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.
Autorentext
Dr. Wen Xin Chen, Dr. Wen Feng Chen and Dr. Chang Fu Tian currently work at the College of Biological Sciences and Rhizobium Research Center, China Agricultural University. Dr. Wen Xin Chen was elected into the Chinese Academy of Sciences in 2001. Dr. Wen Xin Chen and Dr. Chang Fu Tian are members of the ICSP Subcommittee on the Taxonomy of Rhizobia and Agrobacteria.
Dr. En Tao Wang works at the Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico.
Dr. J Peter W Young is an Emeritus Professor of Molecular Ecology at the University of York. He is the Chairman of the ICSP Subcommittee on the Taxonomy of Rhizobia and Agrobacteria.
Inhalt
Preface
Wen Xin Chen
Unit 1. General description of rhizobia
En Tao Wang
Chapter 1. Symbiosis between rhizobia and legumes
Section 1. Symbiosis of rhizobia and legumes
Rhizobia
Rhizobia-legume symbiosis
Section 2. Importance of rhizobia and rhizobial research
History of rhizobial studies
Ecological and economic importance of rhizobia
Model of microbe-plant interaction
Concluding remarks and perspectivesReferences
Unit 2. Diversity and evolution of rhizobia
En Tao Wang, Chang Fu Tian, and J. Peter W. Young
Chapter 2. History of rhizobial taxonomy
Section 1. Bacterial diversity and taxonomy
Classification, identification and nomenclature.
Section 2. History of studies on rhizobial diversity and taxonomy
Cross-nodulation groups
Numerical taxonomy
DNA/DNA hybridization
Polyphasic taxonomyChapter 3. Current Systematics of rhizobia
Section 1. Current methodology for studying diversity and taxonomy
Sampling strategies: how many strains to sample
Recommended genes for studying phylogeny and genomic diversity
Current criteria for identification and description of novel species
Section 2. Phylogeny and systematics of rhizobia.
Section 3. Alpha-rhizobia.
Section 4. Beta-rhizobia.
Chapter 4. Genomics and evolution of rhizobia
Section 1. The general organization of rhizobial genomes.Replicons: chromosome, chromid, and plasmid.
Symbiosis plasmid and symbiosis island.
Section 2. Evolution of core and accessory genes.
Characteristics of core and accessory genes.
Main evolutionary forces shaping the diversity of core and accessory genes.
Concluding remarks and perspectives
References
Unit 3. Diversity and evolution of rhizobial symbiosis genes
Chang Fu Tian, Wen Feng Chen, and J. Peter W. Young
Chapter 5. Symbiosis genes: diversity and organizationSection 1. Pathways of diverse functions involved in symbiosis.
Key symbiosis genes: nodulation and nitrogen fixation genes, nod-independent rhizobia.
Symbiosis related functions: exopolysaccharides, secretion systems, and others.
Section 2. The organization of symbiosis related genes.
The distribution of symbiosis related genes in rhizobial genomes.
Chapter 6. Evolution of symbiosis genes: Vertical and horizontal gene transfer
Section 1. Interaction between the symbiosis genes and the core genome
Section 2. Horizontal transfer of symbiosis genes and their integration into the core genomeChapter 7. Diversity of interactions between rhizobia and legumes
Section 1. Rhizobia with wide host ranges.
NGR 234, etc.
Section 2. Rhizobia associated with symbiotically specific plants.
Alfalfa, chickpea, Amorpha, etc.
Section 3. Rhizobia associated with promiscuous plants.
Soybean, Sophora, common bean, peanut.
Section 4. Rhizobial infection through root hair or crack.
Section 5. Determinate or indeterminate root nodules.
Section 6. Swollen or non-swollen bacteroids.
Concluding remarks and perspectives
References
Unit 4. Interaction of rhizobia, environments and legumes
Wen Feng Chen, and Chang Fu Tian
Chapter 8. Geographical distribution of rhizobia
Section 1. Biogeography of rhizobial species.
Specific focus on soybean, Caragana, Astragalus, broad bean, peanut, Sophora, Phaseolus vulgaris.
Section 2. Biogeography of rhizobial populations
Alfalfa rhizobia, soybean rhizobiaC...