Witzany Biocommunication in Soil Microorganisms

1. Auflage 2010
ISBN: 978-3-642-14512-4
Verlag: Springer
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 476 Seiten

Communication is defined as an interaction between at least two living agents which share a repertoire of signs. These are combined according to syntactic, semantic and context-dependent, pragmatic rules in order to coordinate behavior. This volume deals with the important roles of soil bacteria in parasitic and symbiotic interactions with viruses, plants, animals and fungi. Starting with a general overview of the key levels of communication between bacteria, further reviews examine the various aspects of intracellular as well as intercellular biocommunication between soil microorganisms. This includes the various levels of biocommunication between phages and bacteria, between soil algae and bacteria, and between bacteria, fungi and plants in the rhizosphere, the role of plasmids and transposons, horizontal gene transfer, quorum sensing and quorum quenching, bacterial-host cohabitation, phage-mediated genetic exchange and soil viral ecology.

Autoren/Hrsg.

Witzany, Günther

Inhaltsverzeichnis

1;Preface;6
1.1;Why Biocommunication of Soil Microorganisms?;6
1.1.1;On the Interorganismic Level (Between Same and Related Organisms);8
1.1.2;On the Intraorganismic Level;9
1.1.3;In Vitro Analyses Lack Context-Dependent Behaviors of Real Life Habitats;11
1.1.4;Biocommunication of Soil Microorganisms;11
1.1.5;Contributions to the biocommunication of soil microorganisms;12
1.2;References;13
2;Contents;14
3;Contributors;18
4;Chapter 1: Introduction: Key Levels of Biocommunication of Bacteria;22
4.1;1.1 Introduction: Communicative Competences of Bacteria;22
4.2;1.2 Semiochemical Vocabulary and Communicative Goals of Bacteria;24
4.3;1.3 Transorganismic Communication of Soil Bacteria;25
4.4;1.4 Interorganismic Communication;26
4.4.1;1.4.1 Interpretation and Coordination;27
4.5;1.5 Intraorganismic Communication;30
4.5.1;1.5.1 Intracellular Communication;32
4.5.2;1.5.2 Bacterial Evolution and the Agents of Natural Genome Editing;33
4.5.3;1.5.3 Lytic vs. Persistent Viral Life Strategies;33
4.5.4;1.5.4 Bacteria as Global Habitat for Viruses;35
4.6;1.6 The Origins of Bacterial Group Identity;37
4.6.1;1.6.1 Obligate Viral Settlers of Bacteria;37
4.6.2;1.6.2 The Role of Persistent Viruses in Gene Word Order of Bacteria;39
4.6.3;1.6.3 Infection-Driven Group Identity and Group Immunity;40
4.7;1.7 Transfer of Viral Competences as Modular Tools;41
4.7.1;1.7.1 Molecular Identity Markers;41
4.7.2;1.7.2 Persistent Phages Determine Bacterial Identity;41
4.7.3;1.7.3 Addiction Modules Function as Counterbalanced Viral Competences;43
4.7.4;1.7.4 The Persistent Viral Lifestyle of Plasmids and the Role of tRNAs;44
