Includes index/glossary(489-503 p.)

1 Plant Cell and Water

2 Water Has Unıque Physıcal and Chemıcal Propertıes

3 The Thermal Propertıes of Water are Bıologıcally Important

3 Water Exhıbıts a Unıque Thermal Capacıty

3 Water Exhıbıts a Hıgh Heat of Fusıon and Heat of Vaporızatıon

4 Water ıs the Unıversal Solvent

4 Polarıty of Water Molecules Results in Cohesion and Adhesion

5 Water Movement may be Governed by Diffusion or by Bulk Flow

5 Bulk Flow is Driven by Hydrostatic Pressure

5 Fick's First Law Describes the Process Diffusion

6 Osmosis is the Diffusion of water Across a Selectively Permeable Membrane

7 Plant Cells Contain on Array of Selectivity Permeable Membrane

8 Osmosis in plant Cells is Indirectly Energy Dependent

9 The Chemical Potential of Water has an Osmotic as Well as a Pressure Component

11 Hydrostatic Pressure and Osmotic Pressure are Two Components of Water Potential

11 Water Potential is the Sum of its Component Potentials

12 Dynamic Flux of H2O is Associated with Changes in Water Potential

13 Aquaporins Facilities the Cellular Movement of Water

15 Two-Component Sensing /Signaling Systems are involved in Osmoregulation

17 Summary

17 Chapter Review

17 Further Reading

19 Whole Plant Water Relations

20 Transpiration is Driven by Differences in Vapor Pressure

21 The Driving Force of Transpiration is Differences in Vapor Pressure

22 The Rate of Transpiration is Influenced by Environmental Factors

23 What the effect of Humidity ?

23 What is the Effect of Temperature ?

24 What is the effect of Wind?

24 Water Conduction Occurs via Tracheary Elements

27 The Ascent of Xylem SAP is Explained by Combining Transpiration with the Cohesive Forces of Water

28 Root Pressure is Related to Root Structure

29 Water Rise By Capillarity is due to Adhesion and Surface Tension

30 The Cohesion Theory Best Explains the Ascent of Xylem Sap

33 Water Loss due to Transpiration must be Replenished

33 Soil is a Complex Medium

34 Roots Absorb and Transport Water Varies

36 Radial Movement of Water Through the Root Involves Two Possible Pathways

37 SuMMARY

37 Chapter Review

37 Further Reading

25 Why Transpiration?

39 Roots, Soils, and Nutrients Uptake

40 The Soil as a Significant Component of Most Soils

40 Colloids Presents a Large, Negativity Charged Surface Area

41 Soil Colloids Reversibly Adsorb Cations From the Soil Solution

41 The Anion Exchange Capacity of Soil Colloids is Relatively Low

42 Nutrient Uptake

42 Nutrient Uptake by Plants Requires Transport of the Nutrient Across Root Cell Membranes

42 Simple Diffusion is a Purely Physical Process

43 The Movement of Most Solutes Across Membranes Requires the Participation of Specific Transport Proteins

43 Active Transport Requires the Expenditure of Metabolic Energy

46 Selective Accumulation of Icon by Roots

46 Electrochemical Gradients and Ion Movement

46 Ions Move in Response to Electrochemical Gradients

47 The Nernst Equation Helps to Predict Whether an Ion is Exchanged Actively or Passively

49 Electrogenic Pumps are Critical for Cellular Active Transport

49 Active Transport is Driven by ATPase-Proton Pumps

50 The ATPase-Proton Pumps of Plasma Membranes and Vacuolar Membranes are Different

51 K+ Exchange is Medicated by two Classes of Transport Proteins

52 Cellular Ion Uptake Processes are Interactive

52 Root Architecture is Important to Maximize Iomn Uptake

53 A Frist Step in Mineral Uptake by Roots is Diffusion into the Apparent Free Space

54 Apparent Free Space is Equivalent to the Apoplast of the Root Epidermal and cortical Cells

54 The Radical Path of Ion Movement Through Roots

54 Ions Entering the Scale Must First be Transported From the Apparent Free Space into the Symplast

55 Ions are Actively Secreted into the Xylem Apoplast

55 Emerging Secondary Roots May Contribute to the Uptake of Some Solutes

56 Root-Microbe Interactions

56 Bacteria Other than Nitrogen Fixers Contribute to Uptake of Some Solutes

57 Mycorrhizae are Fungi that Increase the Volume of the Nutrient Depletion Zone Around Roots

44 Electrophysiology - Exploring Ion Channels

61 Plants and Inorganic Nutrients

62 Methods and Nutrient Solutions

62 Interest in Plant Nutrition is Rooted in the Study of Agriculture and Corp Productivity

62 The Use of Hydroponic Culture Helped to Define the Mineral Requirements of Plants

63 Modern Techniques Overcome Inherent Disadvantages of Simple Solution Culture

65 The Essential Nutrient Elements

65 Seventeen Elements Are Deemed to be Essential for Plant Growth and Development

65 The Essential Nutrients are Generally Classes as Either Macronutrients or Micronutrients

65 Determining Essentiality of Micronutrients Presents Special Problem

66 Beneficial Elements

66 Sodium is An Essential Micronutrient for C4 Plants

67 Silicon May be Beneficial for a Variety of Species

67 Cobalt is Required by Nitrogen-fixing Bacteria

67 Some Plants Tolerate High Concentrations of Selenium

67 Nutrient Function and Deficiency Symptoms 67 A Plant's Requirement For a Particular Element is Defined in Terms of Critical Concentration

68 Nitrogen is a Constituent of many Critical Macromolecules

69 Phosphorus is part of the Nucleic Acid Backbone and has a Central Function in Intermediary Metabolism

69 Potassium Activates Enzymes and Functions in Osmoregulation

70 Sulphur is an Important Constituents of Proteins Coenzymes and Vitamins

70 Calcium is Important in Cell Division, Cell Adhesion and as a Second Messenger

70 Magnesium is a constituent of the Chlorophyll Molecule and an Important Regulator of Enzyme Reaction

71 Iron is Required for Chlorophyll Synthesis and Election Transfer Reactions

Boron Appears to have a Role in Cell Division and Elongation and Contribution to the Structural Integrity of the cell Wall

