Abiotic Stress Adaptation in Plants (eBook)

Contents 6
Preface 13
Chapter 1 37
Abiotic Tolerance and Crop Improvement 37
I Introduction 38
A Hunter Evolves as Collector and Cultivator 38
B Projected Food Demands 39
C What Does Stress Mean to an Agriculturalist? 39
II Types of Abiotic Stress in Plants 39
III High Temperature Stress 39
A Temperature Periodicity 40
B Temperature-Induced Male Sterility 40
C High Temperature and Heat Stress 40
D Impact on Quality of the Harvest 41
IV Cold and Frost Stress 42
V Water Deficit Stress 43
A Effect on Root Pattern 43
B Effect on Development 43
B Effect on Fertility Status 44
C Tolerance to Moisture Stress 44
VI Water Logging Stress 44
A Flood Tolerance in Rice 44
1 Role of Root Aerenchyma 45
B Effect on Fruit Crops 45
VII Soil-Related Stresses 45
A Impact on Soil Microbes 46
VIII Climate Change and Stress in Plants 46
IX Conclusions 47
References 47
Chapter 2 49
Sensors and Signal Transducers of Environmental Stress in Cyanobacteria 49
I Introduction 50
II Potential Sensors and Signal Transducers in Cyanobacteria 51
III Involvement of Two-Component Regulatory Systems in Signal Perception and Transduction during Exposure to Environmental St 52
A Positive and Negative Regulation of Gene Expression 52
B Most Two-Component Systems Regulate Stress-Inducible Gene Expression in a Positive Manner 53
1 The Hik33-Rre26 System Regulates the Expression of Cold-Inducible Genes 53
2 Five Two-Component Systems Contribute to the Perception and Transduction of Salt-Stress and Hyperosmotic-Stress Signals bu 56
3 Hik33 is a Major Contributor to Signal Transduction during Oxidative Stress 56
4 Several Hiks Are Involved in the Perception and Transduction of Light-Stress Signals 57
5 The Hik7-Rre29 System Regulates Gene Expression in Response to Phosphate Limitation 57
6 The Hik30-Rre33 System Regulates Gene Expression in Response to Excess Nickel Ions 58
C Negative Regulation and Its Involvement in the Transduction of Manganese-Limitation and Heat-Stress Signals 58
1 The Hik27-Rre16 System Negatively Regulates Gene Expression in Response to Manganese Limitation 58
2 Hik34 Is Involved in Control of the Heat–Stress Response 59
3 Hik20 Is Involved in the Regulation of Expression of the kpdABC Operon 59
IV Other Potential Sensors and Transducers of Environmental Signals 59
A Serine/Threonine Protein Kinases, Tyrosine Protein Kinases and Protein Phosphatases 59
B Sigma Factors and Transcription Factors 60
C Supercoiling of DNA Is Involved in the Perception of Stress Signals and the Regulation of Gene Expression 60
V Conclusions and Perspectives 61
References 62
Chapter 3 66
Stress Signaling I: The Role of Abscisic Acid (ABA) 66
I Introduction 68
II Initial Perception of the Stress 68
III ABA Receptors 69
A G Protein-Coupled Receptor-Like Protein 69
B Genomes Uncoupled 5/Mg Chelatase H (GUN5/CHLH) 70
C Flowering Control Locus A (FCA) 71
D ABA Receptors in Animals 72
IV Transduction of the Stress Signal 72
A Second Messengers 72
B MAPK Signaling Components 74
C Sucrose Non-fermenting-Related Protein Kinase 2 (SnRK2) Proteins 74
D Phosphatases 75
E Protein Modification 76
V Regulation of Abiotic Stresses at the Level of Gene Expression 77
A Cis-Acting Elements for ABA-dependent Gene Expression 77
Box 3.1 Systems Approaches to Stress Tolerance 79
VI Responses to Temperature Stresses 79
Cold Stress Responses 79
B Heat Stress Responses 81
VII Cross-Talk Between Abiotic and Biotic Stress Responses 82
Box 3.2 Comparative Genomics Approaches to Stress Tolerance 86
VIII Regulation of ABA Metabolism 87
References 90
Chapter 4 1
Stress Signaling II: Calcium Sensing and Signaling 1
I Introduction 108
II Calcium Signals 108
A Calcium Signatures 108
B Role of Calcium Signatures 109
