Induced Resistance for Plant Defense (2^nd Ed.)
A sustainable approach to crop protection

Plant diseases worldwide are responsible for billions of dollars worth of crop losses every year. With less agrochemicals being used and less new fungicides coming on the market due to environmental concerns, more effort is now being put into the use of genetic potential of plants for pathogen resistance and the development of induced or acquired resistance as an environmentally safe means of disease control. This comprehensive book examines in depth the development and exploitation of induced resistance. Chapters review current knowledge of the agents that can elicit induced resistance, genomics, signalling cascades, mechanisms of defence to pests and pathogens and molecular tools. Further chapters consider the topical application of inducers for disease control, microbial induction of pathogen resistance, transgenic approaches, pathogen population biology, trade offs associated with induced resistance and integration of induced resistance in crop protection. The book concludes with a consideration of socio-economic drivers determining the use of induced resistance, and the future of induced resistance in crop protection.

Contributors xiii

Preface to Second Edition xvii

Preface to First Edition xix

1 Introduction: Definitions and Some History 1
Ray Hammerschmidt

1.1 Induced Resistance: An Established Phenomenon 1

1.2 Terminology and Types of Induced Resistance 2

1.2.1 Local and systemic induction of resistance 2

1.2.2 Systemic acquired resistance (SAR) and induced systemic resistance (ISR) 2

1.2.3 Protection 3

1.2.4 Cross protection 3

1.2.5 Priming 4

1.3 A Little History 4

1.3.1 Early reports 4

1.3.2 Developments leading towards today’s state of knowledge 5

1.4 It’s All About Interactions 7

1.5 Acknowledgements 8

References 8

2 Agents That Can Elicit Induced Resistance 11
Gary D. Lyon

2.1 Introduction 11

2.2 Compounds Inducing Resistance 12

2.2.1 Acibenzolar-S-methyl (ASM) 12

2.2.2 Adipic acid 12

2.2.3 Algal extracts 12

2.2.4 Alkamides 12

2.2.5 Allose 13

2.2.6 Antibiotics 13

2.2.7 Azelaic acid 13

2.2.8 DL-3-Aminobutyric acid (BABA) 13

2.2.9 Benzothiadiazole (BTH) and other synthetic resistance inducers 14

2.2.10 Bestcure® 15

2.2.11 Brassinolide 15

2.2.12 β-1,4 Cellodextrins 15

2.2.13 Chitin 15

2.2.14 Chitosan 16

2.2.15 Cholic acid 16

2.2.16 Curdlan sulfate 17

2.2.17 Dehydroabietinal 17

2.2.18 3,5-Dichloroanthranilic acid (DCA) 17

2.2.19 Dichloroisonicotinic acid (INA) 17

2.2.20 Dimethyl disulfide 17

2.2.21 Dufulin 17

2.2.22 Ergosterol 17

2.2.23 Ethylene 17

2.2.24 Fatty acids and lipids 18

2.2.25 2-(2-Fluoro-6-nitrobenzylsulfanyl)pyridine-4-carbothioamide 18

2.2.26 Fructooligosaccharide 18

2.2.27 Fungicides 18

2.2.28 Galactinol 19

2.2.29 Grape marc 19

2.2.30 Glucans 19

2.2.31 Harpin 20

2.2.32 Hexanoic acid 20

2.2.33 Imprimatin 20

2.2.34 INF1 elicitin 21

2.2.35 Jasmonates and related compounds 21

2.2.36 Cis-jasmone 21

2.2.37 Laminarin 21

2.2.38 Lipids/fatty acids 21

2.2.39 Lipopolysaccharides (LPS) 22

2.2.40 Nitric oxide 22

2.2.41 Oligo-carrageenans 22

2.2.42 Oligogalacturonides (OGAs) 22