73 Copper is a Necessary Cofactor for Oxidative Enzymes

73 Zinc is an Activator of Numerous Enzymes

74 Manganese is an Enzymes Cofactor as Well as part of the Oxygen -Evolving Complex in the Chloroplast

74 Molybdenum is a key Component of Nitrogen Metabolism

74 Chlorine has a Role in Photosynthetic Oxygen Evolution and Charge Balance Across Cellular Membranes

74 The Role of Nickel is Not Clear

75 Toxicity of Micronutrients

75 Summary

76 Chapter Review

76 Further Reading

77 Bioenergetics and ATP Synthesis

78 Bioenergetics and Energy Transformation in Living Organisms

78 The Sun is a Primary Source of Energy

78 What is Bioenergetics ?

79 The First Law of Thermodynamics Refers to Energy Conservation

79 The Second Law of Thermodynamics Refers to Entropy and Disorder

80 The Ability to do work is Dependent on the Availability of Free Energy

80 Free Energy is Related to Chemical Equilibria

81 Energy Transformation and Coupled Reactions

81 Free Energy of ATP is Associated with Coupled Phosphate Transfer Reactions

83 Free Energy Changes are Associated with Coupled Oxidation -Reduction Reactions

85 Energy Transduction and the Chemiosmosis Synthesis of ATP

85 Chloroplasts and Mitochondria Exhibit Specific Compartments

90 Chloroplasts and Mitochondria Synthesize ATP by Chemiosmosis

91 Summary

91 Chapter Review

91 Further Reading

86 Plastid Biogenesis

93 The Dual Role of Sunlight Energy and Information

93 The Physical Nature of Light

93 Light is Electromagnetic Energy Which Exists in two Forms

94 Light can be Characterized as a wave phenomenon

94 Light can be Characterized as Stream of Discrete Particles

95 Light Energy can Interact with Matter

97 How Does one Illustrate the Efficiency of Light Absorption and its Physiological Effects

98 Accurate Measurement of Light is Important in Photobiology

99 The Natural Radiation Environment

100 Photoreceptors Absorbs Light for use in a Physiological Process

100 Chlorophylls are Primarily Responsible for Harvesting Light Energy for Photosynthesis

102 Phycobilin Serve as Accessory Light- Harvesting Pigments in Red Algae and Cyanobacteria

103 Carotenoids Account for the Autumn Colors

103 Cryptochrome and phytotropin are Photoreceptors sensitive to Blue Light and UV-A radiation

105 UV-B Radiation May Act as a Developmental Signal

105 Flavonoids Provide the myriad flower Colors and Act as a Natural Sunscreen

106 Betacyanin and Beets

107 Summary

107 Chapter Review

107 Further Reading

109

110 Leaves are Photosynthetic Machines that Maximize

112 Photosynthesis is an Oxidation -Reduction Process

114 Photosynthetic Electron Transport

114 Photosystems are Major Components of the Photosynthetic is an Electron Transport Chain

117 Photosystem II Oxidizes Water to Produce Oxygen

119 The Cytochrome Complex and Photosystem I Oxidize Plastoquinol

120 Photophosphorylation is the light dependent synthesis of ATP

122 lateral Heterogenicity if the Unequal Distribution of Thylakoid Complexes

123 Cyanobacteria are Oxygenic

124 Inhibitors of Photosynthetic Electron Transport are Effective Herbicides

127

127 Chapter Review

128 Further Reading

113 Historical Perspective -The Discovery or Photosynthesis

125 The Case for Two Photosystems

129 Energy Conservation in Photosynthesis CO2 Assimilation

130 Stomatal Complex Control Leaf Gas Exchange and Water Loss

132 C02 Enters the Leaf by Diffusion

133 How Do Stomata Open and Close ?