C Calcium Channels, Pumps and Transporters 110
III Calcium Sensing and Signaling 110
A Sensor Relays 111
1 Calmodulin and Calmodulin-Like Sensors 111
1.1 Biochemical Functions and Regulation of Calmodulin 111
1.2 Calmodulin and Calmodulin-Like in Abiotic Stresses 111
1.3 Calmodulin-Binding Proteins in Abiotic Stresses 112
2 Calcineurin B-Like Sensors 113
2.1 Structure and Functions of Calcineurin B-Like proteins in Abiotic Stresses 113
2.2 Calcineurin B-Like-Interacting Protein Kinases in Abiotic Stresses 114
B Sensor Protein Kinases 115
1 Calcium-Dependent Protein Kinases 115
1.1 Structure and Regulation of Calcium-Dependent Protein Kinases 115
1.2 Calcium-Dependent Protein Kinases in Abiotic Stress Signaling 116
2 Calcium and Calmodulin-Dependent Protein Kinases 117
3 Other Calcium-Binding Proteins 117
IV Conclusions 118
References 118
Chapter 5 123
Stress Signaling III: Reactive Oxygen Species (ROS) 123
I Introduction 124
II ROS Production and Control 124
A The Cytosol and ROS Movement 124
B Chloroplasts and Photosynthesis 125
C Peroxisomes and Photorespiration 125
D Mitochondrial Respiration 126
E Apoplastic ROS Production 126
F Antioxidant Regulation 126
III The Perception of ROS 127
A Redox Regulation and ROS Perception 127
B ROS Downstream Signaling Networks 129
IV Insights from Genetic and Genomic Strategies 129
A Genomics and Microarrays 129
B Transgenic Approaches 130
C 1O2 Signal Transduction 131
V Conclusions 131
References 132
Chapter 6 135
A Biotic or Abiotic Stress? 135
I Introduction 136
II Biotic Stress Versus Abiotic Stress 137
III General Stress Response 137
IV ABA and Jasmonic Acid: Usual Suspects for Interaction 139
V New Points of Interaction 141
A Auxin, Cytokinin and Brassinosteroids: New Stress Hormones? 141
1 Auxin 141
2 Cytokinin and Brassinosteroids 143
B Salicylic Acid 144
C DELLA Proteins as Central Integrators? 145
Conclusions 148
Box 6.1 Biotic Stress Pathways 148
References 149
Chapter 7 1
Protein Kinases and Phosphatases for Stress Signal Transduction in Plants1 1
I Introduction 157
II Receptor-Like Kinases 157
A Gene Families 157
B Functions 160
1 Disease Resistance 160
2 Hormone Signaling 162
3 Plant Development 163
III Mitogen Activated Protein (MAP) Kinases and MAPK Cascades 164
A Gene Families 164
1 MAPKs 164
2 MAPKKs 165
3 MAPKKKs 166
B Functions 166
1 Disease Resistance 166
2 Hormone Signaling 169
3 Abiotic Stress Signaling 170
IV Calcium-Activated Protein Kinases 170
A Gene Families 171
1 CDPKs 171
2 CRKs 172
3 CCaMKs and CaMKs 172
4 CIPKs and CBLs 172
B Functions of the CBL–CIPK Complexes 174
1 Osmotic Stress 174
2 Potassium Deficiency 175
3 High pH 175
4 Salt Stress 175
5 Novel Stress-Related Interactions 176
V Protein Phosphatases 177
A Gene Families 177
1 Protein Phosphatase P 177
2 Protein Phosphatase M 179
3 Protein Tyrosine Phosphatases 179
B Functions 180
1 Hormone Signaling and Development 180
2 MAPK Interactions 181
3 Novel Interactions 181
VI Conclusions 182
References 182
Chapter 8 196
Nitrogen Source Influences Root to Shoot Signaling Under Drought 196
I Introduction 197
II Nitrogen Source and Availability Influences Signaling Under Drought 197
A Ammonium and Nitrate Nutrition Methods 199
B Ammonium and Nitrate Fertilization Alters Response to Drought 199
III Charge Balance in the Xylem Accounts for Changes Induced by Nutrition and Drought 200
IV Ammonium and Nitrate Grown Plants: Changes in Xylem Sap Composition 201
A Ammonium Nutrition 201
B Nitrate Nutrition 202
V Conclusions 203
References 203
Chapter 9 206
Abiotic Stress Responses: Complexities in Gene Expression 206
I Introduction 207
II Signal Transduction Pathways Under Abiotic Stresses 208
Box 9.1 The Major Signaling Pathways Operative Under Abiotic Stress in Plants 208
MAPK Pathway 208
LEA Genes 208
SOS Pathway 209
