Phosphorus (P) is an essential macronutrient for plant growth. It is as phosphate that plants take up P from the soil solution. Since little phosphate is available to plants in most soils, plants have evolved a range of mechanisms to acquire and use P efficiently - including the development of symbiotic relationships that help them access sources of phosphorus beyond the plant's own range. At the same time, in agricultural systems, applications of inorganic phosphate fertilizers aimed at overcoming phosphate limitation are unsustainable and can cause pollution. This latest volume in Springer's Plant Ecophysiology series takes an in-depth look at these diverse plant-phosphorus interactions in natural and agricultural environments, presenting a series of critical reviews on the current status of research. In particular, the book presents a wealth of information on the genetic and phenotypic variation in natural plant ecosystems adapted to low P availability, which could be of particular relevance to developing new crop varieties with enhanced abilities to grow under P-limiting conditions. The book provides a valuable reference material for graduates and research scientists working in the field of plant-phosphorus interactions, as well as for those working in plant breeding and sustainable agricultural development.

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences. The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.

The Annual Beltsville Symposium provides a forum for interaction among scientists involved in research that is vitally important to agri culture and to the agricultural sciences. The Twelfth Symposium in this series focused on the unifying biochemical and physiological mechan isms controlling growth and development of biological systems - ani mals, plants insects. Unraveling the complex biochemical mechanisms associated with the sequencing of organism growth and development and identifying, locating, and manipulating key control mechanisms are essential in utilizing the full potential of biotechnology for improving the composition and quality of agricultural products and the profitability of agriculture. Accordingly, speakers directed their remarks to basic aspects of biological mechanisms in their area of specialization with considera tion given to current status, future direction, potential impact, and limitations to progress. The Symposium addressed fundamental questions in: -Tissue specific gene regulation: cell division and differentiation -Mechanisms for regulating hormone concentration -Hormonal regulation of growth and development -Non-hormonal regulation of growth and development -Nutritional regulation of growth and development Because the backgrounds of the symposium attendees covered a wide spectrum in the basic biological and physical sciences, each topic was introduced by a brief overview, but general reviews were avoided in favor of findings from on-going research projects. The symposium brought together a distinguished group of invited scientists from around the world who are leaders. Many attendees made poster presentations which increased the exchange of ideas and sti mulated informal discussion."

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.

Sulfur is one of the most versatile elements in life. This book provides, for the first time, in-depth and integrated coverage of the functions of sulfur in phototrophic organisms including bacteria, plants and algae. It bridges gaps between biochemistry and cellular biology of sulfur in these organisms, and of biology and environments dominated by them. The book therefore provides a comprehensive overview of plant sulfur relations from genome to environment.

The importance of mycorrhiza for the improvement of plant growth is increasingly being realised in Agriculture and Forestry and several mycorrhizal fungi have been commercially recognised for the purpose. The aim of this book is to describe the various techniques used to study the mycorrhizal biology. Problems with preparing such a book are many. Mainly mailing of manuscripts to and from authors resulted in irregular and final editing. Every effort was made not to change the peer review original manuscript to ensure accuracy. Our sole aims is to communicate to the greatest extent possible a current world need in mycorrhizal research. Plant productivity is regulated by microbial associations established in the plant root systems. The interactions of microorganisms and plant roots are especially important in providing nutritional requirements of the plant and the associated microorganisms. Plant growth and development are controlled largely by the soil environment in the root region -rhizosphere. This is a very complex environment in which the effects of the plant on soil microorganisms and the effects of microorganisms on the plant are interacting, interdependent and highly complex. Plant root exudates and breakdown products feed the microbes and the microbe in tum often benefit the plant. Mycorrhizal fungi are important tools for increasing growth, development and yield of economically important plants, they play important role of biofertilizer which can help establish plants in nutrient deficient soils, particularly phosphorus deficient soils, arid, semi-arid and waste lands.

Studies on the phenomenon of plant pathogenesis (disease development) have been useful to have a deep insight into the interactions between host plant and the pathogen. Depending on the levels of susceptibility (compatibility) or resistance (incompatibility) of the host plant and virulence of the pathogen, disease development may progress, either leading to symptom expression or result in the suppression of pathogen proliferation. Molecular techniques have been applied to elucidate the nature of interactions between the gene products of the plant and pathogen at cellular and molecular levels. Successful evasion of host's surveillance system and subsequent activities of metabolites of the pathogen (enzymes and toxins) encoded by pathogen genes counteracting the effects of various defense-related antimicrobial compounds present already or produced by the host plants, after initiation of infection have been critically studied by applying various molecular techniques. In addition to studying various phases of disease development in individual plants, molecular methods have been demonstrated to be effective, in gathering data on various aspects of epidemiology under natural conditions where the interaction of pathogen with populations of plants is influenced significantly by the environmental conditions existing in different ecosystems. This volume focuses on the possibility of applying the knowledge on pathogenesis and molecular epidemiology to determine the vulnerable stages in the life cycles of the pathogens that can be disrupted to achieve more effective disease control.