135 Stomatal Movements are also Comtrolled by External Environmental Factors

135 Light aqnd Carbon Dioxide Regulate Stomatal Opening

136 Stomatal Movements Follow Endogenous Rhythms

136 The Photosynthetic Carbon Reduction (PCR) Cycle

137 The PCR4 Cycle Reduce CO2 to Produce a Three- Carbon Sugar

137 The Carbohydrates Reaction Fixes the Co2

ATP and NADPH are Consumed in the PCR cycle

139 What are the Energetic of the PCR Cycle

139 The PCR Cycle is Highly Regulated

140 The Regeneration of RuBP is Autocatalytic

140 Rubisco Activity Is Regulated Indirectly by Light

141 Other PCR Enzymes are also Regulated by Light

142 Chloroplasts of C3 Plants Also Exhibits Competing Carbon Oxidation Processes

142 Rubisco Activity the Fixation of Both CO2 and O2

143 Why Photorespiration ?

145 In Addition to PCR, Chloroplasts Exhibit an Oxidative Pentose Phosphate Cycle

149 Summary

149 Chapter Review

Further Reading

146 Enzymes

151 Allocation, Tranlocation and Partitioning of Phostassimilates

152 Starch and Sucrose are Biosynthesized in Two Different Compartments

152 Starch is Biosynthesized in the Stroma

153 Sucrose is Biosynthesized in the Cytosol

154 Starch and Sucrose Biosynthesis are Competitive Processes

156 Fructan Biosynthesis is an Alternative Pathway for Carbon Allocation

156 Photassililates are translocated Over Long Distance

158 What is the Composition of the Photoassimilate Translocated by the Pheom

159 Sieve Elements Are the Principles Cellular Constituents of the Phloem 1460

160 Phloem Exudate Contains a Significant Amount of Protein

161 Direction of Translocation is determined by Source -Sink Relationship

161 Phloem Translocation Occurs by Mass Transfer

163 Phloem Loading and Unloading Regulate Translocation and Partitioning

164 Phloem Loading Can Occur Symplastically or Apoplastically

166 Phloem Loading Unloading May Occur Symplastically of Apoplasticaly

166 Photoassimilate is Distributed Between Different Metabolic Pathway and plant Organs

167 Photoassimilate May be Allocated to a Variety of Metabolic Functions in the Source or the Sink

168 Distribution of Photoassimilates Between Competing Sinks is Determined by Sink Strength

170 Xenobiotic Agrochemicals are Translocated in the Phloem

170 Summary

171 Chapter Review

171 Further Reading

173 Cellular Respiration Unlocking the Energy Stored In Photoassimilates

174 Cellular Respiration Consists of a Series of Pathways by which Photoassimilates are oxidized

175 Starch Mobilization

175 The Hydrolytic Degradation of Stomach Produces Glucose

176 α-Amylase Produce Maltose and Limit Destrins

176 β-Amylase Produce Maltose

176 Limit Dextrinase is a Debranching Enzyme

177 α-Glucosidase Hydrolyses Maltose

177 Starch Phosphorolytic Degradation of Starch

178 Fructan Mobilization is Constitutive

178 Glycolysis Converts Sugars to Pyruvic Acid

178 Hexoses Must be Phosphorylated to Enter Glycolysis

180 Triose Phosphates are Oxidized to Pyruvate

180 The Oxidation Pentose Phosphate Pathway is an Alternative Route for Glucose Metabolism

181 The Fate of Pyruvate Depend on the Availability of Molecular Oxygen

182 Oxidative Respiration is Carried Out by the Mitochindrion

182 In the Presence of Molecular Oxygen Pyruvate is Completely Oxidative to O2 and water By the Citric Acid Cycles

183 Electron Removed From Substrate in the Citric Acid Cycle are passed to Molecular Oxygen Through the Mitochondrial Electron Transport Chain

