Contributors xi
Preface xv
Chapter 1 The Rice Xa21 Immune Receptor Recognizes a Novel Bacterial Quorum Sensing Factor 1
Chang Jin Park and Pamela C. Ronald
Introduction 1
Plants and Animal Immune Systems 2
A Plethora of Immune Receptors Recognize Conserved Microbial Signatures 2
Ax21 Conserved Molecular Signature 3
Non-RD Receptor Kinase Xa21 8
XA21-Mediated Signaling Components 11
Cleavage and Nuclear Localization of the Rice XA21 Immune Receptor 13
Regulation in the Endoplasmic Reticulum: Quality Control of XA21 14
Systems Biology of the Innate Immune Response 15
Acknowledgments 16
References 16
Chapter 2 Molecular Basis of Effector Recognition by Plant NB-LRR Proteins 23
Lisong Ma, Harrold A. van den Burg, Ben J. C. Cornelissen, and Frank L. W. Takken
Introduction 23
Building Blocks of NB-LRRs; Classification and Structural Features of Subdomains 24
Putting the Parts Together: Combining the Domains to Build a Signaling Competent NB-LRR Protein 29
Stabilization and Accumulation of NB-LRR Proteins: Their Maturation and Stabilization 30
When the Pathogen Attacks: Perception and Signaling by NB-LRR Proteins 33
Conclusion 35
Acknowledgments 35
References 36
Chapter 3 Signal Transduction Pathways Activated by R Proteins 41
Gitta Coaker and Douglas Baker
Introduction 41
R Protein Stability 42
Genetic Separation of CC and TIR-NB-LRR Signaling 42
NB-LRRs Exhibit Modular Structure and Function 44
Subcellular Localization of NB-LRRs 45
NB-LRRs Can Function in Pairs 47
Common Immune Signaling Events Downstream of R Protein Activation 48
Conclusion 50
Acknowledgments 50
References 50
Chapter 4 The Roles of Salicylic Acid and Jasmonic Acid in Plant Immunity 55
Pradeep Kachroo and Aardra Kachroo
Introduction 55
Biosynthesis of SA 55
Derivatives of SA 57
SA and Systemic Acquired Resistance 58
SA Signaling Pathway 60
Jasmonates Mediate Plant Immunity 62
JA Biosynthetic Mutants Are Altered in Microbial Defense 63
Receptor Protein Complex Perceives JA 65
Transcription Factors Regulate JA-Derived Signaling 66
JA Regulates Defense Gene Expression 68
Conclusion 68
Acknowledgments 68
References 69
Chapter 5 Effectors of Bacterial Pathogens: Modes of Action and Plant Targets 81
Feng Feng and Jian-Min Zhou
Introduction 81
Overview of Plant Innate Immunity 81
Overview of Type III Effectors 83
Host Targets and Biochemical Functions 86
Conclusion 99
Acknowledgments 99
References 99
Chapter 6 The Roles of Transcription Activator-Like (TAL) Effectors in Virulence and Avirulence of Xanthomonas 107
Aaron W. Hummel and Adam J. Bogdanove
Introduction 107
TAL Effectors Are Delivered into and May Dimerize in the Host Cell 107
TAL Effectors Function in the Plant Cell Nucleus 108
AvrBs4 Is Recognized in the Plant Cell Cytoplasm 109
TAL Effectors Activate Host Gene Expression 109
Central Repeat Region of TAL Effectors Determines DNA Binding Specificity 110
TAL Effectors Wrap Around DNA in a Right-Handed Superhelix 111
TAL Effector Targets Include Different Susceptibility and Candidate Susceptibility Genes 112
MtN3 Gene Family Is Targeted by Multiple TAL Effectors 114
Promoter Polymorphisms Prevent S Gene Activation to Provide Disease Resistance 115
Nature of the Rice Bacterial Blight Resistance Gene xa5 Suggests TAL Effector Interaction With Plant Transcriptional Machinery 115
Executor R Genes Exploit TAL Effector Activity for Resistance 116
Diversity of TAL Effectors in Xanthomonas Populations Is Largely Unexplored 117
TAL Effectors Are Useful Tools for DNA Targeting 118
Conclusion 118
References 119
Chapter 7 Effectors of Fungi and Oomycetes: Their Virulence and Avirulence Functions and Translocation From Pathogen to Host Cells 123
Brett M. Tyler and Thierry Rouxel
Introduction 123
Plant-Associated Fungi and Oomycetes 125
Identification of Fungal and Oomycete Effectors 126
Defensive Effectors: Effectors That Interfere With Plant Immunity 137
Offensive Effectors: Effectors That Debilitate Plant Tissue 146
Effectors That Contribute to Fitness via Unknown Mechanisms 149
Entry of Intracellular Effectors 149
Genome Location and Consequences for Adaptation/Dispensability 152
Conclusion 153
Acknowledgments 154
References 154
Chapter 8 Plant-Virus Interaction: Defense and Counter-Defense 169
Amy Wahba Foreman, Gail J. Pruss, and Vicki Vance
Introduction 169
RNA Silencing as an Antiviral Defense Pathway - the Beginning of the Story 169
Small Regulatory RNA Biogenesis and Function 172
The Silencing Mafia - the Protein Families 174
Defense: Antiviral RNA Silencing Pathways 177
Counter-Defense: Viral Suppressors of Silencing and Their Targets 178
Viral Suppressors of Silencing and Endogenous Small Regulatory RNA Pathways 181
References 182
Chapter 9 Molecular Mechanisms Involved in the Interaction Between Tomato and Pseudomonas syringae pv. tomato 187
Andre C. Velasquez and Gregory B. Martin
Introduction 187
PAMP-Triggered Immunity in Solanaceae 188
Pseudomonas syringae pv. tomato Virulence Mechanisms 192
Effector-Triggered Immunity in Solanaceae 197
Races of Pseudomonas syringae pv. tomato 200
ETI Is Involved in Nonhost Resistance to Pseudomonas syringae Pathovars 200
ETI Signaling Pathways in Solanaceae 201
Conclusion 203
Acknowledgments 204
References 204
Chapter 10 Cladosporium fulvum-Tomato Pathosystem: Fungal Infection Strategy and Plant Responses 211
Bilal O kmen and Pierre J. G. M. de Wit
Introduction 211
History of the Interaction Between C. fulvum and Tomato 212
Compatible and Incompatible Interactions 212
Cf-Mediated Downstream Signaling 219
Effectors in Other Fungi with Similar Infection Strategies 220
Conclusion 221
References 221
Chapter 11 Cucumber Mosaic Virus-Arabidopsis Interaction: Interplay of Virulence Strategies and Plant Responses 225
Jack H. Westwood and John P. Carr
Introduction 225
Biology of CMV 226
Host Resistance Responses to Virus Infection 230
Targeting of Host Factors by the Virus 236
Phenomenon of Cross-Protection 237
Functions of SA in Antiviral Defense 237
Metabolic Responses to CMV Infection 239
Vector-Mediated Transmission 240
Conclusion 242
Acknowledgments 242
References 243
Chapter 12 Future Prospects for Genetically Engineering Disease-Resistant Plants 251
Yan-Jun Chen, Michael F. Lyngkjær, and David B. Collinge
Introduction 251
Targets for Second-Generation Transgenic Strategies for Resistance 252
Hormones 253
Defense Modulation 256
Transcription Factors 260
Promoters for Transgenic Disease Resistance 265
Implementation of Transgenic Resistance in the Field 266
Why Choose a Transgenic Approach? 267
Conclusion 269
Acknowledgments 269
References 269
Index 277
