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.

The plasma membrane is at once the window through which the cell senses the environment and the portal through which the environment influences the structure and activities of the cell. Its importance in cellular physiology can thus hardly be overestimated, since constant flow of materials between cell and environment is essential to the well-being of any biological system. The nature of the materials mov ing into the cell is also critical, since some substances are required for maintenance and growth, while others, because of their toxicity, must either be rigorously excluded or permitted to enter only after chemical alteration. Such alteration frequently permits the compounds to be sequestered in special cellular compartments having different types of membranes. This type of homogeneity, plus the fact that the wear and tear of transmembrane molecular traffic compels the system to be constantly monitored and repaired, means that the membrane system of any organism must be both structurally complex and dy namic. Membranes have been traditionally difficult to study because of their fragility and small diameter. In the last several decades, however, remarkable advances have been made because of techniques permit ting the bulk isolation of membranes from homogenized cells. From such isolated membranes have come detailed physical and chemical analyses that have given us a detailed working model of membrane. We now can make intelligent guesses about the structural and func tional interactions of membrane lipids, phospholipids, proteins, sterols and water.

A collection of papers that comprehensively describe the major areas of research on lipid metabolism of plants. State-of-the-art knowledge about research on fatty acid and glycerolipid biosynthesis, isoprenoid metabolism, membrane structure and organization, lipid oxidation and degradation, lipids as intracellular and extracellular messengers, lipids and environment, oil seeds and gene technology is reviewed. The different topics covered show that modern tools of plant cellular and molecular biology, as well as molecular genetics, have been recently used to characterize several key enzymes of plant lipid metabolism (in particular, desaturases, thioesterases, fatty acid synthetase) and to isolate corresponding cDNAs and genomic clones, allowing the use of genetic engineering methods to modify the composition of membranes or storage lipids. These findings open fascinating perspectives, both for establishing the roles of lipids in membrane function and intracellular signalling and for adapting the composition of seed oil to the industrial needs. This book will be a good reference source for research scientists, advanced students and industrialists wishing to follow the considerable progress made in recent years on plant lipid metabolism and to envision the new opportunities offered by genetic engineering for the development of novel oil seeds.

The NATO Advanced Research Workshop (ARW) on "Regulation of Enzymatic Systems Detoxifying Xenobiotics in Plants" intended to provide a forum to scientists from academia, industry, and govemment for discussing and critically assessing recent advances in the field of xenobiotic metabolism in plants and for identifying new directions for future research. Plants function in a chemical environment made up of nutrients and xenobiotics. Xenobiotics (foreign chemicals) are natural or synthetic compounds that can not be utilized by plants for energy-yielding metabolism. Plants may be exposed to xenobiotics either deliberately, due to their use as pesticides or accidentally, from industrial, agricultural, and other uses. Plants, like most other organisms, evolved a remarkable battery or metabolic reactions to defend themselves against the potentially toxic effects of xenobiotics. The main enzymatic reactions utilized by plants for xenobiotic detoxification include oxidation, reduction, hydrolysis and conjugation with glutathione, sugars (e.g., glucose), and amino acids. Eventually, xenobiotic conjugates are converted to insoluble bound residues or to secondary conjugates, which are deposited in the vacuole of plant cells.

The beginnings of human civili zation can be traced back to the time , ne- ly 12 ,000 years ago , when th e early humans gradually ch anged from a life of hunting and gathering food , to producing food. This beginning of pri- tive agriculture ensured a dependable supply of food , and fostered the living together of people in groups and the development of s o c i e ty. During th is time, plant s e e ds were recognized a s a valuable s o ur c e of food and nutrition , and began to be used for growing plants for food. Ever s i n c e , plant seeds have played an important role in the development of the human civilization . Even today, s e e ds of a few crop s p e c i e s , s uc h as the cereals and legume s, are the primary s o u r c e of most human food , and the predominant commodity in international agriculture. Owing to their great importance as food for human s and in international trade , seeds have been a favorite object of s t u d y by developmental biologists and physiologi sts , nutritionist s and chem i sts . A wealth of useful information i s available on th e biology of seed s .