185 Energy is Conserved in the Form of ATP in Accordance with Chemiosmosis

186 Plants Contain Several Alternative Electron Transport Pathways

186 Plant Mitochondria Contain External Dehydrogenase

186 Plants Have a Rotenone -Insensitive NADH dehydrogenases

187 Plants Exhibits Cyanide-Resistant Respiration

188 Many Seeds Store Carbons as Oils that are Converted to Sugar

189 Respiration Provides Carbon Skeletons for Biosynthesis

Respiratory Rate Varies with Development and Metabolic State

192 Respiration Rate Respond to Environmental Conditions

192 Light

192 Temperature

193 Oxygen Availability

193 Summary

Chapter Review

194 Further Reading

195 Nitrogen Assimilation

195 The Nitrogen Cycles A Complex Pattern of Exchanges

196 Ammonification. Nitrification and Denitrification and Essential Process in the Nitrogen Cycle

196 Biological Nitrogen Fixation is Exclusively Prokaryotic

196 Some Nitrogen Fixating bacteria are Free-Living Organisms

197 Symbiotic Nitrogen Fixation Involves Specific Associations Between Bacteria and Plant

197 Legumes Exhibit Symbiotic Nitrogen Fixation

198 Rhizobia Infect the Host Roots, Which Induce Nodule Development

200 The Biochemistry of Nitrogen Fixation

201 Nitrogen Fixation is Energetically Costly

202 Dinitrogenase is Sensitive to oxygen

202 Dinitrogenase Results in the Production of Hydrogen Gas

203 The Genetics of Nitrogen Fixation

203 NIF Gene Code for Dinitrogenase

203 NOD Genes and NIF Gene Regulate Nodulation

204 What is the Source of Home For Leghemoglobin

204 NH3 Produced by Nitrogen Fixation is Converted to Organic Nitrogen

204 Ammonium is Assimilated by GS/ GOGAT

205 PII Protein Regulate GS/ GOGAT

206 Fixed Nitrogen is Exported as Asparagine and Ureides

207 Plants Generally Take Up Nitrogen in the Form of Nitrate

208 Nitrogen Cycling Simultaneous import and Export

209 Agricultural and Ecosystem Productivity is Dependent on Nitrogen Supply

211 Summary

211 Chapter Review

211 Further Reading

213 Carbon and Nitrogen Assimilation and plant Productivity

213 Productivity Refers to an Increase in Biomass

214 Carbon Economy is Dependent on the Balance Between Photosynthesis and Respiration

215 Productivity is Influenced by a Variety of Environment Factors

215 Fluence Rate

216 Available CO2

218 Temperature

219 Soil Water Potential

219 Nitrogen Supply Limits Productivity

220 Leaf Factors

221 Summary

222 Chapter Review

222 Factor Reading

223 What is plant Stress?

224 Plant Respond to Stress in Several Different ways

225 Too Much Light Inhibits Photosynthesis

227 The DI Repair Cycle Overcomes Photodamage to PSII

229 Water Stress is Persistent Threat to Plant Survival

230 Water Stress leads to Membrane Damage

230 Photosynthesis is Particularly Sensitive to Water Stress

230 Stomata Respond to Water Deficit

233 Plant are Sensitive to Fluctuations In Temperature

233 Many Plant are Chilling Sensitive

234 High -Temperature Stress Causes Protein Denaturation

235 Insect Pests and Disease Represent Potential Biotic Stresses

236 Systemic Acquired Resistance Represents a Plants Immune Response

237 Jasmonates Mediate Insect and Disease Resistance

237 There are Feature Common to all Stresses

238 Summary

238 Chapter Review

238 Further Reading

238 Monitoring Plant Stress By Chlorophyll Fluorescence

241 Acclimation to Environmental Stress

242 Plant Acclimation is a Time -Dependent Phenomenon

242 Acclimation is Initiated by Rapid Short-Term Response

242 State Transitions Regulate Energy Distribution in Response to Changes to Spectral Distribution

242 Carotenoids Serve a Dual Function Light Harvesting and Photoprotection