ABA Mediated Pathway 209
III Resources for Identification of Novel Genes 209
IV Genomics-based Approaches for Understanding the Response of Plants Towards Abiotic Stresses 211
A Identification of QTLs for Tolerance to Abiotic Stresses 212
B Analysis of Transcript Profiles: Transcriptomics 212
1 Transcriptome Analysis using High-Throughput Techniques 214
1.1 Differential Display PCR 214
1.2 cDNA-Amplified Fragment Length Polymorphism (AFLP) 214
1.3 Subtractive Hybridization 215
1.4 Microarray 215
1.5 Serial Analysis of Gene Expression (SAGE) 215
2 Transcriptional Profiling Reveals That Metabolic Re-Adjustment is a Hallmark of Abiotic Stress Response 215
2.1 Kinetics of Gene Expression Pattern: Early versus Late Responses 216
2.2 Kinetics of Gene Expression Patterns: Developmental Stage/Organ-specific Regulation 217
2.3 Cross Talk between Various Abiotic Stress Responses 218
C Large Scale Study of Proteins: Proteomics 218
D Metabolomics 221
Box 9.2 Recent Techniques Being Used for Analysis of Stress Response in Plants 213
Transcriptomics 213
Differential Display PCR 213
cDNA AFLP 213
Subtractive Hybridization 214
Microarray 214
SAGE 214
Box 9.3 Tools of Proteomics 219
Gas Chromatography 220
Nuclear Magnetic Resonance (NMR) Spectroscopy 220
Yeast Two Hybrid System 220
V Interactome 221
A Interacting Partners of Two Component System 221
B High Throughput Yeast Two Hybrid Analysis 222
C Prediction of Protein–Protein Interactions Using Bioinformatics and Development of Protein Interactome Databases 223
VI Future Prospects 223
References 224
Chapter 10 228
Promoters and Transcription Factors in Abiotic Stress-Responsive Gene Expression 228
I Introduction 229
II Significant ABA-Independent Gene Expression Under Abiotic Stress 230
A DREB1/CBFs: Major Transcription Factors that Regulate Many Cold-Inducible Genes Involved in Stress Tolerance 231
B The DREB/DRE Regulons in Plants Other than Arabidopsis 232
C Cis-Acting Regulatory Elements and Transcription Factors that Function Upstream of DREB1/CBF 233
D DREB2 Proteins Function in Drought, High Salinity and Heat Stress-Responsive Gene Expression 233
III Other ABA-Independent Gene Expression Under Abiotic Stress 235
IV ABA-Responsive Gene Expression Under Abiotic Stresses 235
V Other Types of ABA-Dependent Gene Expression Under Abiotic Stresses 238
VI Conclusions and Future Perspectives 239
References 240
Chapter 11 246
Epigenetic Regulation: Chromatin Modeling and Small RNAs 246
I Introduction 248
II Epigenetics 248
A Chromatin Modeling 249
1 Histone Code 249
1.1 Acetylation 249
1.2 Methylation 250
1.3 Phosphorylation 250
1.4 ADP-Ribosylation 251
1.5 Biotinylation 251
1.6 Ubiquitination 251
1.7 Sumoylation 251
2 DNA Methylation 252
2.1 Box Essay: Analysis of DNA Methylation 253
2.1.1 Methylation-Specific Restriction Analysis 253
2.1.2 Methylated DNA Immunoprecipitation (MeDIP) 253
2.1.3 Bisulfite Method 253
3 Interaction Between Histone Code and DNA Methylation 257
3.1 Small RNAs 258
Box 11.1 Sequencing Methods for Detecting Methylated Alleles 255
Direct DNA Sequencing 255
Pyrosequencing 255
Methylation-Specific PCR (MSP) 255
Methylation-Sensitive Single-Strand Conformation Analysis (MS-SSCA) 255
Methylation-Sensitive High Resolution Melting Analysis (MS-HRM) 256
Methylation-Sensitive Single Nucleotide Primer Extension (MS-SnuPE) 256
Base-Specific Cleavage Reaction Combined with MALDI-TOF Mass Spectrometry 256
Microarray-Based Methods 257
III Abiotic Stress-Induced Epigenetic Changes 259
A Abiotic Stress-Induced Changes in Histone Code 259
B Regulation of DNA Methylation by Abiotic Stresses 262
C siRNAs in Abiotic Stresses 263
D Transgeneration Stress Memory 263
Conclusions and Perspectives 264
References 265
Chapter 12 272
Ion Homeostasis 272
I Introduction 273