This book summarizes the experimental work conducted during a trans-disciplinary research program conducted for six years by the German Research Foundation. Each chapter includes introductory remarks written by internationally recognized scientists in their research areas.

Contributiing authors representing outstanding German scientists from such different disciplines as Physics, Biochemistry, Plant Nutrition, Botany, and Molecular Biology not only report original research but also review the state of knowledge in their fields of research.

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have allowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of all crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

The present book provides a comprehensive overview of our current knowledge on plastid biogenesis, plastid-nuclear communication, and the regulation of plastid gene expression at all levels. It also assesses the state-of-the-art in key technologies, such as proteomics and chloroplast transformation. Written by recognized experts in the field, the book further covers crucial post-translational processes in plastid biogenesis and function, including protein processing.

Af ter a kind mo ti va tion by Judit Si mon (Ed i tor-in-Chief of the Jour nal of Ther mal Anal y s is and Cal o ri m e t r y , Kluwe r Ac a dem ic Pub lis her) and ne go ti a tions with po- si ble con tri bu tors - lasting for m ore than one year - it was de cided to write a book about the ap pli ca tion of ther mal meth ods in bi ol ogy. Its aim was to be a guide how to per form ex per i ments and what kind of in for mation m ight be gained by them. We tried to col lect in for mation tha t could be achieved only dur ing a long per sonal pra- tice. In this way sci en tists from bi ol ogy and med i cine , e. g. , who are not so skilled in phys ics and math e mat ics may re al ize very soon the beauty and power of this tool at one hand. On the other hand, those sci en tists with better back ground in nat u ral sc- ences can be more sensitive to find out exciting biological problems.

The 18 chapters making up In Vitro Haploid Production in Higher Plants are divided into two sections. Section 1 (eight chapters) covers historical and fundamental aspects of haploidy in crop improvement. Section 2 deals with methods of haploid production, including anther culture, micropore culture, ovary culture, pollination with irradiated pollen, in vitro pollination, and special culture techniques, including polyhaploid production in the Triticeae by sexual hybridization, the influence of ethylene and gelling agents on anther culture, conditional lethal markers, and methods of chromosome doubling.

In order to understand a process as complex as nitrogen fixation and to be in a position to manipulate it for the benefit of mankind, researchers are now working at the frontiers of science in many different areas: protein structure and function; catalytic mechanisms; electron transfer processes; regulatory circuits and environmental sensing; metabolic integration; chemical communication between organisms; differentiation; genome structure and function; microbial ecology; plant physiology; plant molecular biology; and agronomy. This volume represents a testimony to the advances in nitrogen fixation research that have been made and the contribution of these efforts to the solution of many other varied scientific problems. Limiting steps for future advances are analyzed and new horizons in nitrogen fixation research are proposed.

This volume contains a selection of 14 articles dealing with different aspects of biomonitoring and their relation to questions of global change. During the last 10 - 15 years, vegetation changes due to various causes have been more intensively studied in biological and environmental sciences. Especially aspects of global warming lead to a great variety of tasks for vegetation science (see e.g. the articles by Grabherr, Gottfried & Pauli; Carraro, Gianoni, Mossi, KlOtzli & Walther; Walther; Defila; Stampfli & Zeiter; Rothlisberger; Burga & Perret and Moller, WUthrich & Thannheiser). The different aspects of applied biomonitoring related to (possible) environmental changes concern various ecosystems, e.g. Central European beechwoods, Insubrian evergreen broad-leaved forests, thermophilous lowland deciduous forests, dry grasslands of the lower montane belt of the Ticino Alps, alpine mountain peaks of Switzerland and Austria, Swiss alpine timberline ecotones, and high arctic tundra vegetation. The volume is divided into three parts: A. General aspects of biomonitoring (contributions by KlOtzli; Wildi and Labasch & Otte) , B. Examples of applied biomonitoring in Germany and Switzerland (articles by Hakes; Herpin, Siewers, Kreimes & Markert; Defila; Stampfli & Zeiter; Rothlisberger and Ruoss, Burga & Eschmann), and C. Aspects of global change in the Alps and in the high arctic tundra (Grabherr, Gottfried & Pauli; Burga & Perret; Carraro, Gianoni, Mossi, KlOtzli & Walther; Walther and Moller, WUthrich & Thannheiser).

