Plant hormones play a crucial role in controlling the way in which plants growand develop. Whilemetabolism providesthepowerand buildingblocks for plant life, it is the hormones that regulate the speed of growth of the individual parts and integrate these parts to produce the form that we recognize as a plant. In addition, theyplayacontrolling role inthe processes of reproduction. This book is a description ofthese natural chemicals: how they are synthesizedand metabolized; howthey work; whatwe knowoftheir molecular biology; how we measure them; and a description ofsome ofthe roles they play in regulating plant growth and development. Emphasis has also been placed on the new findings on plant hormones deriving from the expanding use ofmolecular biology as a tool to understand these fascinating regulatory molecules. Even at the present time, when the role of genes in regulating all aspects of growth and development is considered of prime importance, it is still clear that the path of development is nonetheless very much under hormonal control, either via changes in hormone levels in response to changes in gene transcription, or with the hormones themselves as regulators ofgene transcription. This is not a conference proceedings, but a selected collection ofnewly written, integrated, illustrated reviews describing our knowledge of plant hormones, and the experimental work that is the foundation of this knowledge.

Iron is a major constituent of the earth crust. However, under alkaline conditions commonly found in arid and semi-arid environments iron becomes unavailable to plants. When plants are affected by a shortage of iron their leaves become yellow (chlorotic), and both plant growth and crop yield are reduced. The roots of plants affected by iron deficiency may develop a series of responses directed to improve iron uptake, such as increased proton excretion and iron reduction capabilities or excretion of iron chela tors called siderophores. Iron deficiency affects major crops worldwide, including some of major economic importance such as fruit trees and others. Correction of iron deficiency is usually implemented through costly application of synthetic chelates. Since these correction methods are very expensive, the competitivity of farmers is often reduced and iron deficiency may become a limiting factor for the maintenance, introduction or expansion of some crops. In spite of the many years devoted to the study of iron deficiency, the knowledge of iron deficiency in soils and plants is still fragmentary in many aspects. We have only incomplete information on the processes at the molecular level that make some plant species and cultivars unable to take and utilize iron from the soil, whereas other plants grow satisfactorily under the same conditions.

Plant cell and tissue culture is a relevant area of experimental biology that has been developed for some decades to become an indispensable tool of plant biotechnology. Progress in this area, sometimes tumultuous, has been regularly recorded by the proceedings of the congresses of the International Association for Plant Tissue Culture which have been held every four years in several continents. This book reports plenary lectures, keynote lectures and invited oral presentations given at the last congress held in Florence. It is a useful reference guide both for established scientists and students on both traditional and emerging fields of plant biology. The following topics are covered: In vitro Culture and Plant Regeneration; Plant Propagation; Haploids; Somatic Hybridisation; Reproductive Systems; Genetic Variability; Gene Transfer; Organelles; Biotechnology of Tropical and Subtropical Species; Agronomic Traits; Somatic Embryogenesis; Meristems; Cell Surface; Growth Regulators; Reception and Transduction of Signals; Gene Expression under Extreme Conditions; Primary Metabolism; Secondary Metabolism; Transport; Large Scale Production.

In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and increasing attention is being given to carbon exchange and storage in natural ecosystems. We need to know how much photosynthesis of terrestrial and aquatic vegetation will change as global CO2 increases. Are there major ecosystems, such as the boreal forests, which may become important sinks of CO2 and slow down the effects of anthropogenic CO2 emissions on climate? Will the composition of the vegetation change as a result of CO2 increase?
This volume reviews the progress which has been made in understanding photosynthesis in the past few decades at several levels of integration from the molecular level to canopy, ecosystem and global scales.

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.

This is the fifth time a "Horticultural Research International" has been published, again revised and extended. Since 1986 a lot has changed in the world: new countries with old names appeared on the map, while recognized frontiers vanished. As the organizing editors we tried to follow these evolutions as closely as possible. In many cases we were able to establish communication with our correspondents as usual; nevertheless we had to delete a total of 8 countries. Thanks to correspondents from 74 different countries we are now able to present this edition, comprising a total of 1800 institutes, including 20,000 names of individual research workers. We are very grateful to the correspondents from 17 newly enlisted countries who performed pioneer work for us. Noteworthy is the fact that especially the Asian continent made a leap forward with contributions from 13 countries in 1986 to 19 in the present volume of "Horticultural Research International". At the secretariat we will continue to extend our network, so please feel free to send us any suggestions or additions you would like to make. For the first time we added a list of international organizations relevant to horticulture. In the editing process a further standardization has been used to reach an easily readable and comparable survey per country. Hopefully this directory will again facilitate cooperation on a worldwide scale among horticulturists active in governmental, academic, extensional, educational, technical or commercial fields.

