is concerned with investigating the mechanisms of the distribution and movement of water in the plant organism and the way in which physiolo gical processes are influenced by water deficiency. From the practical point of view, water deficiency is a major factor limiting plant production. It has been progressively shown that water deficiency is not by far* only a factor in plant life in dry climates, that obvious wilting is not the first warning sign of water deficiency and that moderate water stress, caused by temporary negative water balance during the day, affects physiological ac tivity and decreases prodnction in the ecological conditions of the temperate zone. In addition, even general water deficiency is not today confined to arid or semi-arid zones and to the absolutely dry season of the year. The tremend ous consumption of water in our civilization has become today, even in the temperate zone, an important competitor with the plant cover. The study of water relations from the aspect of water stress is, therefore, important both theoretically and practically. I assume, therefore, that it was useful, important and interesting to meet in a symposium on water stress in plants and to discuss, as far as possible, in detail problems which are obviously among the main, whose solution would help plant physiology in increasing and improving plant production.

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.

Calcium plays pivotal role in regulating the physiological as well as developmental processes in plants. Till now, several calcium sensors have been discovered, which regulate the diverse signaling pathways involved in plant growth and development. One of the major calcium sensors CBL (calcineurin B-like) is decoding the calcium signal during various environmental stresses in plants. Calcium mediated signal is transduced downstream by CBL-interacting protein kinases (CIPKs), which generally phosphorylate the target proteins such as transcription factors or transporters/channel leading to a response. Mutant based approach has provided valuable information in the functional analysis of individual members of CBL and CIPK gene family in Arabidopsis. Both CBL and CIPK gene families have previously been identified and characterized in Arabidopsis and rice. Identification and characterization of CBLs and CIPKs in other plant species such as Oryza sativa, Pisum sativum, Cicer arietinum, Zea mays, Populus euphratica, Vitis vinifera, Malus domestica, Gossypium hirsutum, Sorghum bicolor, Brassica napus, Vicia faba, Phaseolus vulgaris, Ammopiptanthus mongolicus and Triticum aestivum are still in juvenile stage. Overall, Global Comparative Analysis of CBL-CIPK Gene Families in Plants is a comprehensive study focused on the diverse role of CBL-CIPK module in different stress signaling and also to identify a newly emerging role of this calcium-signaling module in plant growth and development across different plant species. In addition, beside Arabidopsis, it will provide backbone of knowledge to perform a detail molecular investigation in crop plant species and could possibly enable in designing strategies to tame abiotic stress tolerance and development in important agronomical crop plants. This book will act as handy and informative source in this field for students as well as advanced researchers.

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.

The rapid population growth and the increase in the per capita income, especially in the group of emerging countries referred to as BRIC countries (Brazil, Russia, India, China and South Africa) has created huge pressure for the expansion of the agricultural growing area and the crop yields to meet the rising demand. As a result, many areas that have been considered marginal for growing crops, due to their low fertility, drought, salinity, and many other abiotic stresses, have now been incorporated in the production system. Additionally, climate change has brought new challenges to agriculture to produce food, feed, fiber and biofuels. To cope with these new challenges, many plant breeding programs have reoriented their breeding scope to stress tolerance in the last years. The authors of this book have collected the most recent advances and discoveries applied to breeding for abiotic stresses in this book, starting with new physiological concepts and breeding methods, and moving on to discuss modern molecular biological approaches geared to the development of improved cultivars tolerant to most sorts of abiotic stress. Written in an easy to understand style, this book is an excellent reference work for students, scientists and farmers interested in learning how to breed for abiotic stresses scenarios, presenting the state-of-the-art in plant stresses and allowing the reader to develop a greater understanding of the basic mechanisms of tolerance to abiotic stresses and how to breed for them.

Rice is the staple food for half of the world s population. Consumption of rice is the major exposure route globally to the class one, non-threshold carcinogen inorganic arsenic. This book explains the sources of arsenic to paddy soils and the biogeochemical processes and plant physiological attributes of paddy soil-rice ecosystems that lead to high concentrations of arsenic in rice grain. It presents the global pattern of arsenic concentration and speciation in rice, discusses human exposures to inorganic arsenic from rice and the resulting health risks. It also highlights particular populations that have the highest rice consumptions, which include Southern and South East Asians, weaning babies, gluten intolerance sufferers and those consuming rice milk. The book also presents the information of arsenic concentration and speciation in other major crops and outlines approaches for lowering arsenic in rice grain and in the human diet through agronomic management."

