Sangeeta Pandey is Assistant Professor at the Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Noida, India. Durgesh Kumar Tripathi is Assistant Professor at the Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Noida, India. Vijay Pratap Singh is Assistant Professor, CMP Degree Collage, University of Allahabad, Prayagraj, India. Shivesh Sharma is Professor at the Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, India. Devendra Kumar Chauhan is Professor and Head of the Department of Botany at the DD Pant Interdisciplinary Research Laboratory, University of Allahabad, Allahabad, India.

• Preface xiiiList of Contributors xv1 Beneficial Elements in Plant Life Under A Changing Environment 1Misbah Naz, Muhammad Ammar Raza, Muhammad Adnan Bodlah, Sarah Bouzroud, Muhammad Imran Ghani, Muhammad Riaz, Tariq Shah, Akmal Zubair, Imran Bodlah, and Xiaorong FanIntroduction 1Beneficial Element Interaction with Environment 2Aluminium (Al) in Plants 3Aluminium (Al) in Soil – Aluminium, a Friend or Foe of Higher Plants in Acidic Soils 4Cobalt (Co) in Plants 5Cobalt (Co) in Soil 6Silicon (Si) 9Function of Silicon 10Silicon in Soil 11Sodium in Plants 12Sodium in Soil 12Selenium (Se) 13Selenium in Environment 13Physiological Functions of Beneficial Elements Under A Changing Environment 135-Beneficial Elements Against Stresses 14Conclusion 15References 152 Role of Beneficial Elements in Epigenetic Regulation of Plants in Response to AbioticStress Factors 22Muhittin Kulak and Adnan AydinIntroduction 22Beneficial Elements for Crop and Non-Crop Plants 22Selenium 22Silicon 23Aluminium 23Sodium 23Cobalt 23Abiotic Stress Factors 23Epigenetic Modifications Under Stressful Conditions 24Studies Regarding the Effect of Beneficial Elements on Epigenetic Changes in the Genome of Plants 28Selenium 28Cobalt 28Sodium 29Aluminium 29Silicon 30Conclusion 30References 303 Beneficial Elements and Status of ROS and RNS in Plants: Current Evidence and Future Prospects 38Biswajita Pradhan, Rabindra Nayak, Srimanta Patra, Chhandashree Behera, Soumya Ranjan Dash, and Mrutyunjay JenaIntroduction 38Essential and Beneficial Elements in Plant Physiology: A Pleasant Dilemma 39Aluminium 40Cobalt 41Sodium 42Selenium 42Silicon 44ROS and RNS Production Sites in Plant Cells: Cellular Redox Compartments with Regards to Essential Elements 45ROS and RNS Production and Their Function in Plants: Connecting Physiology to Stress Physiology 47Conclusion and Future Perspectives 48Acknowledgments 49Conflicts of Interest 49References 494 Biostimulant Effects and Concentration Patterns of Beneficial Elements in Plants 58Libia I. Trejo- Téllez, Libia F. Gómez- Trejo, and Fernando C. Gómez- MerinoIntroduction 58Aluminium 59Cerium 69Cobalt 70Iodine 72Lanthanum 73Selenium 75Silicon 77Sodium 79Titanium 80Vanadium 82Conclusions and Perspectives 83References 845 Targeted Effects of Beneficial Elements in Plant Photosynthetic Process 103Costanza Ceccanti, Ermes Lo Piccolo, Lucia Guidi, and Marco LandiIntroduction 103Effect of Metal Beneficial Elements 104Effect of Non-metal Beneficial Elements 114Conclusion 116References 1166 Aluminium Stress in Plants: Consequences and Mitigation Mechanisms 123Akbar Hossain, Sagar Maitra, Sukamal Sarker, Abdullah Al Mahmud, Zahoor Ahmad, Reza Mohammad Emon, Hindu Vemuri, Md Abdul Malek, M. Ashraful Alam, Md Atikur Rahman, Md Jahangir Alam, Nasrin Jahan, Preetha Bhadra, Debojyoti Moulick, Saikat Saha, Milan Skalicky, and Marian BresticIntroduction 123An Overview of Al Toxicity in Plants 124Effect on Root Growth 124Oxidative Stress 126Nutrient Imbalances 127Mechanisms for Al Stress Tolerance in Plants 127Phenotyping for Al-toxicity Tolerance in Plants 128Physiological Mechanisms of Al Tolerance in Plants 128Morpho-physiological Mechanisms 129Biochemical Mechanisms 130Cellular Mechanisms 130Phytohormones-based Aluminium Stress Tolerance in Plants 133Antioxidants-based Aluminium Stress Tolerance in Plants 134Potential Transgenic Approach for Aluminium Toxicity Improvement 134Genes Responsive Under Aluminium Toxicity 135Gene Family Variation 136Interference in the Resistance Mechanism 136Expression and Regulation of Gene Families 136Genetic Engineering 138Pyramiding of Genes 138Phytoremediation of Al Stress in Plants 139Microorganism-mediated Aluminium Stress Tolerance in Plants 142Agronomic Management for Mitigating Aluminium Stress in Plants 143Role of Inorganic Amendments for Mitigating Al Toxicity