Historically, scientists and laymen have regarded salinity as a hazar dous, detrimental phenomenon. This negative view was a principal reason for the lack of agricultural development of most arid and semi arid zones of the world where the major sources of water for biological production are saline. The late Hugo Boyko was probably the first scientist in recent times to challenge this commonly held, pessimistic view of salinity. His research in Israel indicated that many plants can be irrigated with saline water, even at seawater strength, if they are in sandy soil - a technique that could open much barren land to agriculture. This new, even radical, approach to salinity was clearly enunciated in the book he edited and most appropriately entitled 'Salinity and Aridity: New Approaches to Old Problems' (1966). A decade later, three members of the United States National Science Foundation (NSF), Lewis Mayfield, James Aller and Oskar Zaborsky, formulated the 'Biosaline Concept'; namely, that poor soils, high solar insolation and saline water, which prevail in arid lands, should be viewed as useful resources rather than as disadvantages, and that these resources can be used for non-traditional production of food, fuels and chemicals. The First International Workshop on Biosaline Research was con vened at Kiawah Island, South Carolina, in 1977 by A. San Pietro."

This book was developed from the proceedings of the 2nd North American Tan nin Conference held in Houghton, Michigan, June, 1991. The objective of this con ference was to bring together people with a common interest in plant polyphenols and to promote interdisciplinary interactions that will lead to a bet ter understand ing of the importance of these substances. Another objective of this conference was to extend the 'tannin family' by making special efforts to encourage participation by scientists outside the United States, obtain more coverage of the hydrolyzable tannins, and further broaden the scope of coverage from the initial concentration on forestry and forest products. Com parison of the contents of this book with 'Chemistry and Significance of Condensed Tannins' that resulted from the proceedings of the 1st North American Tannin Conference shows the degree that these objectives were met. In developing the second conference, care was taken to assure that this book extends rather than duplicates the coverage of the first conference. Therefore, the two books should be taken together to obtain an up to date coverage of the broad area of chemistry and significance of plant polyphenols. Our thanks go to the authors who so kindly contributed chapters and so pa tiently responded to our requests. We thank the Conference Assistance Staff of Michigan Technological University for their help in planning and conducting the conference."

Metal contamination is an increasing ecological and eco-toxicological risk. Understanding the processes involved in metal mobilization, sorption and mineralization in soils are key features for soil bioremediation.

Following an introduction to the physical, chemical and biological components of contaminated soils, various chapters address the interactions of soil, microorganisms, plants and the water phase necessary to transfer metals into biological systems. These include topics such as potential hazards at mining sites; rare earth elements in biotic and abiotic acidic systems; manganese redox reactions; biomineralisation, uranium in seepage water; metal-resistant streptomycetes; mycorrhiza in re-forestation; metal (hyper)accummulation in plants; microbial metal uptake; and their potential for bioremediation.

This book will be of interest to soil biologists, geologists and chemists, researchers and graduate students, as well as consulting companies and small enterprises involved in bioremediation.

Rinie Hofstra has been a member of the Department of Plant Physiology, University of Groningen, the Netherlands, for 24 years. The nearer we came to 31 March 1985, her 65th birthday, the more we all realized how we would miss her - not only scientifically, but also socially. She left her mark on both research and teaching, always with an open mind and willing to change. After her PhD Thesis on 'Nitrogen Metabolism in Tomato Plants' she first continued working in that field, but soon started a joint project with the Department of Plant Ecology on hemiparasites. She then became involved in carbon metabolism, which resulted in her giving a Biotrop Course on C /C metabolism in 3 4 Indonesia. Her own research group, originally working on 'Nitrogen Metabolism', soon embraced 'Energy and Nitrogen Metabolism', as the research on respiration became more and more important. In running her group she showed all sides of her person. She used to stimulate and encourage everyone around her and to integrate the various lines of research. At the same time she always had an open mind for the opinion of all members of her group. And together they regularly criticized and evaluated the various projects and decided how to continue.

This book summarizes our current knowledge on belowground defence strategies in plants by world-class scientists actively working in the area. The volume includes chapters covering belowground defence to main soil pathogens such as Fusarium, Rhizoctonia, Verticillium, Phytophthora, Pythium and Plasmodiophora, as well as to migratory and sedentary plant parasitic nematodes. In addition, the role of root exudates in belowground plant defence will be highlighted, as well as the crucial roles of pathogen effectors in overcoming root defences. Finally, accumulating evidence on how plants can differentiate beneficial soil microbes from the pathogenic ones will be covered as well. Better understanding of belowground defences can lead to the development of environmentally friendly plant protection strategies effective against soil-borne pathogens which cause substantial damage on many crop plants all over the world. The book will be a useful reference for plant pathologists, agronomists, plant molecular biologists as well as students working on these and related areas.