4.8;1.8 Swarming Group Behavior and Group Identity;45
4.9;1.9 Genetic Content Operators and Viral Gene Factories;47
4.10;1.10 Conclusion;48
4.11;References;48
5;Part I: Intracellular Biocommunication;56
5.1;Chapter 2: Communication Among Phages, Bacteria, and Soil Environments;57
5.1.1;2.1 Introduction;57
5.1.2;2.2 General Concepts;58
5.1.2.1;2.2.1 Microbe-Containing Environments;58
5.1.2.2;2.2.2 Communication and Microorganisms;61
5.1.2.3;2.2.3 Bacteriophages, Bacteria, and Environments;62
5.1.3;2.3 Pathways of Communication in Soil;64
5.1.3.1;2.3.1 Bacteria-to-Phage Communication;65
5.1.3.1.1;2.3.1.1 Bacterial Impact on Phage Phenotype;65
5.1.3.1.1.1;Destructive Infection: Antagonism, Deception, and Primitive Immunity;65
5.1.3.1.1.2;Reductive Infection: Sleeping with the Enemy;66
5.1.3.1.2;2.3.1.2 Bacterial Impact on Phage Genotype (Evolution);66
5.1.3.1.3;2.3.1.3 Bacterial Impact on Phage Location;67
5.1.3.2;2.3.2 Phage-to-Bacteria Communication;68
5.1.3.2.1;2.3.2.1 The Many Costs of Phage;68
5.1.3.2.2;2.3.2.2 Phage Infection as Symbiosis;68
5.1.3.2.3;2.3.2.3 Phage-Mediated Horizontal Gene Transfer (Transduction);70
5.1.3.2.4;2.3.2.4 Kill the Winner;70
5.1.3.3;2.3.3 Phage-to-Bacteria-to-Environment Communication;73
5.1.3.3.1;2.3.3.1 Lysis-Mediated Phage-Environment Communication;73
5.1.3.3.2;2.3.3.2 Prophage-Mediated Environmental Modification;74
5.1.3.4;2.3.4 Phage-to-Environment Communication;75
5.1.3.5;2.3.5 Environment-to-Phage and/or to-Bacteria Communication;75
5.1.3.6;2.3.6 Environment-to-Phage Communication;77
5.1.3.6.1;2.3.6.1 Predation of Phages;77
5.1.3.6.2;2.3.6.2 Phage Movement;77
5.1.3.6.3;2.3.6.3 Phage Survival;78
5.1.4;2.4 Conclusion;79
5.1.5;References;79
5.2;Chapter 3: Soil Bacteria and Bacteriophages;86
5.2.1;3.1 Soil Bacteria Types, Characteristics, Prevalence, Genetic Diversity, and Source;86
5.2.1.1;3.1.1 Soil (General);86
5.2.1.1.1;3.1.1.1 Soil Bacteria Characteristics, Prevalence, Genetic Diversity, and Source;86
5.2.1.2;3.1.2 Soil Bacteria (Pathogens, Phytopathogens) and Nonpathogenic;94
5.2.1.2.1;3.1.2.1 Human Pathogens;94
5.2.1.2.2;3.1.2.2 Phytopathogens;95
5.2.1.2.3;3.1.2.3 Nonpathogenic Bacteria;96
5.2.1.3;3.1.3 Bacteriophages (Abbr. Phages) (Systematics, Life Cycle, and Genetics);97
5.2.1.3.1;3.1.3.1 Phages Systematic;97
5.2.1.3.2;3.1.3.2 Phages Life Cycles;101
5.2.1.3.3;3.1.3.3 Phages Genetic;103
5.2.1.4;3.1.4 Interaction Between Phages and Soil-Bacteria;104
5.2.1.5;3.1.5 Mutual Effect of Microbial Activity in Soil and Effect on Bacteriophages;107
5.2.1.6;3.1.6 Genetic Transfer Involving Bacteriophages and Bacteria in Soil Environment;112
5.2.1.7;3.1.7 Bacteriophage Transport in the Subsurface and Soil Bacteria;114
5.2.1.8;3.1.8 Discussion, Remarks and Thoughts;118
5.2.2;References;121
5.3;Chapter 4: Soil Phage Ecology: Abundance, Distribution, and Interactions with Bacterial Hosts;132
