Understand the impact of climate change on plant growth with this timely introduction
Climate change has had unprecedented consequences for plant metabolism and plant growth. In botany, adverse effects of this kind are called plant stress conditions; in recent years, the plant stress conditions generated by climate change have been the subject of considerable study. Plants have exhibited increased photosynthesis, increased water requirements, and more. There is an urgent need to understand and address these changes as we adapt to drastic changes in the global climate.
Global Climate Change and Plant Stress Management presents a comprehensive guide to the effects of global climate change on plants and plant metabolism. It introduces and describes each climate change-related condition and its components, offering a detailed analysis of the resulting stress conditions, the environmental factors which ameliorate or exacerbate them, and possible solutions. The result is a thorough, rigorous introduction to this critical subject for the future of our biome.
Readers will also find:
- Analysis of global climate change impact on various agricultural practices
- Socio-economic consequences of climate change and plant stress conditions, and possible solutions
- Strategies for sustainable agriculture
Global Climate Change and Plant Stress Management is essential for researchers, scientists, and industry professionals working in the life sciences, as well as for advanced graduate students.
Table of Contents
List of Contributors xvii
Foreword xxiii
Preface xxv
Author Biographies xxvii
Part 1 Views and Visions 1
1 Boosting Resilience of Global Crop Production Through Sustainable Stress Management 3
Rajeev K. Varshney and Abhishek Bohra
References 5
2 Sustaining Food Security Under Changing Stress Environment 7
Sudhir K. Sopory
References 8
3 Crop Improvement Under Climate Change 9
Shivendra Bajaj and Ratna Kumria
3.1 Crop Diversity to Mitigate Climate Change 10
3.2 Technology to Mitigate Climate Change 10
3.3 Farm Practices to Mitigate Climate Change 11
3.4 Conclusion 11
References 11
4 Reactive Nitrogen in Climate Change, Crop Stress, and Sustainable Agriculture: A Personal Journey 13
Nandula Raghuram
4.1 Introduction 13
4.2 Reactive Nitrogen in Climate Change, Agriculture, and Beyond 13
4.3 Nitrogen, Climate, and Planetary Boundaries of Sustainability 14
4.4 Emerging Global Response and India’s Leadership in It 14
4.5 Regional and Global Partnerships for Effective Interventions 15
4.6 Building Crop NUE Paradigm Amidst Growing Focus on Stress 16
4.7 From NUE Phenotype to Genotype in Rice 17
4.8 Furthering the Research and Policy Agenda 18
References 18
Part 2 Climate Change: Global Impact 23
5 Climate-Resilient Crops for CO 2 Rich-Warmer Environment: Opportunities and Challenges 25
Sayanta Kundu, Sudeshna Das, Satish K. Singh, Ratnesh K. Jha, and Rajeev Nayan Bahuguna
5.1 Introduction 25
5.2 Climate Change Trend and Abiotic Stress: Yield Losses Due to Major Climate Change Associated Stresses Heat, Drought and Their Combination 26
5.3 Update on Crop Improvement Strategies Under Changing Climate 27
5.3.1 Advances in Breeding and Genomics 27
