Handbook of Plant and Crop Physiology

Cover
Half Title
Title Page
Copyright Page
Dedication
Table of Contents
Preface
Acknowledgments
Editor
List of Contributors
Abbreviations
Section I Soil–plant–water–nutrients–microorganisms Physiological Relations
	1 Evaluating the Recruitment of Soilborne Microbes to Seeds and Their Effects On Seed Germination...
		1.1 Introduction
		1.2 Case Study
			1.2.1 Field Deployment
			1.2.2 Soil Chemistry
			1.2.3 Seed Processing
			1.2.4 Molecular Analysis
			1.2.5 Data Analysis
			1.2.6 Results of the Case Study
		1.3 Perspectives
		1.4 Conclusions
		References
	2 Regulation of Phosphate Starvation in Higher Plants and Role of Mycorrhizae
		2.1 Introduction
		2.2 Growth Responses and Physiological and Metabolic Adaptations of Phosphate-Starved Plants
		2.3 Phosphate Starvation regulators
			2.3.1 Phosphate Transport
			2.3.2 Transcriptional Regulation of the Phosphate Starvation Response
			2.3.3 Posttranscriptional Regulation of the Phosphate Starvation Response
			2.3.4 Posttranslational Regulation of the Phosphate Starvation Response
		2.4 Mycorrhiza-Induced Transcriptional Reprogramming of Plant Root Cortical Cells
		2.5 Phosphate Regulation of Arbuscular Mycorrhizal Symbiosis
		2.6 Integration of Phosphate Starvation Response and Mycorrhizal Signaling Pathways
		2.7 Conclusions and Future Prospects
		References
	3 Effect of Potassium On Growth and Physiology of Alfalfa
		3.1 Introduction
		3.2 Principles Underlying the Growth of Alfalfa
		3.3 Role of Potassium in Physiological Mechanisms for Growth and Development of Alfalfa
		3.4 Dynamics of Alfalfa’s Response to Potassium
			3.4.1 Forms of Potassium in the Soil
			3.4.2 Potassium Availability and Uptake
			3.4.3 Factors Affecting Potassium Availability and Uptake By Alfalfa
				3.4.3.1 Soil Factors
				3.4.3.2 Plant Factors
				3.4.3.3 Factors Related to Fertilizer    management
		3.5 Potassium Management for the Optimal Growth of Alfalfa
		3.6 Summary and Conclusions
		References
	4 Evaluating and Managing Water Requirement of Crops: Theoretical Methods and Remote Sensing Technology
		4.1 Introduction
		4.2 Evapotranspiration
		4.3 Theoretical Methods for Calculating Et
			4.3.1 Crop Coefficient (kc)
			4.3.2 Calculating Growing Degree days (gdd)
			4.3.3 Irrigation Interval
			4.3.4 Perennial Crops
			4.3.5 Alternative Method for Calculating Et Without Gdd
			4.3.6 Calculating Kc and Et for Partial Canopy/young Orchards
			4.3.7 Remote Sensing
			4.3.8 Simplified Pan Evaporation Method
		References
Section II Physiology of Plant/crop Growth and Development Stages
	5 Seed Dormancy and Germination in Medicinal Plants: Inhibitors and Promoters
		5.1 Introduction
		5.2 Seed Dormancy
		5.3 Plant Growth Regulators and Dormancy: Facilitators and Inhibitors
			5.3.1 Gibberellins
				5.3.1.1 Biosynthesis and Regulation
				5.3.1.2 Ga and Dormancy
				5.3.1.3 Interactions of Ga and Aba
			5.3.2 Auxin, a Brand New Player
			5.3.3 Ethylene
		5.4 The Role of N-Containing Compounds
		5.5 Nitric Oxide and Dormancy Breaking
		5.6 Scarification, An Ancient and Efficient Tool
		5.7 Stratification, a Pattern From Nature
		5.8 Conclusions
		References
	6 Plant Aging and Developmental Stages: Reproductive and the Beginning of Flowering Stage
		6.1 Introduction
		6.2 Plant Age and Flower Initiation
			6.2.1 Juvenile Phase
			6.2.2 The Role of Leaf in Flowering
			6.2.3 Floral Meristem Development
			6.2.4 Role of Mirna in Flowering
		6.3 Light
			6.3.1 Photoperiodism in Plants
			6.3.2 Plant Response to Light
			6.3.3 How Does Phytochrome Detect Light?
		6.4 The Role of Cold Stress in Vernalization and Flowering
		6.5 Conclusions
		References
	7 Longan Fruit Tree Physiology and Its Flowering Induction
		7.1 Botany of the Longan Tree
			7.1.1 Longan Trees and Its Fruits
			7.1.2 Botanical Management of the Longan Tree
		7.2 Longan Tree’s Irregular Flowering Habit and Its Influencing Factors
			7.2.1 Longan Tree’s Inherent Issue: Irregular Flowering
			7.2.2 Factors Affecting Longan Tree Flowering
				7.2.2.1 Winter Seasonal Temperatures
				7.2.2.2 Auxin and Gibberellins
				7.2.2.3 Florigen
				7.2.2.4 Potassium Chlorate
				7.2.2.5 Potassium
				7.2.2.6 Chlorine
				7.2.2.7 Phosphorus
		7.3 Longan Tree Physiological Responses to Flowering Induction
			7.3.1 Case Study: Longan Tree Flowering Induction in Tropical Coastal Areas
				7.3.1.1 Flowering Induction Materials
				7.3.1.2 Technical Steps of Kclo3-Ga3-Kh2po4-Based Longan Flowering Induction
				7.3.1.3 Tree and Soil Measurements and Growing Degree-Days for Longan
			7.3.2 Auxin, Gibberellins, Photosynthesis, and Potassium Patterns in Flowering Induction
				7.3.2.1 Temporal Changes of Auxin and Gibberellins Between Leaves and    shoot Tips
				7.3.2.2 Longan Tree Flowering and Photosynthesis Relationships
				7.3.2.3 Longan Leaf K, P, and Cl Holding and Fruit Yield Differences
				7.3.2.4 Discussion
		Acknowledgments
		References
	8 Senescence: The Final Phase of Plant Life
		8.1 Introduction
		8.2 Senescence, Abscission, and Programmed Cell Death
		8.3 Leaf Senescence
		8.4 Senescence of Flowers and Reproductive Organs
		8.5 Senescence Dependent On Plant Hormones
			8.5.1 Ethylene and Senescence
				8.5.1.1 Ethylene Biosynthesis and Signal Transduction Pathway
			8.5.2 Abscisic Acid
			8.5.3 Cytokinin
			8.5.4 Auxin
			8.5.5 Jasmonic Acid
			8.5.6 Salicylic Acid
			8.5.7 Dark-Induced Leaf Senescence
			8.5.8 Fatty Acids, Amino Acids, and Proteins During Senescence
			8.5.9 Role of Sugars During the Senescence Process
		8.6 Senescence-Related Genes
		8.7 Conclusions
		References
