Front Cover

Emerging Technologies and Management of Crop Stress Tolerance

Copyright Page

Dedication

Contents

Preface

Acknowledgments

About the Editors

List of Contributors

1 Improvement of Legume Crop Production Under Environmental Stresses Through Biotechnological Intervention

1.1 Introduction

1.2 Major stresses affecting legume crop production

1.3 Biotic stresses for legumes

1.3.1 Fungi

1.3.2 Foliar diseases

1.3.3 Plant viruses

1.3.4 Insects and pests

1.3.5 Parasitic weeds

1.4 Biotechnological interventions for biotic stress tolerance in legumes

1.4.1 Focus on fungal stress

1.4.1.1 Chickpea

1.4.1.1.1 Resistance to Ascochyta blight

1.4.1.2 Alfalfa

1.4.1.2.1 Resistance to anthracnose

1.4.1.2.2 Use of Medicago truncatula to study resistance to other pathogenic fungi

1.5 Abiotic stresses in legumes

1.5.1 Drought

1.5.2 Salinity

1.5.3 Temperature

1.6 Biotechnological interventions for abiotic stress tolerance in legumes

1.6.1 Soybean

1.6.1.1 Response to drought

1.6.1.1.1 Biotechnological intervention for drought resistance

1.6.1.1.2 Marker-assisted selection for drought resistance

1.6.1.2 Genetic engineering

1.6.2 Cowpea

1.6.2.1 Effect of heat

1.6.2.1.1 Responses to heat stress

1.6.2.1.2 Biotechnological interventions for heat stress

1.7 Conclusion and future prospects

References

2 Abiotic Stress Tolerance in Plants

2.1 Introduction

2.2 Plant responses to abiotic stresses

2.3 Proteomic analysis of responses to abiotic stresses

2.3.1 Water stress

2.3.1.1 Drought stress

2.3.1.2 Flooding stress

2.3.2 Imbalances in mineral nutrition

2.3.2.1 Deficient concentrations of mineral nutrients

2.3.3 Heavy metal stress

2.3.4 Salt stress

2.3.5 Temperature stress

2.3.5.1 Heat stress

2.3.5.2 Cold stress

2.4 Conclusion and future prospects

References

3 Arbuscular Mycorrhiza in Crop Improvement under Environmental Stress

3.1 Introduction

3.2 Diversity of arbuscular mycorrhizal fungi

3.3 Effect of arbuscular mycorrhizal fungi on soil fertility

3.4 Arbuscular mycorrhizal fungi and environmental stresses in plants

3.4.1 Arbuscular mycorrhizal fungi and water stress

3.4.2 Arbuscular mycorrhizal fungi and salinity stress

3.4.3 Arbuscular mycorrhizal fungi and pathogen attack

3.4.4 AMF and herbicides and pesticides

3.5 Ion transport in plants under stress and the role of arbuscular mycorrhizal fungi

3.6 Arbuscular mycorrhizal fungi and mineral nutrition

3.6.1 Phosphorus

3.6.2 Nitrogen

3.6.3 Potassium and K+/Na+ ratio

3.6.4 Calcium

3.6.5 Magnesium

3.7 Conclusion and future prospects

References

4 Role of Endophytic Microbes in Mitigation of Abiotic Stress in Plants

4.1 Introduction

4.2 Endophyte diversity

4.3 Sustainable use of endophytes and habitat-imposed abiotic stress

4.4 Conclusion and future prospects

Acknowledgments

References

5 Plant Growth-Promoting Bacteria Elicited Induced Systemic Resistance and Tolerance in Plants

5.1 Introduction

5.2 PGPB-elicited response of plants against biotic stress

5.3 PGPB-produced elicitors of ISR against biotic stress

5.3.1 Siderophore

5.3.2 Antibiotics

5.3.3 Volatiles

5.4 PGPB-elicited plant response against abiotic stress

5.5 Conclusion and future prospects

Acknowledgments

References

6 Arbuscular Mycorrhizal Fungi and Metal Phytoremediation: Ecophysiological Complementarity in Relation to Environmental Stress