5.3.2 Advances in Phenomics and High Throughput Platforms 28
5.3.3 Non-destructive Phenotyping to Exploit Untapped Potential of Natural Genetic Diversity 28
5.4 Exploiting Climate-Smart Cultivation Practices 29
5.5 CO 2 -Responsive C 3 Crops for Future Environment 30
5.6 Conclusion 31
References 31
6 Potential Push of Climate Change on Crop Production, Crop Adaptation, and Possible Strategies to Mitigate This 35
Narendra Kumar and SM Paul Khurana
6.1 Introduction 35
6.2 Influence of Climate Change on the Yield of Plants 36
6.3 Crop Adaptation in Mitigating Extreme Climatic Stresses 38
6.4 Factors That Limit Crop Development 39
6.5 Influence of Climate Change on Plants’ Morphobiochemical and Physiological Processes 39
6.6 Responses of Plant Hormones in Abiotic Stresses 40
6.7 Approaches to Combat Climate Changes 41
6.7.1 Cultural Methodologies 41
6.7.2 Conventional Techniques 41
6.7.3 Strategies Concerned with Genetics and Genomics 41
6.7.3.1 Omics-Led Breeding and Marker-Assisted Selection (MAS) 41
6.7.3.2 Genome-Wide Association Studies (GWAS) for Evaluating Stress Tolerance 42
6.7.3.3 Genome Selection (GS) Investigations for Crop Improvement 42
6.7.3.4 Genetic Engineering of Plants in Developing Stress Tolerance 43
6.7.4 Strategies of Genome Editing 43
6.7.5 Involvement of CRISPR/Cas 9 43
6.8 Conclusions 44
Conflict of Interest Statement 44
Acknowledgment 44
References 45
7 Agrifood and Climate Change: Impact, Mitigation, and Adaptation Strategies 53
Sudarshna Kumari and Gurdeep Bains
7.1 Introduction 53
7.2 Causes of Climate Change 54
7.2.1 Greenhouse Gases 54
7.2.2 Fossil Fuel Combustion 54
7.2.3 Deforestation 55
7.2.4 Agricultural Expansion 55
7.3 Impact of Climate Change on Agriculture 55
7.3.1 Crop Productivity 56
7.3.2 Disease Development 58
7.3.3 Plant Responses to Climate Change 58
7.3.4 Livestock 59
7.3.5 Agriculture Economy 59
7.4 Mitigation and Adaptation to Climate Change 60
7.4.1 Climate-Smart Cultural Practices 60
7.4.2 Climate-Smart Agriculture Technologies 60
7.4.3 Stress-Tolerant Varieties 61
7.4.4 Precision Management of Nutrients 61
7.4.5 Forestry and Agroforestry 61
7.5 Conclusions and Future Prospects 61
References 62
8 Dynamic Photosynthetic Apparatus in Plants Combats Climate Change 65
Ramwant Gupta and Ravinesh Rohit Prasad
8.1 Introduction 65
8.2 Climate Change and Photosynthetic Apparatus 66
8.3 Engineered Dynamic Photosynthetic Apparatus 66
8.4 Conclusion and Prospects 68
References 68
9 CRISPR/Cas Enables the Remodeling of Crops for Sustainable Climate-Smart Agriculture and Nutritional Security 71
Tanushri Kaul, Rachana Verma, Sonia Khan Sony, Jyotsna Bharti, Khaled Fathy Abdel Motelb, Arul Prakash Thangaraj, Rashmi Kaul, Mamta Nehra, and Murugesh Eswaran
9.1 Introduction: CRISPR/Cas Facilitated Remodeling of Crops 71
9.2 Impact of Climate Changes on Agriculture and Food Supply 72
9.3 Nutritionally Secure Climate-Smart Crops 73
9.4 Novel Game Changing Genome-Editing Approaches 74
9.4.1 Knockout-Based Approach 87
9.4.2 Knock-in-Based Approach 87
9.4.3 Activation or Repression-Based Approach 87
9.5 Genome Editing for Crop Enhancement: Ushering Towards Green Revolution 2.0 88