in Plants 144Calcium (Ca) as a Mitigator of Al Toxicity 144Phosphorus (P) as a Mitigator of Al Toxicity 146Magnesium (Mg) as a Mitigator of Al Toxicity 146Boron (B) as a Mitigator of Al Toxicity 147Sulphur (S) as a Mitigator of Al Toxicity 147Silicon (Si) as a Mitigator of Al Toxicity 147Role of Organic Amendments for Mitigating Al Toxicity in Plants 147Biochar as a Mitigator of Al Toxicity 147Compost or Organic Matter as a Mitigator of Al Toxicity 148Conclusion 148Conflict of Interest 149References 1497 Mechanisms of Cobalt Uptake, Transport, and Beneficial Aspects in Plants 169Zaid Ulhassan, Aamir Mehmood Shah, Ali Raza Khan, Wardah Azhar, Yasir Hamid, and Weijun ZhouIntroduction 169Mechanisms of Cobalt Uptake and Transport in Plants 170Beneficial Aspects of Cobalt in Plants 172Growth and Yield 172Nitrogen Fixation and Nodule Formation 173Alterations in Nutrient Status 173Alterations in Physiological and Biochemical Constituents 174Antioxidant Enzyme Activities and Synthesis of Hormones 175Protective Roles of Cobalt Against Abiotic Stresses 175Conclusions and Future Prospects 176Acknowledgments 177References 1778 Cobalt in Plant Life: Responses and Deficiency Symptoms 182Xiu Hu, Xiangying Wei, Jie Ling, and Jianjun ChenIntroduction 182Cobalt in Lower Plants 184Bryophytes 184Algae 185Cobalt in Higher Plants 186Root Absorption of Cobalt 186Cobalt Transport in Plants 187Cobalt Effects on Plant Growth 188Cobalt is Essential for N 2 Fixation in Nodulated Legumes 188Cobalt Enhances Growth of Non-Leguminous Crops 190Possible Mechanisms 190Other Beneficial Effects on Plants 192Cobalt Deficiency in Plants 192Cobalt Toxicity in Plants 194Conclusions and Future Perspectives 196References 1979 Silicon Uptake, Transport, and Accumulation in Plants 205Shivani Sharma, Muntazir Mushtaq, Sreeja Sudhakaran, Vandana Thakral, Gaurav Raturi, Ruchi Bansal, Virender Kumar, Sanskriti Vats, S. M. Shivaraj, and Rupesh DeshmukhIntroduction 205Molecular Mechanism Involved in Silicon Uptake 206Seminal Studies Defining Uptake of Silicon in Different Plant Species 206Silicon Influx Transporter 207Silicon Efflux Transporter 209Cordial Activity of Silicon Influx and Efflux Transporter 211Other Homologs of Silicon Influx and Efflux Transporter 213Silicon Transporters yet to be Discovered 213Silicon Deposition in Different Tissues 214Silicon Deposition in Roots 214Silicon Deposition in Shoot 214Silicon Deposition in Leaves 216Phytoliths: Biochemical Composition and Deposition Patterns 217Silicon Deposition and the Phytolith Formation 218Role of Phytoliths in the Silicon Biogeochemical Cycle 220References 22210 Silicon in Soil, Plants, and Environment 227Mujahid Ali, Muhammad Zia Ur Rehman, Asad Jamil, Muhammad Ashar Ayub,and Muhammad Tahir ShehzadIntroduction 227Sources of Silicon in Soil, Plants and Environment 228Natural Sources 228Artificial/Synthetic Sources 228Uses of Silicon 229Industrial Use 229Application in Agro-ecosystems 229Role of Silicon in Plant Nutrition-Growth Responses 230Nutrient Acquisition 230Plant Growth Promotion 230Gas Exchange Attributes Modulation 230Plant Water Balance 230Antioxidant Enzymes Activities 231Uptake and Translocation Mechanisms of Silicon 231Role of Silicon in Agriculture 232Role of Silicon in Abiotic Stress Management 232Heavy Metals 232Salinity 232Water Stress 234Temperature Stress 234Role of Silicon in Biotic Stress Management 237Pest Attack 237Role of Silicon in Disease Management 237Silicon-Mediated Endogenous Modifications in Plants 238C. Mechanism of Silicon-Mediated Abiotic Stress Management 238D. Mechanism of Silicon-Mediated Biotic Stress Management 241Source of Silicon for Agricultural Application 241Recommendations for Exogenous Silicon Applications 242Conclusion and Future Perspectives 242References 24211 Silicon- Mediated Alleviation of Heavy Metal Stress in Plants 256Sana Rana, Muhammad Zia ur Rehman, Muhammad Umair, Muhammad Ashar Ayub, and Muhammad ArifIntroduction 256Heavy Metal (HM) Sources in Agro-ecosystem 257The Response of Plants Towards HM Stress 257Sources of Silicon in Soil 258Role of Silicon in HM Stress Management 258Silicon Role in Plant Nutrition 259Silicon-Mediated HM Management Mechanisms 259Reduction of HM Uptake 259Modification of Rhizosphere Chemistry/Making Si Complexes with Metals 260Stimulation of Antioxidants 260Help in Compartmentation of HM Inside Plants 260Gene Expression Modification 261Structural and Physiological Modification 261Exogenous Application of Silicon to Manage HM Toxicity 261Silicon Fertilizer 262Biogenic Si Sources (Organic Amendments Enriched in Si) 262Silicon Nanoparticles 265Summary 266References 26612 How Does Sodium Content in Growing Media Affect the Chemical Content of Medicinal and Aromatic Plants? Two Sides of the Coin 277Ahmet Metin Kumlay, Muhittin Kulak, Mehmet Zeki Kocak, Ferdi Celikcan, and Mehmet Hakki AlmaIntroduction 277What Kinds of Functions Have Been Attributed to Sodium for Proper Metabolism of the Plant? 