Environmental stresses represent the most limiting factors for agricultural productivity. Apart from biotic stress caused by plant pathogens, there are a number of abiotic stresses such as extremes in temperature, drought, salinity, heavy metals and radiation which all have detrimental effects on plant growth and yield. However, certain plant species and ecotypes have developed various mechanisms to adapt to such stress conditions. Recent advances in the understanding of these abiotic stress responses provided the impetus for compiling up-to-date reviews discussing all relevant topics in abiotic stress signaling of plants in a single volume. Topical reviews were prepared by selected experts and contain an introduction, discussion of the state of the art and important future tasks of the particular fields.

In continuation of Volumes 8, 9, 22, and 23, this new volume deals with the regeneration of plants from isolated protoplasts and genetic transformation in various species of "Actinidia," "Allocasuarina," "Anthurium," "Antirrhinum," "Asparagus," "Beta," "Brassica," "Carica," "Casuarina," "Cyphomandra," "Eucalyptus," "Ipomoea," "Larix," "Limonium," "Liriodendron," "Malus," "Musa," "Physcomitrella," "Physalis," "Picea," "Rosa," "Tagetes," "Triticum," and "Ulmus."
These studies reflect the far-reaching implications of protoplast technology in genetic engineering of plants. The book contains a wealth of useful information for advanced students, teachers, and researchers in the field of plant tissue culture, molecular biology, genetic engineering, plant breeding, and general biotechnology.

In the past there were many attempts to change natural foodstuffs into high-value products. Cheese, bread, wine, and beer were pro duced, traditionally using microorganisms as biological tools. Later, people influenced the natural process of evolution by artificial selection. In the 19th century, observations regarding the depen dence of growth and reproduction on the nutrient supply led to the establishment of agricultural chemistry. Simultaneously, efforts were directed at defining the correlation between special forms of morphological differentiation and related biochemical processes. New experimental systems were developed after the discovery of phytohormones and their possible use as regulators of growth and differentiation. In these systems, intact plants or only parts of them are cultivated under axenic conditions. These methods, called "in vitro techniques," were introduced to modern plant breeding. In the field of basic research, plant cell cultures were increasingly developed and the correlations between biochemical processes and visible cell variations were explored further. It should be possible to manipulate the basic laws of regulation and the respective biochemi cal processes should be regarded as being independent of morpho logical processes of plant development."

Plants are sessile, highly sensitive organisms that actively compete for environmental resources both above and below the ground. They assess their surroundings, estimate how much energy they need for particular goals, and then realise the optimum variant. They take measures to control certain environmental resources. They perceive themselves and can distinguish between 'self' and 'non-self'. They process and evaluate information and then modify their behaviour accordingly. These highly diverse competences are made possible by parallel sign(alling)-mediated communication processes within the plant body (intraorganismic), between the same, related and different species (interorganismic), and between plants and non-plant organisms (transorganismic). Intraorganismic communication involves sign-mediated interactions within cells (intracellular) and between cells (intercellular). This is crucial in coordinating growth and development, shape and dynamics. Such communication must function both on the local level and between widely separated plant parts. This allows plants to coordinate appropriate response behaviours in a differentiated manner, depending on their current developmental status and physiological influences. Lastly, this volume documents how plant ecosphere inhabitants communicate with each other to coordinate their behavioural patterns, as well as the role of viruses in these highly dynamic interactional networks.

Allelochemicals play a great role in managed and natural ecosystems. Apart from plant growth, allelochemicals also may influence nutrient dynamics, mycorrhizae, soil chemical characteristics, and microbial ecology. Synergistic action of various factors may better explain plant growth and distribution in natural systems. The book emphasizes the role of allelochemicals in shaping the structure of plant communities in a broader ecological perspective. The book addresses the following questions: (1) How do allelochemicals influence different components of the ecosystem in terms of shaping community structure? (2) Why is it difficult to demonstrate interference by allelochemicals (i.e., allelopathy) in a natural system in its entirety? Despite a large amount of existing literature on allelopathy, why are ecologists still skeptical about the existence of allelopathy in nature? (3) Why are there only scarce data on aquatic ecosystems? (4) What role do allelochemicals play in microbial ecology?.....

