Heavy Metal Toxicity and Tolerance in Plants provides a comprehensive overview of the physiological, biochemical, and molecular basis of heavy metal tolerance and functional omics that allow for a deeper understanding of using heavy metal tolerance for deliberate manipulation of plants. Through the authors’ unique approach, the text enables researchers to develop strategies to enhance metal toxicity and deficiency tolerance as well as crop productivity under stressful conditions, in order to better utilize natural resources to ensure future food security.
The text presents the basic knowledge of plant heavy metal/metalloid tolerance using modern approaches, including omics, nanotechnology, and genetic manipulation, and covers molecular breeding, genetic engineering, and approaches for high yield and quality under metal toxicity or deficiency stress conditions.
With a collection of 26 chapters contributed by the leading experts in the fields surrounding heavy metal and metalloids toxicity and tolerance in crop plants, Heavy Metal Toxicity and Tolerance in Plants includes further information on: - Advanced techniques in omics research in relation to heavy metals/metalloids toxicity and tolerance - Heavy metals/metalloids in food crops and their implications for human health - Molecular mechanisms of heavy metals/metalloids toxicity and tolerance in plants - Molecular breeding approaches for reducing heavy metals load in the edible plant parts - Hormonal regulation of heavy metals toxicity and tolerance - Applications of nanotechnology for improving heavy metals stress tolerance - Genetic engineering for heavy metals/metalloids stress tolerance in plants
With comprehensive coverage of the subject, Heavy Metal Toxicity and Tolerance in Plants is an essential reference for researchers working on developing plants tolerant to metals/metalloids stress and effective strategies for reducing the risk of health hazards.
Table of Contents
List of Contributors xix
Preface xxix
Editor Biographies xxxi
1 Plant Response and Tolerance to Heavy Metal Toxicity: An Overview of Chemical Biology, Omics Studies, and Genetic Engineering 1
Lovely Mahawar, Sakshi Pandey, Aparna Pandey, and Sheo Mohan Prasad
1.1 Introduction 1
1.2 Plant-Metal Interaction 2
1.3 Effect of Heavy Metals on Plants 3
1.3.1 Morphoanatomical Responses 3
1.3.2 Physiological Responses 8
1.3.3 Biochemical Responses 8
1.3.4 Molecular Responses 9
1.4 Mechanisms to Tolerate Heavy Metal Toxicity 10
1.4.1 Avoidance 10
1.4.1.1 Mycorrhizal Association 10
1.4.1.2 Root Exudates 12
1.4.2 Sequestration 12
1.5 Important Strategies for the Enhancement of Metal Tolerance 15
1.5.1 Omics 15
1.5.1.1 Genomics 15
1.5.1.2 Transcriptomics 15
1.5.1.3 Proteomics 17
1.5.1.4 Metabolomics 17
1.5.1.5 Ionomics 18
1.5.1.6 miRNAomics 19
1.5.1.7 Metallomics 19
1.5.2 Genetic Engineering 20
1.5.2.1 CRISPR Technology 20
1.5.2.2 Plastid Transformation 21
1.5.2.3 Gene Silencing 22
1.6 Conclusion and Future Prospects 22
References 23
2 Advanced Techniques in Omics Research in Relation to Heavy Metal/Metalloid Toxicity and Tolerance in Plants 35
Ali Raza, Shanza Bashir , Hajar Salehi , Monica Jamla, Sidra Charagh, Abdolkarim Chehregani Rad, and Mohammad Anwar Hossain
2.1 Introduction 35
2.2 An Overview of Plant Responses to Heavy Metal Toxicity 36
2.3 How the Integration of Multi-omics Data Sets Helps in Studying the Heavy Metal Stress Responses and Tolerance Mechanisms? 39