5.3.1;4.1 Introduction;132
5.3.2;4.2 Measuring Viral Abundance in Soils;133
5.3.2.1;4.2.1 Targeted Assays;133
5.3.2.2;4.2.2 Total Direct Counts of Viruses in Soil;134
5.3.3;4.3 Trends in Soil Viral Abundance and Distribution;135
5.3.4;4.4 The Virus-to-Bacterium Ratio;138
5.3.5;4.5 Viral Diversity in Soil Ecosystems;140
5.3.5.1;4.5.1 Marker Genes;140
5.3.5.2;4.5.2 Pulsed-Field Gel Electrophoresis;141
5.3.5.3;4.5.3 Randomly Amplified Polymorphic DNA-PCR;141
5.3.5.4;4.5.4 Transmission Electron Microscopy;142
5.3.5.5;4.5.5 Metagenomic Analysis of Soil Viral Assemblages;143
5.3.6;4.6 The Importance of Lysogeny in Soil Environments;144
5.3.7;4.7 Viral Impacts in Soil Ecosystems;145
5.3.7.1;4.7.1 Bacterial Mortality, Clonal Diversity, and Community Succession;145
5.3.7.2;4.7.2 Phage Conversion, Host Fitness, and Horizontal Gene Transfer;147
5.3.8;4.8 Conclusion;148
5.3.9;References;149
5.4;Chapter 5: Identification and Analysis of Prophages and Phage Remnants in Soil Bacteria;156
5.4.1;5.1 Introduction;156
5.4.1.1;5.1.1 Overview of Soil Microbes;156
5.4.1.2;5.1.2 Horizontal Gene Transfer in Bacteria;157
5.4.1.3;5.1.3 Significance of Prophages;158
5.4.1.4;5.1.4 Prophages and Associated Fitness Islands;159
5.4.2;5.2 Soil Prophage Genomics;160
5.4.2.1;5.2.1 Prophage Existence in Soil Bacteria;160
5.4.2.1.1;5.2.1.1 Prophages Detected by Protein Similarity Approach;160
5.4.2.1.2;5.2.1.2 Prophages Detected by DRAD;165
5.4.2.1.3;5.2.1.3 Prophages Reported by Other Methods Compared with PSA and DRAD;170
5.4.2.2;5.2.2 Impact of Prophages in Soil Bacteria;172
5.4.2.2.1;5.2.2.1 Organization of Prophages in Selected Soil Bacteria;172
5.4.2.2.2;5.2.2.2 Prophage Encoded Gene Clusters in Soil Bacteria;173
5.4.3;5.3 Summary and Conclusions;175
5.4.4;References;176
5.5;Chapter 6: Back to the Soil: Retroviruses and Transposons;180
5.5.1;6.1 Soil Bacteria and Associated Retroelements;180
5.5.1.1;6.1.1 Insertion Sequences;181
5.5.1.2;6.1.2 Beneficial Effects of Horizontal Transfer of Genes;182
5.5.1.3;6.1.3 Abundance of Transposons in Soil Bacteria;183
5.5.2;6.2 Origin of Transposons;185
5.5.2.1;6.2.1 Single Stranded RNA to Double-Stranded Nucleic Acid;185
5.5.2.2;6.2.2 Pretransposons and Archea;186
5.5.2.3;6.2.3 Birth of Intracellular or Molecular Immunity;187
5.5.2.4;6.2.4 Self vs. Nonself and REs;188
5.5.3;6.3 Endogenous Retroviruses from Soil to Mammals: Protective Lessons;189
5.5.4;6.4 Innate Immunity and Development of Immunity Based on Pattern Recognition;191
5.5.5;6.5 Evolution of Antitransposon Resistance in Bacteria to Large Mammals;192
5.5.6;6.6 The Big Bang of Immunity;197
5.5.6.1;6.6.1 Adaptive Immunity and TEs;197
5.5.6.2;6.6.2 Generation of Deversity and Somatic Recombination;198
5.5.6.3;6.6.3 RAG1/RAG2 Dilemma;199