II The Need for Ion Homeostasis in Salt Tolerance 273
III Essential Components and Parameters of an ‘Ion Homeostat’ 274
A Models for Plant Ion Homeostasis 274
B Driving Force and Fluxes 277
IV Strategies for Na+ Homeostasis 278
A Cellular Na+ Homeostasis 278
B Tissue Na+ Homeostasis 280
V Transporters Involved in Na+ Homeostasis 280
A Transporters Involved in Cellular Na+ Uptake 280
B Transporters Involved in Cellular Na+ Export 282
C Transporters Involved in Na+ Compartmentalization 282
D Transporters Involved in Long Distance Transport of Na+ 283
VI Conclusions and Outlook 284
References 286
Chapter 13 290
Glutathione Homeostasis: Crucial for Abiotic Stress Tolerance in Plants 290
I Introduction 291
II Regulation of Biosynthesis, Turnover and Compartmentation of Glutathione 292
III Uptake and Transport of Glutathione 293
IV Quantification of Redox Status and its Modulation by Abiotic Stresses 294
V Changes in Glutathione Homeostasis in Plants Under Abiotic Stresses 294
A Salt Stress 295
B Water Deficit 297
C Low Temperature 297
D Ozone Toxicity 298
Heavy Metal Toxicity 299
VI Protein Oxidation Under Abiotic Stresses 300
VII Glutathione as Signaling Molecule and Role of Glutaredoxins 300
Crosstalk and Interaction with Other Biomolecules 303
Conclusions and Perspectives 305
References 305
Chapter 14 310
Water Balance and the Regulation of Stomatal Movements 310
I Introduction 311
II How Does Water Balance Affect Stomatal Movements? 312
A Water Balance Sensing and Information Transfer to Stomata 312
1 Stomatal Response to Limited Water Availability in Soils 312
1.1 An Early Root-to-Shoot Signal 312
1.2 ABA Is the Main Signal 312
1.3 The Hydraulic Signal 313
1.4 Additional Root-Sourced Chemical Signals Implicated in Stomatal Responses to Soil Water Status 314
2 Stomatal Response to Decreased Relative Air Humidity 314
B Regulation of Active ABA Concentrations by Water Balance 314
1 ABA Metabolism 314
2 ABA Transport and Sequestration 315
III Mechanism of Stomatal Movements and Its Regulation by Water Balance 315
A Cellular and Molecular Mechanisms of Stomatal Movements 315
1 Changes in Guard Cell Turgor are Responsible for Stomatal Movements 315
2 Channels and Transporters: Important Effectors Mediating Stomatal Movements 317
2.1 Anion Channels Triggered by ABA 317
2.2 Proton Pumps 317
2.3 Potassium Channels 317
2.4 Effectors of Osmotic Fluxes Across the Tonoplast 318
2.5 Carbohydrate Regulation 318
3 Reorganization of Membranes and Cytoskeleton 318
B Signal Transduction Processes Controlling Stomatal Aperture 319
1 Abscisic Acid Signal Transduction Mechanisms in Guard Cells 319
1.1 Abscisic Acid Perception 319
1.2 Genetic Screens Identify Kinases and Phosphatases 319
1.3 Intracellular Calcium 320
1.4 Reactive Oxygen Species and Redox Control 321
1.5 pH 321
1.6 Lipid Derived Signaling Intermediates 321
1.7 G Proteins 322
2 Guard Cell Signal Transduction Network 322
3 Other Stomatal Closing Stimuli Cross-Talk Through the Guard Cell Signaling Network 322
3.1 Extracellular Calcium 322
3.2 Carbon Dioxide Signaling 323
IV Genes and Promoters of Interest to Manipulate Stomatal Function in Crop Plants 324
V Conclusions 324
References 325
Chapter 15 333
Responses to Macronutrient Deprivation 333
I Introduction 335
II Nitrogen Uptake and Assimilation 335
A Nitrogen in the Environment 335
B Transport of Nitrogen-Containing Compounds 336
C Regulation of Transport 339
D Chlamydomonas Nitrate and Nitrite Reductase 340
E Glutamine Synthetase 341
III Responses to Sustained Nitrogen Starvation 342
IV Sulfur Uptake and Assimilation 342
A Sulfur in the Environment 342
B Sulfate Acquisition and Transport 343
1 Hydrolysis 343
2 Transport Across the Plasma Membrane 344
3 Transport into the Chloroplast 345
C Reductive Assimilation 346