2.3.1 The Contribution of State-of-the-Art Genomics-Assisted Breeding 39
2.3.1.1 Quantitative Trait Locus (QTL) Mapping 39
2.3.1.2 Genome-Wide Association Studies 41
2.3.2 Transcriptomics 42
2.3.3 Proteomics 44
2.3.4 Metabolomics 46
2.3.5 miRNAomics 47
2.3.6 Phenomics 49
2.4 Conclusion and Perspectives 50
References 50
3 Heavy Metals/Metalloids in Food Crops and Their Implications for Human Health 59
Shihab Uddin, Hasina Afroz, Mahmud Hossain, Jessica Briffa, Renald Blundell, and Md. Rafiqul Islam
3.1 Introduction 59
3.2 Arsenic 60
3.2.1 Sources and Forms 60
3.2.2 Food Chain Contamination 62
3.2.3 Pharmacokinetic Processes 62
3.2.4 Toxicology Processes 62
3.2.5 Remedial Options 63
3.3 Cadmium 63
3.3.1 Sources and Forms 64
3.3.2 Food Chain Contamination 64
3.3.3 Pharmacokinetic Processes 66
3.3.4 Toxicology Processes 66
3.3.5 Remedial Options 67
3.4 Lead 67
3.4.1 Sources and Forms 68
3.4.2 Food Chain Contamination 68
3.4.3 Pharmacokinetic Processes 68
3.4.4 Toxicology Processes 70
3.4.5 Remedial Options 71
3.5 Chromium 72
3.5.1 Sources and Forms 72
3.5.2 Food Chain Contamination 74
3.5.3 Pharmacokinetic Processes 74
3.5.4 Toxicology Processes 74
3.5.5 Remedial Options 75
3.6 Mercury 76
3.6.1 Sources and Forms 76
3.6.2 Food Chain Contamination 77
3.6.3 Pharmacokinetic Processes 79
3.6.4 Toxicology Processes 79
3.6.5 Remedial Options 80
3.7 Conclusions 81
References 81
4 Aluminum Stress Tolerance in Plants: Insights from Omics Approaches 87
Richa Srivastava, Ayan Sadhukhan, and Hiroyuki Koyama
4.1 Introduction 87
4.2 Exploration of Al Tolerance QTLs 89
4.3 Unraveling the Genetic Architecture of Al Tolerance from Natural Variation 91
4.4 Identification of Novel Al Tolerance Genes Through Genome-Wide Association Studies 91
4.5 Exploring Expression Level Polymorphisms to Identify Upstream Al Signaling 92
4.6 Comparative Transcriptome Analyses Identify Novel Al Tolerance Genes 93
4.7 Identification of Al Tolerance Genes from Proteomics 95
4.8 Conclusion and Future Perspectives 99
References 99
5 Breeding Approaches for Aluminum Toxicity Tolerance in Rice and Wheat 105
Buu Chi Bui and Lang Thi Nguyen
5.1 Introduction 105
5.2 Plant Signaling 107
5.3 Rice Genetic Mapping 107
5.3.1 Linkage Mapping 107
5.3.2 Association Mapping 108
5.4 Root Transcriptome 109
5.5 Wheat Genetic Mapping 114
5.5.1 Wheat MATE Gene Family 116
5.6 Wheat Proteomics 117
5.7 Conclusion 118
References 118
6 Chromium Toxicity and Tolerance in Plants: Insights from Omics Studies 125
Sonali Dubey, Manju Shri, and Debasis Chakrabarty
6.1 Introduction 125
6.2 Chromium Sources and Bioavailability 126
6.3 Chromium Uptake, Translocation, and Sub-cellular Distribution in plants 127
6.4 Detoxification Mechanisms for Cr 129
6.5 Omics Approaches Used by Plants to Combat Cr Toxicity 130
6.5.1 Transcriptomics 130
6.5.2 Chromium-Induced miRNAs in Plants 132
6.5.3 Metabolomics 133
6.5.4 Proteomics 133
6.6 Phytoremediation of Cr Metal by Plants 134
6.6.1 Phytoremediation Approach for Cr Detoxification 134
6.6.2 Other Strategies Involved in Cr Remediation 135
6.6.3 Phytostabilization/Phytoextraction for Cr Decontamination 136
6.7 Conclusion 136
References 136
7 Manganese Toxicity and Tolerance in Photosynthetic Organisms and Breeding Strategy for Improving Manganese Tolerance in Crop Plants: Physiological and Omics Approach Perspectives 141
Daisuke Takagi