9.5.1 Mitigation of Abiotic Stress 88
9.5.2 Alleviation of Biotic Stress 89
9.5.3 Biofortification 89
9.6 Harnessing the Potential of NGS and ML for Crop Design Target 90
9.7 Does CRISPR/Cas Address the Snag of Genome Editing? 94
9.8 Edited Plant Code: Security Risk Assessment 95
9.9 Conclusion: Food Security on the Verge of Climate change 96
References 96
Part 3 Socioeconomic Aspects of Climate Change 113
10 Perspective of Evolution of the C 4 Plants to Develop Climate Designer C 4 Rice as a Strategy for Abiotic Stress Management 115
Shuvobrata Majumder, Karabi Datta, and Swapan K. Datta
10.1 Introduction 115
10.2 How Did Plants Evolve to the C 4 System? 117
10.2.1 Gene Amplification and Modification 117
10.2.2 Anatomical Preconditioning 117
10.2.3 Increase in Bundle Sheath Organelles 118
10.2.4 Glycine Shuttles and Photorespiratory CO 2 Pumps 118
10.2.5 Enhancement of PEPC and PPDK Activity in the Mesophyll Tissue 118
10.2.6 Integration of C 3 and C 4 Cycles 118
10.3 What Are the Advantages of C 4 Plants over C 3 Plants? 118
10.4 Molecular Engineering of C 4 Enzymes in Rice 119
10.4.1 Green Tissue-Specific Promoters 120
10.4.2 Expressing C 4 Enzyme, PEPC in Rice 120
10.4.3 Expressing C 4 Enzyme, PPDK in Rice 120
10.4.4 Expressing C 4 Enzyme, ME and NADP-ME in Rice 121
10.4.5 Expressing Multiple C 4 Enzymes in Rice 121
10.5 Application of CRISPR for Enhanced Photosynthesis 121
10.6 Single-Cell C 4 Species 121
10.7 Conclusion 122
Acknowledgments 122
References 122
11 Role of Legume Genetic Resources in Climate Resilience 125
Ruchi Bansal, Swati Priya, and H. K. Dikshit
11.1 Introduction 125
11.2 Legumes Under Abiotic Stress 126
11.2.1 Legumes Under Drought Stress 126
11.2.2 Legumes Under Waterlogging 126
11.2.3 Legumes Under Salinity Stress 127
11.2.4 Legumes Under Extreme Temperature 127
11.3 Genetic Resources for Legume Improvement 128
11.3.1 Lentil 129
11.3.2 Mungbean 130
11.3.3 Pigeon Pea 131
11.3.4 Chickpea 131
11.4 Conclusion 133
References 134
12 Oxygenic Photosynthesis - a Major Driver of Climate Change and Stress Tolerance 141
Baishnab C. Tripathy
12.1 Introduction 141
12.2 Evolution of Chlorophyll 141
12.3 The Great Oxygenation Event 142
12.4
Role of Forest in the Regulation of O 2 and CO 2 Concentrations in the Atmosphere 142
12.5 Evolution of C 4 Plants 142
12.6 The Impact of High Temperature 143
12.7 c 4 Plants Are Tolerant to Salt Stress 144
12.8 Converting C 3 Plants into C 4 - A Himalayan Challenge 145
12.9 Carbonic Anhydrase 145
12.10 Phosphoenolpyruvate Carboxylase 146
12.11 Malate Dehydrogenase 147
12.12 Decarboxylating Enzymes 147
12.12.1 NAD/NADP-Malic Enzyme 148
12.12.2 Phosphoenolpyruvate Carboxykinase 149
12.13 Pyruvate Orthophosphate Dikinase 149
12.14 Regulation of C 4 Photosynthetic Gene Expression 150
12.15 Use of C 3 Orthologs of C 4 Enzymes 151
12.16 Conclusions and Future Directions 151
Acknowledgment 152
References 152
13 Expand the Survival Limits of Crop Plants Under Cold Climate Region 161
Bhuvnesh Sareen and Rohit Joshi
13.1 Introduction 161
13.2 Physiology of Cold Stress Tolerant Plants 162
13.3 Stress Perception and Signaling 163
13.4 Plant Survival Mechanism 164
