Handbook of Maize: Its Biology	2
	Title Page	3
	Copyright Page	4
	Preface	5
	Contents	7
	Chapter 1	10
	Vegetative Shoot Meristems	10
	1 Introduction	10
	2 SAM Organization and Classical Studies	12
	3 Mutants and Genes in Maize SAM Development	13
	3.1 Mutants Defective in SAM Initiation and Maintenance	14
	3.2 Mutants with Enlarged Meristems	16
	3.3 Other Shoot Meristem Mutants	17
	3.4 SAM Gene Expression	18
	4 Concluding Remarks	18
	References	19
	Chapter 2	22
	Development of the Inflorescences	22
	1 Introduction	22
	2 Features of the Mature Inflorescence	23
	3 Features of the Developing Inflorescenc e	25
	4 Significance as a Developmental System	27
	5 Insights from Analyses and Gene Cloning of Mutants	33
	5.1 Mutants Affecting the Transition to Flowering	33
	5.2 Mutants Affecting Meristem Size	34
	5.3 Mutants Affecting Meristem Initiation and Maintenance	35
	5.4 Mutants Affecting Meristem Identity and Determinacy	36
	5.5 Mutants Affecting Sex Determination	39
	5.6 Mutants Affecting Organ Specification and Floral Meristem Identity	41
	5.7 Mutants Lacking an Inflorescence	42
	6 Relationship of the Inflorescence to the Whole Plant	42
	7 Concluding Remarks	45
	References	46
	Chapter 3	50
	The Maize Floral Transition	50
	1 Overview of Maize Flowering	50
	1.1 Teosinte: An Obligate Short-Day Plant	52
	2 Breeding for Flowering Time	52
	2.1 Quantitative Flowering Time Variation	52
	2.2 QTL Corresponding to Specific Genes	54
	3 Long Distance Floral Inductive Signals	55
	4 Molecular Mechanisms and Genetic Pathways	56
	4.1 Photoperiod Effects on Flowering	56
	4.2 Maize Flowering Time Mutants	57
	4.3 Conserved Elements of Maize Floral Induction	58
	4.4 Molecular Components of Maize Florigenic Signals	59
	5 Future and Perspectives	60
	References	62
	Chapter 4	65
	The Maize Male Gametophyte	65
	1 Introduction	65
	2 Overview of Male Gametophyte Development	66
	3 Premeiotic Development	68
	4 Microsporogenesis and Microgametogenesis	69
	5 Mutations That Affect Pollen Development	71
	6 Transcriptomic Changes During Pollen Development	74
	7 Progamic Development	76
	8 Conclusion	81
	References	81
	Chapter 5	86
	The Maize Megagametophyte	86
	1 Megasporogenesis	86
	2 Megagametophyte Development and Function	88
	2.1 Megagametophyte Growth and Development	89
	2.2 Megagametophyte Maturation and Cell Differentiation	90
	2.2.1 Antipodal Cells	90
	2.2.2 Central Cell	92
	2.2.3 Egg Cell	92
	2.2.4 Synergids	93
	3 Double Fertilization	94
	3.1 Pollen Tube Guidance and Reception	94
	3.2 Fertilization	96
	4 Parent-of-Origin Effects	98
	5 Molecular and Genetic Analysis of Megagametophytes	100
	6 Future Directions	104
	References	104
	Chapter 6	112
	Patterning of the Maize Embryo and the Perspective of Evolutionary Developmental Biology	112
	1 Introduction	112
	2 Histology	112
	2.1 Early Embryo Development	112
	2.2 Establishment of the Embryonic Axis: Shoot and Root Meristems	113
	2.3 Development of Embryonic Leaves and Maturation	114
	3 Cellular Decisions and the Perspective of Evolutionary Developmental Biology	115
	3.1 Early Proembryonic Cell Types	116
	3.2 Establishment of the SAM and the Scutellum Fate	118
	3.3 Formation of Root Meristem and Coleorhiza	119
	3.4 Elaboration of the Root Shoot Axis	120
	3.5 Cell Types Outside the Morphogenic Axis	122
	4 Perspectives	123
	References	124
	Chapter 7	127
