Arbuscular Mycorrhizas: Physiology and Function (eBook)

Arbuscular Mycorrhizas:Physiology and Function 3
Preface 5
Contents 9
Part I Host-fungal Interactions:Pre-penetration 11
Chapter 1: Fungal Spore Germination and Pre-symbiotic Mycelial Growth – Physiological and Genetic Aspects 12
1 Introduction 13
2 Spore Dormancy 13
3 Triggers for Spore Germination 14
3.1 pH 15
3.2 Temperature 16
3.3 Moisture 16
3.4 Mineral and Organic Nutrients 17
3.5 Host/Non Host Plants 18
3.6 Microorganisms 19
4 Modes of Spore Germination 20
5 Development of Pre-symbiotic Mycelium 21
6 Biochemical Changes During Germination and Pre-symbiotic Growth 23
7 Cytological and Genetic Changes During Germination and Pre-symbiotic Growth 26
8 Growth Arrest in the Absence of the Host 29
9 Concluding Remarks 31
References 31
Chapter 2: Functional Categories of Root Exudate Compounds and their Relevance to AM Fungal Growth 42
1 Introduction 43
2 Fourier Transform Ion Cyclotron Mass Spectroscopy 44
3 Plant Growth Regulators During AM Fungal/Host Interactions 47
4 Compounds That Stimulate Elongation Growth of AM Fungi 49
5 Compounds That Promote Morphological Changes, Biochemical Changes, or Inhibit Plant or Fungal Growth 53
6 Sesquiterpenoids and Their Role in AM Fungal/Plant Host Interactions 54
7 Hydroxy Fatty Acids Which May Affect Fungal Growth 56
8 Conclusions 60
References 61
Chapter 3: The Making of Symbiotic Cells in Arbuscular Mycorrhizal Roots 66
1 Introduction 67
2 Rhizospheric Communication 69
3 The Root Epidermis Checkpoint 71
4 The PPA-Associated Transcriptomic Response 73
5 Inside the Root: Symbiosis at Work 74
6 The PPA and the Evolutionary Origin of the Interface Compartment 75
7 Conclusions 76
References 78
Chapter 4: Strigolactones and Their Role in Arbuscular Mycorrhizal Symbiosis 81
1 The Elusive “Branching Factors” 82
2 Structure, Occurrence and Metabolic Origin of Strigolactones 83
2.1 Structural Features 83
2.2 Diversity and Distribution 83
2.3 Biosynthetic Origin 85
3 Importance in AM Symbiosis 86
4 Hormonal Function in Plants 87
5 Strigolactone Synthesis and Its Regulation 89
5.1 Biosynthetic Pathway 89
5.2 Regulatory Factors 90
6 Strigolactone Mode of Action 91
6.1 Cellular Effects 91
6.2 Perception Mechanisms 93
References 94
Part II Host-fungal Interactions:Post-penetration 99
Chapter 5: Molecular–Physiological Aspects of the AM Symbiosis Post Penetration 100
1 Morphological Features and Cytological Aspects 101
2 Non-targeted Approaches 102
2.1 Transcriptomics 103
2.1.1 Differential Expression of Plant Genes 103
2.1.2 Post-transcriptomic Research 106
2.1.3 Differential Expression of Fungal Genes 106
2.2 Proteomics 107
2.3 Metabolomics 109
3 Targeted Approaches 109
3.1 Photosynthesis in Mycorrhizal Plants 109
3.2 Carbon Distribution and Transfer to the Fungus 110
3.3 Carbohydrate Metabolism in AM Fungi 113
4 Final Remarks 114
References 115
Chapter 6: Phosphate Transporters in Arbuscular Mycorrhizal Symbiosis 124
1 Introduction 124
2 Pi Transporters in AM Fungi 125
3 Plant Pi Transporters of the PHT1 Family 127
4 PHT1 Family Transporters in AM Symbiosis 133
5 PHT1 Family Transporters Induced During AM Symbiosis 134
6 Regulation of AM-Inducible PHT1 Transporter Genes 136
7 Function of AM-inducible Pi Transporters 137
8 Conclusions 138
References 139
Chapter 7: Nutrient Uptake: The Arbuscular Mycorrhiza Fungal Symbiosis as a Plant Nutrient Acquisition Strategy 143
1 Introduction 144
2 Physiology of Uptake, Transport and Delivery to the Host Plant of Nutritional Elements by Arbuscular Mycorrhiza Fungal Myce 145
2.1 Development and Morphology of Extraradical Arbuscular Mycorrhiza Hyphal Networks 145
2.2 Nutrient Uptake and Transport by Arbuscular Mycorrhizal Hyphae 148
2.3 Arbuscular Mycorrhiza Fungal Nutrient Transfer and Plant Uptake of Elements via the Symbiotic and Asymbiotic Pathway 150
2.4 Aspects of Functional Compatibility Between Symbiotic Partners in Arbuscular Mycorrhizal Nutrient Acquisition 153
3 Exploitation of Soil Nutrient Resources by Arbuscular Mycorrhizal Root Systems 154
3.1 Coordination of Nutrient Absorbing Surface Formation Between Plant Roots and Arbuscular Mycorrhiza Mycelia 154
3.2 Collaboration Between Roots and Arbuscular Mycorrhiza Fungal Mycelia in Spatial Exploitation of Soil Nutrient Resources: 156