A summary of the ecology of the world's vegetation. The introductory chapters provide a basic back-drop to the subject. The subsequent chapters examine sequentially the form and function of each major biome throughout the world.This book should be of interest to ecologists; biogeographers; botanists; environmental scientists; land managers; conservation biologists and natural resource managers.

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.

Plant reproductive biology has undergone a revolution during the past five years, with the cloning, sequencing and localization of the genes important in reproduction. These advantages in plant molecular biology have led to exciting applications in plant biotechnology, including the genetic engineering of male sterility and other reproductive processes. This book presents an interesting and contemporary account of these new developments from the scientists in whose laboratories they have been made. The chapters focus on two areas: the molecular biology of self-incompatibility, which is the system of self-recognition controlled by the S-gene and related genes; and the cellular and molecular biology of pollen development and genetic dissection of male sterility. Some chapters feature Arabidopsis, with its unique genetic system. Reproduction is vital for seed production in crop plants, and this book presents new approaches to manipulate plant breeding systems for the 21st century.

Higher eukaryotes are characterized by the allocation of distinct functions to numerous types of differentiated cells. Whereas in animals the well-defined, protected cells of the germ line separate early, germ cells in plants differentiate from somatic cells only after many cycles of mitotic division. Therefore somatic mutations in plants can be transmitted via the germ cells to the progeny. There is thus a clear need for somatic tissues to maintain their genetic integrity in the face of environmental challenges, and two types of interactions have been shown to play important roles in the conservation as well as flexibility of plant genomes: homologous recombination of repeated sequences and silencing of multiplied genes. Sensitive methods have been developed that allow greater insights into the dynamics of the genome. This book summarizes current knowledge and working hypotheses about the frequencies and mechanisms of mitochondrial, plastid, nuclear and viral recombination and the inactivation of repeated genes in plants. Despite rapid developments in the field, it is often not possible to provide final answers. Thus, it is an additional task of this book to define the open questions and future challenges. The book is addressed to scientists working on plant biology and recombination, to newcomers in the field and to advanced biology students.

Plant Cell and Tissue Culture gives an exhaustive account of plant cell culture and genetic transformation, including detailed chapters on all major field and plantation crops. Part A presents a comprehensive coverage of all necessary laboratory techniques for the initiation, nutrition, maintenance and storage of plant cell and tissue cultures, including discussions on these topics, as well as on morphogenesis and regeneration, meristem and shoot tip culture, plant protoplasts, mutant cell lines, variation in tissue cultures, isogenic lines, fertilization control, cryopreservation, transformation, and the production of secondary metabolites. Part B then proceeds into detail on the specific in vitro culture of specific crops, including cereals, legumes, vegetables, potatoes, other roots and tubers, oilseeds, temperate fruits, tropical fruits, plantation crops, forest trees and ornamentals. Plant Cell and Tissue Culture is, and is likely to remain, the laboratory manual of choice, as well as a source of inspiration and a guide to all workers in the field.

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."

The symposium on "Zinc in Soils and Plants" is the third in a series which began with "Copper in Soils and Plants" in Perth in 1981 and continued with "Manganese in Soils and Plants" in Adelaide in 1988. The symP9sium brings together a series of valuable accounts of many aspects of the reactions of zinc in soils, the uptake, transport and utilization of zinc in plants, the diagnosis and correction of zinc deficiency in plants and the role of zinc in animal and human nutrition. I am grateful for the financial support provided by Grains Research and Development Corporation, Rural Industries Research and Development Corporation, Wool Research and Development Corporation, Ansett Australia, and Qantas Australian. I am most appreciative of the willingness of many scientists to act as referees: G S P Ritchie, R J Gilkes, N C Uren, K Tiller, BLeach, H Greenway, N E Longnecker, J F Loneragan, Z Rengel, C A Atkins, J W Gartrell, P J Randall, D G Edwards, R J Hannam, R J Moir, J E Dreosti, N Suttle, C L White, H Marschner, N Wilhelm, M McBride. All provided valuable comments on the manuscripts. Finally, I thank Mrs M Davison who provided excellent secretarial assistance. A.D. Robson September 1993 Chapter 1.