6.1 Introduction

6.1.1 Metal phytoremediation

6.1.2 Objectives

6.2 Arbuscular mycorrhizal fungi and plant stress tolerance

6.2.1 Enhanced metal/nutrient uptake

6.2.2 Metal/nutrient biosorption and precipitation

6.2.3 Soil particulate microaggregation

6.3 Adopting arbuscular mycorrhizal plants into metal phytoremediation

6.3.1 Plant–soil experimental perspectives

6.3.2 The burden of metal stress and the dilemma of resource allocation

6.4 Conclusion and future prospects

Acknowledgments

References

7 Biological Control of Fungal Disease by Rhizobacteria under Saline Soil Conditions

7.1 Introduction

7.2 Salinity and plant pathogens

7.3 Plant growth-promoting rhizobacteria

7.4 Biological control

7.5 Mechanisms of action of plant growth-promoting rhizobacteria

7.6 Conclusion and future prospects

References

8 Crop Plants under Saline-Adapted Fungal Pathogens: An Overview

8.1 Introduction

8.2 Effects of salinity on crop plants

8.3 Effects of salinity on fungi

8.3.1 Negative effects of salinity on fungal growth

8.3.2 Positive effects of salinity on fungal growth

8.3.3 Negative effects on plant growth of salinity in combination with fungi

8.4 Behavior of saline-adapted fungi

8.5 Pathological defense mechanisms under salt stress

8.6 Pathological responses of salt-tolerant plants

8.7 Conclusion and future prospects

Acknowledgment

References

9 Preventing Potential Diseases of Crop Plants Under the Impact of a Changing Environment

9.1 Introduction

9.2 Major crops and techniques for preventing hazardous stress

9.2.1 Wheat

9.2.1.1 Powdery mildew

9.2.1.2 Wheat rust disease

9.2.1.3 Karnal bunt and fusarium head blight

9.2.1.4 Stagonospora nodorum blotch

9.2.2 Maize

9.2.2.1 Maize streak virus

9.2.2.2 Leaf blight

9.2.2.3 Head smut

9.2.2.4 Stewart’s disease

9.2.2.5 Gray leaf spot

9.2.2.6 Anthracnose stalk rot

9.2.3 Rice

9.2.3.1 Rice blast

9.2.3.2 Brown spot

9.2.3.3 Sheath blight

9.2.3.4 Bacterial leaf blight and leaf streak

9.2.4 Barley

9.2.4.1 Net blotch

9.2.4.2 Scald

9.2.4.3 Powdery mildew

9.2.4.4 Leaf rust

9.2.4.5 Spot blotch

9.2.5 Cotton

9.2.5.1 Root-knot nematode disease

9.2.5.2 Cotton leaf curl virus

9.2.5.3 Fusarium wilt

9.2.5.4 Verticillium wilt

9.3 Conclusion and future prospects

References

10 Plant Responses to Metal Stress: The Emerging Role of Plant Growth Hormones in Toxicity Alleviation

10.1 Introduction

10.2 Sources of heavy metal pollution

10.3 Transport and distribution of metal in plants

10.4 Heavy metal toxicity in plants

10.4.1 Direct effects

10.4.2 Indirect effects

10.5 Plant defense systems

10.5.1 Enzymatic antioxidants

10.5.1.1 Superoxide dismutase (EC 1.15.1.1; O2•−+O2•−+2H+↔H2O2+O2)

10.5.1.2 Catalase (EC 1.11.1.6; 2H2O2↔O2+2H2O)

10.5.1.3 Ascorbate peroxidase (EC 1.11.1.11; AA+H2O2↔DHA+2H2O)

10.5.1.4 Dehydroascorbate reductase (EC 1.8.5.1; 2GSH+DHA↔GSSG+AA)

10.5.1.5 Glutathione reductase (EC 1.6.4.2; NADPH+GSSG↔NADP++2GSH)

10.5.2 Nonenzymatic antioxidants

10.5.2.1 Glutathione

10.5.2.2 Ascorbate

10.6 Plant growth hormones

10.7 Role of plant growth hormones under stress

10.7.1 Behavior of auxins under stress

10.7.2 Behavior of gibberellic acids under stress

10.7.3 Behavior of cytokinins under stress

10.8 Conclusion and future prospects

Acknowledgments

References

11 Reactive Nitrogen Species and the Role of NO in Abiotic Stress

