Role of Potassium in Abiotic Stress

Description

This book on potassium in abiotic stress tolerance deals with the ongoing trend in increasing abiotic stresses and interlinked issues food security. As mineral nutrient potassium holds an important place in agriculture and is involved in various physiological and biochemical processes. It takes part in protein synthesis, carbohydrate metabolism, enzyme activation, cation-anion balance, osmoregulation, water movement, energy transfer, and regulates stomata and photosynthesis. Potassium plays an important role as abiotic stress buster. This book will deal with potassium relevance to plant functions and adaptations, range of its biological functions, role of potassium in abiotic stress tolerance, analyses of mechanisms responsible for perception and signal transduction of potassium under abiotic stress, critical evaluation of and cross-talks on nutrients and phytohormones signaling pathways under optimal and stressful conditions, and interaction of potassium with other nutrients for abiotic stress tolerance. This book will be of interest to teachers, researchers, scientists working on abiotic stresses. Also the book serves as additional reading material for undergraduate and graduate students of agriculture, forestry, ecology, and environmental sciences. National and international agricultural scientists, policy makers will also find this to be a useful read. Preface Contents Editors and Contributors About the Editors Contributors 1: Role of Potassium in Plant Photosynthesis, Transport, Growth and Yield 1.1 Introduction 1.2 Role of Potassium in Plants 1.3 Potassium Deficiency in Plants 1.4 Potassium Transport in Plants 1.5 Importance of Potassium in Photosynthesis 1.6 Potassium Fertilizers and Importance of Potassium in Agriculture 1.7 Potassium-Solubilizing Microorganisms (KSMs) and Their Role in Crop Productivity 1.8 Conclusion References 2: Potassium Role in Plants´ Response to Abiotic Stresses 2.1 Introduction 2.2 Potassium in the Soil 2.3 Potassium Role in Plants 2.4 Potassium Role in Response to Abiotic Stress 2.4.1 Drought 2.4.2 Cold Stress 2.4.3 Salinity Stress 2.4.4 Heat Stress 2.4.5 Potassium and Lodging 2.4.6 Potassium and Iron Toxicity 2.4.7 Potassium and Light-Induced Cell Damage 2.5 Conclusions References 3: Molecular Approaches to Potassium Uptake and Cellular Homeostasis in Plants Under Abiotic Stress 3.1 Introduction 3.2 Potassium Uptake and Transport Under Abiotic Stress Conditions 3.3 Potassium Homeostasis Under Abiotic Stress Conditions 3.3.1 Potassium and Abiotic Stress Tolerance in Plants 3.3.1.1 Salinity Stress 3.3.1.2 Drought Stress 3.3.1.3 Extreme Temperature Stress High Temperature Stress Chilling/Freezing Stress 3.3.1.4 Stress Due to High Light Intensity 3.3.1.5 Stress Due to Waterlogging 3.3.1.6 Heavy Metal Stress 3.3.2 Potassium-Induced Abiotic Stress Signalling 3.4 Factors Controlling Intracellular K+ Homeostasis in Plants 3.4.1 ROS 3.4.2 Polyamines 3.4.3 Plant Growth Regulators 3.4.4 Gasotransmitters 3.5 Regulation of K+ Uptake and Cellular Homeostasis by Molecular Approaches 3.5.1 Regulation by NHX Transporters 3.6 Regulation of HAK/KUP/KT Transporters 3.6.1 Transcriptional Regulation 3.6.2 Regulation by Transcription Factors 3.7 Voltage-Independent Potassium Channels 3.7.1 Tandem-Pore Potassium Channels 3.7.2 Plant Kir-Like Channels 3.8 Voltage-Dependent K+ Channels 3.8.1 Regulation of AKT1 Channel 3.8.2 Regulation via Heteromerization 3.9 Conclusion and Future Prospective