	Kernel Biology	127
	1 Introduction	127
	1.1 Maize Kernel Structure	127
	1.2 Double Fertilization Generates the Embryo and the Endosperm	128
	1.3 Genetic Analyses of Kernels: An Abundance of Informative Mutants	129
	2 Endosperm Development	130
	2.1 Cellularization and Growth of the Endosperm	130
	2.2 Specification of Cell/Tissue Fate in the Maize Endosperm	132
	2.3 BETL Cell Fate is Patterned Early in Endosperm Development	132
	2.4 Differentiation of the Aleurone and the Starchy Endosperm: Reversible Cell Fates are Specified According to Positional Information	136
	2.5 Endoreduplication: Dosage Effects and Cell Cycle Regulators Control DNA Content of Endosperm Nuclei	138
	2.6 Programmed Cell Death of Endosperm Tissues	140
	3 Embryo–Endosperm Interactions	141
	3.1 Interactions Revealed by Analyses of Discordant Kernels	141
	3.2 The ESR May Mediate Embryo–Endosperm Interaction	142
	4 Future Prospects	143
	References	144
	Chapter 8	150
	The Maize Root System: Morphology, Anatomy, and Genetics	150
	1 Morphology of the Maize Root System	150
	1.1 The Embryonic Primary and Seminal Roots	151
	1.2 The Postembryonic Shoot Borne Crown and Brace Roots	152
	1.3 The Postembryonic Lateral Roots	152
	1.4 Exogenously Induced Adventitious Roots	153
	2 Cellular Organization of Maize Roots	153
	2.1 Radial Organization of Maize Roots	153
	2.2 Longitudinal Organization of Maize Roots	155
	3 Genetic Dissection of Maize Root Formation	155
	3.1 Shoot Borne Root Formation	156
	3.2 Lateral Root Formation	159
	3.3 Root Hair Elongation	160
	4 Conclusion	162
	References	162
	Chapter 9	166
	Axial Patterning of the Maize Leaf	166
	1 Introduction	166
	2 Leaf Initiation – Recruitment of Leaf Founder Cells from the SAM	167
	3 Proximodistal Patterning	169
	3.1 Recessive Liguleless Mutations	169
	3.2 Dominant Knox Mutations	170
	3.3 Negative Regulators of Knox Expression in Leaves	171
	3.4 Other Proximodistal Mutants	172
	4 Adaxial–Abaxial Patterning	173
	4.1 HD-ZIPIII Genes Specify Adaxial Cell Fate	173
	4.2 Regulation of HD-ZIPIII Genes by Mirnas	174
	4.3 Ta-Sirnas Specify Leaf Polarity Through Regulation of Mir166	174
	4.4 KANADI Genes Specify Abaxial Cell Fate	176
	4.5 Interactions Between HD-ZIPIII and KANADI Genes	176
	5 Mediolateral Pattering and Lamina Outgrowth	176
	5.1 NARROW SHEATH Mediates Lateral Founder Cell Recruitment	177
	5.2 Maize YABBY Genes Promote Outgrowth of the Lamina	178
	6 Conclusion	179
	References	179
	Chapter 10	184
	Cell Biology of Maize Leaf Development	184
	1 Overview	184
	2 Cellular Organization	185
	3 Growth Patterns	188
	3.1 Proliferative Cells	188
	3.2 Leaf Elongation	190
	3.3 Epidermis As a Cell Biology Model	191
	4 Cell Division	193
	4.1 Spatial Control of Cytokinesis	193
	4.2 Case Study: Tangled	195
	4.3 Case Study: Stomatal Complex Formation	196
	5 Cell Expansion	198
	5.1 Cell Wall Synthesis	199
	5.2 Cytoskeleton and Cell Expansion	199
	5.3 Case Study: Vesicle Trafficking in Warty	200
	5.4 Case Study: Generation of Lobed Cell Shapes in Brick	201
	6 Future Prospects: Emerging Tools and Analytical Methods	203
	References	204
	Chapter 11	209
	Light Signal Transduction Networks in Maize	209
	1 Introduction	209
	2 Red/Far-Red Signaling in Maize	212
	2.1 Maize Phytochrome Apoprotein Family	214
	2.2 elm1, a Chromophore-Deficient Mutant	214