Section III Cellular and Molecular Aspects of plant/crop Physiology
	9 Carbon Assimilation and Partitioning in Crop Plants: A Biochemical and Physiological View
		9.1 Oxygenic Photosynthesis in Higher Plants
			9.1.1 Carbon Assimilation
			9.1.2 Intra- and Intercellular Photosynthate Partitioning
		9.2 Carbon Metabolism in Source Tissues
		9.3 Different Photosynthetic Products
			9.3.1 Starch
			9.3.2 Sucrose
			9.3.3 Raffinose Family of Oligosaccharides
			9.3.4 Sugar Alcohols
			9.3.5 Oils
			9.3.6 Proteins and Amino Acids
		9.4 Concluding Remarks
		Acknowledgments
		References
	10 Epitranscriptomics in Plant Physiology: M6a Modifications
		10.1 More Than Genetics
		10.2 Epitranscriptome
			10.2.1 Trna Epitranscriptional Modifications
			10.2.2 Rrna Epitranscriptional Modifications
			10.2.3 Mrna Epitranscriptional Modifications
		10.3 N6-Methyladenosine (m6a)
		10.4 Mrna M6a Writer
		10.5 Biological Roles of Mrna M6a Writer
		10.6 M6a Eraser for Mrna
		10.7 Biological Roles of Mrna M6a Eraser
		10.8 Mrna M6a Reader
		10.9 Biological Roles of Mrna M6a Reader
		10.10 Mapping, Quantitative, and Qualitative Analysis of M6a
		10.11 Conclusions
		References
11 Characteristics of Grain Quality in Rice: Physiological and Molecular Aspects
	11.1 Introduction
	11.2 Features and Structure of Rice Grains
	11.3 Rice Grain Quality
		11.3.1 Appearance Quality
		11.3.2 Milling Quality
		11.3.3 Cooking Quality
	11.4 Effect of Environmental Factors On the Rice Grain Quality
	11.5 Effect of Temperature On the Rice Grain Quality
	11.6 Effect of Soil Factors On the Rice Grain Quality
	11.7 Effect of Genetic Factors  on the Rice Grain Quality
	11.8 Effect of Genetic Factors On Amylopectin
	11.9 Effect of Genetic Factors On the Amylose Content (ac)
	11.10 Rice Fragrance
		11.10.1 Chemical Structure of Badh
		11.10.2 Badh-Specific Substrate
		11.10.3 Betaine Aldehyde Dehydrogenase (badh) and Rice Fragrance
	11.11 Factors Affecting the Extent of Rice Aroma
		11.11.1 Genetic Background
		11.11.2 Rice Growing Related Factors
	References
12 Role of Melatonin in Improving  the Tolerance of Plants to Salinity Stress
	12.1 Introduction
	12.2 Soil Salinity
	12.3 Response of Plants to Salinity Stress
		12.3.1 Seed Germination
		12.3.2 Seedling Emergence
		12.3.3 Plant Growth and Development
		12.3.4 Photosynthetic Pigments and Photosystems
		12.3.5 Antioxidant Systems
		12.3.6 Plant Nutrient Balance
		12.3.7 Crop Yield
	12.4 Role of Melatonin in Alleviating Salinity Stress
		12.4.1 Role of Melatonin in Improving Plant Growth and Development Under Salinity
		12.4.2 Role of Melatonin in Improving Plant Antioxidant Systems Under Salinity
		12.4.3 Role of Melatonin in Improving Plant Photosynthesis Under Salinity Stress
		12.4.4 Role of Melatonin in Improving Plant Ion Regulation
	12.5 Conclusions and Future Challenges
	Acknowledgments
	References
13 Phytohormones and Abiotic Stresses: Roles of Phytohormones...
	13.1 Introduction
	13.2 Types of Plant Stresses
	13.3 Plant Responses to Stress
		13.3.1 Escape
		13.3.2 Avoidance
		13.3.3 Tolerance
	13.4 Phytohormones and Stresses
	13.5 Management of Stresses By Hormones
		13.5.1 Breeding and Transgenic Strategies
		13.5.2 Exogenous Application Strategy
	13.6 Auxin
		13.6.1 Location of Auxin Production and Its Action Site
		13.6.2 Role of Auxin in the Plant System
		13.6.3 Changes in Auxin Under Stress Conditions
		13.6.4 Auxin Effects On Crops Under Environmental Stress
	13.7 Gibberellins
		13.7.1 Location of Gibberellin Production and Its Action Site
		13.7.2 Role of Gibberellins in the Plant System
		13.7.3 Changes in Gibberellins Under Stress Conditions
		13.7.4 Gibberellin’s Effects On Crops Under Environmental Stress
	13.8 Cytokinins (cks)
		13.8.1 Location of Ck Production and Its Action Site
		13.8.2 Role of Cks in the Plant System
		13.8.3 Ck’s Effects On Crops Under Environmental Stress
	13.9 Abscisic Acid (aba)
		13.9.1 Location of Aba Production and Its Action Site
		13.9.2 Role of Aba in the Plant System
		13.9.3 Effect of Aba On Crops Under Environmental Stress
	13.10 Ethylene
		13.10.1 Location of Ethylene Production and Its Action Site
		13.10.2 Role of Ethylene in the Plant System
		13.10.3 Changes in Ethylene Under Stress Conditions
		13.10.4 Effect of Ethylene On Crops Under Environmental Stress
	13.11 Conclusions
	References
14 Physiological Roles of Plant Nutrients, Ions, and Phytometabolites Homeostasis in Activating Antioxidative Defense Systems and Conferring Tolerance to Osmotic Stress
	14.1 Introduction
	14.2 Plant Nutrition and Assimilates   partitioning Under Osmotic  stress
		14.2.1 Calcium
		14.2.2 Nitrogen, Phosphorous, and Carbon Metabolism
		14.2.3 Potassium, Sodium, and Chloride
		14.2.4 Other Nutrient Elements
	14.3 Plant Responses to Oxidative Stress Caused By Osmotic Stress
		14.3.1 Redox Homeostasis By Reactive  oxygen Species/reactive Nitrogen  species Balance
		14.3.2 Polyamines
		14.3.3 Nitric Oxide
		14.3.4 Alternative Oxidase
		14.3.5 Aldehydes
	14.4 Protective Roles of Pigments Against Osmotic Stress
		14.4.1 Flavonoids, Anthocyanin, and  phenolic Biosynthesis
		14.4.2 Carotenoids
	14.5 Protective Roles of Plant Stress-Responsive Proteins Against Osmotic Stress
		14.5.1 Late Embryogenesis Abundant Proteins
		14.5.2 Heat-Shock Proteins
		14.5.3 Metallothionein
		14.5.4 Protease and Proteolytic Activity
	14.6 Conclusions
	References
Section IV Plant/crop Physiology and Physiological Aspects of Plant/crop Production Processes
	15 Physiology of Grain Development in Cereals
		15.1 Introduction
		15.2 Flowering Initiation and Development