278What Kind of Perturbations Might Emerge in Case of Deficiency or Excessive Accumulation of Sodium in Growing Media and in Turn, in Plants? 279What Are the Major Mechanisms Associated with the Damage Caused by High Salinity? 279Compartmentalization of Sodium Through Plant Parts 280Why Is the Sodium/Potassium Ratio Important for Plant Metabolism? 280How Do Priming or Osmo-Conditioning Seeds Using NaCl Solutions Imprint the Sequential Growth Performance or Stage of the Plants? An Approach Regarding Imprint Memory with Low Concentration versus Higher Subsequent Concentration of NaCl 281What Are Medicinal and Aromatic Plants and Metabolites of Those Plants? How Do Those Metabolites Respond to Higher Content of Na in Media Regarding Total Content and Their Specific Compounds? 281The Growth, Development, and Yield are Adversely Affected Under High Sodium Concentration of Growing Media, but What Can We Say for Contents of Total Metabolites or Specific Compounds? 282Alkaloids 282Terpenoids 283Phenolics 286What Kinds of Explanations Have Been Postulated for Changes Concerned with Defence-Related Metabolites in Those Plants Exposed to Higher Levels of Sodium in Growing Media? 297Do Lower or Higher Concentration of the Sodium Favour Metabolites? 297Two Sides of the Coin: Is a Third Probability Possible for Plant Production Versus Secondary Metabolite Production? 298Conclusion 298References 29913 Sodium and Abiotic Stress Tolerance in Plants 307Misbah Naz, Muhammad Imran Ghani, Muhammad Jawaad Atif, Muhammad Ammar Raza, Sarah Bouzroud, Muhammad Rahil Afzal, Muhammad Riaz, Maratab Ali, Muhammad Tariq, and Xiaorong FanIntroduction 307Relationship Between Salinity and Plant 309Salinity and the Ideal Sustainable Agricultural System 310Relationship Between Salinity and Sodicity and Soil 311Salt Stress Effects on Plants 311Management Strategies to Mitigate Salt Injury 312Salt Sensitivity 313Genetic Engineering and Salt-Tolerant Transgenic Plants 316Role of Sodium in Plants 317Osmotic Tolerance 318Proteomics Study in Plant Responses and Tolerance to Salt Stress 318Ion Uptake/Homeostasis 319Role of Phytohormones for Abiotic Stress Tolerance 320Interaction Between Na + and K + in Plants321Interactions Between Na + and Mg 2+ in Plants 322Interactions Between Na + and Ca 2+ in Plants 322Conclusion 323References 32314 Selenium Species in Plant Life: Uptake, Transport, Metabolism, and Biochemistry 331Zaid Ulhassan, Ali Raza Khan, Wardah Azhar, Yasir Hamid, Durgesh Kumar Tripathi, and Weijun ZhouSelenium Speciation in the Soil-Plant System 331Accumulation and Uptake of Selenium Species by Plants 331Transport Mechanisms of Selenium Species within Plants 333Selenium Metabolism in Plants 333Step 1: Conversion of Selenate into Selenite and Selenide 333Step 2: Selenide to Selenocysteine (SeCys) Transformation 334Step 3: Transformation of Selenocysteine (SeCys) into Elemental Se 0 and Alanine (Ala) 335Step 4: Metabolic Pathways of Methyl Selenomethionine (MeSeMet) 335Biochemistry of Selenium 335Is Selenium an Essential Trace Element for Plants? 335Conversion of Inorganic to Organic Selenium Forms (The First Step of the Se-Assimilation Pathway) 336Adaptive Mechanisms by Plants to Evade Selenium Toxicity Participation of Se-Amino Acids 338Volatilization of Selenium Organic Compounds 338Involvement of Selenocysteine Lyase 339Sequestration of Selenium Organic Compounds 339Antioxidant Defense Mechanisms 340Involvement of Phytohormones or Signalling Molecules 340General Conclusions and Future Prospects 341Acknowledgments 342References 34215 Lanthanides as Beneficial Elements for Plants 349Fernando C. Gómez- Merino, Libia F. Gómez- Trejo, Rubén Ruvalcaba- Ramírez, and Libia I. Trejo- TéllezIntroduction 349Lanthanides in Biological Systems 353Lanthanides in Plants 355Beneficial Effects of Lanthanides in Plants 356Conclusions and Future Research Needs 360References 360Index 370