"Plant Endosomes: Methods and Protocols" explores a collection of protocols and techniques to analyze in vivo trafficking of endocytic/endosomal cargo, including lipids, fluids, proteins and ligands, ultrastructural features of endosomes by high-pressure freezing/freeze-substitution and electron tomography, as well as protein-protein interactions in the endosomal and endomembrane system. The volume continues with coverage of the sorting defects in the transport of vacuolar storage proteins, function conservation of plant endosomal proteins, endosomal trafficking during plant responses to pathogens, protein composition of endosomes and endocytic vesicles, ubiquitination of endosomal cargo proteins and the identification of novel endosomal components by chemical genomics and proteomics. Written in the highly successful "Methods in Molecular Biology" series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols and tips on troubleshooting and avoiding known pitfalls.

Detailed and practical, "Plant Endosomes: Methods and Protocols" gathers contributions from many leading and emerging plant membrane trafficking researchers in order to promote and facilitate novel studies and ideas in this vital field.

Well designed, constructed and maintained reinforced or prestressed concrete structures are generally very durable. In aggressive environments though, corrosion of steel can be a significant problem and structures such as bridges, industrial buildings and those subjected to marine conditions can be particularly at risk. Over the last decade there has been fast growing interest in reinforcing concrete with fibre reinforced plastic materials which cannot rust or deteriorate like steel. This proceedings of the Second International RILEM Symposium on the subject, held in Ghent, August 1995, deals with a wide range of non-metallic materials and opens up possibilities of lighter, more durable structures. The contributions by leading international researchers and design engineers are divided into parts covering material development and properties, bond behaviour of FRP elements, structural behaviour of reinforced and prestressed concrete members, rehabilitation and strengthening, and design methods and applications. This complete overview of knowledge on the subject will provide an essential update for structural engineers, concrete specialists and researchers into materials and structures.

The first edition of The Science of Photobiology was published in 1977, and was the first textbook to cover all of the major areas of photobiology. The science of photobiology is currently divided into 14 subspecialty areas by the American Society for Photobiology. In this edition, however, the topics of phototechnology and spectroscopy have been com bined in a new chapter entitled "Photophysics." The other subspecialty areas remain the same, i.e., Photochemistry, Photosensitization, UV Radiation Effects, Environmental Photobiology, Photomedicine, Circadian Rhythms, Extraretinal Photoreception, Vision, Photomorphogenesis, Photomovement, Photosynthesis, and Bioluminescence. This book has been written as a textbook to introduce the science of photobiology to advanced undergraduate and graduate students. The chapters are written to provide a broad overview of each topic. They are designed to contain the amount of information that might be presented in a one-to two-hour general lecture. The references are not meant to be exhaustive, but key references are included to give students an entry into the literature. Frequently a more recent reference that reviews the literature will be cited rather than the first paper by the author making the original discovery. The chapters are not meant to be a repository of facts for research workers in the field, but rather are concerned with demon strating the importance of each specialty area of photobiology, and documenting its relevance to current and/or future problems of man."

Research on the interaction between plants and microbes continues to attract increasing attention, both within the field as well as in the scientific community at large. Many of the major scientific journals have recently reviewed various aspects of the field. Several papers dealing with plant-microbe interactions have been featured on the covers of scientific publications in the past several months, and the lay press have recently presented feature articles of this field. An additional sign of the interest in this field is that the International Society of Molecular Plant-Microbe Interactions has almost 500 members. This book is a collection of the papers that were given at the Sixth Inlernational Symposium on the Molecular Genetics of Plant-Microbe Interactions which was held in Seattle, Washington in July, 1992. Approximately 650 scientists attended and approximately 50 lectures covering the topics of Agrobacterium-plant interactions, Rhizobium-plant interactions, bacteria-plant interactions, fungal-plant interactions and new aspects of biotechnology were presented. In addition, many sessions were devoted to the plant response to the microbe. Over 400 posters were presented of which the authors of 20 were selected to give an oral presentation. These papers are included in this volume as well. The symposium also included speakers whose research interests are not directly related to plant-microbe interactions but who are at the cutting edge of research areas that impact on the theme of the symposium. These individuals kindly agreed to summarize their talks and their papers are also included.