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 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.

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.

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.

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.

This book contains the proceedings of a symposium, held in the Limburgs Universitair Centrum, Diepenbeek, Belgium, from July 23 to 29, 1978.1t can be considered as a continuation of the publication 'Environmental and Biological Control of Photosynthesis' (Dr. W. Junk b.v. Publishers, The Hague, 1975). In the last meeting, however, emphasis was much more on the biological control of photosynthesis. The sequence of the different topic sessions and papers on the symposium programme is maintained in the publication; the editors are aware of the fact that different contributions might figure equally well in more than one session. A limited number of speakers was invited; time for discussion therefore could generously be provided to the audience. We thank all the participants for their active contribution to the success of this conception of organizing a meeting. The quality of a discussion session also depends on the performance of the discussion leader; thanks are due to Drs. G. Bernier, J.J. Landsberg, C.J. Pearson, R. Sachs, I.A. Tamas and K.J. Treharne who took the chair with scientific authority and enthusiasm. In order to keep in memory the flavor of this aspect of the meeting, an account of the discussion on one particular topic, the relationship between photosynthesis and flowering, was made by Dr. R. Sachs (reporter) and Dr. G. Bernier (discussion leader) and is published here after the reports on this topic.

In plant cells, the plasma membrane is a highly elaborated structure that functions as the point of exchange with adjoining cells, cell walls and the external environment. Transactions at the plasma membrane include uptake of water and essential mineral nutrients, gas exchange, movement of metabolites, transport and perception of signaling molecules, and initial responses to external biota. Selective transporters control the rates and direction of small molecule movement across the membrane barrier and manipulate the turgor that maintains plant form and drives plant cell expansion. The plasma membrane provides an environment in which molecular and macromolecular interactions are enhanced by the clustering of proteins in oligimeric complexes for more efficient retention of biosynthetic intermediates, and by the anchoring of protein complexes to promote regulatory interactions. The coupling of signal perception at the membrane surface with intracellular second messengers also involves transduction across the plasma membrane. Finally, the generation and ordering of the external cell walls involves processes mediated at the plant cell surface by the plasma membrane. This volume is divided into three sections. The first section describes the basic mechanisms that regulate all plasma membrane functions. The second describes plasma membrane transport activity. The final section of the book describes signaling interactions at the plasma membrane. These topics are given a unique treatment in this volume, as the discussions are restricted to the plasma membrane itself as much as possible. A more complete knowledge of the plasma membrane's structure and function is essential to current efforts to increase the sustainability of agricultural production of food, fiber, and fuel crops.

Due to their sessile lifestyle, plants need to efficiently adapt to changing environmental conditions during their life cycle. Nutrient acquisition from the soil has to be able to adapt to considerable fluctuations in concentrations to ensure adequate distribution between tissues, cells and organelles. The storage and retrieval of nutrients, metabolites or toxic substances in vacuoles plays an important part in cellular homeostasis in plants. The long-range transport and maintenance of turgor is critically dependent on the availability of water and rate of evaporation, while at the same time photosynthetic products have to be transported to all plant parts. As a result plants contain a large number of ATP-dependent pumps and secondary transporters that, in order to adapt to the changing environment, need to be regulated by a complex network of sensing and signaling mechanisms. Plants share many basic elements of signal transduction with animals, but also contain plant-specific signaling molecules and mechanisms. In this volume, the role of transporters and pumps in the regulation of movement, long-range transport and compartmentalization of water, solutes, nutrients and classical signaling molecules is highlighted, and the function, regulation and membrane-transporter interaction and their roles in plant signaling controlling plant physiology and development are discussed.

Precise regulation of gene expression in both time and space is vital to plant growth, development and adaptation to biotic and abiotic stress conditions. This is achieved by multiple mechanisms, with perhaps the most important control being exerted at the level of transcription. However, with the recent discovery of microRNAs another ubiquitous mode of gene regulation that occurs at the post-transcriptional level has been identified. MicroRNAs can silence gene expression by targeting complementary or partially complementary mRNAs for degradation or translational inhibition. Recent studies have revealed that microRNAs play fundamental roles in plant growth and development, as well as in adaptation to biotic and abiotic stresses. This book highlights the roles of individual miRNAs that control and regulate diverse aspects of plant processes.