13.5 Engineering Cold Stress Tolerance 165
13.6 Future Directions 168
Acknowledgment 168
References 168
14 Arbuscular Mycorrhizal Fungi (AMF) and Climate-Smart Agriculture: Prospects and Challenges 175
Sharma Deepika, Vikrant Goswami, and David Kothamasi
14.1 Introduction 175
14.2 What Is Climate-Smart Agriculture? 176
14.3 AMF as a Tool to Practice Climate-Smart Agriculture 177
14.3.1 AMF in Increasing Productivity of Agricultural Systems 177
14.3.1.1 Plant Nutrition and Growth 177
14.3.1.2 Improved Soil Structure and Fertility 181
14.3.2 AMF-Induced Resilience in Crops to Climate Change 182
14.3.2.1 AMF and Salinity Stress 182
14.3.2.2 AMF and Drought Stress 183
14.3.2.3 AMF and Heat Stress 184
14.3.2.4 AMF and Cold Stress 184
14.3.3 AMF-Mediated Mitigation of Climate Change 186
14.3.4 Agricultural Practices and AMF Symbiosis - Crop Rotations, Tillage, and Agrochemicals 187
14.3.5 AMF Symbiosis and Climate Change 187
14.3.6 Conclusions and Future Perspectives 188
Acknowledgment 189
References 189
Part 4 Plant Stress Under Climate Change: Molecular Insights 201
15 Plant Stress and Climate Change: Molecular Insight 203
Anamika Roy , Mamun Mandal, Ganesh Kumar Agrawal, Randeep Rakwal, and Abhijit Sarkar
15.1 Introduction 203
15.2 Different Stress Factors and Climate Changes Effects in Plants 206
15.2.1 Water Stress 206
15.2.1.1 Drought 206
15.2.1.2 Flooding or Waterlogging 206
15.2.2 Temperature Stress 207
15.2.2.1 High Temperature Stress 207
15.2.2.2 Low Temperature Stress 207
15.2.3 Salinity Stress 207
15.2.4 Ultraviolet (UV) Radiation Stress 207
15.2.5 Heavy Metal Stress 207
15.2.6 Air Pollution Stress 208
15.2.7 Climate Change 208
15.3 Plant Responses Against Stress 208
15.3.1 Water Stress Responses 208
15.3.1.1 Drought Responses 208
15.3.1.2 Waterlogging Responses 210
15.3.2 Temperature Stress Responses 210
15.3.2.1 High Temperature Stress Responses 210
15.3.2.2 Low Temperature Stress Responses 211
15.3.3 Salinity Stress Responses 212
15.3.3.1 Genomic Responses 212
15.3.3.2 Proteomic Responses 212
15.3.3.3 Transcriptomic Responses 212
15.3.3.4 Metabolomic Responses 213
15.3.4 Ultraviolet (UV) Radiation Stress 213
15.3.4.1 Genomic Responses 213
15.3.4.2 Proteomic Responses 213
15.3.4.3 Transcriptomic Responses 213
15.3.4.4 Metabolomic Responses 213
15.3.5 Heavy Metal Stress Responses 214
15.3.5.1 Genomic Responses 214
15.3.5.2 Proteomic Responses 214
15.3.5.3 Transcriptomic Responses 214
15.3.5.4 Metabolomic Responses 214
15.3.6 Air Pollution Stress Responses 214
15.3.6.1 Genomic Responses 215
15.3.6.2 Proteomic Responses 215
15.3.6.3 Transcriptomic Responses 215
15.3.6.4 Metabolomic Responses 215
15.3.7 Climate Change Responses 215
15.3.7.1 Genomic Responses 215
15.3.7.2 Proteomic Responses 216
15.3.7.3 Transcriptomic Responses 216
15.3.7.4 Metabolomic Responses 216
15.4 Conclusion 216
References 216
16 Developing Stress-Tolerant Plants: Role of Small GTP Binding Proteins (RAB and RAN) 229
Manas K. Tripathy and Sudhir K. Sopory
16.1 Introduction 229
16.2 A Brief Overview of GTP-Binding Proteins 230
16.3 Small GTP-Binding Proteins 230
16.3.1 Rab 231
16.3.1.1 Role of RAB’s in Plant 231