2.2.43 Oligoglucuronans 23

2.2.44 Oxalate 23

2.2.45 Phosphite 23

2.2.46 Phytogard® 23

2.2.47 Pipecolic acid 23

2.2.48 Plant extracts 23

2.2.49 Probenazole (PBZ) 24

2.2.50 Proteins and peptides 24

2.2.51 Psicose 26

2.2.52 Rhamnolipids 26

2.2.53 Saccharin 26

2.2.54 Salicylic acid 26

2.2.55 Silicon 27

2.2.56 Spermine 27

2.2.57 Sphingolipids 27

2.2.58 Sulfated fucan oligosaccharides 27

2.2.59 Tiadinil 27

2.2.60 Vitamins 27

2.2.61 Volatile organic compounds 28

2.3 Redox Regulation 28

2.3.1 Factors affecting efficacy 29

2.4 Elicitor Combinations and Synergism 29

2.5 Assays 30

2.6 Conclusions 30

References 31

3 Transcriptome Analysis of Induced Resistance 41
Brendan Kidd, Kemal Kazan and Peer M. Schenk

3.1 Introduction 41

3.2 The Impact of Arabidopsis thaliana on Induced Resistance 42

3.3 Techniques Used for Studying Gene Expression 42

3.3.1 EST sequencing 42

3.3.2 Real-time quantitative RT-PCR (qRT-PCR) 42

3.3.3 cDNA microarrays and DNA chips 43

3.3.4 Novel insights into induced resistance revealed through microarray analysis 45

3.3.5 Systems biology and network approaches using microarrays 48

3.3.6 Next-generation sequencing 48

3.4 How Sequencing Helps Crop Research 50

3.4.1 Converting knowledge from model organisms to crop plants 50

3.5 Conclusion 51

3.6 Acknowledgements 52

References 52

4 Signalling Networks Involved in Induced Resistance 58
Corné M.J. Pieterse, Christos Zamioudis, Dieuwertje Van der Does and Saskia C.M. Van Wees

4.1 Introduction 58

4.2 The SA–JA Backbone of the Plant Immune Signalling Network 59

4.2.1 Salicylic acid 60

4.2.2 Jasmonic acid 61

4.3 SA and JA: Important Signals in Systemically Induced Defence 63

4.3.1 Pathogen-induced SAR 63

4.3.2 ISR triggered by beneficial microbes 64

4.3.3 Rhizobacteria-ISR signal transduction 65

4.4 ISR and Priming for Enhanced Defence 66

4.4.1 Molecular mechanisms of priming 67

4.5 Hormonal Crosstalk During Induced Defence 68

4.5.1 Mechanisms of crosstalk between SA and JA signalling 69

4.5.2 Rewiring of the hormone signalling network by plant enemies 70

4.6 Outlook 71

4.7 Acknowledgements 71

References 72

5 Types and Mechanisms of Rapidly Induced Plant Resistance to Herbivorous Arthropods 81
Michael J. Stout

5.1 Introduction: Induced Resistance in Context 81

5.2 Comparison of the Threats Posed by Pathogens and Herbivores 83

5.3 Types of Induced Resistance 85

5.3.1 Hypersensitive responses 85

5.3.2 Direct induced resistance 86

5.3.3 Indirect induced resistance 88

5.3.4 Plant stress-induced resistance 90

5.3.5 Tolerance 91

5.3.6 Priming 91

5.3.7 Interplant signalling 92

5.3.8 Concurrent expression of multiple types of induced resistance 92

5.4 Establishing the Causal Basis of Induced Resistance 93

5.4.1 The complex causal basis of induced resistance 93

5.4.2 Approaches to understanding the causal basis of induced resistance 95

5.5 Arthropods as Dynamic Participants in Plant–Arthropod Interactions 98

5.6 Summary and Conclusions 99

References 100

6 Mechanisms of Defence to Pathogens: Biochemistry and Physiology 106
Christophe Garcion, Olivier Lamotte, Jean-Luc Cacas and Jean-Pierre Métraux