247 Osmotic Adjustment is a Response to Water Stress

248 Low Temperatures Induce Lipid Unsaturation and Cold Regulated Gene in Cold Tolerant Plants

248 Q10 For Plant Respiration Varies as a Function of Temperature

249 Long Term Acclimation Alters Phenotype

249 Light Regulates Nuclear Gene Expression and Photoacclimation

252 Does the Photosynthesis Apparatus Respond to Changes in Light Quality ?

253 Acclimation to Drought Affects Shoot-Root Ratio and Leaf Area

254 Cold Acclimation Mimics Photoacclimation

255 Freezing Tolerance in Herbaceous Species is a Complex Interaction Between Light and Low Temperature

256 Cold Acclimated Plants Secrete Antifreeze Proteins

256 North Temperature Woody Plant Survive Freezing Stress

257 Plant Adjust Photosynthetic Capacity in Response to High Temperature

258 Oxygen May Protect During Acclimation to Various Stresses

259 Summary

259 Chapter Review

260 Further Reading

261 Adaptations to the Environment

262 Sun and Shade Adapted Plants Respond Differently to Irradiance

263 C4 Plants are Adapted to High Temperature and Drought

263 The C4 Syndrome is Another Biochemical Mechanism to Assimilate Co2

265 The C4 Syndrome is Usually Associated with Kranz Leaf Anatomy

265 The Syndrome is Differentially Sensitive to Temperature

265 The C4 Syndrome is Differentially Sensitive to Temperature

266 The C4 Syndrome is Associated with water Stress

267 Crassulacean Acid Metabolism is an Adaptation to Desert Life

268 Is CAM A Variation of the C4 Syndrome ?

269 CAM Plan an Particularly Suited to Dry Habitats

269 C4 and CAM Photosynthesis Require Precise Regulation and Temporal Integration

270 Plant Biomes Reflect Myriad Physiological Adaptations

270 Tropical Rain Forest Biomes Exhibits the Greatest Plant Biodiversity

271 Evapotranspiration is s Major Contributors to Weather

Desert Perennials are Adapted to Reduce Transpiration and Heat Load

273 Desert Annuals Are Ephemeral

273 Summary

274 Chapter Review

274 Further Reading

275 Development: An Overview

275 Growth, Differentiation, and Development

275 Development is the sum of Growth and Differentiation

276 Growth is an Irreversible Increase to Size

276 Differentiation refers to To Qualitative Changes that Normally Accompany Growth

277 Meristems are Centers of Plant Growth

279 Seed Development and Germination

279 Seeds are formed in the Flower

280 Seed Development and Maturation

281 Seed Germination

283 The Level and Activities of Various Hormones Changes Dramatically During Seed Development

284 Many Seeds Have Additional Requirements for Germination

285 From Embryo to Adult

286 Senescence and Programmed Cell Death are the Find Stages of Development

287 Summary

287 Chapter Review

288 Further Reading

282 Development in a Mutant Weed

289 Growth and Development of Cells

289 Growth of Plant Cells is Complicated by the Presence of A cell wall

289 The Primary Cell wall is a Network of Cellulose Microfibrils and Cross- Linking Glycans

290 The Cellulose -Glycan lattice is Embedded in a Matrix of Pectin and Protein

292 Cellulose Microfibrils are Assembled at the Plasma Membrane as They Extruded into the Cell wall

292 Cell Division

292 The Cell Cycle

293 Cytokinesis

294 Plasmodesmata are Cytoplasmic Channels that Extend Through the Wall to connect the Protoplasts of Adjacent Cells

294 Cell walls and Cell Growth

296 Cell Growth is Division by Water Uptake and Limited by the Strength and Rigidity of the Cell Wall 296 Extension of the Cell Wall Requires Wall Loosening Events that Enable Load Bearing Elements in the Wall to Yield to Turgor Pressure

