In GABA in Plants: Biosynthesis, Plant Development, and Food Security, the editors deliver an expertly balanced discussion of the role played by GABA as a signaling molecule in plants, plant development, stress acclimation, as well as its potential impact on crop productivity under changing environmental conditions.
From explorations of the discovery of GABA in plants to presentations of GABA biosynthesis pathways, GABA crosstalk with other metabolites, and GABA’s role in programmed cell death in plants, this book is an essential treatment of a four-carbon signaling molecule that may yet prove pivotal in sustaining crop production in the face of climate change.
Readers will also find: - A thorough introduction to GABA and its involvement in nodulation in and wounding stress in plants - Comprehensive explorations of plant stress responses and tolerance mechanisms - Practical discussions of GABA priming induced modulations in the redox homeostasis of plants under osmotic stress - Complete treatments of GABA and heat, oxidative, cold, bacterial, mediated salt, and chilling stressors
Perfect for students and scientists working in plant biology and physiology, crop protection, food security, nutrition, and biotechnology, GABA in Plants will also benefit professionals working in the agricultural, food, and pharmaceutical industries.
Table of Contents
Contributors xiii
Preface xix
1 Discovery and Background of GABA in Plants 1
Gubbi Vani Ishika, Deepthi Puttegowda, Ranjith Raj, Manjunath Dammalli, and Ramith Ramu
Abbreviations 1
Introduction 1
History 2
Background 3
The GABA Metabolic Pathway in Plants 4
Structure and Conformation of GABA 6
Roles and Functions of GABA 7
Plant Development 8
Carbon and Nitrogen Metabolic Balance 8
Enhancement of Storage Quality and Shelf Life 9
pH Regulation 9
Compatible Osmolyte 10
Biotic and Abiotic Stress 10
Temperature Stress 11
Low Temperature 11
High Temperature 11
Drought 12
Heavy Metals 12
Ros 12
Salt 13
Conclusion 14
What People Will Learn by Reading This Chapter 14
How This Chapter Helps People Due to its Collective Content 15
References 15
2 GABA Biosynthesis Pathways and its Signaling in Plants 19
Nader Adamipour, Farzad Nazari, and Jaime A. Teixeira da Silva
GABA Production and Degradation Pathway 19
Is GABA Only a Metabolite? 21
Role of GABA in Signaling between Eukaryotes and Bacteria 22
The Role of GABA Signaling in Regulating Pollen Tube Growth 23
The Role of GABA Signaling in Regulating Stomatal Aperture 23
Role of the GABA Shunt in Plants 24
The Effect of GABA on Plant Growth 24
The Effect of GABA on the Regulation of C:N Metabolism 25
The Role of GABA in Improving Shelf Life and the Storage Quality of Products 26
Role of GABA in Cytosolic pH Homeostasis 28
The Impact of GABA on ROS 28
Crosstalk of GABA with Other Signaling Molecules 29
Abscisic Acid 29
Ethylene 29
Auxins 30
Cytokinins 30
Gibberellins 31
Interaction of GABA, PAs, NO, and H 2 O 2 31
GABA and Proline Interaction 32
Conclusion and Future Prospects 32
References 33
3 GABA and Its Crosstalk with Other Metabolites in Relation to Abiotic Stress Responses in Plants 43
Akhilesh Kumar Pandey and Nishtha Srivastava
Introduction 43
Enzymes in GABA Metabolic Pathways 44
Role of GABA Under Stressful Conditions in Plants 45
GABA and Salt Stress 46
GABA and Drought Stress 46
GABA and Chilling Stress 48
Crosstalk of GABA with Other Metabolites and Chemicals 48
GABA with H 2 O 2 49
GABA with Nitric Oxide (NO) 50
GABA with Calcium 50
Interplay of GABA with Plant Hormones 51
GABA with Auxin 51
GABA with Abscisic Acid 51
GABA with Ethylene 52
Mechanisms of Action of GABA in Plants Under Stress 52
Conclusions and Future Perspectives 54
References 54
4 GABA as a Signaling Molecule in Plants 65
Navya Sreepathi, Deepthi Puttegowda, Nagma Firdose, Bhavya Somaplara Gangadharappa, V B Chandana Kumari, and Ramith Ramu
Abbreviations 65
Introduction 66
GABA in Plants as a Stress Response 67
GABA as a Drought-Induced Stress Response in Plants 68