16.3.2 Ran 234
16.3.2.1 Role of RAN in Plants 234
16.4 Conclusions 236
Acknowledgments 237
References 237
17 Biotechnological Strategies to Generate Climate-Smart Crops: Recent Advances and Way Forward 241
Jyoti Maurya, Roshan Kumar Singh, and Manoj Prasad
17.1 Introduction 241
17.2 Climate Change and Crop Yield 242
17.3 Effect of Climate Change on Crop Morpho-physiology, and Molecular Level 243
17.4 Plant Responses to Stress Conditions 244
17.5 Strategies to Combat Climate Change 245
17.5.1 Cultural and Conventional Methods 245
17.5.2 Multi-omics Approach 245
17.5.3 Biotechnological Approaches 248
17.5.3.1 Combating Climate Change Through Overexpression of Candidate Gene(s) 248
17.5.3.2 Small RNA-Mediated Gene Silencing Approach 249
17.5.3.3 Gene Editing Through Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Approach 250
17.6 Conclusion and Way Forward 251
Acknowledgments 252
Declaration of Interest Statement 252
References 252
18 Receptor-Like Kinases and ROS Signaling: Critical Arms of Plant Response to Stress 263
Samir Sharma
18.1 Preamble 263
18.2 Climate Change: The Agent of Stress 264
18.3 Abiotic Stress: A Severe Threat by Itself and a Window of Opportunity for Biotic Stress Agents 264
18.4 Plant Receptor-Like Kinases (RLKs) 265
18.5 Receptor-Like Cytosolic Kinases 267
18.6 Why Are Receptor-Like Cytosolic Kinases Needed? 268
18.7 Receptor-Like Cytosolic Kinases in Plant Defense 269
18.8 Receptor-Like Cytosolic Kinases in Plant Development 270
18.9 Reactive Oxygen Species: Dual Role in Plants and Links to Receptor-Like Protein Kinases 272
18.10 Conclusion 273
References 273
19 Phytohormones as a Novel Weapon in Management of Plant Stress Against Biotic Agents 277
Rewaj Subba, Swarnendu Roy, and Piyush Mathur
19.1 Introduction 277
19.2 Phytohormones and Biotic Stress Management 278
19.2.1 Salicylic Acid 278
19.2.2 Jasmonic Acid (JA) 278
19.2.3 Ethylene (ET) 279
19.2.4 Abscisic Acid (ABA) 279
19.3 Phytohormone Mediated Cross-Talk in Plant Defense Under Biotic Stress 281
References 282
20 Recent Perspectives of Drought Tolerance Traits: Physiology and Biochemistry 287
Priya Yadav, Mohammad Wahid Ansari, Narendra Tuteja, and Moaed Al Meselmani
20.1 Introduction 287
20.2 Effects and Response During Drought Stress on Physiological and Biochemical Traits of Plants 288
20.3 Recent Advances in Drought Stress Tolerance 289
20.4 Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth-Promoting Rhizobacteria (PGPRs) in Drought Stress Tolerance 291
20.5 Genomic Level Approach in Drought Stress Tolerance 291
20.6 Conclusion 293
References 293
21 Understanding the Role of Key Transcription Factors in Regulating Salinity Tolerance in Plants 299
Sahana Basu and Gautam Kumar
21.1 Introduction 299
21.2 Transcription Factors Conferring Salinity Tolerance 299
21.2.1 APETALA2/Ethylene Responsive Factor 299
21.2.1.1 Structure of AP2/ERF Transcription Factors 301
21.2.1.2 Classification of AP2/ERF Transcription Factors 301
21.2.1.3 Role of AP2/ERF Transcription Factors in Salinity Tolerance 302
21.2.2 Wrky 302
21.2.2.1 Structure of WRKY Transcription Factors 302
21.2.2.2 Classification of WRKY Transcription Factors 302
