During the past three decades there has been a large amount of research on biological nitrogen fixation, in part stimulated by increasing world prices of nitrogen-containing fertilizers and environmental concerns. In the last several years, research on plant--microbe interactions, and symbiotic and asymbiotic nitrogen fixation has become truly interdisciplinary in nature, stimulated to some degree by the use of modern genetic techniques. These methodologies have allowed us to make detailed analyses of plant and bacterial genes involved in symbiotic processes and to follow the growth and persistence of the root-nodule bacteria and free-living nitrogen-fixing bacteria in soils. Through the efforts of a large number of researchers we now have a better understanding of the ecology of rhizobia, environmental parameters affecting the infection and nodulation process, the nature of specificity, the biochemistry of host plants and microsymbionts, and chemical signalling between symbiotic partners. This volume gives a summary of current research efforts and knowledge in the field of biological nitrogen fixation. Since the research field is diverse in nature, this book presents a collection of papers in the major research area of physiology and metabolism, genetics, evolution, taxonomy, ecology, and international programs.

This important book provides a comprehensive review of our current knowledge of the world's leguminous plants and their symbiotic bacteria. Written by Professor Janet Sprent, a world authority in the area, Legume Nodulation contains comprehensive details of the following: An up to date review of legume taxonomy and a full list of the world's genera Details of how legumes are distributed throughout the world A review of the evolution of legume nodulation Comprehensive details of all microorganisms known to be symbiotic with legumes Ecological and environmental aspects of legume-bacteria symbiosis Legume Nodulation is an essential purchase for plant scientists, agronomists, ecologists and microbiologists. Libraries in all universities and research establishments where biological and agricultural sciences are studied and taught should have copies of this landmark publication.

General information on the symbiotic nitrogen fixation. Isolation, identification and counting of rhizobia. Production of an inoculant and inoculation of legumes. Experiments.

"The aim of this book is to provide an up-to-date picture of the nodulation status of legumes, using largely the same taxonomic system as its companion volume 'Legumes of the World'."--Back cover.

Plants and animals have evolved ever since their appearance in a largely microbial world. Their own cells are less numerous than the microorganisms that they host and with whom they interact closely. The study of these interactions, termed microbial symbioses, has benefited from the development of new conceptual and technical tools. We are gaining an increasing understanding of the functioning, evolution and central importance of symbiosis in the biosphere. Since the origin of eukaryotic cells, microscopic organisms of our planet have integrated our very existence into their ways of life. The interaction between host and symbiont brings into question the notion of the individual and the traditional representation of the evolution of species, and the manipulation of symbioses facilitates fascinating new perspectives in biotechnology and health. Recent discoveries show that association is one of the main properties of organisms, making a more integrated view of biology necessary. Microbial Symbioses provides a deliberately "symbiocentric outlook, to exhibit how the exploration of microbial symbioses enriches our understanding of life, and the potential future for this discipline. - Offers a concise summary of the most recent discoveries in the field - Shows how symbiosis is acquiring a central role in the biology of the 21st century by transforming our understanding of living things - Presents scientific issues, but also societal and economic related issues (biodiversity, biotechnology) through examples from all branches of the tree of life

Rhizobia are bacteria which inhabit the roots of plants in the pea family and "fix" atmospheric nitrogen for plant growth. They are thus of enormous economic importance internationally and the subject of intense research interest. Handbook for Rhizobia is a monumental book of practical methods for working with these bacteria and their plant hosts. Topics include the general microbiological properties of rhizobia and their identification, their potential as symbionts, methods for inoculating rhizobia onto plants, and molecular genetics methods for Rhizobium in the laboratory. The book will be invaluable to Rhizobium scientists, soil microbiologists, field and laboratory researchers at agricultural research centers, agronomists, and crop scientists.

In the 100 years since the legume-Rhizobium symbiotic nitrogen fixation interaction was first described, interest in this field has grown rapidly. The types of studies have been cyclical in nature, involving a cross-section of disciplines. The availability of cheap nitrogenous fertilizers caused much of the biological nitrogen fixation research to become more theoretical in the developed world. The high cost of energy, coupled with environmental concerns and the interest in sustainable agriculture, has stimulated research in symbiotic nitrogen fixation. The development of modern genetic techniques has resulted in interdisciplinary research on plant-microbe interactions controlling nitrogen fixation. This has resulted in a better understanding of environmental factors influencing the nodulation process, chemical signalling between the symbiotic partners and the nature of the specificity between host plant and microsymbiotant. This volume summarizes the diverse research efforts in biological nitrogen fixation by presenting a collection of papers in the areas of physiology and metabolism, taxonomy and evolution, genetics and ecology.

Nodules produced on legume roots by root-nodule bacteria provide the major nitrogenous input into natural and agricultural systems worldwide. This book provides an in-depth and up-to-the-minute analysis of what is known about this symbiosis, its origins, the process of nodule formation and development, and the biochemistry and genetics of nodular nitrogen fixation. It also reviews the physiology of the root-nodule bacteria themselves, their ecology in both natural and agricultural systems, and how we can introduce new legumes along with the bacteria they require. This book is recommended for scientists working with root nodule bacteria or host legumes, agronomists, forestry scientists, and soil scientists.

Phylogenetic classification of nitrogen-fixing organisms. Physiology of nitrogen fixation in free-living heterotrophs. Nitrogen fixation by photosynthetic bacteria. Nitrogen fixation in cyanobacteria. Nitrogen fixation by methanogenic bacteria. Associative nitrogen-fixing bacteria. Actinorhizal symbioses. Ecology of bradyrhizobium and rhizobium. The rhizobium infection process. Physiology of nitrogen-fixing legume nodules: compartments, and functions. Hydrogen cycling in symbiotic bacteria. Evolution of nitrogen-fixing symbioses. The rhizobium symbiosis of the nonlegume parasponia. Genetic analysis of rhizobium nodulation. Nodulins in root nodule development. Plant genetics of symbiotic nitrogen fixation. Molecular genetics of bradyrhizobium symbioses. The enzymology of molybdenum-dependent nitrogen fixation. Alternative nitrogen fixation systems. Biochemical genetics of nitrogenase. Regulation of nitrogen fixation genes in free-living and symbiotic bacteria. Isolated iron-molybdenum cofactor of nitrogenase.

Biological nitrogen fixation has essential role in N cycle in global ecosystem. Several types of nitrogen fixing bacteria are recognized: the free-living bacteria in soil or water; symbiotic bacteria making root nodules in legumes or non-legumes; associative nitrogen fixing bacteria that resides outside the plant roots and provides fixed nitrogen to the plants; endophytic nitrogen fixing bacteria living in the roots, stems and leaves of plants. In this book there are 11 chapters related to biological nitrogen fixation, regulation of legume-rhizobium symbiosis, and agriculture and ecology of biological nitrogen fixation, including new models for autoregulation of nodulation in legumes, endophytic nitrogen fixation in sugarcane or forest trees, etc. Hopefully, this book will contribute to biological, ecological, and agricultural sciences.