297 Wall Loosening and Cell Expansion is Stimulated by Low ph and Expansion

298 In Maturing Cells a Secondary Cell Wall is Deposited on the Inside of the Primary Wall

298 Acontinous Stream of Signals Provides Information That Plant Cell Use to Modify Development

299 Signal Perception and Transduction

299 The G-Protein System is a Ubiquitous Receptor System

300 Signal Transduction Includes a Diverse Array of Second Messengers

300 Protein Kinase -Based Signaling

300 Phospholipid Based Signaling

301 Calcium -Based Signaling

303 Transcriptional -Based Signaling

303 There is Extensive Crosstalk Among Signal Pathways

304 Summary

304 Chapter Review

304 Further Reading

295 Cytoskeleton

302 Ubiquitin and Proteasomes-* Cleaning up Unwanted Proteins

305 Hormones I Auxins

305 The Hormone Concept in Plant

306 Auxins is Distributed Throughout the Plant

307 The Principal Auxins in Plants in Indole -3-Acetic Acid (IAA)

309 IAA ıs Synthesızed From the Amıno Acıd I-Tryptophan

310 Some Plants do not Requıre Tryptophan for IAA bıosynthesıs

310 IAA may be stored as Inactıve

311 IAA ıs Deactıvated by Oxıdatıon and Conjugatıon wıth Amıno Acıds

311 Auxıns ıs Involved ın Vırtually Every Stage of Plant Development

311

311 Auxın Regulates Vascular Dıfferentıatıon

313 Auxın Control the Growth of Auxiliary Buds

314 The Acıd -Growth Hypothesıs Explaıns Auxın Control of Cell Enlargement

316 Maıntenance of Auxıns Induced Growth and Other Auxın Effects Requıres Gene Activation

317 Many Aspects of Plant Developments are Lınked to the Polar Transport of Auxıns

320 Summary

321 Chapter Revıew

321 Further

307 Dıscoverıng Auxın

314 Commercıal Applıcatıons of Auxıns

323 Hormones II Gıbberellıns

323 There are a Large Number of Gıbberellıns

324 There are Three Prıncıples Sıtes For Gıbberellın Bıosynthesıs

325 Gıbberellıns are Terpenes Sharıng a Core Pathway wıth Several Other Hormones and a Wıde Range of Secondary Products

327 Gıbberellıns are Synthesızed from Geranylgeranyl Pyrophosphate (GGPP)

329 Gibberellins are Deactivated by 2β-Hydroxylation

329 Growth Retardants Block the Synthesis of Gibberellins

330 Gibberellins Transport is Poorly Understood

Gibberellins Affect Many Aspects of Plant Growth and Development

330 Gibberellins Stimulate Hyper-elongation of Intact Stems Especially in Dwarf and Rosette Plant

332 Gibberellins Stimulate Mobilization of Nutrient Reserves During Germination of Cereal Grains

333 Gibberellins Act by Regulating Gene EXPRESSION

336 Summary

336 Chapter Review

339 Further Reading

325 Discovery of Gibberellins

330 Commercial Applications of Gibberellins

335 Dells Proteins and the Green Revolution

339 Hormones III Cytokines

339

339 Cytokines Biosynthesis Begins with the Condensation of an Isopentenyl Group with the Amino Group of Andesine

340 Cytokinin's may be Deactivated by Conjugation or Oxidation

341 Cytokinins are synthesized Primarily in the Root and Translocated in the Xylem

343 Cytokinin are Required for Cell Proliferation

343 Cytokinin Regulate Progression through the Cell Cycle

344 The Ratio of Cytikinins and Auxin Control Roots and Shoots Initiation in Callus Tissues and the Growth of Axillary Buds