		15.3 Flowering Time and Adaptation of Plants to Marginal Environments
		15.4 Gametophyte Development and Anthesis
		15.5 Pollination, Fertilization, and Grain Initiation
		15.6 Grain Development
			15.6.1 Endosperm Development
			15.6.2 Starch Synthesis
			15.6.3 Synthesis of Grain Storage Proteins
			15.6.4 Seed Coat Development
		15.7 Conclusion
		References
	16 Plant Nutrition: Rates of Transport and Metabolism
		16.1 Introduction
		16.2 Rates of Absorption of Essential Nutrients By Plants
			16.2.1 Algae
			16.2.2 Vascular Plants
				16.2.2.1 Roots
				16.2.2.2 Leaves
		16.3 Factors Affecting Rates of Movement of Essential Nutrients Within Plants
			16.3.1 Saturation Kinetics
			16.3.2 External Or Internal Concentration of the Nutrient Itself
			16.3.3 Competing Or Noncompeting Ions, Including H+ (ph)
			16.3.4 Salinity, Nacl
			16.3.5 Moisture Stress Or Drought
			16.3.6 Temperature and Radiant Energy
			16.3.7 Oxygen and Carbon Dioxide
			16.3.8 Hormones, Enzymes, and Genes
			16.3.9 Nanoparticles
			16.3.10 Mycorrhizal Fungi
			16.3.11 Rates of Transport of Essential Plant Nutrients in the Vascular System
				16.3.11.1 Xylem
				16.3.11.2 Phloem
			16.3.12 Reproductive Organs (e.g., Flowers, Fruit, Seeds) and Storage Organs  (e.g., Tubers)
		16.4 Multi-Compartment Models of Plants
			16.4.1 Compartments and Concepts of Influx, Efflux, and Net Flux In and Among Plants
			16.4.2 Flux Rates in Multi-Compartment  models of Plants
		16.5 Rates of Transport of Elements Other Than Essential Plant Nutrients
		References
	17 Plant Nutrition: Interactions of Mineral and Organic Substances
		17.1 Introduction
		17.2 Properties of the Essential Plant Nutrients
		17.3 Properties of Soil Organic Matter
		17.4 Interaction of Mineral Nutrients and Organic Substances Near and at the  soil–root Interface
			17.4.1  Root Exudates
			17.4.2 Interactions of Iron and Organic Substances
			17.4.3 Aggregates of Minerals, Mineral Nutrients, and Organic Substances
		17.5 Interaction of Mineral Nutrients and Organic Substances at the Leaf
		17.6 Some Aspects of Transport of Mineral Nutrients in the Plant
		References
	18 Roles and Implications of Arbuscular Mycorrhizas in Plant Nutrition
		18.1 Introduction
		18.2 Endophytic Fungi
		18.3 Molecular Dialogue and Symbiotic Interaction Between Plant and Fungi
			18.3.1 Carbon Flow From Host Plants to Arbuscular Mycorrhizal (am) Fungi
				18.3.1.1 Sucrose Transport and Metabolism in Mycorrhizal Roots
				18.3.1.2 Lipid Transfer From Host Plants to Am Fungi
			18.3.2 Mineral Nutrient Flow From Fungi to Host Plants
				18.3.2.1 Nitrogen
				18.3.2.2 Phosphorus
				18.3.2.3 Potassium
				18.3.2.4 Calcium
		18.4 Conclusions
		References
	19 Turfgrass Nitrogen Management: A Review
		19.1 Introduction
		19.2 A Brief Overall Review of Plant Nitrogen
		19.3 Turfgrass Nitrogen Requirement and Uptake
			19.3.1 N Forms Available to Turfgrasses
			19.3.2 Turfgrass N Requirement
			19.3.3 Turfgrass N Use Efficiency
			19.3.4 Nitrate Uptake
			19.3.5 Ammonium Uptake
			19.3.6 Urea Uptake
			19.3.7 Amino Acid Uptake
			19.3.8 Uptake of Other N Forms
		19.4 Nitrogen Metabolism
			19.4.1 N Assimilation
			19.4.2 N Transportation
			19.4.3 N Metabolism Associated With Carbon Metabolism of Photosynthesis and Photorespiration
			19.4.4 N Interactions With Other Nutrients and Elements
		19.5 Nitrogen Interactions With Abiotic and Biotic Factors
			19.5.1 Abiotic Stresses
				19.5.1.1 Water Deficit and Waterlogging
				19.5.1.2 Temperature Extremes
				19.5.1.3 Light
				19.5.1.4 Traffic
				19.5.1.5  Salinity
				19.5.1.6 Heavy Metals
				19.5.1.7 Acidic Soil and Aluminum Toxicity
				19.5.1.8 Excessive Root-Zone Organic Matter
				19.5.1.9 Nutrient Imbalances
			19.5.2 Biotic Stresses
				19.5.2.1 Weeds
				19.5.2.2 Diseases
				19.5.2.3 Insect-Mite Pests
				19.5.2.4 Nematodes
				19.5.2.5 Earthworms
				19.5.2.6 Other Living Forms
		19.6 Nitrogen Cycles and N Loss From Turf–soil–atmosphere Systems
			19.6.1 Mowing and Clipping Recycle
			19.6.2 Natural N Input and Cycling in Turf–soil–atmosphere Systems
				19.6.2.1 Natural N Input
				19.6.2.2 Nitrification
				19.6.2.3 Mineralization
				19.6.2.4 Immobilization
				19.6.2.5  N and Carbon Cycles
			19.6.3 N Losses
				19.6.3.1 N Leaching
				19.6.3.2 N Volatilization
				19.6.3.3 Ammonium Fixation
				19.6.3.4 Denitrification
				19.6.3.5 N2o Emission
				19.6.3.6 Runoff and Erosion
		19.7 Turfgrass Nitrogen Management
			19.7.1 N Fertilizers and Advancements
				19.7.1.1 Balance Nh4+, No3-, Urea, Amino Acids, and Other Types of Fertilizers
				19.7.1.2 Use of Controlled-Release Fertilizers
				19.7.1.3 Balanced Foliar and Granular N Fertilizers
				19.7.1.4 Integrating N Application With Plant Growth Regulators (pgr) and Bio-Stimulants
			19.7.2 Symbiosis
			19.7.3 N Osmic Management
			19.7.4 N Digital Management
			19.7.5 Integrated Turfgrass N Management
		19.8 Conclusions and Future Perspectives
		Acknowledgments
		References
Section V Plant Growth Regulators: The Natural Hormones (growth Promoters and Inhibitors)
	20 Plant Growth Regulators and Secondary Metabolites, Downregulation and Upregulation
		20.1 Introduction
		20.2 Auxin, An Extremely Potent Regulator
		20.3 Gibberellins: Accumulation and Interactions
		20.4 Abscisic Acid (aba), a Classical Plant Hormone
		20.5 Cytokinins, the Well-Known Stimulators
		20.6 Ethylene, the First Identified Regulator
		20.7 Brassinosteroids
		20.8 Jasmonate Biosynthesis and Signaling
		20.9 Salicylic Acid (sa), a Multifaceted Plant Hormone
		20.10 Conclusions
		References
Section VI Physiological Responses of Plants/crops Under Stressful...