5.5.6.4;6.6.4 Classical Immunity Barrowed Its Model from Molecular Immunity;200
5.5.7;6.7 Summary and Conclusion;201
5.5.8;Appendix;202
5.5.9;References;203
5.6;Chapter 7: Ubiquitous Bacteriophage Hosts in Rice Paddy Soil;207
5.6.1;7.1 Introduction;207
5.6.2;7.2 Abundance and Morphology of Viruses in the Floodwater;208
5.6.3;7.3 Abundance of Bacteriophages of Common Heterotrophic Bacteria in the Floodwater;210
5.6.4;7.4 Morphology and Host Range of Sphingomonas/Novosphingobium Phages;212
5.6.5;7.5 Frequency of Phage-Infected Bacterial Cells in the Floodwater;215
5.6.6;7.6 Comparison of Lysogeny Between Copiotrophic and Oligotrophic Bacteria;217
5.6.7;7.7 Characteristics and Diversity of Phages in Rice Field Soils - Estimation by g23 Gene Sequences of T4-Type Phages;221
5.6.8;7.8 Changes in Major Capsid Genes (g23) of T4-Type Bacteriophages with Soil Depth;225
5.6.9;7.9 Conclusions;228
5.6.10;References;229
5.7;Chapter 8: Phage Biopesticides and Soil Bacteria: Multilayered and Complex Interactions;232
5.7.1;8.1 Phages as Biopesticides;232
5.7.1.1;8.1.1 Aerial Application of Phage Biopesticides and Impact on Soil Ecology;233
5.7.2;8.2 Phage Biopesticides in Greenhouse Soils: Control of Pectobacterium carotovorum;234
5.7.3;8.3 Phages and Rhizobacteria;235
5.7.3.1;8.3.1 Effect of Soil on Phages;236
5.7.3.2;8.3.2 Phages in the Rhizosphere;237
5.7.3.3;8.3.3 Effect of Phages on Root Nodulation;238
5.7.3.4;8.3.4 Effect of Phages on Yield and Disease Control;238
5.7.4;8.4 Lysogeny and Soil-Phage Interaction;239
5.7.4.1;8.4.1 Lysogeny as a Bacteriophage Survival Mechanism;239
5.7.4.2;8.4.2 Phage Gene Transfer in Soil;240
5.7.5;8.5 Detection of Phages in Soil Systems;241
5.7.5.1;8.5.1 Isolation of Phage Particles;242
5.7.5.1.1;8.5.1.1 Enrichment Methods;242
5.7.5.1.2;8.5.1.2 Elution Methods;243
5.7.5.2;8.5.2 Direct Detection by Microscopy;244
5.7.5.3;8.5.3 Direct Detection of Biopesticides by Molecular Methods;244
5.7.6;8.6 Summary;246
5.7.7;References;247
5.8;Chapter 9: Interactions Between Bacteriophage DinoHI and a Network of Integrated Elements Which Control Virulence in Dichelobacter nodosus, the Causative Agent of Ovine Footrot;253
5.8.1;9.1 Introduction;253
5.8.2;9.2 Transmission of Ovine Footrot;253
5.8.2.1;9.2.1 Virulence of D. nodosus;254
5.8.3;9.3 Mobile Genetic Elements in the D. nodosus Genome;254
5.8.3.1;9.3.1 The intA Element;255
5.8.3.2;9.3.2 The intB Element;255
5.8.3.3;9.3.3 The intC Element;256
5.8.3.4;9.3.4 The intD Element;257
5.8.3.5;9.3.5 The Virulence-Related Locus, vrl;257
5.8.3.6;9.3.6 The Bacteriophage DinoHI;258
5.8.3.7;9.3.7 Element X;258
5.8.4;9.4 A Model for the Control of Virulence by Integrated Genetic Elements;258
5.8.4.1;9.4.1 CsrA;258
5.8.4.2;9.4.2 PnpA;260
5.8.4.3;9.4.3 10Sa RNA;260
5.8.4.4;9.4.4 Model for Virulence;260
5.8.5;9.5 Different Forms of the intA Element;261