The molecular mechanisms which determine whether the cells of a multicellular organism will live or commit suicide have become a popular field of research in biology during the last decade. Cell death research in the plant field has also been expanding rapidly in the past 5 years. This special volume of Plant Molecular Biology seeks to bring together examples of a diverse array of experimental approaches in a single volume. From the differentiation of tracheary elements in vascular plants to the more specialized cell death model of the aleurone in cereals, this volume will bring the reader up-to-date with the characterization of different plant model systems that are currently being studied. This endeavor should complement general overviews of plant cell death mechanisms that have been published elsewhere by providing more detailed information on various aspects of this field to interested graduate students and more senior biologists alike.

This timely reference provides an in-depth and up-to-date study of the most important groups of plant secondary compounds. No other work features such detailed diagrams of the biosynthetic pathways leading to the most important groups of secondary metabolites, as well as the structures of major types of compounds, their distribution in various taxonomic groupings of plants, and the evolutionary and ecological roles of these compounds. Plant Secondary Metabolism presents a basic understanding of the origin of the compounds, the nature of the precursors involved, and the basic reactions, mechanisms, and stereochemistry. The origin of groups of secondary metabolites is linked to evolutionary principles, and their biological activity is viewed in a context of chemical ecology. Topics are treated comprehensively, enabling the reader to understand not only a particular group of compounds, but also how each group fits into the whole. In addition, the text allows readers to systematically survey various secondary metabolites and gain a quick working knowledge which can be applied to problems in a particular field.Those researchers and students who will be most intrigued by this publication's broad overview on plant secondary metabolites come from a diverse range of disciplines, including agronomy, anthropology, biochemistry, biology, botany, chemistry, ecology, entomology, food science, forestry, geology, horticulture, pharmacognosy, plant biology, plant sciences, toxicology, and zoology.

In the field of plant analysis there is a confusing variety of methods and procedures, both for digestions and determinations. In many cases the digestion and the subsequent determination are interrelated. For example, a separate digestion is needed for trace elements in order to obtain determinable concentrations. The authors have chosen a design in which the digestion/extraction procedure is described in one chapter together with all determination procedures that may be carried out on that particular digest/extract. All the necessary information (such as standardizations) appears in appendices. As a consequence, several determination procedures are described two or three times, however, each based on a particular digestion or extraction method. Two types of determination procedure are described: manual and automated. Manual procedures are mainly used in research laboratories, whereas automated procedures are more frequently applied in routine laboratories. Both types of determinations can be used freely, provided that appropriate equipment is available. The determination procedures are only for inorganic components, usually elements. Besides, most procedures are designed to give a total content value of the element under consideration, regardless of the chemical structure in which it occurs in the plant. The Plant Analysis Manual is intended for the practicing (agricultural) chemist.

The double helix architecture of DNA was elucidated in 1953. Twenty years later, in 1973, the discovery of restriction enzymes helped to create recombinant DNA molecules in vitro. The implications of these powerful and novel methods of molecular biology, and their potential in the genetic manipulation and improvement of microbes, plants and animals, became increasingly evident, and led to the birth of modern biotechnology. The first transgenic plants in which a bacterial gene had been stably integrated were produced in 1983, and by 1993 transgenic plants had been produced in all major crop species, including the cereals and the legumes. These remarkable achievements have resulted in the production of crops that are resistant to potent but environmentally safe herbicides, or to viral pathogens and insect pests. In other instances genes have been introduced that delay fruit ripening, or increase starch content, or cause male sterility. Most of these manipulations are based on the introduction of a single gene - generally of bacterial origin - that regulates an important monogenic trait, into the crop of choice. Many of the engineered crops are now under field trials and are expected to be commercially produced within the next few years. The early successes in plant biotechnology led to the realization that further molecular improvement of plants will require a thorough understanding of the molecular basis of plant development, and the identification and character ization of genes that regulate agronomically important multi genic traits.

Research in animals and plants is frequently 'departmentalized' and funded according to Kingdoms by granting bodies. The use of transgenes to address biological questions in all Kingdoms led us to propose to the Royal Society that fundamental and strategic studies in animals and plants involving trans genes should be presented in one meeting, rather than, as so often happens, in different scientific societies. The two-day Discussion Meeting held inJuly 1992, and reported here provided insights into how trans genes are being exploited to discover new knowledge in animals and plants. The papers were presented by leading investigators in the biological sciences, and the book reflects an experiment in interdisciplinarity which was declared a successful venture by the large crowd of participants and delegates. The transgenic area is one of high scientific interest and sporadic, yet intense biotechnological euphoria. This is dramatically illustrated among the following papers which show how genetic maps of animals and plants produce new knowledge of disease incidence in humans, and how the design of transgenes can result in biodegradable plastic in higher plants, human pharmaceutical proteins in livestock, or bacterial proteins in cotton crops to protect against insect damage.