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have allowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of all crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

Our image of plants is changing dramatically away from passive entities merely subject to environmental forces and organisms that are designed solely for the accumulation of photosynthate. Plants are revealing themselves to be dynamic and highly sensitive organisms that actively and competitively forage for limited resources, both above and below ground, organisms that accurately gauge their circumstances, use sophisticated cost-benefit analysis, and take clear actions to mitigate and control diverse environmental threats. Moreover, plants are also capable of complex recognition of self and non-self and are territorial in behavior. They are as sophisticated in behavior as animals but their potential has been masked because it operates on time scales many orders of magnitude less than those of animals. Plants are sessile organisms. As such, the only alternative to a rapidly changing environment is rapid adaptation. This book will focus on all these new and exciting aspects of plant biology.

Actin is an extremely abundant protein that comprises a dynamic polymeric network present in all eukaryotic cells, known as the actin cytoskeleton. The structure and function of the actin cytoskeleton, which is modulated by a plethora of actin-binding proteins, performs a diverse range of cellular roles. Well-documented functions for actin include: providing the molecular tracks for cytoplasmic streaming and organelle movements; formation of tethers that guide the cell plate to the division site during cytokinesis; creation of honeycomb-like arrays that enmesh and immobilize plastids in unique subcellular patterns; supporting the vesicle traffic and cytoplasmic organization essential for the directional secretory mechanism that underpins tip growth of certain cells; and coordinating the elaborate cytoplasmic responses to extra- and intracellular signals. The previous two decades have witnessed an immense accumulation of data relating to the cellular, biochemical, and molecular aspects of all these fundamental cellular processes. This prompted the editors to put together a diverse collection of topics, contributed by established international experts, related to the plant actin cytoskeleton. Because the actin cytoskeleton impinges on a multitude of processes critical for plant growth and development, as well as for responses to the environment, the book will be invaluable to any researcher, from the advanced undergraduate to the senior investigator, who is interested in these areas of plant cell biology.

A state-of-the-art overview of the intricate functional virus/host relationships that allow a virus or viroid to move cell-to-cell and systemically through the plant, as well as from plant to plant, and, thus, to spread infection. The book also illustrates the mechanisms by which viruses overcome plant defence responses, such as RNA silencing. Arabidopsis is used as an illustration of a plant host eminently suitable for genetic approaches to identify novel players in plant/virus interactions.

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 .

In the two decades since the last comprehensive work on plant peroxisomes appeared, the scientific approaches employed in the study of plant biology have changed beyond all recognition. The accelerating pace of plant research in the post-genomic era is leading us to appreciate that peroxisomes have many important roles in plant cells, including reserve mobilisation, nitrogen assimilation, defence against stress, and metabolism of plant hormones, which are vital for productivity and normal plant development. Many plant scientists are finding, and will no doubt continue to find, that their own area of research is connected in some way to peroxisomes.

Written by the leading experts in the field, this book surveys peroxisomal metabolic pathways, protein targeting and biogenesis of the organelle and prospects for the manipulation of peroxisomal function for biotechnological purposes. It aims to draw together the current state of the art as a convenient starting point for anyone, student or researcher, who wishes to know about plant peroxisomes.

Oxidation-reduction (i.e. redox) processes at the plasma membrane of any cell have been attracting more and more attention, both in basic and in applied research, since the first workshop dealing with the plasma membrane oxidoreductases was organized in Cordoba, Spain, in 1988. This evolution is evident considering the numerous cell functions performed by plasma membrane redox systems not only in healthy cells but also in cells that escaped from the normal metabolic control (e.g. cancer cells) and cells under attack by pathogens. Plasma membrane redox processes have now been demonstrated to play an essential role in growth control and defense mechanisms of these cells. The great importance of the plasma membrane redox systems originates in the fact that they are located in the membrane which is essentially the site of communication between the living cell and its environment. We may say that the plasma membrane can be considered as the "sensory part" of the cell. No chemical substance can enter the cell interior without interaction with the plasma membrane.

Phytohormones are very much involved in directing the plant growth, in a coordinated fashion in association with metabolism that provides energy and the building blocks to develop the form that we recognize as plant. Out of the recognized hormones, attention has largely been focused on Auxins, Gibberellins, Cytokinins, Abscisic acid, Ethylene and more recently to Brassinosteroids. However, in this book we are providing the information about a natural chemical, Salicylic Acid, that could be raised to the status of the above phytohormones because it has significant impact on various aspects of the plant life.