	Chapter 21 Physiological Basis of Abiotic Stress Tolerance in Plants
		21.1 Introduction
		21.2 Physiological Basis of Salinity Tolerance in Plants
			21.2.1 Ion Homeostasis
				21.2.1.1 Regulation of Ion Uptake
				21.2.1.2 Ion Exclusion
				21.2.1.3 Ion Compartmentation
			21.2.2 Maintenance of Potassium Under Salt Stress
			21.2.3 Tissue Tolerance in Plants
			21.2.4 Production and Accumulation of Compatible Solutes
			21.2.5 Regulation of Antioxidant Enzymes
			21.2.6 Production of Polyamines
			21.2.7 Regulation of Plant Hormones
			21.2.8 Regulation of Ion Fluxes in Roots
		21.3 Physiological Basis of Drought Tolerance
			21.3.1 Chlorophyll Fluorescence
			21.3.2 Photosynthesis, Stomatal Conductance, and Transpiration Rate
			21.3.3 Chlorophyll Content
			21.3.4 Accumulation of Reactive Oxygen Species and Antioxidants
			21.3.5 Maintenance of K+ in Leaf Tissues
			21.3.6 Production of Plant Growth Regulators
			21.3.7 Regulation of Electrolyte Leakage
			21.3.8 Dynamics of Leaf Relative Water  content
			21.3.9 Compatible Solutes and Osmotic Adjustment
			21.3.10 Accumulation of Proline
		21.4 Physiological Basis of Waterlogging Tolerance In Plants
			21.4.1 Formation of Aerenchyma
			21.4.2 Diffusion of Oxygen in Roots
			21.4.3 Control of Radial Oxygen Loss  in Roots
			21.4.4 Production and Accumulation of Ethylene
			21.4.5 Ethylene and Formation of Aerenchyma Cells
			21.4.6 Ethylene and Formation of Adventitious Roots
		21.5 Conclusions
		References
	22 Physiological Adaptations in  temperate Crops to Environmental...
		22.1 Introduction
		22.2 Plant Physiological Mechanisms Involved in Response to Environmental Stresses
		22.3 Crop Adaptations to Environmental Stress Factors in the Temperate Climate
			22.3.1 Plant Adaptations to Winter Season-Related Stresses
				22.3.1.1 Plant Adaptation to Low Temperatures: Cold Acclimation
				22.3.1.2 Plant Developmental Adaptation to Winter Season: A Phenomenon of Vernalization
				22.3.1.3 Low Temperatures in the Spring
				22.3.1.4 Plant Adaptations to Winter Stresses Related to Water Regime
		22.3.2 Plant Adaptations to Flooding and Waterlogging
			22.3.3 Plant Adaptations to Drought
				22.3.3.1 Overview of Plant Adaptations to Drought During Different Stages of the Growing Season
				22.3.3.2 Summary of Plant Adaptations  to Drought
			22.3.4 Plant Adaptations to Salinity
		22.4 Molecular Mechanisms Underlying Crop Adaptation to Environmental Stresses During the Growing Season
		22.5 Concluding Remarks
		Acknowledgment
		References
	23 Osmotic Stress: An Outcome of Drought and Salinity
		23.1 Introduction
		23.2 Osmolytes
		23.3 Organic Acids, Sugars, Sugar Alcohols, Polyols, and Phenylpropanoids
		23.4 Proline
		23.5 Amino Acids: Protein and Non-Protein Amino Acids: Glycinebetaine (gb), Expansins, Non-Protein-Defensinsβ-Aminobutyric Acid (baba), Non-Protein-Defensinsβ-Aminobutyric-Gamma-Aminobutyric Acid...
		23.6 Conclusions
		References
24 Drought Stress Sensing-Signaling in Plants
	24.1 Introduction
	24.2 How Drought Stress Generates Signals? How Plants Sense Drought Stress Signals?
	24.3 How Plants Pprs Mediate Drought-Induced Signal Drought-Induced-Perception-Transduction?...
	24.4 How Ca2+ Sensors Perceive and Transduce Ca2+ Signature? How Interplay Between Ca2+, Redox, and Ph Signals Control...
	24.5 Regulation of Ca2+ Signature: how [ca2+]i Signals Are Regulated Across...
	24.6 Aba-Dependent and Aba-Dependent--Independent Signaling Pathways Confer Drought Tolerance Through...
	24.7 Conclusions
	Authors’ Contributions
	References
25 Plant Morphological and Physiological Responses to Drought Stress
	25.1 Introduction
	25.2 Effects of Drought Stress at Whole Plant Level in Connection With Circadian Rhythms
		25.2.1 Protection Mechanisms Against Drought Stress
		25.2.2 How Internal and External Factors Induce Oscillations of Root Hydraulic Conductance and What Are the Consequences?