Human activity is producing changes to our environment on an unprecedented global scale. Learning and understanding how plants respond to these changes will be crucial to our ability to feed human populations in the future. This book gives a broad coverage of the ways in which plants respond and adjust to environmental variables, and identifies unifying concepts spanning different levels of plant organization from the subcellular to the whole natural plant community. The 18 chapters were given as invited contributions at a meeting sponsored by the Rank Prize Funds in October 1992. The book will be of great interest and use to all plant scientists and upper level students concerned with the impact of the environment on plants.

This is an exciting period in plant biology as many disciplines, such as genetics and biochemistry, are merging to provide a more detailed understanding of plant growth and development. The purpose of this meeting was to provide a sampling of some of this exciting work in the area of cellular communication and signal transduction. R. M. Amasino vii CONTENTS Auxin-Binding Proteins and their Possible Role in Cell Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Alan M. Jones Signal Perception in Plants: Hepta-B-Glucoside Elicitor Binding Proteins in Soybean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Michael G. Hahn, Jong-Joo Cheong, Robert M. Alba, and Franfois Cote The Role of Salicylic Acid as a Plant Signal Molecule . . . . . . . . . . . . . . . . . . . . . . 15 Paul Silverman, Rebecca A. Linzer, and Ilya Raskin Blue-Light Regulated Gene Expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Lon S. Kaufman, Kathleen A. Marrs, Katherine M. F. Warpeha, Jie Gao, Keshab Bhattacharya, Judi TIlghman, and John F. Marsh III Role of the Maize Viviparous-l Gene in Regulation of Seed Maturation . . . . . . . . . 27 Donald R. McCarty Lovastatin Induces Cytokinin Dependence in Tobacco Cultures . . . . . . . . . . . . . . . . 37 Dring N. Crowell and Michael S. Salaz Molecular Genetic Approaches to Elucidating the Role of Hormones in Plant Development . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Harry Klee and Charles Romano Reversible Inhibition of Tomato Fruit Ripening by Antisense ACC Synthase RNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Athanasios Theologis, Paul W. Oeller and Lu Min-Wong Genetic Dissection of Signal Transduction Pathways that Regulate cab Gene Expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Joanne Chory, Lothar Altschmied, Hector Cabrera, Hsou-min Li, and Ronald Susek The Role of KNI in Plant Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The International Symposium on "Cellular and Molecular Aspects of Biosynthesis and Action of the Plant Hormone Ethylenc" ,vas held in Agen, France from August 31 st and September 4th, 1992. The planning and management of the scientific and social programme of the Conference were carried out jointly by the "Ethylene Research Group" of ENSAlIN"P (Toulouse) and Agropole Congres Service (Agen). Since the last meetings in Israel (1984) and in Belgium (1988), ethylene physiology has gone through a period of exciting progress due to new developments in cellular and molecular bioiogy. New methods and tools have been developed to better understand the role and functions of ethylene in fruit ripening, flower senescence, abscission, piant growth, and cell differentiation. Genes involved in ethylene biosynthesis have been characterized and transgenic plants with altered ethylene production have been generated. The feasibility of delaying fruit ripening or flower senescence by genetic manipulation is now demonstrated, thus opening new perspectives for the postharvest handling of plant products. Some progress has also been made on the understanding of ethylene action. However, much remains to be done in this area to elucidate the ethylene signal transduction pathway. Around 140 scientists from 20 countries attended the Symposium. They presented 47 oral reports and 40 poster demonstrations. All of them are published in these proceedings. It has been a pleasure for us to organize this important Symposium and to edit this book.

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 collection of papers on the anatomy, physiology and action of stomata by experts in the field, presented in a form suitable for students of botany and plant science, and related subjects such as agriculture, forestry, and horticulture, at the undergraduate and postgraduate level. Special care has been taken to ensure that the book can be used as a text for undergraduate courses in plant, environmental and cell physiology at a reasonably advanced level. It provides an up-to-date assessment of our knowledge of stomata and the articles include: the structure and development of stomata; the measurement of stomatal aperture and conductance; the ion exchanges and metabolism of guard cells; work on isolated guard-cell protoplasts; the responses of stomata to a wide range of stimuli, including light, carbon dioxide, humidity, water stress, pollutants and disease organisms; the behaviour of stomata in the field; and a discussion of stomatal control of transpiration and photosynthesis.