7.1 Introduction 141
7.2 The Change in Mn Availability Within the Soil 143
7.3 Why Should We Consider the Occurrence of Mn Toxicity in Plants? Possible Threats of Mn Toxicity in Agricultural Land 144
7.4 The History of Mn Toxicity 146
7.5 The Features of Mn Toxicity in Terrestrial Plants and Possible Molecular Mechanisms 147
7.5.1 The Mechanisms of Emergence of Brownish Patchy Spots in Leaves: The Apoplastic Mn Toxicity 147
7.5.2 The Mechanisms of Foliar Chlorosis Under Excess Mn: Symplastic Mn Toxicity 150
7.6 Breeding Strategy for Overcoming the Future Threat of Excess Mn Conditions 154
7.6.1 Limiting Mn Absorption from Soil to Root 155
7.6.2 Sequestration of Mn from Cytosol to the Vacuole or Apoplast 156
7.6.3 Maintenance of Auxin Homeostasis 157
7.6.4 The Reinforcement of Silicon Uptake and Its Distribution 157
7.7 Conclusion and Future Prospects 158
Acknowledgments 158
References 158
8 Iron Excess Toxicity and Tolerance in Crop Plants: Insights from Omics Studies 169
May Sann Aung and Hiroshi Masuda
8.1 Iron Uptake and Translocation Mechanism in Plants 169
8.1.1 Importance of Iron in Living Organisms 169
8.1.2 Fe Acquisition Systems in Plants 170
8.1.3 Fe Translocation Mechanisms in Plants 171
8.2 Fe Excess Toxicity in Plants 171
8.2.1 Fe Excess Toxicity in Global Agriculture 171
8.2.2 Causes of Fe Excess Toxicity in Soils and Its Interaction with Plants 172
8.2.2.1 State of Fe in Soils and Soil pH Effects on Fe Excess Toxicity 172
8.2.2.2 Soil Improvement Methods to Ameliorate Fe Excess Toxicity 173
8.2.2.3 Soil Water and Drainage Effects on Fe Excess Toxicity 173
8.2.3 Effects of Fe Excess Toxicity on Plant Growth 174
8.3 Crop Defense Mechanisms Against Excess Fe and Genes Regulating Fe Excess 175
8.3.1 Defense I: Fe Exclusion from Roots 175
8.3.1.1 Genes Involved in Defense I 176
8.3.2 Defense II: Fe Retention in Roots and Suppression of Fe Translocation to Shoots 177
8.3.3 Defense III: Fe Compartmentalization in Shoots 177
8.3.3.1 Genes Involved in Defense II and IIi 178
8.3.3.2 Role of YSL4 and YSL6 Transporters in Preventing Fe Excess in Early Plant Development 179
8.3.4 Defense IV: ROS Detoxification 179
8.3.4.1 Genes Involved in Defense IV 180
8.3.4.2 GLY1 as a Detoxifying Agent 180
8.4 Research Outlook on Fe Excess Response of Plants 180
8.4.1 Regulation of Fe homeostasis in Plants in Response to Fe Excess Stress 180
8.4.2 Transcription Factors 181
8.4.3 Cis-Regulatory Elements 182
8.5 Conclusion and Future Prospects 183
Acknowledgments 183
Author Contributions 183
Disclosures 183
References 183
9 Molecular Breeding for Iron Toxicity Tolerance in Rice (Oryza sativa L.) 191
Dorothy A. Onyango, Mathew M. Dida, Khady N. Drame, Benson O. Nyongesa, and Kayode A. Sanni
9.1 Introduction 191
9.2 Role of Iron in Plants and Rice 192
9.3 Iron Toxicity and Its Effects on Rice 192
9.4 Iron Toxicity Tolerance Mechanisms in Rice Plants 193
9.4.1 Fe Exclusion from Roots 193
9.4.2 Fe Retention in Roots and Suppression of Fe Translocation to Shoots 194
9.4.3 Fe Compartmentalization in Shoots 194
9.4.4 ROS Detoxification 195
9.4.5 Candidate Genes Involved in the Mechanisms of Fe Toxicity 196
9.4.6 Genetic Variants for Iron Toxicity Tolerance in Rice Germplasm 197
9.5 Molecular Breeding for Fe Toxicity Tolerance in Rice 197
9.6 Conclusion 200
References 202
10 Cobalt Induced Toxicity and Tolerance in Plants: Insights from Omics Approaches 207