	2.3 Phytochrome Apoprotein Mutants	215
	3 Blue Light Signaling in Maize	216
	4 Light Regulation of C4 Photosynthetic Development	218
	5 Light Regulation of Anthocyanin Biosynthesis	219
	6 The Shade Avoidance Syndrome	220
	7 Dissecting the Light Signal Transduction Networks	222
	8 Manipulation of Light Signaling Pathways	222
	9 Conclusion	223
	References	224
	Chapter 12	232
	Maize Disease Resistance	232
	1 Introduction	232
	2 Types of Disease Resistance	233
	3 Seminal Disease Resistance Genetic Studies in Maize	233
	3.1 The First Cloning of a Susceptibility Gene to Pathogens	234
	3.2 The First Cloning and Characterization of a Disease Resistance Gene	234
	3.3 The Genesis of a Plant Disease and a Grass-Lineage-Specific Disease Resistance Gene	235
	3.4 First Indications of the Complex Nature and Function of R Genes	235
	4 The Genetic Architecture of Disease Resistance in Maize	236
	5 The Genetic Bases of Resistance to Specific Maize Diseases	238
	5.1 Stalk and Ear Rots	238
	5.1.1 The Genetics of Stalk Rot Resistance	239
	5.1.2 The Genetics of Ear Rot Resistance	239
	Fusarium Ear Rot	239
	Aspergillus Ear Rot	240
	Gibberella Ear Rot	240
	5.2 The Genetics of Resistance to Foliar Diseases	241
	5.2.1 Gray Leaf Spot	241
	5.2.2 Northern Leaf Blight	241
	5.2.3 Southern Rust	242
	6 Systemic Acquired Resistance and Induced Systemic Resistance in Maize	243
	7 The Future	244
	7.1 Prospects for Genetically Engineered Plant Disease Resistance in Maize	244
	7.2 Maize as a System for Disease Resistance Genetics Studies	245
	References	246
	Chapter 13	254
	Virus Resistance	254
	1 Introduction	254
	2 Identification and Assessment of Virus Resistance	256
	2.1 Virus Transmission	256
	2.2 Viral Inocula	257
	2.3 Identifying Resistant Germplasm	258
	3 Genetics of Virus Resistance	258
	3.1 The Potyviridae	258
	3.2 Maize Streak Virus	259
	3.3 Maize Chlorotic Dwarf Virus	259
	3.4 Maize Mosaic Virus and Maize Fine Streak Virus	260
	3.5 Wheat Mosaic Virus	261
	3.6 Maize Stripe Virus	261
	3.7 Fijiviruses	261
	3.8 Other Viruses	262
	3.9 Clustering and Durability of Resistance Genes	262
	4 Breeding for Virus Resistance	262
	5 Virus Resistance Genes and Mechanisms	265
	6 Alternatives to Naturally Occurring Resistance in Maize	266
	6.1 Genes from Closely Related Species	266
	6.2 Insect Resistance	266
	6.3 Pathogen-Derived Virus Resistance	267
	7 Concluding Remarks	267
	References	267
	Chapter 14	274
	Genetics and Biochemistry of Insect Resistance in Maize	274
	1 Introduction	274
	2 Biochemistry of Resistance	275
	2.1 Chemical Defense	275
	2.1.1 Benzoxazinoids	275
	2.1.2 Phenolic Acids and Cell Wall Components	277
	2.2 Defense-Related Proteins	278
	2.2.1 Maize Proteinase Inhibitor and Cysteine Proteinase	278
	2.2.2 Maize Ribosome-inactivating Proteins	279
	3 Genetics of Insect Resistance in Maize	279
	3.1 QTL for Resistance to Tropical and Subtropical Maize Leaf Feeding Insects	279
	3.2 QTL for Resistance to European Corn Borer	281
	3.3 Maysin and Corn Earworm Resistance	282
	3.3.1 Genetic Regulation of Maysin Synthesis	282
	3.3.2 Maysin: How Much Is Possible? How Much Is Enough?	284
	4 Maize–Insect Tritrophic Interactions	285
	References	287
	Chapter 15	293
	Chilling Stress in Maize Seedlings	293
	1 Introduction	293
	2 Physiological Effects of Short-Term Low-Temperature Stress	294