Salicylic acid (SA) was first discovered as a major component in the extracts from Salix (willow) whose bark from ancient time, was used as an anti-inflammatory drug. This acid (SA) is a phenol, ubiquitous in plants generating a significant impact on plant growth and development, photosynthesis, transpiration, ion uptake and transport and also induces specific changes in leaf anatomy and chloroplast structure. SA is recognized as an endogenous signal, mediating in plant defence, against pathogens.

This book includes contributions made by various experts, spread over the world. Since the work on Salicylic Acid is currently rather scattered it was thought prudent to draw this all together in one volume. This will naturally facilitate a ready reference of the material to students and researchers, alike.

The adv antages of those systems are counterbalanced by some important dis- vantages. For one, in heterotrophic and mixotrophic systems high concentrations of organic ingredients are required in the nutrient medium (particularly sugar at 2% or more), associated with a high risk of microbial contamination. How, and to which extent this can be avoided will be dealt with in Chapter 3. Other disadvantages are the difficulties and limitations of extrapolating results based on tissue or cell c- tures, to interpreting phenomena occurring in an intact plant during its development. It has always to be kept in mind that tissue cultures are only model systems, with all positive and negative characteristics inherent of such experimental setups. To be realistic, a direct duplication of in situ conditions in tissue culture systems is still not possible even today in the 21st century, and probably never will be. The organization of the genetic system and of basic cell structures is, however, essentially the same, and therefore tissue cultures of higher plants should be better suited as model s- tems than, e.g., cultures of algae, often employed as model systems in physiological or biochemical investigations. The domain cell and tissue culture is rather broad, and necessarily unspecif ic. In terms of practical aspects, basically five areas can be distinguished (see Figs. 1.1, 1.2 ), which here shall be briefly surveyed before being discussed later at length.

The 12th International Symposium on Plant Lipids was held at the University of Toronto, Canada, from July 7th to 12th, 1996. The conference was attended by over 200 scientists from university, government and corporate laboratories from 24 different countries. The topics covered in the symposium ranged from basic physiology, biochemistry and molecular biology of plant lipids to transformation and genetic engineering of crop plants. Oil seed plants were a particular focus of the symposium. There were 62 oral and 96 posters presentations. A special lecture in memory of the founder of this series of symposium, Terry Galliard, was presented by John Shanklin. This Proceedings Book has been dedicated to Grattan Roughan for his important contributions to our knowledge of plant lipid metabolism. This volume contains manuscripts submitted from most of the presentations at the symposium. It provides a useful summary of the major fields of plant lipid studies and our present state of knowledge. The papers are arranged in eight sections covering the major areas in the field of plant physiology, biochemistry and molecular biology of plant lipids. We would like to thank Valerie Imperial, Rajesh Khetarpal and Mary Williams for their invaluable help in organizing and running the meetings and excursions. John P. Williams, Mobashsher U. Khan and Nora W. Lem Toronto, Canada, October 1996 xvii DEDICATION This volume is dedicated to Grattan Roughan.

The Handbook of Plant Ecophysiology Techniques you have now in your hands is the result of several combined events and efforts. The birth of this handbook can be traced as far as 1997, when our Plant Ecophysiology lab at the University of Vigo hosted a practical course on Plant Ecophysiology Techniques. That course showed us how much useful a handbook presenting a bunch of techniques would be for the scientists beginning to work on Plant Ecophysiology. In fact, we wrote a short handbook explaining the basics of the techniques taught in that 1997 course: Flow cytometry to measure ploidy levels, Use of a Steady-State porometer to measure transpiration, In vivo measure of fluorescence, HPLC analysis of low molecular weight phenolics, Spectrophotometric determinations of free proline and soluble proteins, TLC polyamines contents measures, Isoenzymatic electrophoresis, Use of IRGA and oxygen electrode. That modest handbook, written in Spanish, was very helpful, both for the people who attended the course and for other who have used it for beginning to work in Plant Ecophysiology. The present Handbook is much more ambitious, and it includes more techniques. But we have also had in mind the young scientists beginning to work on Plant Ecophysiology. In 1999 Francois Pellissier leaded a proposal presented to the European Commission in the Fifth Framework Program in the High Level * Scientific Conferences, including three EuroLab Courses about lab and field techniques useful to improve allelopathic research."