GABA as a Stress Response in Plants Induced by Salinity 70
GABA as a Temperature-Induced Stress Response in Plants 73
GABA’s Role in Mediating Oxidative Stress-Induced Responses in Plants 74
GABA’s Role in Mediating Pathogen and Herbivore Attack Stress-Induced Responses in Plants 76
GABA Signaling in attKLM Operon (Bacteria) 76
GABA Signaling Against Viruses, Fungi, and Insect Attack 77
GABA Signaling in Plant Growth and Development 78
GABA Signaling in Seed Germination 79
GABA in ABA (Abscisic Acid) Signaling Pathway 80
GABA Signaling for Auxin Biosynthesis for Plant Growth Under Fe Deficiency 81
GABA in Root and Shoot Development 81
GABA Influence in Pollen Tube Elongation 83
GABA in Flowering, Fruit Development, and Ripening 83
GABA-Mediated Regulation of Stomatal Aperture in Plants 85
GABA Regulation in Stomatal Closure 85
GABA Signaling for GORK Channels Under Hypoxia 86
GABA in Ion-Exchange Regulation 86
GABA’s Interplay with Diverse Signaling Pathways in Plants 88
Conclusion and Future Prospectives 89
References 90
5 GABA and Drought Stress 97
Petronia Carillo and Andrea Carra
Introduction 97
GABA Shunt in Plants 99
GABA Accumulates in Plants Under Drought Stress 99
GABA Accumulation Increases Drought Tolerance 100
GABA Signaling and the Regulation of Stomatal Opening 102
Conclusion 105
References 105
6 The Role of GABA on Programmed Cell Death and Senescence in Plants 111
Fazilet Özlem Albayrak, Filiz Vardar, and Nihal Gören-Sağlam
Introduction 111
GABA Pathways 112
The Roles of GABA under Stress Conditions 113
GABA as a Signal Molecule 115
GABA-Mediated Avoidance from PCD 116
The Role of GABA on Leaf Senescence 118
Conclusions 121
References 121
7 GABA and Nodulation in Plants 129
Shubhra Khare, Ajey Singh, Km Niharika, Nimisha Amist, Zeba Azim, Rangoli Krishna, Nishtha Srivastava, and Narsingh Bahadur Singh
Introduction 129
Nodulation in Leguminous Plants 130
Functioning of γ-Aminobutyric Acid in Plants 132
Functioning of GABA in Nodulation 134
Conclusions and Future Prospects 136
References 137
8 GABA and Wounding Stress in Plants 143
Neeraj Kumar Dubey, Vijay Bahadur Yadav, Kunwar Deelip Singh, Satyendra Kumar Yadav, Ran Vijay Singh, Amarjeet Singh, and Jogeswar Panigrahi
Introduction 143
GABA: An Important Molecule for Plant 144
GABA and Abiotic Stress 145
Biotic Stress and Wound-Mediated GABA Fluctuation 146
Transgenic Plants Expressing GABA and Effect on Herbivorous Performance 147
References 148
9 GABA in Plant Stress Response and Tolerance Mechanisms 155
Şerife Palabıyık, İrem Çetinkaya, Tülay Öztürk, and Melike Bor
Introduction 155
Abiotic Stress and GABA 158
Salt Stress and GABA 159
Drought and GABA 161
High Temperature and GABA 162
Cold Stress and GABA 163
Heavy Metal Stress and GABA 164
Biotic Stress and GABA 165
Conclusion and Future Prospects 166
References 166
10 GABA Priming Induced Modulations in the Redox Homeostasis of Plants under Osmotic Stress 173
Kakkuzhiyulla Parambath Raj Aswathi, Kolothodi Chandran Jisha, Mathew Veena, Akhila Sen, Nair Gopalakrishnan Sarath, and Jos Thomas Puthur
Introduction 173
Role of GABA in Plants 174
GABA Priming and Oxidative Stress Mitigation 174
Morphological Response 176
Physiological Response: With Special Emphasis on ROS and Antioxidant Machinery 176
Molecular Response 180
Stress Signaling Cross-Talk 181
Conclusion and Future Prospects 182
Acknowledgments 182
References 182
11 Gamma-Aminobutyric acid-Mediated Heavy Metal Stress Tolerance in Plants 189
Srijita Ghosh and Aryadeep Roychoudhury
Introduction 189
Health Benefits of GABA 191
Biosynthesis of GABA 191
GABA Transport in Plants 192
Role of GABA in Abiotic Stress Tolerance 194
GABA and Drought Stress 194
GABA and Polyamines in Drought Stress 197
GABA and Salt Stress 198
GABA and Heat Stress 199
GABA and Cold Stress 200
GABA and Heavy Metal Stress 200
Conclusion 202
Acknowledgments 202
References 203
12 GABA and Heat Stress 211
Zeba Azim, Shubhra Khare, Narsingh Bahadur Singh, Km Niharika, Ajey Singh, Ravi Kumar Yadav, and Nimisha Amist
Introduction 211