	2.1 Effects of Chilling on Photosynthesis and Down-Stream Processes	294
	2.2 The Role of Antioxidants	296
	3 Physiological and Developmental Effects of the Growth of Maize Seedlings at Suboptimal Temperature	298
	3.1 Primary Sites Affected by Suboptimal Growth Temperature	298
	3.2 Development of the Photosynthetic Apparatus Under Chilling Conditions	299
	3.3 Consequences of Chill-Induced Changes in the Photosynthetic Machinery	301
	4 The Role of the Root System During Chilling Stress	302
	5 The Genetic Basis of Chilling Tolerance	303
	5.1 The Genetic Basis of Chilling Tolerance Studied by QTL Analyses	303
	5.2 Molecular Basis of Chilling Tolerance	304
	6 Conclusions and Future Perspectives	306
	References	307
	Chapter 16	313
	Drought Tolerance in Maize	313
	1 Background and Introduction	313
	2 Germplasm Evaluation	315
	2.1 Definition of Breeding Targets	315
	2.2 Evaluation of Segregating Populations Under Managed and Multilocation Drought-Stress Environments	317
	3 Secondary Breeding Traits	318
	3.1 The Use of Secondary Traits for Selection Under Drought Conditions	318
	3.2 Traits Associated with Drought Tolerance	319
	3.3 The Need for Further Secondary Traits	322
	4 Selected Metabolic Pathways and Signaling	325
	4.1 Resource Partitioning and Signaling Under Moisture Stress Conditions	325
	4.1.1 At the Plant Level	325
	4.1.2 From the Root to the Aerial Tissues	325
	4.1.3 In the Reproductive Organs	326
	4.2 Root Growth Responses to Water Deficit	326
	4.3 Osmotic Adjustment	327
	4.4 Stomatal Regulation	327
	5 The Genetic Basis of Drought Tolerance in Maize	328
	5.1 The QTL Approach	328
	5.2 Expression Profiles in Response to Water Stress	330
	5.3 The Candidate Gene Approach	331
	6 Genetic Gains	332
	6.1 Improvement of Drought Tolerance Through Conventional Breeding	332
	6.1.1 Population Improvement for Drought Tolerance in Tropical Maize	332
	6.1.2 Hybrid Improvement for Drought Tolerance in Tropical Maize	333
	6.1.3 Hybrid Improvement of Drought Tolerance in Temperate Maize	335
	6.2 Molecular Breeding (MB) Approach	335
	6.2.1 The Marker-Assisted Back-Cross (MABC) Approach	335
	6.2.2 The Marker-Assisted Recurrent Selection (MARS) Approach	336
	6.3 The Transgenic Approach	336
	6.4 Perspectives for New Segregating Populations and MB Strategies	337
	7 Conclusions	338
	References	338
	Chapter 17	347
	Responses to Oxygen Deprivation and Potential for Enhanced Flooding Tolerance in Maize	347
	1 Maize Growth and Productivity Under Oxygen Deprivation	348
	2 Methods of Imposing Flooding Stress in Laboratory Studies	348
	3 Gene Expression Changes in Response to Oxygen Deprivation	349
	4 Calcium Perturbations Are Critical for Anoxic Gene Induction in Maize	350
	4.1 Ionic Homeostasis As an Integral Part of Adaptation to Anoxia	351
	5 Regulation of Sucrose Synthase (SUS) Under Anoxia	352
	5.1 Reversible Phosphorylation of SUS Under Oxygen Deprivation: A Mechanism of Carbon Flux Control?	353
	5.2 Organelle Distribution of SUS: A Signaling Role?	354
	6 Cell Death Pathways Under Oxygen Deprivation	354
	6.1 Lysigenous Aerenchyma Formation	355
	6.2 Root Tip Death	355
	6.3 Anoxia-Induced Protease (AIP) in Root Tip Death	356
	7 Mechanisms and Potential Strategies to Improve Flooding Tolerance	357
	7.1 Fermentative Pathway Enzymes and Flooding Tolerance	357
	7.2 Hemoglobin Overexpression Confers Anoxic Tolerance	357