	25.3 Water Relations and Effects On Plant Growth: Root and Cell Hydraulic Conductance, Root Architecture...
		25.3.1 Regulation of Cell Division and Expansion Under Drought Stress
		25.3.2 Regulation of Water Uptake and Transport Under Drought Stress
			25.3.2.1 Root System Architecture: Genetic and Phenotypic Traits and Imaging Techniques
			25.3.2.2 Regulatory Roles of Aquaporin (aqp) in Modulating Hydraulic Conductivity Under Drought Stress
		25.3.3 Effects of Drought Stress On Shoot and Leaves Growth and Physiological Responses in Relation With Gas Exchange and Photosynthesis
	25.4 Transpiration and Evaporation Processes Through Plant Cuticle
	25.5 Role of Effective Use of Water (euw) and Water Use Efficiency (wue), and Energy Use Efficiency (eue) in Crop Improvement
	25.6 Variations of Crop Yield and Qualitative Traits Under Drought Stress
	25.7 Alterations in Composition and Structure-Conformation of Biomembranes: Lipid Peroxidation and Role...
	25.8 Effects of Drought Stress On Photosynthesis and Photorespiration
	25.9 Conclusions
	References
26 Morphological, Physiological, and Biochemical Responses of Plants to Drought and Oxidative Stresses
	26.1 Introduction
	26.2 Common Effects of Drought Stress On Plants
	26.3 Plant Responses to Water    deficit
		26.3.1 Drought Escape
		26.3.2 Drought Avoidance
		26.3.3 Drought Tolerance
		26.3.4 Drought Recovery
	26.4 Mechanisms of Plants’ Tolerance to Drought
		26.4.1 Morphological Responses to Water Deficit
			26.4.1.1 Germination and Plant Establishment
			26.4.1.2 Number and Size of the Leaves
			26.4.1.3 Root Changes
		26.4.2 Physiological Responses to water Deficit
			26.4.2.1 Plant Water Relations
			26.4.2.2 Cell Membrane Stability
			26.4.2.3 Photosynthesis
			26.4.2.4 Photosynthetic Pigments
			26.4.2.5 Chlorophyll a Fluorescence
			26.4.2.6 Osmotic Adjustment
			26.4.2.7 Plant Growth Regulators (phytohormones)
			26.4.2.8 Mineral Nutrition Relations
			26.4.2.9 Changes in the Secondary Metabolite Content
		26.4.3 Drought-Induced Oxidative Stress and Biochemical Responses of the Plant
			26.4.3.1 Reactive Oxygen Species (ros)
			26.4.3.2 Enzymatic and Nonenzymatic Components of the Antioxidative Defense System
	26.5 Some Agronomical Methods for Enhancing Plants’ Tolerance to Water Deficit
		26.5.1 Seed Pretreatment (seed Priming)
		26.5.2 Application of Plant Growth-Promoting Rhizobacteria (pgpr)
		26.5.3 Application of Silicon
		26.5.4 Application of Hydrogels
		26.5.5 Application of Chitosan
		26.5.6 Plant Anti-Stress Biostimulants
		26.5.7 Foliar Application of Other Plant Growth Regulators
	26.6 Conclusions
	References
27 Effects of Salinity Stress On  morpho-Physiology, Biochemistry, and Proteomic Responses  of Plants
	27.1 Introduction
	27.2 Salinity
		27.2.1 Primary Salinity
		27.2.2 Secondary Salinity
		27.2.3 How Are Plants Responding to Soil Salinity?
		27.2.4 Effects of Salinity On Plants
			27.2.4.1 Salinity Effects On Physiological and Biochemical Processes and Morphological Characteristics of Plants
			27.2.4.2 Leaf Chlorophyll Content Under Salt Stress Conditions
			27.2.4.3 Disturbances in Photosynthesis under Salt Stress Conditions
			27.2.4.4 Compatible Osmotic and Solute Accumulation in Plants Under    salt Stress Conditions
			27.2.4.5 Role of Antioxidants in Plants’ tolerance to Salinity Stress
			27.2.4.6 Changes in Plant Enzymatic Antioxidant (cat, Pox, Apx) Activity Under    salt Stress Conditions
			27.2.4.7 Role of Polyamine in Plants’ Salinity Tolerance
			27.2.4.8 Changes in Plant’s Potassium (k) and Sodium (na) Ratio Under Salt Stress Conditions
			27.2.4.9 Hormone Regulation of Salinity tolerance in Plants
			27.2.4.10 Effects of Salinity On Plant/crop growth and Yield
			27.2.4.11 Approaches for Reducing Soil salinity’s Detrimental Effects On plant/crop Growth
			27.2.4.12 Strategies for Salt Tolerance in Plants
			27.2.4.13 Proteomic Responses of Plants to Salinity Stress
	27.3 Conclusions
	References
28 Metabolic Regulation of Cytokinins for Conferring Heat...
	28.1 Introduction
	28.2 Metabolic Changes Associated With Ck Regulation of Heat Tolerance
		28.2.1 Sugars and Sugar Alcohols
		28.2.2 Organic Acids and Amino Acids
		28.2.3 Antioxidants and Secondary    metabolites
		28.2.4 Hormone Interaction
	28.3 Metabolic Changes Associated With Ck Regulation of Drought Tolerance
		28.3.1 Sugar Metabolism
		28.3.2 Amino Acids and Polyamines
		28.3.3 Antioxidant Metabolism
		28.3.4 Hormone Interaction
	28.4 Conclusions and Future Prospects
	References
29 Drought Physiology of Forage Crops
	29.1 Introduction
	29.2 Physiological Impacts of Drought On Forage Crops
	29.3 Mechanisms of Plant Response to Drought
		29.3.1 Drought Escape
		29.3.2 Dehydration Postponement
			29.3.2.1 Reduction of Water Loss
			29.3.2.2 Maintenance Or Increase Water Uptake
			29.3.2.3 Osmotic Adjustment
		29.3.3 Dehydration Tolerance