6.1 Introduction 106

6.2 Structural Barriers 106

6.2.1 Early events: The cytoskeleton and traffic of vesicles 107

6.2.2 The nature of cell wall appositions 108

6.2.3 Lignification 109

6.3 Phytoalexins 109

6.3.1 The concept of phytoalexins 109

6.3.2 Distribution of phytoalexins among taxons and individuals 110

6.3.3 Biosynthetic pathways and their regulation 110

6.3.4 Role of the phytoalexins in the defence response 113

6.4 The Hypersensitive Response (HR) 115

6.4.1 In the death car – en route to plant resistance to pathogens 115

6.4.2 The role of reactive oxygen and nitrogen species (ROS and RNS) 116

6.4.3 On the highway of hypersensitive cell death: Signalling and regulation 118

6.4.4 License to kill: Where do we stand on execution of hypersensitive cell death? 120

6.5 Antimicrobial Proteins or Defence-Related Proteins 122

6.5.1 Introduction 122

6.5.2 Use of PRs for crop protection: Current status 122

6.5.3 Other changes in the transcriptome related to pathogenesis 123

6.6 Conclusions 125

References 125

7 Induced Resistance in Natural Ecosystems and Pathogen Population Biology: Exploiting Interactions 137
Adrian C. Newton and Jörn Pons-Kühnemann

7.1 Introduction 137

7.2 Environmental Variability 137

7.3 Ecology of the Plant Environment 139

7.4 Environmental Parameters 140

7.5 Plant and Pathogen Population Genetics 141

7.6 Consequences of Resistance Induction 143

7.7 Conclusions 144

7.8 Acknowledgements 145

References 145

8 Microbial Induction of Resistance to Pathogens 149
Dale R. Walters and Alison E. Bennett

8.1 Introduction 149

8.2 Resistance Induced by Plant Growth Promoting Rhizobacteria and Fungi 149

8.2.1 PGPR 150

8.2.1.1 Spectrum of activity 150

8.2.1.2 Interactions between plant roots and PGPR 152

8.2.1.3 PGPR and plant growth 152

8.2.1.4 PGPR in the field 153

8.2.2 PGPF 155

8.3 Induction of Resistance by Biological Control Agents 155

8.4 Resistance Induced by Composts 157

8.5 Disease Control Provided by Endophytes 159

8.6 Arbuscular Mycorrhizal Symbiosis and Induced Resistance 160

8.7 Acknowledgements 162

References 163

9 Trade-offs Associated with Induced Resistance 171
Martin Heil

9.1 Introduction 171

9.2 Resistance Inducers 172

9.2.1 Eliciting resistance to biotrophic pathogens 172

9.2.2 Eliciting resistance to necrotrophic pathogens and herbivores 174

9.2.3 Volatile elicitors 176

9.2.4 Priming 177

9.3 Costs of Induced Resistance 178

9.3.1 Allocation costs 179

9.3.2 Priming as cost-reducing mechanism 181

9.3.3 Ecological costs 182

9.3.4 Dependency on cultivars 183

9.3.5 Context dependency 183

9.4 Outlook 184

References 185

10 Topical Application of Inducers for Disease Control 193
Christine Tayeh, Ali Siah, Béatrice Randoux, Patrice Halama, Dale R. Walters and Philippe Reignault