5.8.6;9.6 Interactions Between the Integrated Genetic Elements;262
5.8.6.1;9.6.1 vapGH and Bacteriophage Immunity;262
5.8.6.2;9.6.2 A Repressor Gene Common to Bacteriophage DinoHI and the intB Element;264
5.8.6.3;9.6.3 Interactions Between the vrl, DinoHI and the intA Element;265
5.8.6.4;9.6.4 Mobilisation of the intA Element by the intD Mobilisation Cassette;265
5.8.6.5;9.6.5 Common Repeated Sequences on the intA and intD Elements;266
5.8.6.6;9.6.6 Relationships Between the intC and intD Elements;266
5.8.7;9.7 Evolutionary Significance;266
5.8.8;9.8 Conclusions;267
5.8.9;References;267
5.9;Chapter 10: Gene Network Holography of the Soil Bacterium Bacillus subtilis;270
5.9.1;10.1 Introduction;270
5.9.2;10.2 Functional Holography Analysis of Gene Expression;272
5.9.2.1;10.2.1 Holographic Presentation of the Genes;272
5.9.2.2;10.2.2 Internal Structure of Gene Operons;273
5.9.3;10.3 Minimal Spanning Tree Analysis;276
5.9.4;10.4 Time Progression of the Sporulation and Competence Networks;278
5.9.4.1;10.4.1 Time Progress of Sporulation Initiation Gene Network;279
5.9.4.2;10.4.2 Time Progress of Competence Gene Network Response;282
5.9.5;10.5 Time Progress of Cannibalism Gene Network;285
5.9.6;10.6 Discussion;291
5.9.7;References;293
5.10;Chapter 11: Population and Comparative Genomics Inform Our Understanding of Bacterial Species Diversity in the Soil;297
5.10.1;11.1 Introduction;297
5.10.2;11.2 Species Classification by 16s rRNA Comparison;298
5.10.3;11.3 Whole Genome Comparisons Aid Species Classification;299
5.10.4;11.4 Analyses by Genome-Tree Building;300
5.10.5;11.5 The Core Genome Hypothesis;301
5.10.6;11.6 Conclusion;303
5.10.7;References;304
6;Part II: Intercellular and Trans-Kingdom Biocommunication;307
6.1;Chapter 12: Plasmids of the Rhizobiaceae and Their Role in Interbacterial and Transkingdom Interactions;308
6.1.1;12.1 Introduction;308
6.1.2;12.2 Pathogenic Members of the Rhizobiaceae: Agrobacteria;309
6.1.2.1;12.2.1 Agrobacterium and Plant Hypertrophies;309
6.1.2.2;12.2.2 Ti and Ri Plasmids;312
6.1.2.3;12.2.3 Interbacterial and Host-Bacterial Signaling;316
6.1.2.4;12.2.4 Agrobacterial Genomes;320
6.1.3;12.3 Symbiotic Members of the Rhizobiaceae: Rhizobia;322
6.1.3.1;12.3.1 Rhizobia, Legumes, and Nitrogen Fixation;322
6.1.3.2;12.3.2 Nodules and the Nodulation Process;324
6.1.3.3;12.3.3 Rhizobial Genomes;326
6.1.3.4;12.3.4 Horizontal Transfer and Quorum Sensing;331
6.1.3.5;12.3.5 Genome Plasticity in Alpha-Rhizobia;334
6.1.4;12.4 Conclusions;335
6.1.5;References;338
6.2;Chapter 13: Quorum Sensing and Quorum Quenching in Soil Ecosystems;351
6.2.1;13.1 Introduction;352
6.2.1.1;13.1.1 Quorum Sensing;352
6.2.1.1.1;13.1.1.1 A Brief History;352
6.2.1.1.2;13.1.1.2 Multiple Systems, Multiple Signals;353
6.2.1.2;13.1.2 Quorum Quenching;357