Abdul Salam, Muhammad Siddique Afridi, Ali Raza Khan, Wardah Azhar, Yang Shuaiqi, Zaid Ulhassan, Jiaxuan Qi, Nu Xuo, Yang Chunyan, Nana Chen, and Yinbo Gan
10.1 Introduction 207
10.2 Plant Response to Cobalt Stress 208
10.2.1 Uptake and Translocation of Cobalt in Plants 209
10.3 Cobalt-Induced ROS Generation and Their Damaging Effects 211
10.3.1 ROS-Induced Lipid Peroxidation 211
10.3.2 ROS-Induced Damage to Genetic Material 212
10.4 Cobalt-Induced Plant Antioxidant Defense System 213
10.4.1 Enzymatic Antioxidants 213
10.4.1.1 Superoxide Dismutase (SOD) 213
10.4.1.2 Catalases (CAT) 213
10.4.1.3 Glutathione Peroxidases (GPX) 214
10.4.1.4 Glutathione Reductase (GR) 214
10.4.2 Nonenzymatic Antioxidants 215
10.4.2.1 Ascorbic Acid 215
10.4.2.2 Tocopherols 215
10.4.2.3 Reduced Glutathione (GSH) 216
10.5 Omics Approaches in Cobalt Stress Tolerance 216
10.5.1 Transcriptomic 216
10.5.2 Metabolomics 218
10.5.3 Proteomics 219
10.6 Conclusion and Future Prospects 220
Acknowledgments 221
References 221
11 Nickel Toxicity and Tolerance in Plants 231
Sondes Helaoui, Marouane Mkhinini, Iteb Boughattas, Noureddine Bousserrhine, and Mohamed Banni
11.1 Introduction 231
11.2 Sources of Ni 232
11.2.1 Natural Sources of Ni 232
11.2.2 Anthropogenic Sources of Ni 233
11.3 Role of Ni in Plants 233
11.4 Ni Uptake and Accumulation in Plants 233
11.5 Ni Toxicity in Plants 234
11.5.1 Growth Inhibition 234
11.5.2 Photosynthesis Inhibition of Ni 236
11.5.3 Induction of Oxidative Stress 236
11.6 Tolerance Mechanisms 237
11.7 Omics Approaches in Ni Stress Tolerance 238
11.7.1 Transcriptomics 238
11.7.2 Proteomics 239
11.7.3 Metabolomics 240
11.8 Conclusion 240
References 241
12 Copper Toxicity and Tolerance in Plants: Insights from Omics Studies 251
Moreira A, Moraes LAC, Delfim JJ, and Moreti LG
12.1 Introduction 251
12.2 Copper in Plants 253
12.2.1 Functions of Copper 253
12.2.2 Uptake, Transport, Distribution, and Remobilization Mechanisms 255
12.2.3 Deficient, Sufficient, and Toxic Levels of Copper in Plants 255
12.2.4 Copper Sources: Fertilizers and Fungicides 256
12.3 Omics Approaches for Cu Responses and Tolerance in Plants 259
12.3.1 Genomics 259
12.3.2 Transcriptomics 259
12.3.3 Proteomics 261
12.3.4 Metabolomics 263
12.3.5 miRNAomics 264
12.4 Concluding Remarks 266
Acknowledgments 266
References 267
13 Zinc Toxicity and Tolerance in Plants: Insights from Omics Studies 275
Imran Haider Shamsi, Qichun Zhang, Zhengxin Ma, Sibgha Noreen, Muhammad Salim Akhter, Ummar Iqbal, Muhammad Faheem Adil, Muhammad Fazal Karim, and Najeeb Ullah
13.1 Introduction 275
13.1.1 Zinc Uptake and Translocation Mechanisms in Plants 275
13.1.2 Transporters and Metal-Binding Compounds Involved in Zinc Homeostasis 277
13.2 Impact of Excess Zinc on Physio-genetics Aspects of Plants 277
13.2.1 Effect of Zinc Toxicity on Seed Germination and Growth of Plants 278
13.2.2 Effect of Zinc Toxicity on Oxidative Metabolism in Plants 279
13.2.3 Effect of Zn Toxicity on Physiology and Biochemistry of Plants 280
13.3 Plants Stress Adaptation to Zinc Toxicity 281
13.4 Multi-omics Approaches for Zinc Toxicity and Tolerance in Plants 281
13.4.1 Genomics and Metabolomics 281
13.4.2 Proteomics and Transcriptomics 283
13.4.3 miRNA Omics and CRISPR/Cas9 System 284
13.4.4 Quantitative Trait Locus Mapping and Genome-Wide Association Study 286
13.5 Conclusion and Future Prospective 286
Acknowledgments 286
