The Rhizobiaceae

The Rhizobiaceae, Molecular Biology of Model Plant-Associated Bacteria. This book gives a comprehensive overview on our present molecular biological knowledge about the Rhizobiaceae, which currently can be called the best-studied family of soil bacteria. For many centuries they have attracted the attention of scientists because of their capacity to associate with plants and as a consequence also to specifically modify plant development. Some of these associations are beneficial for the plant, as is the case for the Rhizobiaceae subgroups collectively called rhizobia, which are able to fix nitrogen in a symbiosis with the plant hosts. This symbiosis results in the fonnation of root or stem nodules, as illustrated on the front cover. In contrast, several Rhizobiaceae subgroups can negatively affect plant development and evoke plant diseases. Examples are Agrobacterium tumefaciens andA. rhizogenes which induce the formation of crown galls or hairy roots on the stems of their host plants, respectively (bottom panels on front cover). In addition to the obvious importance of studies on the Rhizobiaceae for agronomy, this research field has resulted in the discovery of many fundamental scientific principles of general interest, which are highlighted in this book. To mention three examples: (i) the discovery of DNA transfer of A.

Biology of the Rhizobiaceae covers the genetics, molecular biology, agricultural, and morphological aspects of the rhizobia. The book discusses the taxonomy and identification of the Rhizobiaceae; the biology of Agrobacterium tumefaciens and the specific events in the disease cycle of crown gall; and the agricultural control of Agrobacterium tumefaciens. The text also describes the growth potential of crown gall tumors and crown gall teratoma; plasmid studies in crown gall tumorigenesis; and the biology and microbiology of Agrobacterium rhizogenes. The recognition in rhizobium-legume symbioses; the rhizobium bacteroid state; and the exchange of metabolites and energy between legume and rhizobium are also considered. The book further tackles the mutants of rhizobium that are altered in legume interaction and nitrogen fixation; as well as the significance and application of Rhizobium in agriculture. Botanists, agriculturists, geneticists, molecular biologists, microbiologists, plant pathologists, and agronomists will find the book invaluable.

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.

This book provides in-depth reviews of the role of Rhizobium in agriculture and its biotechnological applications. Individual chapters explore topics such as: the occurrence and distribution of Rhizobium; phenotypic and molecular characteristics of Rhizobium; impact of Rhizobium on other microbial communities in the rhizosphere; N2-fixation ability of Rhizobium; Rhizobium and biotic stress; Rhizobium-mediated restoration of an ecosystem; in silico analysis of the rhizobia pool; further biotechnological perspectives of Rhizobium.

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.

Advances in Rhizobiaceae Research and Application: 2011 Edition is a ScholarlyPaper™ that delivers timely, authoritative, and intensively focused information about Rhizobiaceae in a compact format. The editors have built Advances in Rhizobiaceae Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Rhizobiaceae in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Advances in Rhizobiaceae Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

This book reviews the history and development of rhizobial ecology (diversity, function and interactions with the biotic and abiotic environments), evolution (genome diversification, systematics of symbiotic genes) and application. Further, it describes the new concept of rhizobia, the latest systematic methods, biogeographic study methods, and genomic studies to identify the interactions between rhizobia, legumes and environments. To enable readers to gain a comprehensive understanding of rhizobial biogeography, the book provides effective protocols for the selection and application of high-efficiency rhizobial inoculants. In addition, it presents standard and modern methods used in studies on rhizobial ecology and evolution in dedicated appendices, making it a unique and valuable handbook for researchers.

Rhizobia are composed of specific groups of bacteria that have the ability to induce symbiotic nitrogen-fixing nodules on the roots or stems of leguminous plants. Rhizobia have attracted a great attention for more than 4 decades because of their enormous agricultural and economic value in sustainable agriculture. Up to the present time, many legumes have been found to be nodulated by several rhizobial species in diverse taxonomic groups. An assessment of rhizobial diversity provides pivotal information in understanding the horizontal gene transfer among bacterial genera and species, the bacterial evolution and the symbiotic effectiveness. the classification of rhizobia is becoming increasingly complex and is revised periodically because of new findings that propose new genera and new species. Phenotypic and Genotypic Diversity of Rhizobia presents the application of conventional and molecular analyses, including numerical analysis, enzyme patterns, serological studies, plasmid profile, polymerase chain reaction (PCR)-fingerprinting, amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), PCR-RFLP and sequence-based methods, to the examination of rhizobial diversity. Principles of these techniques, the resolving power, the advantage and the limitation of these techniques are evaluated. Current taxonomy of rhizobia classifies them into 17 genera and 118 species. The book explains background knowledge about rhizobia and follows this up with a broad perspective on rhizobial diversity, information on characteristics specific to each group of rhizobia, the relationship among rhizobial groups as well as genetic factors contributed to rhizobial diversity. Contemporary methods for examination of rhizobial diversity are also suggested and discussed. Readers of this e-book will find updated information on key concepts in classification and taxonomy of rhizobia, the categories and techniques used to examine the phenotypic and genotypic diversity of rhizobia (including numerical analysis, enzyme patterns, serological study, plasmid profile, polymerase chain reaction (PCR)-fingerprinting, amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), PCR-RFLP and sequence analysis).