Plant Communication from an Ecological Perspective (eBook)

Preface 6
Further Reading 7
Contents 8
Evolutionary Ecology of Plant Signals and Toxins: A Conceptual Framework 10
Introduction 10
What Is Communication? 11
What Is Information? 11
What Is Biological Communication? 11
What Is a Signal? 12
What Is Allelopathy? 13
What Is the Difference Between a Toxin and a Signal? 14
Differences Between Plant and Animal Communication 15
How Can Communication Between Plants Evolve? 16
Evolution of Signaling Through Individual Selection 17
Evolution of Signaling Through Kin or Group Selection 21
Evolution of Signaling Through Sexual Selection 22
A Conceptual Framework for the Evolutionary Ecology of Plant Signals 23
Conclusions 23
References 25
The Chemistry of Plant Signalling 29
Introduction 29
Approaches to the Isolation and Identification of Plant and Insect-Derived Signals 30
Collection of Biological Samples for Analysis 30
Dynamic Headspace Collection 30
Solid Phase Microextraction (SPME) 31
Vacuum Distillation 32
Liquid-Liquid Extraction 32
Solid Phase Extraction (SPE) 32
Stir Bar Sorptive Extraction (SBSE) 33
Other PDMS Materials 33
Vapour Phase Extraction (VPE) 33
In-Situ Derivatisation 34
Recent Advances 34
Plant Derived Chemical Signals 36
cis-Jasmone 36
Oxylipins and Phytohormones 36
Insect-Derived Chemical Signals 38
Bruchins 38
Volicitin and Related Compounds 38
Caeliferins 40
Structure-Activity Relationships 40
Biosynthetic Studies 42
Future Prospects 43
References 45
Plant Defense Signaling from the Underground Primes Aboveground Defenses to Confer Enhanced Resistance in a Cost-Efficient Ma 50
Introduction 50
Perception of PGPR by the Plant 51
ISR Signal Transduction 52
Priming for Enhanced Defense 54
Mechanisms of Priming of Defense Responses 56
Costs of Induced Defenses 57
Fitness Benefits of Priming Under Disease Pressure 58
To What Extent are Plants in the Field Already Primed? 60
Outlook 61
References 62
Allelopathy and Exotic Plant Invasion 68
Introduction 68
Allelopathy and Exotic Plant Invasion 69
Allelopathy and Microbial Accomplices in Invasion 72
Nitrogen Fixers 75
Mutualists 76
Future Directions 77
References 77
Volatile Interaction Between Undamaged Plants: A Short Cut to Coexistence 81
Introduction 81
Role of Plant Volatiles 83
The Role of Plant Volatiles in Allelopathy 84
VOCs as Cues in Plant-Plant Interaction 85
Plant Responses to Allelobiosis, Methyl Salicylate and Methyl Jasmonate 87
Conclusions 88
References 89
Volatile Chemical Interaction Between Undamaged Plants: Effects at Higher Trophic Levels 93
Introduction 93
Increased Plant Genetic Diversity Affects Higher Trophic Levels 94
Between Species Diversity 94
Within-Species Genotype Diversity 95
Volatile Interactions Between Undamaged Plants Affect Higher Trophic Levels 95
Allelobiosis Between Different Plant Species 96
Allelobiosis Between Different Genotypes of the Same Plant Species 98
Does Plant Genetic Diversity Affect Natural Enemies Via Volatile Interaction and Diversity? 101
Conclusions 102
References 103
Within-Plant Signalling by Volatiles Triggers Systemic Defences 105
Introduction 106
Talking Trees 107
VOCs as Within-Plant Signals 109
Shortcomings of Signalling by VOCs 109
Benefits of VOCs as Plant Signals 111
Airborne Cues as Within-Plant Signals: Exotic Cases or Common Strategy? 113
References 114
Volatile Interactions Between Undamaged Plants: Effects and Potential for Breeding Resistance to Aphids 119
Introduction 120
Aphids as Herbivores in Plant-Plant Chemical Interactions 120