10.1 Introduction 193

10.2 Biotic Inducers 193

10.2.1 Chitin and chitosan 196

10.2.2 Fragments and extracts of fungal cell walls 197

10.2.3 Extracts and materials derived from marine macroalgae 198

10.2.4 Lipids 198

10.3 Abiotic Inducers 198

10.3.1 Benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH)/acibenzolar-S-methyl (ASM) 199

10.3.1.1 Diseases caused by leaf and stem-infecting fungi 199

10.3.1.2 Diseases caused by oomycetes 201

10.3.1.3 Fungal soil-borne diseases 201

10.3.1.4 Fungal postharvest diseases 202

10.3.1.5 Diseases caused by bacteria, viruses and insects 203

10.3.2 Salicylic acid and structurally related compounds 205

10.3.2.1 Salicylic acid 205

10.3.2.2 SA derivatives 207

10.3.3 Proteins, peptides and amino acid-derived inducers 208

10.3.3.1 β-aminobutyric acid (BABA) 208

10.3.3.2 Harpin 209

10.3.3.3 Other purified proteins 210

10.3.4 Lipids 211

10.3.4.1 Oxylipins 211

10.3.4.2 Fatty acids 214

10.3.5 Active oxygen species 214

10.3.6 Sugars 215

10.3.7 Phytohormones 215

10.3.8 Mineral and ions 216

10.3.8.1 Copper 216

10.3.8.2 Other minerals 216

10.3.8.3 Silicon 216

10.3.8.4 Calcium-based compounds 217

10.3.8.5 Other inducers 217

10.3.9 Vitamins 217

10.3.10 Physical treatments 218

10.4 Conclusions 218

10.5 Acknowledgements 218

References 219

11 How do Beneficial Microbes Induce Systemic Resistance? 232
Emily Beardon, Julie Scholes and Jurriaan Ton

11.1 Plant-Beneficial Microbes 232

11.2 The Plant Immune System as a Regulator of Plant–Biotic Interactions 233

11.2.1 The plant innate immune system: Induced defence 234

11.2.2 The plant adaptive immune system: Priming of defence 235

11.3 How do Beneficial Microbes Cope with the Plant Immune System? 236

11.3.1 Evasion and suppression of plant immunity by rhizobia 236

11.3.2 Suppression of plant immunity by mycorrhizal fungi 237

11.3.3 Evasion and suppression of plant immunity by PGPR 238

11.4 The ISR Paradox: Local Suppression of Immunity Leads to Systemic Resistance 239

11.4.1 The hormone hypothesis 239

11.4.2 The autoregulation hypothesis 240

11.4.3 The sRNA hypothesis 241

11.5 Concluding Remarks and Future Directions 241

References 242

12 Implementation of Induced Resistance for Crop Protection 249
Tony Reglinski, Elizabeth Dann and Brian Deverall

12.1 Introduction 249

12.2 Induced Resistance for Disease Control 250

12.2.1 Commercially available activators for glasshouse, orchard and field crops 251

12.2.1.1 Acibenzolar-S-methyl 251

12.2.1.2 Tiadinil 253

12.2.1.3 Probenazole 253

12.2.1.4 Isotianil 253

12.2.1.5 Phosphite 254

12.2.1.6 Plant extracts 254

12.2.1.7 Polysaccharides 254

12.2.1.8 Harpin protein 255

12.2.1.9 Silicon 256

12.3 Induced Resistance for Postharvest Disease Control 257

12.4 Compatibility of Activators with Other Control Methods 260

12.4.1 Fungicides 260

12.4.2 Bactericides 262

12.4.3 Insecticides 263

12.4.4 Beneficial microorganisms 264

12.5 Influence of Genotype, Environment and Management Practices on Induced Resistance 266

12.6 Integration of Plant Activators in Crop Management 273

12.7 Challenges and Future Directions 276

12.8 Conclusions 281

References 282

13 Exploitation of Induced Resistance: A Commercial Perspective 300
Andy Leadbeater and Theo Staub

13.1 Introduction 300

13.2 Science and Serendipitous Discovery of Resistance-Inducing Compounds 301

13.3 Discovery of INAs and BTHs 302

13.4 Identification of BION® and other SAR Activators 303

13.5 The Role of Basic Studies in the Discovery of BION® and other SAR/ISR Products 304

13.6 Identification of Harpin 305

13.7 Extracts from Reynoutria sachalinensis 305

13.8 The Commercial Development of an Induced Resistance Product 306

13.9 Legislative Framework 308

13.10 Commercial Experiences with Induced Resistance Products 309

13.11 Conclusions 312

References 312

14 Induced Resistance in Crop Protection: The Future, Drivers and Barriers 316
Gary D. Lyon, Adrian C. Newton and Dale R. Walters

14.1 Introduction 316

14.2 Strategies to Increase Efficacy and Durability in the Field 317

14.3 What Research is Required to Make Induced Resistance Work in Practice? 318

14.4 Can We Breed Plants with Enhanced Responsiveness to Inducers? 321

14.5 The Potential for GM Plants Containing SAR-related Genes 321

14.6 Political, Economic and Legislation Issues 322

14.7 Conclusion 322

14.8 Acknowledgements 323

References 323

Index 327

Dale Walters is based at the Crop and Soil Systems Research Group, Scotland's Rural College (SRUC), Edinburgh, UK, where he is Professor of Plant Pathology.

Adrian Newton is based at the James Hutton Institute, Invergowrie, Dundee, UK, and is also Visiting Professor of Cereal Pathology at SRUC (Scotland's Rural College, UK).

Until recently, Gary Lyon was based at the James Hutton Institute in Dundee, UK.