Several fundamental advances were announced at the Seventh International Symposium on Molecular Plant--Microbe Interactions held in Edinburgh in 1994. These included the cloning and identification of plant resistance genes involved in recognition of pathogens; the description of genetically engineered plants with novel resistance to pathogens; characterization of the molecular basis of pathogenicity of fungal and bacterial plant pathogens; and the mechanisms of communication used during recognition between symbiotic rhizobia and their host legumes. Participants in the Symposium contributed a series of papers that represent the leading edge of research in this important area of plant and microbial science. These articles are brought together to form this book, which will be essential reading for research workers, advanced students and others interested in keeping abreast of this rapidly developing area.

Volumes I and 2 of this Plant Biotechnology series reviewed fundamental aspects of plant molecular biology and discussed production and analysis of the first generation of transgenic plants of potential use in agriculture and horticulture. These included plants resistant to insects, viruses and herbicides, which were produced by adding genes from other organisms. Realisation of the potential of plant breeding has led to a resurgence of interest in methods of altering the structure, composition and function of plant constituents, which represents an even greater challenge and offers scope for improving the quality of a wide range of agricultural products. This, in tum, has resulted in a re-evaluation of priorities and targets by industry. Volume 3 of this series considers the biochemical and gentic basis of the biosynthesis of plant products such as starch, lipids, carotenoids and cell walls, and evaluates the ways in which biosynthesis of these products can be modified for use in the food industries. Authors also cover the biosynthesis of rare secondary products and the function and application of proteins for plant protection and therapeutic use. The emphasis throughout is on the relationship between fundamen tal aspects of biosynthesis and structure-function relationships, and application of this knowledge to the redesigning and altering of plant products by molecular genetics."

Optical screening of excessive and potentially harmful solar radiation is an important photoprotective mechanism, though it has received much less attention in comparison with other systems preventing photooxidative damage to photoautotrophic organisms. This photoprotection in the form of screening appears to be especially important for juvenile and senescing plants as well as under environmental stresses-i.e. in situations where the efficiency of enzymatic ROS elimination, DNA repair and other 'classical' photoprotective systems could be impaired. This book represents an attempt to develop an integral view of optical screening-based photoprotection in microalgae and higher plants. Towards this end, the key groups of pigments involved in the screening of ultraviolet and visible components of solar radiation in microalgae and higher plants, and the patterns of their accumulation and distribution within plant cells and tissues, are described. Special attention is paid to the manifestations of screening pigment accumulation in the optical spectra of plants. It is also demonstrated that understanding these effects and their relationships to screening pigments' makeup and spectroscopy in plants provides valuable insights into the state of plants' long-term photoacclimation, as well as ample opportunities for the non-destructive quantification of screening pigments and the assessment of the efficiency of photoprotection providing by these pigments in situ.

This is the second volume in the series Nutrients in Ecosystems. Sulphur as an essential plant nutrient has received little attention. This is explained by the facts that sulphur was obviously in sufficient supply from the atmosphere, from soil and as a by-product in mineral fertilizers. Increases in the yield potential and thus in the nutrient requirement of modern crops, however, as well as remarkable changes in SO2 emissions by private households, power stations and industry, associated with legislative measures to reduce air and water pollution, have altered the situation to a large extent. In particular the public concerns about forest decline and pollution-induced climatic changes have initiated extensive research programs on the physiological functions of sulphur in plants, on the occurrence and plant availability of sulphur in agricultural and forest soils and on the chemistry of sulphur compounds in the tropo- and stratosphere. This book cannot be an encylcopedia of sulphur in all the media mentioned nor in all ecozones of the globe. However, it aims to give an overview of our present knowledge with a special focus on the sulphur situation in agrosystems of industrialised Western Europe. The ecological trends for sulphur observed in this region during recent decades are likely to be mirrored wherever industrialisation and urbanisation take place and where an increasing standard of living demands clean air, good drinking water and nutritious food. Agricultural production systems, therefore, require well-founded information on the actual sulphur nutrition and potential sulphur-fertilizer requirement of crops and soils respectively. It is hoped that this book will provide this information and will encourage further research where open questions still exist.