3.3 Effects of AM Fungal Mycelia on Chemical and Physical Mycorrhizosphere Properties, and Implications for Mineral Element A 160
4 Conclusions 163
References 164
Chapter 8: Hormonal Responses in Host Plants Triggered by Arbuscular Mycorrhizal Fungi 174
1 Introduction 175
2 Auxins: Triggers of Organ Formation? 177
2.1 Auxin Production by Mycorrhizal Fungi 177
2.2 The Occurrence of Auxins in the Arbuscular Mycorrhiza Symbiosis 178
2.3 Control of Auxin Homeostasis in AM Symbiosis 179
2.4 Pharmacological Approaches to Understand the AM Symbiosis 179
3 Cytokinins: Initial Recognition, Repressors of Defense Responses or Regulators of Growth? 180
4 Gibberellins: Hormones Without Obvious Function in AM Formation? 182
5 Abscisic Acid: Involved in Stress Protection and Arbuscule Formation 182
6 Jasmonic Acid Contributes to the Life Cycle of the AM Fungus 184
7 Defense Related Hormones 186
7.1 Ethylene 186
7.2 Salicylic Acid 187
8 The Interaction of Different Hormones Is Necessary for the Beneficial Effects of the Symbiosis on the Host Plant 189
References 189
Part III Influence of the Symbiosis on the Hostand its Surrounding: Host Responseto Biotic Stress 196
Chapter 9: Impact of Arbuscular Mycorrhizal Symbiosis on Plant Response to Biotic Stress: The Role of Plant Defence Mechanisms 197
1 Introduction 198
2 Impact of the AM Symbioses on Soil-Borne Pathogens 199
3 Effects of AM Symbioses on Root Parasitic Plants 200
4 Impact of AM Symbioses on Above-Ground Interactions 200
5 Effects of AM Symbioses on Phytophagous Insects 201
6 AM Symbiosis Modulate Host Defence Responses 202
7 AM Symbiosis Primes JA-Dependent Responses 203
8 Conclusions and Outlook 205
References 206
Chapter 10: Biotic Environment of the Arbuscular Mycorrhizal Fungi in Soil 212
1 Introduction 213
2 The Players 214
3 Mechanisms of Interactions 219
4 Ecological Consequences 226
5 Research Outlook 228
6 Conclusions 229
References 230
Part IV Influence of the Symbiosis on the Hostand its Surrounding: Host Responseto Abiotic Stress 240
Chapter 11: Host Response to Osmotic Stresses: Stomatal Behaviour and Water Use Efficiency of Arbuscular Mycorrhizal Plants 241
1 Introduction 242
2 Stomatal Behaviour of Arbuscular Mycorrhizal Plants Under Osmotic Stress 243
2.1 Influence of the Host Plant Life-Style and of AMF Origin 245
2.2 Influence of Combined Salt Stress and of Environmental Conditions 247
2.3 Influence of Soil Colonization by AMF 248
3 Water Use Efficiency of Arbuscular Mycorrhizal Plants Under Osmotic Stress 252
3.1 Influence of AMF ont Leaf Photosynthetic Efficiency 252
3.2 Influence of AMF on Leaf Morphology Parameters 254
References 255
Chapter 12: Metal Tolerant Mycorrhizal Plants: A Review from the Perspective on Industrial Waste in Temperate Region 259
1 Introduction 260
2 Plant Reaction to Heavy Metals 260
3 Revegetation Technologies Non Assisted by Microorganisms 261
4 Why Mycorrhizal Fungi Are Important in Restoration of Metal Rich Wastes 262
5 Role of Arbuscular Mycorrhizal Fungi in Revegetation of Metal Rich Wastes 264
6 Abundance and Diversity of Arbuscular Mycorrhizal Fungi in the Wastes 267
7 Metal Accumulation in Plants Growing on Industrial Wastes 268
8 Introduction of Plants from Xerothermic Grasslands into the Metal Rich Wastes: New Approach 269
9 Attenuation of Stress by Mycorrhizal Fungi and Monitoring 270
10 Use of Photosynthesis to Show Adaptation of the Plant to Survive 271
11 Use of Hyperaccumulators in Phytoremediation of Areas Surrounding Industrial Tailings 272
12 Conclusions 272
References 273
Part V Evolutionary and Diversity Perspectivesof Mycorrhizal Association 279
Chapter 13: Effect of Differences Among Crop Species and Cultivars on the Arbuscular Mycorrhizal Symbiosis 280
1 Legume Crops and Mycorrhiza 281
2 Cereal Crops 283
3 Tree Crops 286
4 Conclusions 291
References 292
Chapter 14: Mycorrhizal Symbiosis and Plant Reproduction 297
1 Introduction 297
2 Mycorrhizal Effects Mediated by Enhanced Nutrient Uptake 299
2.1 Temporal Variation in Response to Infection by Mycorrhizal Fungi 300
2.2 The Components of Sexual Reproduction 302
2.3 Offspring Quality 306
3 Population-Level Phenomena 309
4 Community-Level Phenomena 311
5 Mycorrhizal Effects Mediated by Altered Herbivory or Disease 312
6 Negative Effects of Infection by Mycorrhizal Fungi 314
7 Conclusions 314
References 315
Index 321