V Control of Sulfur Starvation Responses 348
A Specific and General Responses 348
B Genes Responsive to Sulfur Deprivation 348
C Genes Controlling Sulfur Deprivation Responses 349
D Sequence of Regulatory Events 351
VI Phosphate Uptake and Assimilation 353
A Phosphate in the Environment 353
B Phosphatases 354
C Phosphate Transport 354
D Polyphosphate Synthesis and Mobilization 355
E Nucleic Acids 355
F Phospholipids 356
G Phosphorus Deficiency and Photosynthesis 356
VII Control of Phosphorus Starvation Responses 356
A Mutant Isolation 356
1 PSR1 (Regulator in Chlamydomonas reinhardtii Associated with Phosphate Stress Response) 357
2 Low Phosphorus Bleaching Strains 358
B PSR1-Dependent Gene Expression 358
1 Phosphatases 358
2 Transporters 359
3 Other Genes 359
4 “Electron Valves” 359
C Sequence of Regulatory Events 360
VIII Conclusions 360
References 361
Chapter 16 375
Osmolyte Regulation in Abiotic Stress 375
I Introduction 376
II Osmolytes and their Types 376
A Glycine Betaine 377
B Ectoine 379
C Trehalose 379
D Proline 379
E Myo-inositol and Methylated Inositols 379
III Regulation of Osmolyte Concentration in Plants: Cell and Organ Level 380
A Regulation of Proline Metabolism Under Stress 380
B Glycine Betaine in Stress Regulation 382
C Myo-Inositol and Its Role in Stress Tolerance 382
IV Role of Compatible Solutes/Osmolytes in Other Organisms and Animal Cells 384
A Organic Osmolytes in Renal Cells 384
B Organic Osmolytes in External Epithelial cells 386
C Organic Osmolytes in Brain cells 386
V Mechanism of Action of Osmolytes 387
A Osmolytes as Chaperones 388
B Osmolytes in Stabilization of Proteins 389
VI Unique Osmolytes: Glucosylglycerol/Diphosphoinositols 390
VII Transgenics with Compatible Solutes for Salinity Stress Tolerance 391
VIII Conclusions 393
References 393
Chapter 17 397
Programmed Cell Death in Plants 397
I Introduction 398
II Anatomy of Cell Death 399
III Biochemistry of Cell Death 400
IV Role of Vacuole 401
V Role of Mitochondrion 401
VI Role of Chloroplast 402
VII Signals in Cell Death 403
VIII Cell Death Regulator 404
IX Conclusions 405
References 405
Chapter 18 411
Varietal Improvement for Abiotic Stress Tolerance in Crop Plants: Special Reference to Salinity in Rice 411
I. Introduction 413
The Need for Abiotic Stress-Tolerant Cultivars 413
III Past Breeding Efforts 414
IV Limits of Plant Stress Tolerance 416
A Intercrop Variability 416
B Intracrop Variability (Intervarietal/Genotypic Tolerance) 416
V Breeding Salinity Tolerance with High Yield 417
VI The Concept of Heritability 418
VII Genetics of Salt Tolerance 420
A Inheritance Studies 420
B Association Studies 420
C Gene Action and Heritability 421
D Combining Ability Analysis 421
E Heterosis 421
VIII Breeding Methodology 422
A Conventional Approaches 422
1 Selection and Introduction 422
2 Pedigree Method 422
3 Modified Bulk Pedigree Method 422
4 Shuttle Breeding 422
5 Mutation Breeding 422
6 Diallel Selective Mating System Supplemented by MAS 423
B DSMS Methodology 423
C Non-conventional Approaches 425
1 F1 Anther Culture Technique 425
2 MAS and Transgenics 425
IX Screening Methodology 425
A Screening Techniques 425
1 In-situ Field Evaluation 425
2 Screening in Microplots 425
3 Screening in Pots 426
4 Salinity Screening in Solution Culture 426
5 Screening in Trays 427
B Screening Criteria 427
1 Morphological Parameters 428
2 Germination Parameters 428
3 Plant Survival 428
4 Injury Score 428
5 Phenotypic Expression 428
6 Growth Parameters 428
7 Grain Yield 428
8 Stability of Traits over Environments 428
9 Mean Tolerance Index (MTI) 428
10 Associated Traits 429
11 Physiological and Biochemical Parameters 429
C Selection Pressure 429
X Breeding Strategy to Enhance Salinity Tolerance Through Pyramiding of Mechanisms 429