References 287
14 Arsenic Toxicity and Tolerance in Plants: Insights from Omics Studies 293
Barsha Majumder, Palin Sil, and Asok K. Biswas
14.1 Introduction 293
14.2 Occurrence and Distribution of As in the Environment 295
14.3 Arsenic Uptake, Accumulation, and Detoxification in Plants 296
14.3.1 Uptake of Inorganic Arsenic 296
14.3.2 Uptake of Methylated Arsenic 297
14.3.3 Arsenic Accumulation and Detoxification 297
14.3.4 Arsenic Methylation and Volatilization 298
14.4 Influence of Arsenic on Phytotoxicity 298
14.4.1 Germination and Growth 298
14.4.2 Nutrient Uptake 299
14.4.3 Oxidative Stress and Antioxidative Defense 299
14.4.4 Ascorbate-Glutathione Cycle 300
14.4.5 Photosynthesis 300
14.4.6 Respiration 301
14.4.7 Carbohydrate Metabolism 302
14.4.8 Nitrogen Metabolism 302
14.5 Modulation in “Omics” Profiling Under As Challenged Environment 303
14.5.1 Genomic Profiling 303
14.5.2 Transcriptomic Profiling 304
14.5.3 Proteomic Profiling 307
14.5.4 Metabolomic Profiling 308
14.6 Progress in Molecular Biotechnology to Evolve As-Tolerant Plants 308
14.7 Conclusion and Future Perspective 311
Acknowledgment 311
Author Contributions 312
References 312
15 Selenium Toxicity and Tolerance in Plants: Insights from Omics Studies 323
Ali Kıyak, Selman Uluısık, Ertugrul Filiz, and Firat Kurt
15.1 Introduction 323
15.2 Selenium Toxicity in Plants 324
15.2.1 Se-Induced Protein Malformation 324
15.2.2 ROS-Induced Se Phytotoxicity 325
15.3 Selenium Tolerance in Plants 326
15.4 Selenium Biofortification in Plants 328
15.5 Conclusion 329
References 330
16 Breeding for Rice Cultivars with Low Cadmium Accumulation 335
li Tang, Yaokui li, Yan Peng, Bigang Mao, Ye Shao, Zhongying Ji, and Bingran Zhao
16.1 Introduction 335
16.2 Molecular Mechanisms of Cd Accumulation in Rice 335
16.2.1 Cd Uptake 336
16.2.2 Radial Transport and Xylem Loading 338
16.2.3 Distribution of Cd in Shoots 338
16.3 Transgenic Approach for Breeding Low-Cd Rice 339
16.3.1 Traditional Transgenic Technology 339
16.3.2 Genome-Editing Technology 340
16.4 Mutation Breeding for Low-Cd Rice Cultivars 341
16.5 Molecular Marker-Assisted Breeding for Low-Cd Rice Cultivars 342
16.6 Future Perspectives 343
References 344
17 Mercury Toxicity: Plant Response and Tolerance 349
Arifin Sandhi, Abu Bakar Siddique, and Meththika Vithanage
17.1 Introduction 349
17.2 Global Mercury Pollution 350
17.3 Mercury Uptake and Toxicity in Plants 352
17.4 Existence of Differential Plant Response to Hg Stress 353
17.4.1 Plant Morphological Responses 353
17.4.2 Plant Anatomical Responses 354
17.4.3 Cellular Responses 354
17.4.4 Plant Photosynthetic Response 355
17.4.5 Enzymatic and Metabolic Responses 355
17.4.6 Plant Hormonal Responses 356
17.4.7 Reactive Oxygen Species and Oxidative Responses 356
17.5 Plant Tolerance Mechanisms 357
17.5.1 Chelation 357
17.5.2 Enzymatic and Antioxidative Tolerance 358
17.5.3 Hormonal Regulations 359
17.5.4 miRNA-Mediated Tolerance 360
17.6 Phytoremediation Prospects 360
17.7 Conclusion 361
References 362
18 Lead Toxicity and Tolerance in Plants: Insights from Omics Studies 373
Sayyeda Hira Hassan, Yassine Chafik, Manhattan Lebrun, Gabriella Sferra, Sylvain Bourgerie, Gabriella Stefania Scippa, Domenico Morabito, and Dalila Trupiano
18.1 Introduction 373
18.2 Omics’ Contribution in Uncovering Molecular Alterations in Plants Under Pb Exposure 375
18.3 Genetics and Epigenetics Regulations of Pb Toxicity and Tolerance 380