6.2.2;13.2 Biological Significance of QQ;358
6.2.2.1;13.2.1 Known Organisms and Activities Involved in AHL Signal Degradation;358
6.2.2.1.1;13.2.1.1 Oxidase and Reductase;359
6.2.2.1.2;13.2.1.2 Amidohydrolases;361
6.2.2.1.3;13.2.1.3 Lactonases;362
6.2.2.2;13.2.2 The Biology of QS Signal Degradation;362
6.2.2.2.1;13.2.2.1 The Agrobacterium Paradigm;363
6.2.2.2.2;13.2.2.2 QS and QQ Among Natural Microbial Communities in Soils;365
6.2.2.2.2.1;AHL-Based QS and QQ in the Soil Environment;365
6.2.2.2.2.2;Degradation of Non-AHL, QS Signals;366
6.2.3;13.3 Applied Outcomes: Ecological Engineering of QQ-Bacteria in the Rhizosphere;367
6.2.4;13.4 QS: A Broad Communication System;368
6.2.4.1;13.4.1 QS Regulation Is Not Restricted to Bacteria;368
6.2.4.2;13.4.2 Beyond Sensing a Quorum;368
6.2.4.3;13.4.3 QS Signals May Be Involved in Interkingdom Communications;369
6.2.5;13.5 Concluding Remarks;370
6.2.6;References;371
6.3;Chapter 14: Integration of Cell-to-Cell Signals in Soil Bacterial Communities;380
6.3.1;14.1 Introduction;380
6.3.2;14.2 Examples of QS in Soil Bacterial Communities;381
6.3.2.1;14.2.1 The Role of Sinorhizobium meliloti Quorum Sensing in the Interaction with Its Plant Hosts;383
6.3.2.1.1;14.2.1.1 Signal Exchange Leading to the Establishment of the S. meliloti-Medicago Symbiosis;383
6.3.2.1.2;14.2.1.2 QS Signal Generation During S. meliloti-Medicago Interactions;384
6.3.2.1.3;14.2.1.3 Responses of S. meliloti to AHL QS Signals;385
6.3.2.1.4;14.2.1.4 Plant Hosts Detect Rhizobial AHLs and Manipulate Bacterial Signaling;386
6.3.2.1.5;14.2.1.5 S. meliloti Responds to Non-AHL QS Signals from Other Microbes;387
6.3.2.2;14.2.2 QS in Pseudomonas aeruginosa, a Model Environmental Bacterium and Opportunistic Pathogen;388
6.3.2.3;14.2.3 Integration of QS into Global Regulatory Networks;391
6.3.3;14.3 GacS/GacA Is a Two-Component System Controlling Environmental Adaptation, Biofilm Formation, and Motility in gamma-Proteobacteria;391
6.3.3.1;14.3.1 Discovery of GacA and GacS in gamma-Proteobacteria;391
6.3.3.2;14.3.2 GacS-GacA Signal Transduction;393
6.3.3.2.1;14.3.2.1 Structure/Function Analysis of GacS Orthologs;393
6.3.3.2.2;14.3.2.2 Sensor Kinases RetS and LadS Modulate Function of GacS;395
6.3.3.3;14.3.3 Structure/Function Analysis of GacA Orthologs;396
6.3.3.4;14.3.4 GacA Regulons in Soil gamma-Proteobacteria;399
6.3.3.4.1;14.3.4.1 Evolutionarily Conserved Targets of the GacS/GacA Orthologs: The csr RNA;399
6.3.3.4.2;14.3.4.2 Orthologs of gacS/gacA Are Central to Biofilm Formation in gamma-Proteobacteria;401
6.3.4;14.4 The Elusive GacS Signal;401
6.3.4.1;14.4.1 Evidence for the Self-Produced GacS Signal;402
6.3.4.2;14.4.2 Evidence for the Eukaryotic Contribution to the GacS/GacA-Mediated Signaling;402
6.3.5;14.5 Conclusions and Future Directions;403
6.3.6;References;404