XI Testing Approaches for Varietal Adaptability 430
A Station Trials 430
B Target Area-Based/Network Approach 430
C Farmer’s Participatory Approach 430
XII Factors Affecting Salt Tolerance 432
A Agronomic Factors 432
B Climatic Factors 432
C Soil Texture and Structure 433
D Rainfall 433
XIII Collaborative Research 433
XIV Rice Varieties Developed for Salt Tolerance 434
XV Impact of Salt-Tolerant Rice Varieties 435
A Direct Impact 435
B Indirect Impact 435
XVI Conclusions 435
XVII Recommendations and Future Lines of Research 436
References 436
Chapter 19 440
Transgenic Approaches 440
I Introduction 441
II Transgenic Approaches for Producing Abiotic Stress Tolerant Plants 442
A Engineering Genes for Stress Signaling 442
1 Sensors of Stress Signal 442
2 Downstream Signaling Cascades 443
Protein Kinases 443
Calcium-Dependent Proteins 444
SOS Signaling 445
B Engineering Genes of Transcriptional Regulation 445
1 Zinc Finger Proteins 446
2 Ethylene Responsive Element Binding Proteins (EREBPs) 447
3 Dehydration Responsive Element Binding Proteins/C-Repeat Binding Factors 448
4 MYB and MYC Transcription Factors 449
5 NAC Proteins 449
6 Other Transcription Factors and DNA/RNA Binding Proteins 450
C Engineering Genes for Redox Regulation 450
D Engineering Genes for Osmotic Regulation 452
E Engineering Genes for Cellular Protection 457
F Engineering Genes for Ionic Balance 458
III Future Perspectives 461
References 461
Chapter 20 474
Marker Assisted Breeding 474
I Introduction 475
II Molecular Markers as Tools for Dissecting Quantitative Traits 476
A Dissecting Complex Traits Using QTL Mapping 477
B Gene Discovery: Genomics and Positional Cloning 477
C Strategies for Marker-Assisted Selection 478
III Case Studies from a Model Crop: MAS for Abiotic Stress Tolerance in Rice 480
A Flooding 481
B Salinity 481
C Phosphorus Deficiency 483
D Drought 484
IV Future Perspectives 485
A Association Mapping for Abiotic Stress Tolerance 485
B Variety Development and Gene Deployment 486
C Bioinformatics Supporting Molecular Breeding 487
1 Integrating Marker Genotype and Plant Phenotype Data 487
2 Using a Gene and Plant Ontology 487
3 Databases for the Next Generation of Plant Breeders 488
V Conclusions 488
Box 20.1 How Will New Marker Technologies Impact Marker-Assisted Breeding? 477
References 489
Chapter 21 493
Stress, Mutators, Mutations and Stress Resistance 493
I Introduction-Stress Induced Changes in Mutation Frequency 494
II Mutator Genes 494
Mutators in Bacteria 494
B Mutators in Eukaryotes 496
C Organellar Mutators 497
III Mutators in Stress Resistance – Implications 498
Genetic, Circumstantial and Speculative Evidence for Mutators in Resistance to Stress 499
Can Stress Increase the Mutation Frequency to Resistance? 500
VI Conclusions 502
References 503
Chapter 22 506
Systems Biology of Abiotic Stress: The Elephant and the Blind Men 506
I Introduction 507
II First Responders: Stomatal Guard Cells 508
A Signaling 509
B Vesicular Trafficking 510
C Cytoskeletal Restructuring 511
III A Systems View of the Stress Response: The Elephant 511
A The Stomate as a System 511
1 Integrating Signal, Structure and Function 511
B Stress Beyond the Stomate 515
C Wherein Lies the Specificity? 516
IV The Future 516
References 516
Chapter 23 524
Global Climate Change, Stress and Plant Productivity 524
I Introduction 525
II Elevated Carbon Dioxide 525
A Photosynthesis 526
B Respiration 526
C Transpiration 527
D Nitrogen Assimilation 527
E Water Use Efficiency 528
F Crop Productivity 529
III High Temperature 530
A Oxidative Stress 531
B Photosynthesis 531
C Crop Phenology 532
D Crop Productivity 534
IV Ultraviolet Radiation 535
V Troposphoric Ozone 536
VI Biotic Stress 536
VII Conclusions and Future Prospects 537
References 538
Subject Index 543