18.4 The Role of Plant Cell Wall, Cell Signaling, and Transduction 382
18.5 Pb-Binding Proteins/Transporters and Their Involvement in Tolerance 384
18.6 Pb-Induced Oxidative Stress and Antioxidative Mechanisms 385
18.7 Metabolic Pathways Associated with Pb Tolerance 388
18.7.1 Sugar/Carbohydrate and Energy Metabolic Pathway 388
18.7.2 Phenylpropanoid Pathway 389
18.7.3 Sulfur-Related Pathway and Phytohormones 390
18.8 Conclusion and Future Perspective 392
References 394
19 Interaction of Heavy Metal with Drought/Salinity Stress in Plants 407
Ziqian Li, Wentao Chen, Qianlong Tan, Yuanyuan Hou, Taimoor Hassan Farooq, Baber Iqbal, and Yong li
19.1 Introduction 407
19.2 Plant Physiology and Biochemistry 409
19.2.1 Zinc (Zn) 409
19.2.2 Cadmium (Cd) 410
19.2.3 Aluminium (Al) 411
19.2.4 Other Metals 412
19.3 Photosynthesis 413
19.4 Antioxidant System 414
19.5 Conclusions and Prospects 415
Acknowledgments 416
References 416
20 Hormonal Regulation of Heavy Metal Toxicity and Tolerance in Crop Plants 425
Éderson Akio Kido, Gizele de Andrade Luz, Valquíria da Silva, Maria Fernanda da Costa Gomes, and José Ribamar Costa Ferreira Neto
20.1 Introduction 425
20.2 General Aspects of Plants Under HM Stress 426
20.3 Phytohormone-Mediating Plant Response to HM Stress 427
20.3.1 Abscisic Acid 430
20.3.2 Auxin 432
20.3.3 Brassinosteroid 434
20.3.4 Cytokinin 435
20.3.5 Ethylene 437
20.3.6 Gibberellin 438
20.3.7 Jasmonate 439
20.3.8 Melatonin (MT) 440
20.3.9 Salicylic Acid (SA) 442
20.3.10 Strigolactone (SL) 444
20.4 Crosstalk of Phytohormones in Plants Responding to Heavy Metals 445
20.5 Final Considerations 447
References 448
21 Heavy-Metal-Induced Reactive Oxygen Species and Methylglyoxal Formation
and Detoxification in Crop Plants: Modulation of Tolerance by Exogenous Chemical Compounds 461
Beatrycze Nowicka, Tahsina Sharmin Hoque, Sheikh Mahfuja Khatun, Jannatul Naim, Ahmed Khairul Hasan, and Mohammad Anwar Hossain
21.1 Introduction 461
21.2 Heavy-Metal-Induced ROS and Methylglyoxal Production in Plant Cells 464
21.3 Detoxification of ROS and Methylglyoxal in Plant Cells 468
21.4 Exogenous Chemical-Compounds-Mediated Heavy Metal/Metalloid Tolerance in Crop Plants 473
21.5 Conclusions and Future Perspectives 484
References 486
22 Biochar Amendments in Soils and Heavy Metal Tolerance in Crop Plants 493
Agnieszka Medyńska-Juraszek and Bhakti Jadhav
22.1 Introduction 493
22.2 Heavy Metal Immobilization Mechanisms on Biochar 495
22.2.1 Heavy Metal Immobilization Through Soil pH Modification 496
22.3 Biochar Interactions Through Rhizosphere 496
22.3.1 Effect on Plant Root Development 497
22.3.2 Changes in Elements Uptake from Rhizosphere 498
22.4 Biochar-Induced Plant Respond to Metal Stress 499
22.4.1 Biochar Induces Changes in Photosynthetic Activity 499
22.4.2 Biochar Induces Changes in Antioxidant and Phytohormone Activity 499
22.4.3 Biochar as a Source of Specific Chemical Compounds Affecting Heavy Metal Uptake By Plants 501
22.5 Effect of Biochar on Heavy Metal Concentrations in Different Crops 503
22.6 Effect of Biochar Type on Heavy Metal Immobilization 503
References 504
23 Plant-Growth-Promoting Rhizobacteria and Their Metabolites: Clean and Green Approaches to Deal with Heavy Metal Toxicity 513
Imtinen Sghaier, Ameur Cherif, and Mohamed Neifar
23.1 Introduction 513
23.2 Chemical Fertilizers and Their Impacts 515