	29.4 Management Considerations in Drought
	29.5 Summary and Conclusions
	References
30 Physiological Mechanisms of Nitrogen Absorption and Assimilation in Plants Under Stressful Conditions
	30.1 Introduction
	30.2 Nitrogen Sources, Their Uptake, and Assimilation
		30.2.1 Sources of Nitrogen
		30.2.2 Absorption and Assimilation of    nitrogen
			30.2.2.1 Nitrate Transport Systems
			30.2.2.2 Nitrate Transporters
			30.2.2.3 Reduction of Nitrate
	30.3 Nitrogen Absorption and Assimilation Under Different Stresses
		30.3.1 Salinity
		30.3.2 Water Stress
		30.3.3 Light
		30.3.4 Heat
		30.3.5 Chilling
		30.3.6 Metal Toxicity
		30.3.7 Ultraviolet B Radiation
	30.4 Concluding Remarks
	References
31 Reactive Oxygen Species Generation, Hazards, and Defense Mechanisms in Plants Under...
	31.1 Introduction
	31.2 Reactive Oxygen Species: Sites of Production and Their Effects
		31.2.1 Types of Ros
		31.2.2 Sites of Production of Ros
			31.2.2.1 Chloroplasts
			31.2.2.2 Mitochondria
			31.2.2.3 Endoplasmic Reticula
			31.2.2.4 Peroxisomes
			31.2.2.5 Plasma Membranes
			31.2.2.6 Cell Walls
			31.2.2.7 Apoplasts
		31.2.3 Role of Ros As Messengers
		31.2.4 Ros and Oxidative Damage to Biomolecules
			31.2.4.1 Lipids
			31.2.4.2 Proteins
			31.2.4.3 Dna
	31.3 Antioxidative Defense System in Plants
		31.3.1 Nonenzymatic Components of Antioxidative Defense System
			31.3.1.1 Ascorbate
			31.3.1.2 Glutathione
			31.3.1.3 Tocopherols
			31.3.1.4 Carotenoids
			31.3.1.5 Phenolic Compounds
		31.3.2 Enzymatic Components
			31.3.2.1 Superoxide Dismutase
			31.3.2.2 Catalase
			31.3.2.3 Guaiacol Peroxidase
			31.3.2.4 Enzymes of Ascorbate–glutathione  cycle
	31.4 Ros Production, Oxidative Damage and Antioxidants Status Under Stressful Conditions
		31.4.1 Drought
		31.4.2 Salinity
		31.4.3 Chilling
		31.4.4 Metal Toxicity
		31.4.5 Uv-B Radiations
		31.4.6 Pathogens
	31.5 Concluding Remarks
	References
32 Oxidative Stress: Repercussions for Crop Productivity
	32.1 Introduction
	32.2 Diversity and Metabolism  of Ros in Plants
		32.2.1 Superoxide Anion
		32.2.2 Hydrogen Peroxide
		32.2.3 Hydroxyl Radicle
		32.2.4 Singlet Oxygen
	32.3 Ros-Mediated Plant Growth  and Development
	32.4 Oxidative Stress and Plant Productivity
	32.5 Conclusions
	References
33 Physiological and Biophysical Responses of Plants Under Low and Ultralow Temperatures
	33.1 Heat and Temperature
		33.1.1 Heat Transfer
		33.1.2 Temperature and Heat Capacity
		33.1.3 Energy of Phase Transition
	33.2 Low Temperatures
		33.2.1 Frost Stress
			33.2.1.1 Plant Response to Frost
			33.2.1.2 Coping With Frost
			33.2.1.3 Plant Protection Against Frost
		33.2.2 Freezing Stress
			33.2.2.1 Freezing of Water
			33.2.2.2 Ice Nucleation
			33.2.2.3 Ice Crystal Growth
			33.2.2.4 Crystal Size Distribution
			33.2.2.5 Coping With Freezing Stress
		33.2.3 Plant Adaptations to Freezing Stress
			33.2.3.1 Cold Hardening
			33.2.3.2 Osmotic Adjustment
			33.2.3.3 Ice Growth Inhibitors
			33.2.3.4 Antifreezers
			33.2.3.5 Barriers to Ice Propagation
			33.2.3.6 Adaptation of Herbs and Trees to Low Temperatures
	33.3 Ultralow Temperatures
		33.3.1 Glass Transition
		33.3.2 Water and Glass Formation
		33.3.3 Cryoprotectants
		33.3.4 Plant Long-Term Storage at Ultralow Temperatures
	Acknowledgment
	References
34 Physiological Responses of Cotton (gossypium Hirsutum L.) to Salt Stress
	34.1 Introduction
	34.2 Responses of Cotton to Salt Stress
		34.2.1 Dry-Matter Production of Cotton Plants Under Salt Stress
		34.2.2 Nitrogen Absorption By Cotton Plants Under Salt Stress
			34.2.2.1 Nitrogen (15n) Absorption and Concentration in Plant Tissues
			34.2.2.2 Total N Uptake By Plants
		34.2.3 Nitrogen Metabolism and Assimilation in Cotton Plants Under Salt Stress
			34.2.3.1 Protein-N Content of Plants
			34.2.3.2 Total Soluble-N Content of Plants
			34.2.3.3 Ammonium Plus Amide-N Content of Plants
			34.2.3.4 Free Amino-N Content of Plants
		34.2.4 Total Water Uptake By Plants Under Salt Stress
	34.3 Summary and Conclusions
	34.4 Future Perspectives
	References
35 Growth and Physiological Responses of Turfgrasses Under Stressful Conditions
	35.1 Introduction
	35.2 Growth and Physiological Responses of Turfgrasses Under Stressful Conditions
		35.2.1 Turfgrass Stress and Turf Quality
		35.2.2 Examples of Complex Combinations of Stressors
			35.2.2.1 Summer Decline
			35.2.2.2 Winter Injuries and Kills
			35.2.2.3 Root Dysfunction Associated With Combinations of Other Stressors
		35.2.3 Turfgrass Responses to Stresses
			35.2.3.1 Oxidative Stresses and Antioxidants
			35.2.3.2 Signal Transduction Responses to Stresses and Approaches
			35.2.3.3 Morphological, Physiological, and Metabolic Responses
			35.2.3.4 Genomic Responses and Approaches
			35.2.3.5 Symbiotic Eco-Evolutions
		35.2.4 Turfgrass Responses to Mowing and Cultivation
		35.2.5 Turfgrass Responses to Overseeding