21.2.2.3 Role of WRKY Transcription Factors in Salinity Tolerance 306
21.2.3 Basic Helix-Loop-Helix 307
21.2.3.1 Structure of bHLH Transcription Factors 307
21.2.3.2 Classification of bHLH Transcription Factors 307
21.2.3.3 Role of bHLH Transcription Factors in Salinity Tolerance 307
21.2.4 v-Myb Myeloblastosis Viral Oncogene Homolog 308
21.2.4.1 Structure of MYB Transcription Factors 308
21.2.4.2 Classification of MYB Transcription Factors 308
21.2.4.3 Role of MYB Transcription Factors in Salinity Tolerance 309
21.2.5 NAM (for no apical meristem), ATAF1 and −2, and CUC2 (for cup-shaped cotyledon) 309
21.2.5.1 Structure of NAC Transcription Factors 309
21.2.5.2 Classification of NAC Transcription Factors 309
21.2.5.3 Role of NAC Transcription Factors in Salinity Tolerance 310
21.2.6 Nuclear Factor-Y 310
21.2.6.1 Structure of NF-Y Transcription Factors 310
21.2.6.2 Classification of NF-Y Transcription Factors 310
21.2.6.3 Role of NF-Y Transcription Factors in Salinity Tolerance 311
21.2.7 Basic Leucine Zipper 311
21.2.7.1 Structure of bZIP Transcription Factors 311
21.2.7.2 Classification of bZIP Transcription Factors 312
21.2.7.3 Role of bZIP Transcription Factors in Salinity Tolerance 312
21.3 Conclusion 312
References 312
Part 5 Stress Management Strategies for Sustainable Agriculture 317
22 Seed Quality Assessment and Improvement Between Advancing Agriculture and Changing Environments 319
Andrea Pagano, Paola Pagano, Conrado Dueñas, Adriano Griffo, Shraddha Shridhar Gaonkar, Francesca Messina, Alma Balestrazzi, and Anca Macovei
22.1 Introduction: A Seed’s Viewpoint on Climate Change 319
22.2 Assessing Seed Quality: Invasive and Non-invasive Techniques for Grain Testing 321
22.3 Improving Seed Quality: Optimizing Priming Techniques to Face the Challenges of Climate Changes 324
22.4 Understanding Seed Quality: Molecular Hallmarks and Experimental Models for Future Perspectives in Seed Technology 327
22.5 Conclusive Remarks 329
References 329
23 CRISPR/Cas9 Genome Editing and Plant Stress Management 335
Isorchand Chongtham and Priya Yadav
23.1 Introduction 335
23.2 CRISPR/Cas 9 336
23.2.1 CRISPR Cas System 336
23.2.2 CRISPR Cas 9 337
23.2.3 CRISPR/Cas9 Mechanism 338
23.2.4 CRISPR/Cas9 Types of Gene Editing 339
23.3 Construct of the CRISPR/Cas 9 341
23.3.1 The gRNA 341
23.3.2 The Choice of Gene Regulatory Elements (GREs) 341
23.3.3 Multiplex CRISPR 341
23.4 Plant Genome Editing 343
23.4.1 Procedure 343
23.4.2 Plant Improvement Strategies Based on Genome Editing 344
23.5 Plant Stress 344
23.5.1 Plant Stress and Their Types 344
23.5.2 Plant Remedial Measures Toward Stress 345
23.6 Genome Editing for Plant Stress 346
23.6.1 Biotic Stress 348
23.6.1.1 Bacterium 348
23.6.1.2 Virus 348
23.6.1.3 Fungus 348
23.6.1.4 Insect 349
23.6.2 Abiotic Stress 349
23.6.2.1 Chemicals 349
23.6.2.2 Environmental 349
23.7 Elimination of CRISPR/Cas from the System After Genetic Editing 350
23.8 Prospects and Limitations 350
References 351
24 Ethylene Mediates Plant-Beneficial Fungi Interaction That Leads to Increased Nutrient Uptake, Improved Physiological Attributes, and Enhanced Plant Tolerance Under Salinity Stress 361