This volume highlights the new synthesis of pollination biology and plant mating systems which is rejuvenating the two-hundred-year-old discipline of floral biology. It provides a current examination of the evolution and functional significance of floral traits in animal-pollinated plants, combining ecological and genetic studies with natural history approaches and theoretical modeling. Divided into three sections, the book begins with the first English translation of Christian Konrad. Sprengel's introduction to his classic work and a historical analysis of his observations. The second section addresses current conceptual problems in floral biology, concentrating on floral diversification, floral longevity, pollen dispersal and mating patterns, the ecology of geitonogamous pollination, and flower size dimorphism in plants with unisexual flowers. The final chapters of the book examine model systems and include the evolution of floral morphology and function, deceit pollination, reproductive success and gender variation, stylar polymorphisms, and the evolution of flowers in relation to insect pollinators on islands. With its a detailed treatment of the selective forces shaping floral diversification in animal-pollinated plants, Floral Biology provides ecologists, evolutionary biologists, and botanists with a wealth of current information. Everyone interested in the evolution of flowering plants will benefit from this timely, authoritative resource on the interactions between insects and plants.

This book was tbe result of a symposium beld at tbe American Cbernical Society meeting in Miami Beacb, Florida, September 10-15, 1989. The symposium was jointly sponsored by Tbe Society for Economfc Botany and tbe American Cbernical Society Food and Natural Product sub division. Tbere were five speakers. During tbe social sessions (mostly over drinks in abotel room), it became obvious tbat, regardless of tbe discipline, we were all speaking tbe same language. Yet, prior to tbe symposium, only a few of tbe participants knew one anotber. We decided to expand tbe symposium into a book. The book would, we boped, accomplish for otbers wbat we bad discovered in ourselves. That is, the field of Natural Products is broad, but similar in techniques and approach, ancient but modern, and bas been and continues to be extremely valuable to humankind. We wanted the book to serve as an introductory text for courses and as a reference work for the future. We also determined to include the structure of every chemical in the chapter where it was mentioned so the reader would not have to find the structure somewhere else or to try and deduce the structure from the chemical name. Little did we know what an undertaking these goals would be or the time this would take.

This book presents recent advances in the study of nitric oxide (NO) biology, biochemistry, molecular biology, and physiology in plants. It provides an overview of current understanding of the NO actions involved in adaptive responses of plant fitness to environmental constraints. Coverage places special emphasis on NO-dependent signaling, molecular adjustments, and targets as key elements in plant growth, development, and stress physiology.

The last few years have seen an explosion of new information and resources in the areas of plant molecular genetics and genomics. As a result of developments such as high throughput sequencing, we now have huge amounts of information available on plant genes. But how does this help people charged with the task of improving crop species to create products with altered functions or improved characteristics? This volume considers ways in which the new information, resources and technology can be exploited by the plant breeder. Examples in current use will be quoted wherever possible.

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.

For 31 years, the North American Symbiotic Nitrogen Fixation Conference (for merly Rhizobium Conference) has been a forum for scientists and graduate students to discuss their research advances, extending from basic aspects to agricultural appli cations, and dealing with topics ranging from bacterial genetics and metabolism to plant genetics and physiology. Nitrogen fixation, being a major life-supporting process on this planet, has attracted the interest of researchers for more than one century. Nitrogen fixation is responsible for the conversion of "inert" dinitrogen (N ) gas from the atmos z phere into usable ammonia, replacing the fixed nitrogen constantly being lost to the atmosphere by the denitrification process. Worldwide agricultural productivity is deter mined by the availability of fixed nitrogen in all its forms, which the continually increas ing human population depends upon for survival. An international momentum is developing in the use of biofertilizers to improve legume and non-legume crop yields and in the study of genomics in this area. New studies are being undertaken in several laboratories to study novel nitrogen-fixing systems, including non-legume crops. The North American Conferences on Symbiotic Nitrogen Fixation have periodically chronicled the advances in our knowledge of this area. For the first time, this conference was held in Mexico. Thus, all three North Amer ican countries have been hosts for this event. This year conference brought nearly 200 scientists from 18 different countries presenting lectures and over 80 posters."