11.1 Introduction

11.2 The reactive nitrogen species

11.3 Drought stress

11.4 Waterlogging stress

11.5 High temperature stress

11.6 Low temperature stress

11.7 Salinity stress

11.8 Heavy metal stress

11.8.1 Cadmium

11.8.2 Copper

11.8.3 Arsenic

11.8.4 Zinc

11.9 Air pollutants

11.10 Exposure to high light conditions

11.11 UV-B radiation

11.12 Conclusion and future prospects

Acknowledgments

References

12 Role of Tocopherol (Vitamin E) in Plants: Abiotic Stress Tolerance and Beyond

12.1 Introduction

12.2 Chemistry and types of tocopherol

12.3 Tocopherol biosynthesis and accumulation in plants

12.4 The role of tocopherol in plant growth and physiology

12.5 Tocopherol and abiotic stress tolerance

12.5.1 Salinity

12.5.2 Drought

12.5.3 Extreme temperature

12.5.4 Metal toxicity

12.5.5 Ozone

12.5.6 UV radiation

12.6 The antioxidative role of tocopherol in plants

12.7 Conclusion and future prospects

Acknowledgments

References

13 Land and Water Management Strategies for the Improvement of Crop Production

13.1 Introduction

13.2 Strategies for improving crop production in water-deficient agroecosystems

13.2.1 Improvement of crop production in rain-fed agriculture

13.2.2 Improving crop production in irrigated agriculture

13.3 Strategies for improving crop production in (transiently) waterlogged agroecosystems

13.3.1 Types of waterlogging and the impact on crop production

13.3.2 Agriculture under waterlogging conditions of hydromorphic soils: a Croatian case study

13.3.3 Crop production improvement in waterlogged agroecosystems

13.3.3.1 General, large-scale strategies

13.3.3.2 Specific, small-scale strategies

13.3.3.2.1 Surface drainage systems using an open drainage-channel network

13.3.3.2.2 Subsurface pipeline drainage systems

13.3.3.2.3 Possible other strategies to mitigate waterlogging

13.4 Conclusion and future prospects

Acknowledgments

References

14 Integrating Physiological and Genetic Approaches for Improving Drought Tolerance in Crops

14.1 Introduction

14.2 Drought stress in changing environments

14.3 Water deficit as a major abiotic factor limiting crop yields

14.4 Crop growth and response to water deficits

14.5 Osmotic adjustment during drought stress

14.6 Methodologies for screening genotypes under drought stress

14.7 Key physiological attributes for targeted breeding programs

14.8 Precise phenotyping for drought-tolerance attributes

14.8.1 Near-infrared spectroscopy

14.8.2 Canopy spectral reflectance

14.8.3 Magnetic resonance imaging and nuclear magnetic resonance

14.8.4 Digital imaging platforms

14.9 Identification and characterization of drought-related genes and QTLs

14.9.1 QTL and association mapping for drought tolerance

14.9.2 Candidate genes associated with drought tolerance

14.10 Proteomic studies

14.11 Breeding approaches for developing drought-tolerant superior germplasm

14.11.1 Marker-assisted selection

14.11.2 Genome-wide selection

14.12 Conclusion and future prospects

References

15 The Use of Chlorophyll Fluorescence Kinetics Analysis to Study the Performance of Photosynthetic Machinery in Plants

15.1 Introduction

15.2 Chlorophyll a fluorescence and the heterogeneity of PSII

15.3 Analysis of chlorophyll fluorescence kinetics

15.4 Examples of successful applications of ChlF measurements

15.4.1 Drought

15.4.2 Salinity

15.4.3 Heavy metals