GABA-Biosynthesis and Transport/Pathways in Plant 213
GABA Morphological and Physiological Functions within Plants 213
GABA and Abiotic Stress 214
GABA and Heat Stress 215
Conclusion 217
References 218
13 GABA and Oxidative Stress and the Regulation of Antioxidants 225
Somayeh Rastegar and Pegah Sayyad-Amin
Introduction 225
Types and Characteristics of ROS 226
ROS Generation in Plants under Normal and Stress Conditions 227
The Importance of ROS Compartmentation for Plant Stress Adaptation 228
Antioxidant Defense System in Plants 229
Nonenzymatic Antioxidants 229
Enzymatic Antioxidants 231
Relationships of GABA Shunt and ROS during Stress Conditions 233
The Response of GABA under Abiotic Stress Conditions 235
Synthesis of Ascorbic Acid (AsA) 235
Synthesis of Phenolic Compounds 236
Conclusion 237
References 238
14 GABA in Relation to Cold and Chilling Stress 243
Somayeh Rastegar and Emad Hamdy Khedr
Introduction 243
Plant Strategies to Overcome Cold Stress 245
γ-Aminobutyric Acid (GABA) 247
GABA Biosynthesis in Plants 247
Response Strategies of GABA in Cold Stress Tolerance 248
Mitigating ROS Generation and Improving Antioxidant Systems During Cold Stress in Plants 248
GABA Improves Nonenzyme Antioxidant System 250
Regulating Phenol Metabolism 250
Regulating Ascorbic Acid Metabolism 251
Promoting Polyamine Synthesis 252
Protecting Chloroplast Integrity 253
Maintaining Higher ATP Content and Energy Charge 254
Future Perspectives, Challenges, and Conclusion 256
Future Perspectives 256
Challenges 256
Conclusion 256
References 257
15 Role of GABA Under Bacterial Stress in Plants 263
Kuldeep Lahry, Akhilesh Kumar Pandey, and Sudhir Singh
Introduction 263
GABA and Biotic Stress in Plants 266
GABA and Bacterial Stress Response in Plants 267
Molecular Basis of GABA Accumulation in Response to Bacterial Pathogens 269
Glu-dependent Accumulation of GABA 269
Glu-independent Accumulation of GABA 270
The Involvement of GABA in the Interaction of Microbes with Plants 270
Ralstonia solanacearum 270
Pseudomonas syringae pv. tabaci 271
Conclusions and Future Perspectives 272
References 273
16 GABA-Mediated Salt Stress Tolerance Through Physiological and Molecular Mechanisms 287
Riya Johnson, Joy Mulakkal Joel, Koravantakamparambil Sulaiman Anjitha, Louis Noble, Parammal Faseela, and Jos Thomas Puthur
Introduction 287
Concept of Salt Stress to Plants 288
Salt Stress and Related Metabolic Changes 289
GABA and Salinity Stress Tolerance 290
GABA Improves Photosynthesis and Chlorophyll Fluorescence Parameters Under Salt Stress 291
GABA Alleviates Oxidative Injury Induced by Salt Stress via Accumulation of the Osmolytes in Plants 295
Molecular Changes Associated with GABA-Induced Salinity Stress Tolerance 298
Conclusion 299
Acknowledgments 299
References 299
17 GABA and Nutrient Deficiency 305
Km Niharika, Shubhra Khare, Ajey Singh, Zeba Azim, Nimisha Amist, and Narsingh Bahadur Singh
Introduction 305
An Overview of GABA 306
Role of GABA in Plant Development 306
Role of GABA in Different Stress Tolerance 307
Different Mineral Nutrients and Their Role in Plant Development 308
Different Nutrient Deficiencies in Plants 310
Role of GABA in Nutrient Deficiency 311
Concluding Remarks 315
References 315
18 GABA and Plant-Derived Therapeutics 321
Lakshmi Jayaram, Deepthi Puttegowda, V. H. Pushpa, Shashank M. Patil, and Ramith Ramu
List of Abbreviations 321
Introduction 322
The Mechanism of GABA in Action: Neurotransmission and Its Effect on Neurons 322
Plants with Reported GABAergic Activity: A Novel Source of Therapeutics 325
Passiflora incarnata (Passion Flower) 327
Piper methysticum (Kava) 328
Withania somnifera (Ashwagandha, Indian Ginseng, Winter Cherry) 328
Valeriana officinalis, (Valeriana) 329
Scutellaria lateriflora, (Scullcap, Blue Skullcap) 330
Melissa officinalis, (Lemon Balm) 330
Ginkgo biloba, (Maiden Hair) 330
Humulus lupulus, (Hops) 331
Matricaria recutita, (True Chamomile) 331
Centella asiatica, (Gotu Kola) 332
Conclusion and Future Perspective 332
References 333
Index 343