		35.2.6 Turfgrass Stress Tolerance Variability
		35.2.7 Turfgrass Stress Acclimation and Adaptation
		35.2.8 Turfgrass Stress Management
	35.3 Conclusions and Future Perspectives
	35.4 Acknowledgments
	References
36 Urban Landscape: Trees’ Physiological and Environmental Stresses, Challenges, and Solutions
	36.1 Introduction
	36.2 Effect of Drought Stress  on the Urban Landscape
	36.3 Effect of Salt Stress in the  urban Landscape
	36.4 Effect of Heavy Metals On the Urban Landscape Trees
	36.5 The Urban Tree and Air Pollution
	36.6 Potential Effects of Global Warming On Woody Plants
	36.7 Urban Densification
	36.8 Effect of Pests and Pathogens On Urban Trees
	36.9 Outlook
	References
37 Consequences of Water Stress and Salinity On Plants/crops: Physiobiochemical and Molecular Mitigation Approaches
	37.1 Introduction
	37.2 Water Stress
		37.2.1 Flooding Stress
			37.2.1.1 Flooding Stress and Its Importance
			37.2.1.2 Flooding Stress and Morphological Traits of Crop Plants
			37.2.1.3 Flooding Stress and Crop Yield
			37.2.1.4 Flooding Stress and Nutrient Uptake
			37.2.1.5 Flooding Stress and Physiological Traits of Plants
			37.2.1.6 Molecular Advances for Flooding Stress Tolerance
		37.2.2 Drought Stress
			37.2.2.1 Drought Resistance
			37.2.2.2 Effect of Drought Stress On Plant Growth Characteristics
			37.2.2.3 Relationship Between Drought, Photosynthesis, and Nutrient Uptake
			37.2.2.4 Relationship Between Carbohydrates, Active Ingredients Production, and Drought Stress (osmotic Regulation)
			37.2.2.5 Relationship Between Drought Stress and Oxidative Stress
			37.2.2.6 Crop Varieties and Drought Tolerance
			37.2.2.7 Gene Expression and Drought Stress (osmotic Adjustment)
			37.2.2.8 Drought Stress and the Use of External Chemical Compounds
	37.3 Salinity Stress
		37.3.1 Saline Soils: Definition, Characteristics, and Classification
			37.3.1.1 Sources and Causes of Soil Salinity
		37.3.2 Mechanism of Salinity Effect
		37.3.3 How Do Plants Respond to Salinity Stress?
			37.3.3.1 Mechanisms of Plant Salinity Tolerance
	37.4 Conclusions
	References
Section VII Physiological Responses of Plants/crops to Heavy Metal Concentrations and Agrichemicals
	38 Heavy Metals and Phytoremediation in Plants
		38.1 Introduction
		38.2 Heavy Metals
			38.2.1 Lead (pb)
			38.2.2 Cadmium (cd)
			38.2.3 Copper (cu)
			38.2.4 Nickel (ni)
			38.2.5 Zinc (zn)
		38.3 Effect of Heavy Metals On Humans
		38.4 Effect of Heavy Metals  on Plants
		38.5 Plant’s Defense Mechanism Against Heavy Metals
		38.6 Complications Due to Accumulation of Heavy Metals in the Soil
		38.7 Methods of Soils Remediation Contaminated With Heavy Metals
		38.8 Phytoremediation
			38.8.1 History of the Phytoremediation
			38.8.2 Phytoremediation Methods
				38.8.2.1 Rhizofiltration
				38.8.2.2 Phytostabilization
				38.8.2.3 Phytoextraction
				38.8.2.4 Phytovolatilization
				38.8.2.5 Phytodegradation
				38.8.3 Advantages and Disadvantages of Phytoremediation
				38.8.4 How Are Phytoremediators Consumed?
				38.8.5 Which Plant Species Can Be Used As Phytoremediators?
				38.8.6 Concerns Related to Phytoremediation
		38.9 Conclusions
		References
	39 Arsenic Toxicity and Tolerance Mechanisms in Crop Plants
		39.1 Introduction
		39.2 Arsenic As Toxic Metalloid
			39.2.1 Toxic Species of Arsenic
			39.2.2 Sources of Arsenic to the Soil
			39.2.3 Uptake of Arsenic By Plants
				39.2.3.1 Uptake of Arsenite
				39.2.3.2 Uptake of Arsenate
				39.2.3.3 Uptake of Methylated Arsenic Species
			39.2.4 Symptoms of Arsenic Toxicity
		39.3 Metabolic Alterations in Arsenic-Stressed Plants
		39.4 Oxidative Stress and Antioxidative Defense Under Arsenic Toxicity
			39.4.1 Nonenzymatic Antioxidants
			39.4.2 Enzymatic Antioxidants
		39.5 Arsenic Tolerance Mechanisms in Plants
			39.5.1 Suppression of High-Affinity Phosphate/arsenate Transport
			39.5.2 Reduction of Arsenate to Arsenite
			39.5.3 Increased Synthesis of Glutathione and Phytochelatins
			39.5.4 Arsenic Sequestration in the Vacuoles
			39.5.5 Arsenic Efflux
			39.5.6 Methylation and Volatilization
		39.6 Strategies for Developing Arsenic Tolerance in Plants
		39.7 Phytoremediation of Arsenic-Polluted Soil
		39.8 Conclusions and Future Prospects
		References
	40 Interactions of Nanomaterials and Plants in Remediation of the Heavy Metal Contaminated Soils
		40.1 Introduction
		40.2 Nanotechnology and Its Application in Remediation of Contaminated Soils
		40.3 Important Parameters in Studying the Effects of Nanomaterials On Plants
		40.4 Mechanism of Effects of Nanomaterials On Plants
		40.5 Pragmatic Repercussions of Nanomaterials On Phytoremediation
		40.6 Toxicity of Nanomaterials On Plants
		40.7 Rapport Nanomaterials and Plants to Eradicate Heavy metals From the Contaminated Soils
		40.8 Conclusions and Future Perspectives
		References
Section VIII Physiological Responses of Lower Plants (algae) and...
