Microbes for Legume Improvement (eBook)

Mohammad Saghir Khan, Ph.D., is an Associate Professor at the Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India. Dr. Khan received his M.Sc. from Aligarh Muslim University, Aligarh, India, and his Ph.D. (Microbiology) from Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India. He has been teaching Microbiology to post-graduate students for the last 13 years and has research experience of 17 years. In addition to his teaching, Dr. Khan is engaged in guiding students for their doctoral degree in Microbiology. He has published over 50 scientific papers including original research articles, review articles and book chapters in various national and international publication media. Dr. Khan has also edited three books published by the leading publishers. His interest in the various aspects and applications of Microbiology coupled with his classroom and laboratory experience makes him uniquely qualified to author this book. He is deeply involved in research activities focusing mainly on rhizobiology, microbiology, environmental microbiology, especially heavy metals-microbes-legume interaction, bioremediation, pesticide-PGPR-plant interaction, biofertilizers and rhizo-immunology. Almas Zaidi, received her M.Sc. and Ph.D. (Agricultural Microbiology) from Aligarh Muslim University, Aligarh, India and is currently serving as Guest faculty/Assistant Professor at the Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India. She has been teaching Microbiology at post graduate level for the last five years and has research experience of 13 years. She has published about 40 research papers and review articles in journals of national and international repute. She has also contributed chapters to different books. Dr. Zaidi has edited three books published by the leading publishers. Her main focus of research is to address problems related with rhizo-microbiology, microbiology, environmental microbiology, and biofertilizer technology. Javed Musarrat, M.Sc., Ph.D. (Biochemistry), former Chairman of the Department of Agricultural Microbiology and Ex-Dean, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, India, is presently working as a Professor, DNA Research Chair at the King Saud University, Riyadh, Saudi Arabia. He has been teaching Biochemistry, Microbiology and Molecular Biology to post-graduate students for the last 23 years and has research experience of about 25 years. He has contributed more than 50 national and international scientific publications. Dr. Musarrat has edited two books published by the leading publishers. He is associated with several scientific bodies such as Department of Biotechnology, Council of Scientific and Industrial Research, University Grants Commission, Indian Council of Agricultural Research, UPCST, and CCRUM in various capacities. His major area of interest includes the molecular microbiology, microbial ecology and genetic toxicology.

Preface 5
Editors 8
Contributors 10
Contents 15
Bacteria Involved in Nitrogen-Fixing Legume Symbiosis: Current Taxonomic Perspective 18
1.1 The “Classical” Species of Rhizobia 18
1.2 Biovars and Legume Promiscuity in Rhizobia 25
1.3 The New Rhizobia 28
1.4 Conclusion 31
References 31
Enhancing Rhizobium–Legume Symbiosis Using Signaling Factors 43
2.1 Overview of Rhizobium–Legume Symbiosis 44
2.2 Flavonoids Compounds Inducing Nod Factor Production and Enhancing Symbiosis 51
2.3 Non-Flavonoid Signaling Molecules Influencing Legume Productivity 54
2.4 Nod Factor-Enhancement of Bacterium–Plant Symbiosis 55
2.5 Competitiveness in Natural Populations and Its Effect on Legume Crops 56
2.6 Conclusions 60
References 60
Key Molecules Involved in Beneficial Infection Process in Rhizobia - Legume Symbiosis 71
3.1 Introduction 71
3.2 Flavonoids and Nod Factors 73
3.3 Lectins and Polysaccharides 76
3.4 Cellulases and Polygalacturonases (Pectinases) 79
3.5 Early Nodulins and Leghemoglobins 82
3.6 Nitrogenase and Hydrogenase 84
3.7 Conclusion 86
References 87
Recent Advances in Rhizobium–Legume Interactions: A Proteomic Approach 97
4.1 Introduction 98
4.2 Rhizobia–Legume Interactions: An Overview 100
4.3 What is Proteomics? 103
4.4 Conclusion 111
References 111
Role of Ethylene and Bacterial ACC Deaminase in Nodulation of Legumes 118
5.1 Introduction 118
5.2 Ethylene Vs. Nodulation 120
5.3 Nodulation Improvement Through Chemical/Biological Inhibitors of Ethylene 126
5.4 Transgenic Legumes with ACC deaminase 131
5.5 Conclusion 132
References 132
Microbial Biofilms: How Effective in Rhizobium - Legume Symbiosis? 138
6.1 Introduction 139
6.2 Biofilms in the Rhizosphere of Leguminous Plants 140
6.3 How are Biofilms Important in Rhizobium-Legume Symbiosis? 142
6.4 Potential of Biofilmed Biofertilizers in Improving Legume Performance 146
6.5 Conclusion 147
References 147
Potential of Rhizobia as Plant Growth-Promoting Rhizobacteria 152
7.1 Introduction 152