	7.3 Hypoxic Pre-treatment and Amelioration of Anoxic Injury	358
	7.4 Modulation of Root Tip Death Under Anoxia	358
	7.5 Genetic Analyses and Prospects for Breeding Flooding Tolerance in Maize	359
	8 Conclusions	360
	References	361
	Chapter 18	368
	Maize Al Tolerance	368
	1 Introduction	368
	2 Physiological Mechanisms Underlying Maize Al Tolerance	369
	3 Genetics of Maize Al Tolerance	372
	3.1 Applied Genetic Research	373
	3.2 Basic Genetic Research	374
	3.3 Comparative Genomics-Based Research	376
	4 Sorghum Al Tolerance – Identification of a Novel Al Tolerance Gene	376
	References	378
	Chapter 19	382
	Maize Under Phosphate Limitation	382
	1 Introduction	382
	1.1 Low-Pi Soils: Physical, Biological, and Agricultural Limitations	383
	1.2 Plant Responses and Adaptation to Pi Limitation	384
	2 The Maize Crop Under Pi Limitation	385
	2.1 Growing Maize Under Pi Limitation: Soils and Fertilizers	386
	2.2 Genotype Diversity in Maize	387
	3 Low-Pi Adaptive Traits in Maize Tolerant Genotypes	388
	3.1 Physiological Traits	388
	3.1.1 Associations with Arbuscular Mycorrhizal Fungi	388
	3.1.2 Photosynthesis	389
	3.2 Biochemical Traits	390
	3.3 Morphological Traits	391
	3.3.1 Lateral Roots	393
	3.3.2 Crown and Brace Roots	393
	3.3.3 Root Hairs	394
	3.4 Molecular Traits	394
	4 Conclusions	397
	References	398
	Chapter 20	406
	Agronomic Traits and Maize Modifications: Nitrogen Use Efficiency	406
	1 Introduction	407
	2 Genetic Basis of NUE	407
	2.1 Quantitative Genetic Parameters	407
	2.2 Quantitative Trait Loci (QTL)	408
	2.3 Candidate Genes	410
	3 Correlated Traits	413
	4 Genetic Improvement	415
	4.1 Experimental Prerequisites	415
	4.2 Response to Selection	415
	References	417
	Chapter 21	419
	Seed Phosphate	419
	1 Introduction	419
	2 Practical Issues Concerning Maize Seed P	419
	3 Genetics and Biochemistry of Seed P Composition	421
	3.1 Genetics	421
	3.2 Biochemical Pathways to Seed Phytic Acid	424
	3.3 Compartmentalization of Phytic Acid Synthesis and Storage During Seed Development	426
	4 Agronomic and Nutritional Quality Studies	428
	4.1 Development of High-Yielding Low-Phytate Maize: Breeding Versus Genetic Engineering	428
	4.2 Nutritional Quality Studies of Low-Phytate Genotypes	429
	5 Future Directions: Seed Total P Mutants	430
	5.1 Targets for Reverse Genetics	431
	5.2 Forward Genetic Screens	433
	6 Summary	434
	References	435
	Chapter 22	438
	Seed Starch Synthesis	438
	1 Introduction	438
	2 Production of ADP-Glucose, the Activated Glucosyl Donor	439
	2.1 First Committed Step in Starch Biosynthesis	439
	2.2 Regulation of AGP	439
	3 Starch Structural Organization	440
	4 Synthesis of Amylose	441
	5 Synthesis of Amylopectin	441
	5.1 Elongation of Linear Ap Chains by Starch Synthases	441
	5.2 Branch Linkage Introduction and Placement	444
	6 Potential Functions of Starch Debranching Enzymes	444
	7 Regulation of Starch Biosynthetic Enzymes	446
	7.1 Protein Interaction and Enzyme Coordination	446
	7.2 Protein Modification	448
	7.3 Redox Regulation of Enzyme Activity	448
	7.4 Transcriptional Regulation	449
	8 Future Directions	450
	References	450
	Chapter 23	456
	Heterosis	456
	1 History	456
	2 Inbred Lines, Hybrids, and Heterotic Groups	457
	3 Gain from the Use of Hybrids	458
	4 The Mechanisms Responsible for Heterosis	458
	4.1 Proposed Models	458