6.4;Chapter 15: Beneficial Rhizobacteria Induce Plant Growth: Mapping Signaling Networks in Arabidopsis;413
6.4.1;15.1 Agricultural Impact of Plant Growth-Promoting Rhizobacteria;413
6.4.2;15.2 Low-Molecular Weight Bacterial Signals;414
6.4.3;15.3 Probing Bacterial-Mediated Plant Growth Signaling Pathways;414
6.4.3.1;15.3.1 Bacterial Regulation of Auxin Synthesis, Transport, and Distribution in Planta;415
6.4.3.2;15.3.2 Transcriptional Regulation of Cell Wall Rigidity by GB03;416
6.4.3.3;15.3.3 GB03 Volatile Organic Compounds Elevate Plant Energy Acquisition;417
6.4.3.4;15.3.4 GB03 Regulates Iron Assimilation Independent of Metal Chelation;418
6.4.4;15.4 GB03 Volatile Organic Compounds Augment Arabidopsis Reproductive Success;419
6.4.5;15.5 Induced Growth Promotion Beyond the Model Plant;419
6.4.6;References;420
6.5;Chapter 16: Signal and Nutrient Exchange in the Interactions Between Soil Algae and Bacteria;423
6.5.1;16.1 Introduction;423
6.5.2;16.2 Phylogenetic Diversity of Algal-Associated Prokaryotic Microbiota;424
6.5.3;16.3 Nutrient and Signal Exchange in Algal-Bacterial Interactions;426
6.5.3.1;16.3.1 Carbon and Nitrogen Exchange in the Phycosphere;426
6.5.3.2;16.3.2 Bacterially Produced Plant Hormones Stimulate Algal Growth;428
6.5.3.3;16.3.3 Bidirectional Vitamin Exchange and Vitamin-Mediated Signaling in Algal-Bacterial Interactions;428
6.5.3.4;16.3.4 The Role of Algal Signals in Modulating Bacterial Quorum Sensing;430
6.5.4;16.4 Conclusions and Future Directions;433
6.5.5;References;433
6.6;Chapter 17: Communication Among Soil Bacteria and Fungi;437
6.6.1;17.1 Introduction;437
6.6.2;17.2 Antagonistic Interactions;438
6.6.2.1;17.2.1 Alteration of Abiotic Environmental Factors;438
6.6.2.2;17.2.2 Antibiotic Production;438
6.6.2.3;17.2.3 Trehalose;439
6.6.2.4;17.2.4 Excretion of Extracellular Enzymes;440
6.6.3;17.3 Symbiotic Interactions;441
6.6.3.1;17.3.1 Mycorrhization Helper Bacteria;441
6.6.3.2;17.3.2 Endosymbionts;442
6.6.4;17.4 Concluding Remarks;443
6.6.5;References;444
6.7;Chapter 18: Microbe-Microbe, Microbe-Plant Biocommunication;448
6.7.1;18.1 Introduction;448
6.7.2;18.2 Rhizosphere and Biocommunication;451
6.7.2.1;18.2.1 What Is Rhizosphere/Mycorhizosphere?;451
6.7.2.2;18.2.2 Rhizoplane Organisms;452
6.7.2.3;18.2.3 Root Exudates;454
6.7.3;18.3 Rhizobia-Legumes Symbiosis;456
6.7.4;18.4 QS in Rhizobium;456
6.7.5;18.5 QS in Pseudomonas aeruginosa;456
6.7.6;18.6 QS in Azotobacter;457
6.7.7;18.7 QS in Agrobacterium tumefaciens;457
6.7.8;18.8 Microbe-Plant Communication;460
6.7.9;18.9 QS and Mycorrhizal Fungi or Beneficial Endophytes: Tripartite Associations Between Plants, Fungi, and Bacteria;463
6.7.10;18.10 Parallel Communication of Plant Roots with Bacteria and Fungi;466
6.7.11;18.11 Conclusion;467
6.7.12;18.12 Future Perspectives;468
6.7.13;References;469
7;Index;474