References 4: Soil Potassium Availability and Role of Microorganisms in Influencing Potassium Availability to Plants 4.1 Introduction 4.2 Potassium Level in Soil 4.3 Potassium-Solubilizing Microorganisms (KSMs) in the Soil 4.4 Potassium-Solubilizing Mechanism 4.4.1 Direct Method 4.4.1.1 Bacterial Cell Wall 4.4.2 Indirect Method 4.4.2.1 Microbial Weathering 4.4.2.2 Mineral Weathering 4.4.2.3 Bioleaching 4.4.2.4 Mechanical Fragmentation 4.4.2.5 Biofilm 4.5 Potassium-Solubilizing Microorganism (KSMs) Affecting Growth and Yield of Plants 4.6 Future Perspective References 5: Crosstalk of Potassium and Phytohormones Under Abiotic Stress 5.1 Introduction 5.2 Potassium in Abiotic Stress Tolerance 5.2.1 Potassium and Salt Tolerance 5.2.2 Potassium and Drought Tolerance 5.2.3 Potassium and Low Temperature Stress 5.2.4 Potassium and High Temperature Stress 5.2.5 Potassium and Metal Toxicity/Metalloids 5.3 Potassium and Mineral Nutrient Crosstalk in Abiotic Stress Tolerance 5.4 Potassium Crosstalk with Phytohormones 5.4.1 Role of K in Auxin Signaling 5.4.2 Role of K in Cytokinin Signaling 5.4.3 Role of K in Gibberellin Signaling 5.4.4 Potassium and Abscisic Acids 5.4.5 Potassium Crosstalk with Jasmonic Acid 5.5 Conclusion References 6: Potassium (K+) Regulation by Phytohormones Under Abiotic Stress 6.1 Introduction 6.2 Biological Functions of Potassium (K+) in Plants (Seed Germination, Growth, Reproductive Development, Photosynthesis and N... 6.2.1 Seed Germination 6.2.2 Growth and Development 6.2.3 Photosynthesis 6.2.4 Nutrient Balance 6.2.5 Reproductive Balance 6.3 Potassium (K+) Sensing, Transport and Assimilation in Plants 6.4 Potassium (K+) Transporters and Associated Mechanisms of Transport and Signalling 6.4.1 Transporters Associated with Root System (K+ Sensing and Influx from Soil) 6.4.2 Transporters Associated with Leaves or Shoot System (K+ and Long-Distance Transport) 6.5 Potassium Homeostasis 6.6 Potassium (K+)-Induced Abiotic Stress Resistance in Plants 6.6.1 K+ Regulation Under Drought Stress 6.6.2 K+ Regulation Under Salinity Stress 6.6.3 K+ Regulation Under Temperature Stress 6.6.4 Potassium Regulation Under Waterlogging Conditions 6.7 Potassium Regulation by Phytohormones Under Abiotic Stress 6.7.1 Plant Growth Regulators (PGRs) and Associated K+ Regulation Under Abiotic Stress Conditions 6.7.1.1 Ethylene (ET) 6.7.1.2 Abscisic Acid 6.7.1.3 Jasmonic Acid (JA) 6.7.1.4 Auxin (IAA) 6.8 Crosstalk Between Different PGRs and Potassium (K+) Under Different Abiotic Stressors 6.9 Conclusion and Future Prospects References 7: Role of Potassium in Drought Adaptation: Insights into Physiological and Biochemical Characteristics of Plants 7.1 Introduction 7.2 Role of Potassium in Improvement of Plant Growth Under Drought Stress 7.3 Role of Potassium in Improvement of Photosynthetic Attributes Under Drought Stress 7.4 Role of Potassium in Cell Expansion and Membrane Stability Under Drought Stress 7.5 Role of Potassium in Improvement of Water-Use Efficiency and Water Uptake Under Drought Stress 7.6 Potassium Involvement in Improvement of Osmolytes Under Drought Stress 7.7 Potassium Controls ROS Production and Improvement of Antioxidant System Under Drought Stress 7.8 Potassium Improves Ionic Balance and Yield Components Under Drought Stress 7.9 Conclusion References 8: Role of Potassium in Heavy Metal Stress 8.1 Introduction 8.2 Heavy Metal Stress in Plants 8.3 Heavy Metal Stress Amelioration: Role of Potassium 8.3.1 Potassium Role in Soil as Fertilizers 