These volumes contain an excellent, up-to-date review of the rapidly developing field of photosynthesis research. They comprise the proceedings of the Ninth International Congress on Photosynthesis, held in Nagoya, Japan, in 1992, which was the first in the series to be held in Asia. The Congress was attended by over 1000 active participants from 43 countries, who contributed plenary lectures, symposium talks, posters and discussions. The volumes contain most of these contributions, in the form of review papers and short communications, assembled in 26 chapters, which cover a wide variety of subjects, such as: fundamental aspects, excitation energy transfer, primary reactions, bioenergetic processes, carbon metabolism, and its metabolic and genetic regulations; applied aspects, herbicides and artificial photosynthesis, and environmental aspects, photosynthesis under stress conditions and global climate change. Research in Photosynthesis is therefore an important document, containing the latest high-level information about photosynthesis in its broadest sense. The four volumes are a valuable reference source. Furthermore, the volumes are important for background study for those enetering this exciting and promising field of investigation.

From mulching to greenhouses, the air space between the cover and the soil surface is the key to the classification of climates under cover. The same mechanism governs environments produced by the various covers. This book describes and analyses all the different environments from mulching to greenhouses. The relationship between plants and environment is another important topic in the book. Stress is placed on the link between quantitative phenomena and qualitative analyses. Most phenomena involved are nonlinear and non-steady-state. An approach called System Dynamics is used, and simulation models developed in the simulation language CSMP are fully used. The subjects covered are of relevance to graduate students, to scientists and researchers in agriculture and biological sciences and, of course, to agricultural organizations in both the developing and developed countries.

The majority of the world's people depend research work should be carried out at the local and regional level by locally trained on plants for their livelihood since they grow them for food, fuel, timber, fodder and people. many other uses. A good understanding Following the success of our earlier book of the practical factors which govern the (Techniques in Bioproductivity and Photo synthesis; Pergamon Press, 1985), which productivity of plants through the process of photosynthesis is therefore of paramount was translated into four major languages, importance, especially in the light of cur the editors and contributors have exten rent concern about global climate change sively revised the content and widened the and the response of both crops and natural scope of the text, . so it now bears a title ecosystems. in line with current concern over global The origins of this book lie in a series of climate change. . In particular, we have training courses sponsored by the United added chapters on remote sensing, con Nations Environment Programme (Project trolled-environment studies, chlorophyll No. FP/6108-88-0l (2855); 'Environment fluorescence, metabolite partitioning and changes and the productivity of tropical the use of mass isotopes, all of which grasslands'), with additional support from techniques are increasing in their applica many international and national agencies. tion and importance to this subject 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."

Tropical climates, which occur between 23 Degrees30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.

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.

Life on earth depends on the photosynthetic use of solar energy by plants, and efforts to develop alternative sources of energy include a major thrust toward the use of photosynthesis to yield fuels. The study of photosynthesis is an especially convincing way of bringing together the disciplines of physics, chemistry, and biology and can be a valuable element in the teaching of biophysics and biochemistry. This book provides the only detailed modern treatment of the subject in a concise form. Part I outlines the historical development of the subject, emphasizing the chemical nature of photosynthesis and the roles of chlorophylls and other pigments. Part II reviews our present knowledge of the structure and components of photosynthetic tissues in relation to their function. Part III deals with the photo-chemistry of photosynthesis and with the patterns of chemical events, principally electron and proton transfer, that follow the photo-chemistry. Part IV treats the relationships of electron and proton transport to ATP formation, and the metabolic patterns of carbon assimilation. An epilogue exposes major areas of confusion and ignorance and indicates potentially fruitful directions of research, including the development of photosynthetic systems for solar energy conversion. Throughout the book, there are frequent digressions into those aspects of optics and molecular physics relevant to the subject matter. Suitable for upper undergraduate and graduate course use, this book is also sufficiently detailed to give professional scientists a perspective of the subject at the level of contemporary research.