	4.2 Quantitative and Molecular Approaches for Understanding Heterosis	459
	4.2.1 Modes of Gene Action	459
	4.2.2 Quantitative Trait Analyses	459
	4.2.3 Complementation Model Does Not Explain Dosage Effects	460
	4.2.4 Global Analyses of Modes of Gene Action	460
	4.2.5 Global Analyses of Gene Regulation	461
	5 Investigations of Heterosis in Other Plants	462
	6 Future Directions	463
	References	464
	Chapter 24	467
	Increasing Yield	467
	1 Historical Trends in Maize Yield	467
	2 The Genetics of Yield	469
	2.1 Quantitative Genetics of Yield	469
	2.2 Heterosis	470
	2.3 Breeding for Yield Improvement	472
	3 Physiological Aspects of Yield Improvement	473
	4 The Future of Maize Yield Improvement	474
	4.1 Yield Plateau?	474
	4.2 Marker-Assisted Selection for Yield	475
	4.3 Untapped Genetic Resources	476
	4.4 Increasing Yield for Resource-Poor Farmers	476
	References	477
	Chapter 25	481
	The Illinois Long-Term Selection Experiment, Related Studies, and Perspectives	481
	1 Introduction	482
	2 Molecular Marker Studies	484
	3 Quantitative Trait Loci Studies	488
	4 Random Mated QTL Mapping Population Studies	491
	5 Variation for Other Traits in the Strains	493
	6 Current and Future Directions	494
	7 Summary	495
	References	496
	Chapter 26	499
	QTL for Agronomic Traits in Maize Production	499
	1 Introduction	499
	2 Mapping QTL in Maize: An Historical and Methodological Perspective	500
	2.1 Segregating Populations, Congenic Progenies, and Panels	501
	2.2 QTL Galore: Consensus Maps and Meta-Analyses	503
	2.3 Searching for Valuable QTL Alleles in Unadapted and Wild Germplasm	505
	3 QTL for Traits of Agronomic Interest	506
	3.1 Plant Architecture	506
	3.1.1 Root	507
	3.1.2 Leaf and Inflorescence	509
	3.1.3 Plant and Ear Height	512
	3.2 Lodging Resistance	513
	3.2.1 Root Lodging	514
	3.2.2 Stalk Lodging	514
	3.3 Flowering Time and Maturity	515
	3.4 Growth Rate and Grain Yield	518
	3.4.1 Testing for Heterotic QTL	518
	3.4.2 Physiology of Biomass Accumulation and GY	523
	3.4.3 Testing for QTL × Environment Interaction	525
	3.4.4 Testing for QTL Epistasis	526
	4 Concluding Remarks	527
	References	528
	Chapter 27	540
	The Mexican Landraces: Description, Classification and Diversity	540
	1 Introduction	540
	2 Conservation of Mexican Maize Germplasm	541
	3 Identification and Classification of Mexican Landraces	543
	4 The Classification of Sánchez et al. (2000)	544
	5 Genetic Erosion of Mexican Maize Diversity	554
	6 Landrace Genome Sequencing and Functional Maize Diversity	554
	References	556
	Chapter 28	559
	Production, Breeding and Process of Maize in China	559
	1 Introduction	559
	1.1 History of Maize in China	559
	1.2 Significance of Maize in Chinese Economy	560
	1.3 Utilization and Marketing of Maize	561
	2 Maize Production in China	561
	2.1 Ecological Characterization of Primary Maize-Growing Zone in China	561
	2.2 Cropping Systems and Cultural Practices	564
	2.3 Disease and Pest Control in Maize	565
	3 Maize Breeding in China	565
	3.1 History and Current Status of Hybrid Maize	565
	3.2 Germplasm Resources and Heterotic Groups	567
	3.3 Production of Hybrid Seeds	568
	3.4 Application for Bio-Technology in Maize Breeding	568
	4 Maize Process and Products	569
	4.1 Traditional and Current Maize Food	569
	4.2 Processing Industry of Maize and its Products	570
	5 Future Prospects	571
	References	571
	Index	573