8.3.2 Uptake, Transport, and Assimilation of Potassium in Plants 8.4 Role of Potassium in Mitigating Stress Conditions 8.5 Role of Potassium in Amelioration of Heavy Metal Stress and Detoxification of ROS Species 8.6 Stress Signaling Induced by Potassium in Plants Under Heavy Metal Stress 8.7 Conclusions and Future Perspective References 9: Salt Stress Alleviation Strategies to Maintain Potassium Homeostasis in Plants 9.1 Introduction 9.2 Effect of Salt Stress on Physiological and Biochemical Attributes 9.3 The Oxidative Stress and Antioxidant Response During Salt Stress 9.4 Effect of Salt Stress on Ion Uptake 9.5 Role of Potassium and Impact of Its Starvation in Plants 9.6 Potassium in Homeostasis 9.7 Driving Forces for K+ and Na+ Movement Across Membranes 9.8 Role of Plasma Membrane During Salinity 9.9 Salt Stress Alleviation by Application of Micronutrient Zn 9.10 Salt-Tolerant Plant Growth-Promoting Rhizobacteria (ST-PGPR) for Enhancing Crop Productivity of Saline Soils 9.11 Mechanisms of PGPR-Mediated Salt Stress Tolerance 9.12 Conclusion References 10: Potassium Ion Homeostasis, Signaling, and Changes in Transcriptomes and Metabolomes Enduring Salinity Stress 10.1 Introduction 10.2 Ionic Imbalance: A Consequence of Disturbed K+ Homeostasis 10.3 Mechanisms Regulating Na+ and K+ Fluxes 10.3.1 Signaling Pathways for Ionic Stress 10.3.2 Signaling Pathways for Osmotic Stress 10.4 Plant Mechanisms for Regulating K Uptake During Salinity Stress 10.5 Ion Homeostasis 10.6 Osmotic Adjustment 10.7 ROS Detoxification 10.8 Expression/Activation of Saline-Tolerant Genes and Changes in Transcriptome and Metabolomes 10.9 Mutation in Ion Transporter Amino Acid Sequence Improves Salinity Tolerance 10.10 Conclusion References 11: Potassium: A Potent Modulator of Plant Responses Under Changing Environment 11.1 Introduction 11.2 Signaling and Transport of Potassium 11.3 Effect of Exogenous Potassium on Growth and Bio-productivity 11.4 Effect of Exogenous Potassium on Photosynthesis and Plant Water Relations 11.5 Effect of Exogenous Potassium on Plants Exposed to Water Stress 11.6 Effect of Exogenous Potassium on Plants Exposed to Heavy Metal Stress 11.7 Effect of Exogenous Potassium on Plants Grown Under Salinity Stress 11.8 Effect of Exogenous Potassium on Plants Grown Under Temperature Stress 11.9 Conclusions References 12: An Overview of Potassium in Abiotic Stress: Emphasis on Potassium Transporters and Molecular Mechanism 12.1 Introduction: Role of Potassium in Plants 12.2 Plant K Uptake Under Optimal and Limited K Conditions 12.3 K Uptake Under Drought Stress 12.4 K Uptake Under Salinity Stress 12.5 K Uptake Under Flooding 12.6 K Transport Under Suboptimal Temperature Conditions 12.7 Conclusion References 13: Nitric Oxide Synthesis Affects Potassium and Nitrogen Homeostasis in Plants for Salt Tolerance 13.1 Introduction 13.2 Basic Biochemistry of Nitric Oxide 13.3 Biosynthesis of Nitric Oxide 13.3.1 Enzymatic Pathways 13.3.1.1 Nitrate Reductase (NR) 13.3.1.2 Xanthine Oxidoreductase (XOR) 13.3.1.3 Nitrite:NO Reductase (NiNOR) 13.3.1.4 Nitric Oxide Synthase (NOS)-Like Enzymes 13.3.1.5 Other Notable Enzymes 13.3.2 Nonenzymatic Pathways 13.4 Nitric Oxide Synthesis on Potassium and Nitrogen 13.4.1 Nitric Oxide Synthesis Affects Potassium Homeostasis in Plants 13.4.2 Nitric Oxide Synthesis Affects Nitrogen Uptake and Homeostasis in Plants 13.5 Influence of Nitric Oxide Synthesis on Potassium and Nitrogen Homeostasis Under Salt Stress 13.6 Conclusion References