7.2 Root Colonization 153
7.3 Mechanisms of Plant Growth Promotion by Rhizobia 155
7.4 Conclusion 165
References 165
Engineering Nodulation Competitiveness of Rhizobial Bioinoculants in Soils 171
8.1 Introduction 172
8.2 Traits for Competitiveness 174
8.3 Competitiveness Variation in Legume–Rhizobial Partnerships 191
8.4 Competition Influences at Different Stages of Nodulation 191
8.5 Role of Plasmids 193
8.6 Competition Between Species 194
8.7 Engineering Competitiveness 194
8.8 Conclusion 196
References 197
Growth Promotion of Legumes by Inoculation of Rhizosphere Bacteria 209
9.1 Introduction 210
9.2 Mechanisms Involved in Plant Growth Promotion 211
9.3 Biotic and Abiotic Factors Affecting Rhizosphere Colonization 233
9.4 Development of Bacterial Inoculants and Constraints in Their Use 234
9.5 Conclusion 236
References 237
Mycorrhizosphere Interactions for Legume Improvement 250
10.1 Introduction 250
10.2 Microorganisms and Processes Involved in the Establishment and Functioning of the Mycorrhizosphere 252
10.3 Interactions Between AM Fungi and Rhizobial Bacteria to Improve Legume Productivity 256
10.4 Interactions Between AM Fungi and Phosphate- Solubilizing Microbes to Improve the Use of Natural Phosphate Sources and/ or Agro- Industrial Residues by Legumes 264
10.5 Mycorrhizosphere Interactions to Improve Legumes in Soils Suffering from Environmental/ Cultural Stresses 266
10.6 Biotechnological Developments for Integrated Management of Legume Improvement 269
10.7 Conclusion and Future Perspective 271
References 271
Role of Phosphate-Solubilizing Bacteria in Legume Improvement 285
11.1 Introduction 286
11.2 Phosphate Solubilization and Growth Regulators 287
11.3 Phosphate-Solubilizing Bacteria and Legume Improvement 290
11.4 Conclusion 298
References 298
Legume Responses to Arbuscular Mycorrhizal Fungi Inoculation in Sustainable Agriculture 305
12.1 Introduction 306
12.2 Mycorrhizal Association with Legumes 308
12.3 Composite Inoculation of Legume Plants with Mycorrhizal Fungi and Rhizobia 310
12.4 Mycorrhizal Dependency of Legumes 315
12.5 How Arbuscular Mycorrhizal Fungi Enhance Legumes Performance? 316
12.6 Inoculum Development and Formulations 323
12.7 Conclusion 328
References 329
Bacterial Biofilms: Role in Rhizobium–Legume Symbiosis 336
13.1 Introduction 336
13.2 Plant Products Regulating Associations with Microorganisms 339
13.3 Mechanisms of Biofilm Formation 340
13.4 Conclusion 343
References 344
Role of Metal Tolerant Microbes in Legume Improvement 347
14.1 Introduction 347
14.2 Heavy Metal Toxicity to Legume– Rhizobium Interactions 349
14.3 How to Overcome Heavy Metal Stress? 351
14.4 Performance of Inoculated Legumes in Metal-Stressed Soils 353
14.5 Conclusion 356
References 357
Legumes–Microbes Interactions Under Stressed Environments 363
15.1 Introduction 364
15.2 Arid and Saline Environments 366
15.3 Legume–Rhizobia Associations 368
15.4 Legume–Bacteria Associations Under Stressed Environments 381
15.5 Legume–Fungal Associations under Stressed Environments 383
15.6 Conclusion 385
References 387
Role of Azospirillum in the Improvement of Legumes 398
16.1 Introduction 398
16.2 Taxonomy, General Characteristics, and Host Range 399
16.3 Azospirillum Interaction with Soil 401
16.4 How Azospirilla Facilitate Plant Growth? 403
16.5 Azospirillum as Synthetic Inoculants 407
16.6 Conclusion 411
References 412
Role of Arbuscular Mycorrhizal Fungi in Nitrogen Fixation in Legumes 418
17.1 Introduction 418
17.2 Arbuscular Mycorrhiza and Nitrogen-Fixing Bacterial Associations 421
17.3 Conclusion 429
References 430
Symbiotic Nitrogen Fixation in Tropical Food Grain Legumes: Current Status 436
18.1 A Global View of the Nutrients Supply 436
18.2 Symbiotic Nitrogen Fixation 437
18.3 Soybean 439
18.4 Common Bean 451
18.5 Cowpea 457
18.6 Groundnut 461
18.7 Conclusion 465
References 466
Plant Growth Promoting Rhizobacteria Improving the Legume– Rhizobia Symbiosis 482
19.1 Introduction 483
19.2 Rhizobia Diversity and Root Colonization 484
19.3 Root: A Paradise of Microorganisms in Action 486
19.4 Mechanisms of Plant Growth Promotion by PGPR Affecting Legumes 488
19.5 Relief of Stress and Plant Growth Promotion by PGPR 495
19.6 Conclusion 496
References 497
The Potential Use of Rhizobium-Legume Symbiosis for Enhancing Plant Growth and Management of Plant Diseases 504
20.1 Introduction 504
20.2 Biological Nitrogen Fixation 505
20.3 Factors Limiting Biological Nitrogen Fixation in Arid Climate 507
20.4 Role of Biotechnologies in Improving Nitrogen Fixation in Severe Conditions 512
20.5 Management of Phytopathogens Using Rhizobia 513
20.6 Conclusion 517
References 517
Microbial Inoculants for Sustainable Legume Production 524
21.1 Introduction 525
21.2 Legumes and Biological Nitrogen Fixation 526
21.3 Rhizobium 528
21.4 Microbial Inoculants for Legume Production 532
21.5 Formulations and Strategies of Microbial Inoculants Application 537
21.6 Conclusion 538
References 538