Effects of Plant Diversity on Herbivore Abundance 121
Effects of Inter-Specific Allelobiosis on Aphids 122
Effects of Intra-Specific Allelobiosis on Aphids 123
Potential for Exploiting Volatile Interactions Between Undamaged Plants in Breeding Resistance to Aphids 125
Conclusions and Future Prospects 127
References 128
Communication in Ant-Plant Symbioses 132
Introduction 132
Host-Plant Discrimination 136
Sowing the Right Partner 136
Finding the Right Host Plant: Better to Look for a Needle in a Haystack? 137
Discriminating the Host Plant: Self Versus Non-Self? 140
Signalling for Anti-Herbivore Protection 142
Induced Defence: Signalling Herbivore Activity to Defending Ants 142
Ants as a Constitutive Defence 146
How Specificity Affects Efficiency 148
Optimal Defence Theory 150
The Evolution of Plant-Ant Communication 151
How Can Plant-Ant Communication Signals Have Evolved so Many Times Independently? 151
The Sensory Trap Hypothesis 152
Processes in the Evolution of Communication Signals 154
Conclusions 155
References 156
Photosensory Cues in Plant-Plant Interactions: Regulation and Functional Significance of Shade Avoidance Responses 164
Introduction 164
The Shade Avoidance Syndrome 165
Photoreceptors 167
Cryptochromes 167
Phototropins 168
Phytochromes 169
Hormonal Regulation 169
Gibberellin 170
Auxin 171
Brassinosteroids 172
Ethylene 173
SAS Regulation Downstream of the Hormones 173
Adaptive Value of the SAS in Ecological Context 174
Local Adaptation in Ecotypes 174
Environmental Complexity: Integrating SAS and Defense 176
Conclusions 177
References 177
Global Atmospheric Change and Trophic Interactions: Are There Any General Responses? 184
Introduction 184
Climate Change and Plant-Derived Allelochemicals 186
Plant-Derived Allelochemicals as a Driving Force for Community Structure 186
Elevated CO2 and Resource Allocation to Allelochemicals 187
C and N Allocation to Biosynthetic Classes of Secondary Metabolites 190
Phytohormones: The Molecular Link Between Physiological Responses to Elevated CO2 and Secondary Metabol 196
Trophic Interactions and Climate Change 197
Plant-Herbivore Interactions and Elevated CO2 197
The Effects of Elevated CO2 on Higher Trophic Levels 201
Conclusions 204
References 205
Appendix 1 References Used for Figs. 11.2–11.4, 11.6, and 11.7) 212
Appendix 2 List of Abbreviations for Fig.11.5 217
Exploiting Plant Signals in Sustainable Agriculture 220
Introduction 220
Induction and Priming of Plant Defences 222
Exploiting Plant Semiochemicals for Agriculture 224
Plant Diseases 224
Insect Pests 225
Plant Signals in `Push-Pull´ Strategies 227
Manipulating Plant Genetics to Deliver Semiochemicals 228
Conclusions 229
References 229
Plant Volatiles: Useful Signals to Monitor Crop Health Status in Greenhouses 233
Introduction 234
Emission of VOCs from Greenhouse Crops 235
Factors Affecting the Emission of VOCs from Crops Grown in Greenhouses 235
Stressors Affecting the Emission of VOCs from Crops Grown in Greenhouses 236
Nonstressors Affecting the Emission Rate of VOCs from Greenhouse Crops 237
Specificity of Stress-Induced Emissions 237
Factors that Affect the Gas Balance of Plant VOCs in the Greenhouse 240
Techniques to Measure the Emission of VOCs from Plants at Greenhouse Scale 242
Collection of the Plant-Emitted VOCs 242
Separation of the Plant-Emitted VOCs in the Mixture 243
Identification and Quantification of the Plant-Emitted VOCs 243
Flame Ionization Detector 244
Mass Spectrometer 244
Electronic Nose 245
Biosensor Technology 245
Trends and Future Possibilities 246
References 248
Index 252