15.4.3.1 Lead

15.4.3.2 Cadmium

15.4.4 Nutrient deficiency

15.4.4.1 Nitrogen

15.4.4.2 Phosphorus

15.4.4.3 Potassium

15.4.4.4 Magnesium

15.4.4.5 Iron

15.4.4.6 Sulfur

15.4.4.7 Calcium

15.4.5 Photosynthetically active radiation

15.4.6 Temperature

15.4.7 Ozone

15.4.8 Herbicides

15.5 Conclusion and future prospects

Abbreviations

References

16 Manipulating Osmolytes for Breeding Salinity-Tolerant Plants

16.1 Introduction

16.2 Salinity-induced ionic and osmotic stress and tolerance mechanisms

16.3 General description of osmolytes

16.4 The role of inorganic osmolytes in salinity tolerance

16.5 Organic osmolytes in salinity tolerance

16.5.1 Proline in salinity tolerance

16.5.2 Glycinebetaine in salinity tolerance

16.5.3 Carbohydrates and salinity tolerance

16.6 Conclusion and future prospects

Acknowledgments

References

17 Osmolyte Dynamics: New Strategies for Crop Tolerance to Abiotic Stress Signals

17.1 Introduction

17.2 Osmoprotectants in plants

17.2.1 Sugars and polyols

17.2.1.1 Fructans

17.2.1.2 Raffinose family oligosaccharides

17.2.1.3 Trehalose

17.2.1.4 Mannitol

17.2.1.5 Myo-inositol

17.2.1.6 Sorbitol

17.2.1.7 Glycerol

17.2.2 Amino acids, peptides, and amines

17.2.3 Quaternary ammonium compounds

17.3 Metabolic expression and exogenous application of osmoprotectants under abiotic stresses

17.3.1 Temperature stress

17.3.2 Water deficit

17.3.3 Salinity stress

17.3.4 Heavy metal stress

17.3.5 Pesticide toxicity

17.4 Conclusion and future prospects

References

18 The Emerging Role of Aquaporins in Plant Tolerance of Abiotic Stress

18.1 Introduction

18.2 Aquaporins

18.2.1 Structure and water-conducting properties of aquaporins

18.2.2 Plant aquaporins

18.2.3 Aquaporins in the plant–water relationship

18.2.4 Aquaporins’ response to abiotic stress

18.2.4.1 Drought

18.2.4.2 Salinity

18.2.4.3 Nutrient deficiency

18.2.4.4 Chilling

18.2.5 Aquaporins in tolerance of abiotic stress

18.3 Conclusion and future prospects

References

19 Prospects of Field Crops for Phytoremediation of Contaminants

19.1 Introduction

19.2 Contaminants in soil, water, and plants

19.3 Phytoremediation: a green technology

19.4 Field crops as hyperaccumulators and their potential for phytoremediation

19.5 Facilitated phytoextraction in crops

19.5.1 Chelating agents

19.5.1.1 Amino acids

19.5.1.2 Phytins

19.5.1.3 Organic acids

19.5.2 Growth-promoting bacteria and mycorrhizae

19.5.2.1 Mycorrhizae

19.5.2.2 Plant growth-promoting rhizobacteria

19.5.3 Plant growth regulatory substances

19.5.3.1 Auxins

19.5.3.2 Cytokinins

19.5.3.3 Brassinosteroids

19.5.4 Molecular techniques

19.6 Conclusion and future prospects

References

20 Sustainable Soil Management in Olive Orchards: Effects on Telluric Microorganisms

20.1 Introduction

20.2 Sustainable management systems

20.3 Using in situ compost production

20.4 Conclusion and future prospects

References

21 The Vulnerability of Tunisian Agriculture to Climate Change

21.1 Introduction

21.2 Tunisia’s agricultural constraints

21.2.1 Climate

21.2.2 Water resources and distribution

21.2.3 Agricultural characteristics

21.3 The impact of climate change on wheat production in Tunisia’s semiarid region

21.4 Climatic change parameters that influence evapotranspiration in central Tunisia’s coastal region

21.5 Conclusion and future prospects

References

Index