23.2.1 Impacts of Chemical Fertilizers on Atmospheric Ecosystem 515
23.2.2 Impacts of Chemical Fertilizers on Aquatic Ecosystem 515
23.2.3 Impacts of Chemical Fertilizers on Soil 515
23.2.4 Impacts of Chemical Fertilizers on Plants 516
23.3 PGPR and Biofertilization Traits 516
23.3.1 Acquisition of Nutrients 516
23.3.2 Production of Siderophores 517
23.3.3 Production of Exopolysaccharides 517
23.4 Resistance to Abiotic Stress 518
23.5 Biostimulation Potential and PGPR 519
23.6 Biocontrol Potential and PGPR 520
23.7 PGPR and Heavy Metal Bioremediation 521
23.8 Conclusion and Future Prospects 524
Acknowledgments 525
References 525
24 Applications of Nanotechnology for Improving Heavy Metal Stress Tolerance in Crop Plants 533
Meng Jiang, Yue Song, Mukesh Kumar Kanwar, and Jie Zhou
24.1 Introduction 533
24.2 Impacts of NPs on the HM Stress in Plants 535
24.2.1 Silicon 535
24.2.2 Selenium 535
24.2.3 Iron 536
24.2.4 Zinc Oxide 537
24.2.5 Titanium Dioxide 537
24.2.6 Cerium Dioxide 538
24.3 Mechanisms of NPs to Mitigate the Toxicity of HM 539
24.4 Summary and Prospect 543
References 545
25 The Dynamics of Phytoremediation of Heavy Metals: Recent Progress and Future Perspective 553
Imran Haider Shamsi, Xiaoli Jin, Xin Zhang, Qidong Feng, Zakir Ibrahim, Muhammad Faheem Adil, Muhammad Fazal Karim, and Najeeb Ullah
25.1 Introduction 553
25.1.1 Types of Phytoremediation 554
25.1.1.1 Phytostabilization 554
25.1.1.2 Phytovolatalization 554
25.1.1.3 Phytoextraction 554
25.1.2 Modified Concept 555
25.1.2.1 Chemical-Assisted Phytoremediation Employing Non-hyperaccumulator Plants 556
25.1.2.2 Biochar-Assisted Phytoremediation 556
25.1.2.3 Microbial-Assisted Phytoremediation 557
25.2 Importance of Phytoremediation 557
25.3 Role of Phytoremediation as a Sustainable Solution 558
25.4 Biophilic Design as Phytoremediation in Urban Sustainability 559
25.4.1 Eco-Design 559
25.4.2 Biophilic Design 559
25.4.2.1 Hypothesis of Biophilic 562
25.4.2.2 Dimensions of Biophilic Design 562
25.4.2.3 Direct Experience of Nature 562
25.4.2.4 Indirect Experience of Nature 563
25.4.2.5 Experience of Place and Space 563
25.4.2.6 Sustainable Biophilic Cities 563
25.4.3 Health Benefits 564
25.4.4 Biophilic as an Antidepressant in Urban Environment 565
25.4.5 Economic Benefits 566
25.4.6 Sustainability and Resilience 566
25.5 Conclusion 567
25.6 Future Perspective 568
Acknowledgment 569
References 569
26 Genetic Engineering for Heavy Metal/Metalloid Stress Tolerance in Plants 573
Mohammad Anwar Hossain, Md. Tahjib-Ul-Arif , Sopnil Ahmed Jahin, Abu Bakar Siddique, Mumtarin Haque Mim, Sharif-Ar-Raffi, Muhammad Javidul Haque Bhuiyan, and Beatrycze Nowicka
26.1 Introduction 573
26.2 Mechanisms of Heavy Metal/Metalloid Tolerance in Plants 574
26.3 Strategies for Improving Metal/Metalloid Stress Tolerance in Plants 576
26.4 Transgenic Plants and Heavy Metal/Metalloid Stress Tolerance in Plants 577
26.4.1 Sulfur Metabolism Engineering and Heavy Metal Tolerance 577
26.4.2 Glyoxalase Pathway Genes and Heavy Metal Stress Tolerance 577
26.4.3 Enhanced Antioxidant Defense and Heavy Metal Tolerance 579
26.4.4 Phytochelatin and Metallothionein Genes and Heavy Metal Tolerance 579
26.4.5 Metal Ion Transporter Genes/Proteins and Heavy Metal Stress Tolerance 579
26.5 CRISPR/Cas System and Heavy Metal Tolerance Development 585
26.6 Conclusions and Future Prospects 585
Acknowledgment 586
References 586
Index 593