	41 Impact of Metal Nanoparticles On Marine and Freshwater Algae
		41.1 Introduction
		41.2 Fabrication of Metal Nanoparticles Using Algal Species
		41.3 Biosorption, Uptake, and Accumulation of Metal Nanoparticles in Algae
		41.4 Generation of Reactive Oxygen Species By Metal Nanoparticles
		41.5 Inhibition of the Photosynthetic Electron Transport in Algal Photosystem Ii By Metal Ions and Metal Nanoparticles
		41.6 Impacts and Mechanisms of Action of Individual Metal Nanoparticles On Marine and Freshwater Algae
			41.6.1 Silver Nanoparticles
			41.6.2 Gold Nanoparticles
			41.6.3 Copper-Based Nanoparticles
			41.6.4 Zinc Oxide Nanoparticles
			41.6.5 Nickel Oxide Nanoparticles
			41.6.6 Iron-Based Nanoparticles
			41.6.7 Aluminum Oxide Nanoparticles
			41.6.8 Cerium Dioxide Nanoparticles
			41.6.9 Titanium Dioxide Nanoparticles
			41.6.10 Other Metal-Based Nanoparticles
		41.7 Conclusions
		41.8 Acknowledgments
		References
	42 Risks and Benefits of Metal-Based Nanoparticles for Vascular Plants
		42.1 Introduction
		42.2 Green Synthesis of Metal-Based Nanoparticles
		42.3 Methods for Monitoring of the Formation and Characterization of Metal-Based Nanoparticles
		42.4 Uptake, Transport, and Accumulation of Metal-Based Nanoparticles in Vascular Plants
		42.5 Beneficial and Adverse Effects of Metal-Based Nanoparticles On Photosynthetic Processes in Vascular Plants
		42.6 Negative Effects of Oxidative Stress Induced By Metal-Based Nanoparticles On the Growth of Vascular Plants
		42.7 Genotoxic Effects of Metal-Based Nanoparticles On Vascular Plants
		42.8 Beneficial Effects of Metal-Based Nanoparticles On the Growth of Vascular Plants
		42.9 Mitigation of Abiotic Stresses in Vascular Plants By Metal-Based Nanoparticles
		42.10 Improved Production of Healing Plant Secondary Metabolites By Metal-Based Nanoparticles
		42.11 Conclusions
		42.12 Acknowledgments
		References
Section IX Physiology of Plant/crop Genetics and Development
	43 Genotyping, Phenotyping, Genetic Engineering, and Screening Techniques...
		43.1 Introduction
		43.2 Biotechnological Techniques for Generation of Drought-Tolerant Plants
			43.2.1 Efficacy of Conventional Breeding and Genetic Engineering Techniques
			43.2.2 Genotyping and Gene Expression Analysis
			43.2.3 Quantitative Trait Locus Analysis and Linking Genotyping to Phenotyping Data
			43.2.4 Genetic Mapping By Using Sequencing Methods
			43.2.5 Gene Editing By Using Crispr/cas9 and Talen
		43.3 Prospects for Genetic Engineering for Generation of Drought-Tolerant Plants
			43.3.1 Introduction of Green Revolution Genes Or Key Genes
			43.3.2 Gene Silencing
			43.3.3 Roles of Biotechnology in Improving Plant Performance Indirectly Through Microbiome Breeding and Optimizing Symbiotic Performance
		43.4 Targeting Metabolic and Signaling Pathways to Improve Drought Tolerance
		43.5 Roles of Candidate Transcription Factors and Genes in Improving Tolerance to Water Stress
		43.6 Conclusions
		Abbreviations
		References
	44 Genetic Diversity in Leaf Photosynthesis...
		44.1 Introduction
		44.2 Leaf Photosynthesis in Crop Plants Under Field Conditions
		44.3 Genetic Diversity in Leaf Photosynthesis Among Soybeans
		44.4 Physiological Mechanisms Underlying the Genetic Diversity in Leaf Photosynthesis
			44.4.1 Gas Diffusional Process As the Determinant of Leaf Photosynthesis
			44.4.2 Biochemical Processes As the  determinant of Leaf Photosynthesis
		44.5 Genetic Mechanisms Underlying the Genotypic Variation in Leaf Photosynthesis
		44.6 Future Challenges for the Genetic Improvement in Leaf Photosynthesis
		44.7 Conclusions
		References
Section X Plants/crops Growth Responses to Climate Change and Environmental Factors
	45 Climate Change and Secondary Metabolite Production: An Ecophysiological Perspective
		45.1 Introduction
		45.2 Co2 Elevation and Plant  carbon Metabolism
		45.3 Secondary Metabolites Under Elevated Co2: Responses and Complexities
		45.4 Ozone (o3): Greenhouse Gas  with Paradoxical Roles
		45.5 Rising Temperature: Is It the Decisive Parameter?
		45.6 Conclusions
		References
	46 Regulation of Growth Factors in Plants By Artificial and Supplementary Led Light...
		46.1 Introduction
		46.2 Photoreceptors
			46.2.1 Phytochromes
			46.2.2 Cryptochromes
		46.3 Plants’ Reactions to Light Quality (blue and Red Spectra)
			46.3.1 Growth and Morphology
			46.3.2 Photosynthesis and Physiology
		46.4 Conclusions
		References
Section XI Future Promises: Plants and Crops Adaptation, and Biotechnological Aspects...
	47 Management of Plant Stress Physiology to Improve Crop Production and Quality
		47.1 Introduction
		47.2 Biological-Origin Stress Factors
			47.2.1 Antibacterial Activity
			47.2.2 Antifungal Activity: The Case of Cyclic Lipopeptides
			47.2.3 Antiviral Activity
		47.3 Chemical (nonbiological)  stress Factors
		47.4 Physical Stress Factors
		47.5 Ultraviolet Light As Stress Factor to Increase Plant Production and Quality
		47.6 Controlled Elicitation Used to Enhance Bioactive Metabolites Production
		47.7 Conclusions
		References
	48 Cam Plants As Crops: Metabolically Flexible, Hardy Plants  for a Changing World
		48.1 The Cam Pathway of Carbon Fixation
			48.1.1 Introduction
			48.1.2 The Core Processes of Photosynthetic Carbon Fixation: C3 and C4 Plants
			48.1.3 Cam Plants: General Description
		48.2 Biochemistry of Cam
			48.2.1 Night Period Reactions
			48.2.2 Daytime Reactions
		48.3 Regulation
			48.3.1 Transcriptional Regulation
			48.3.2 Posttranscriptional and Translational Regulation
			48.3.3 Tonoplast
		48.4 Evolution and Taxonomic Distribution
		48.5 Productivity and Use of Cam Plants As Crops
		48.6 Ecophysiology
		48.7 Conclusions and Perspectives
		Acknowledgments
		References
	49 Digging Deeper to Define the Physiological Responses to Environmental...
		49.1 Introduction
		49.2 Major Abiotic Constraints for Crop and Forage Production in the Tropics
			49.2.1 Edaphic Constraints
			49.2.2 Climatic Constraints
		49.3 Adaptation of Common Bean to Abiotic Constraints
			49.3.1 Low Phosphorus Availability in Soil
			49.3.2 Soil Acidity and Aluminum Toxicity
			49.3.3 Drought
			49.3.4 High Temperature
			49.3.5 Multiple Stress Resistance
		49.4 Adaptation of Brachiaria Forage Grasses to Abiotic Constraints
			49.4.1 Soil Acidity and Aluminum Toxicity
			49.4.2 Low Phosphorus Availability in Soil
			49.4.3 Drought
			49.4.4 Waterlogging
			49.4.5 Multiple Stress Resistance
		49.5 Conclusions and Future Perspectives
		Acknowledgments
		References
	50 New Approaches for Improving Turfgrass Nutrition: Usage of Humic Substances and Mycorrhizal Inoculation
		50.1 Introduction
		50.2 Humic Substances
		50.3 Mycorrhizal Inoculation
		50.4 Mode of Action of Humic Substances and Mycorrhizal Inoculation
			50.4.1 Nutrient Uptake
			50.4.2 Plant Growth and Root Development and Architecture
			50.4.3 Plant Quality
			50.4.4 Stress Alleviation
			50.4.5 Other Beneficial and Physiological Effects
		50.5 Conclusions
		References
Index