Priya Yadav, Mohammad Wahid Ansari, Narendra Tuteja, and Ratnum K. Wattal
24.1 Introduction 361
24.2 Plant Response Towards Salinity Stress 361
24.3 Plant-Fungal Interaction and the Mechanism of Plant Growth Promotion by Fungi 362
24.3.1 Nutrient Acquisition and Phytohormones Production 362
24.3.2 Activation of Systemic Resistance 364
24.3.3 Production of Siderophores 364
24.3.4 Production of Antibiotics and Secondary Metabolites 365
24.3.5 Protection to Biotic and Abiotic Stress 365
24.4 Fungi and Ethylene Production and Its Effects 365
24.5 Role and Mechanism of Ethylene in Salinity Stress Tolerance 366
24.6 Conclusion 367
References 367
25 Role of Chemical Additives in Plant Salinity Stress Mitigation 371
Priya Yadav, Mohammad Wahid Ansari, and Narendra Tuteja
25.1 Introduction 371
25.2 Types of Chemical Additives and Their Source 372
25.3 Application and Mechanism of Action 373
25.4 NO (Nitric Oxide) in Salt Stress Tolerance 374
25.5 Melatonin in Salt Stress Tolerance 374
25.6 Polyamines in Salt Stress Tolerance 374
25.7 Salicylic Acid (SA) in Salt Stress Tolerance 375
25.8 Ethylene in Salinity Stress Tolerance 376
25.9 Trehalose in Salinity Stress Tolerance 377
25.10 Kresoxim-Methyl (KM) in Salinity Stress Tolerance 377
25.11 Conclusion 377
References 377
26 Role of Secondary Metabolites in Stress Management Under Changing Climate Conditions 383
Priya Yadav and Zahid Hameed Siddiqui
26.1 Introduction 383
26.1.1 Types of Plant Secondary Metabolites 383
26.1.1.1 Phenolics 384
26.1.1.2 Terpenoids 384
26.1.1.3 Nitrogen-Containing Secondary Metabolites 384
26.2 Biosynthesis of Plant Secondary Metabolites 385
26.2.1 Role of Secondary Metabolites in Mitigating Abiotic Stress 388
26.2.2 Secondary Metabolites in Drought Stress Mitigation 389
26.2.2.1 Phenolic compounds and drought stress 389
26.2.2.2 Terpenoids in drought stress tolerance 389
26.2.3 Secondary Metabolites in Mitigating Salinity Stress 390
26.2.4 Secondary Metabolites as UV Scavengers 390
26.3 Heavy Metal Stress and Secondary Metabolites 390
26.3.1.1 Phenolic compounds and metal stress 391
26.3.2 Role of Secondary Metabolites in Biotic Stress Mitigation 392
26.3.2.1 Terpenoids and Biotic Stress 392
26.3.2.2 Phenolic Compounds and Biotic Stress 392
26.3.2.3 Nitrogen-Containing Compound and Biotic Stress 393
26.4 Counteradaptation of Insects Against Secondary Metabolites 393
26.5 Sustainable Crop Protection and Secondary Metabolites 393
26.6 Conclusion 393
References 394
27 Osmolytes: Efficient Oxidative Stress-Busters in Plants 399
Naser A. Anjum, Palaniswamy Thangavel, Faisal Rasheed, Asim Masood, Hadi Pirasteh-Anosheh, and Nafees A. Khan
27.1 Introduction 399
27.1.1 Plant Health, Stress Factors, and Oxidative Stress and Its Markers 399
27.1.2 Modulators of Oxidative Stress Markers and Antioxidant Metabolism 399
27.2 Osmolytes - An Overview 400
27.2.1 Role of Major Osmolytes in Protection of Plants Against Oxidative Stress 401
27.2.1.1 Betaines and Related Compounds 401
27.2.1.2 Proline 401
27.2.1.3 γ-Aminobutyric Acid (Gamma Amino Butyric Acid) 402
27.2.1.4 Polyols 402
27.2.1.5 Sugars 403
27.3 Conclusion and Perspectives 404
References 404
Index 411