345 Crown Gall Tumors are Genetically Engineered to Overproduce Cytokinin and Auxin

346 Cytokinin Delay Senescence

347 Cytokinin Have an Important Role in Maintaining the Shoot Meristem

348 Cytokinin Levels in the Shoot Apical Meristem Are Regulated by Master Control Gene

350 Cytokinin Receptor and Signaling

350 The Cytokinin Receptor is a Membrane -Based Histidine Kinase

351 The Cytokinin Signaling Chain Involves a Multistep Transfer of Phosphoryl Groups to Response Regulators

353 Summary

353 Chapter Review

354 Further Reading

341 The Discovery of Cytokinins

345 Tissue Culture has Made Possible Large-Scale Closing of Plants by Micropropagation

355 Hormones IV : Abscisic Acid Ethylene and Brassinosteroids

355 Abscisic Acid is Synthesized From a Carotenoid Precursor

357 Abscisic Acid is Synthesized to phaseic Acid by Oxidation

357 Abscisic Acid Regulate

358 Abscisic Acid Regulates Embryo Maturation and Seed Germination

358 Abscisic acid Mediates Response to Water Stress

359 Other Abscisic Acid Response

359 ABA perception and Signal Transduction

362 Ethylene is Synthesized From the Amino Acid Methionine

362 Excess Ethylene is Subject to Oxidation

364 The Study of Ethylene Presents a Unique Set of Problems

364 Ethylene Affects Many Aspects of Vegetative Developments

365 Ethylene Receptors and Signaling

367 Brassinosteriods

367 Brassinosteriods are Polyhydroxylated Sterols Derived From the Triterpene Squalene

369 Several Route for Deactivation of Brassinsteroids have been Identified

369 Braasinolde Receptors and Signaling

369 Summary

370 Chapter Review

370 Further Readıng

356 The Dıscovery of Abscısıc Acıd

363 The Discovery Ethylene

366 Mitogenactivated Protein Kinetics: A Widespread Mechanism For Signal Transduction

373 Photomorphogenesis Responding to Light

373 Photomorphogenesis is Initiated by Photoreceptors

374 Phytochromes Responding to Red and Far Red Light

376 Photoreversibility is the Hallmark of Phytochrome Action

377 Conversion of Pr to Pfr in Etiolated Seeding leads to a loss of both Pfr and Total phytochrome

378 Light Established a State of Dynamic Photoequilibrium between pr and pfr

Photochrome Response can be Grouped According to their fluence Requirements

379 Cryptochrome: Responding to Blue and UV-A Light

379 Photochrome and Cryptochrome mediate numerous Developmental Responses

379 Seed Germination

380 De-Etiolation

381 Shade Avoidance

381 Detecting end of Day Signals

382

382 Rapid Photochrome Response

383 Phy A may Function to Detect the Presence of Light

383 Chemistry and Mode of Action of Phytochrome and Cryptochrome

383 Phytochrome is a Phycobiliprotin

384 phytochrome Signal Transduction

386 Cryptochrome Structure is similar to DNA repairs enzymes

386 Cryptochrome Signal Transduction

387 Some plant Responses are Regulated by UV-B Light

387 De- Etiolation in Arabidopsis : A Case Study in Photoreceptor Interactions

388 Summary

389 Chapter Review

389 Further Reading 375 Historical Perspectives -The Discovery of Phytochrome

391 Tropisms and Nastic Movements: Orienting Plants in Space

392 Phototropism: Reaching for the Sun

392 Phototropism is a response to a light Gradient

393 Phototropism is a Blue light Response

393 Phototropism Orients a plants for Optional Photosynthesis

394 Fluence Response Curves Illustrate the Complexity of Phototropic Response

395 The Phototropiv Response is Attributed to a Lateral Redistribution of Diffusible Auxin

396 Phototropism and Related Response are Regulated by a Family of Blue Sensitive Flavoproteins

397 A Hybrid Red/Blue Light Photoreceptor has been Isolated form a Fern

397 Phytotropin Activity and Signal Chain

398 Phototropism in Green Plants is not well Understood

398 Gravitropism

399 Gravitropism is more than Simple Up and Down

399 The Gravitational Stimulus is the Product of Intensity and Time

401 Root Gravitropism Occurs in four Phases

405 Nastic Movements

406 Nyctinasty Movements are Rhythmic Movements Involving Reversible Turgor Changes

407 Nyctinasty Movements are due to Ion Fluxes and Resulting Osmotic Responses in Specialized Motor Cells

409

410 Summary

411 Chapter Review

411 Further Reading

400 Methods in the Study of Gravitropism

413 Measuring Time Controlling Development by photoperiod and Endogenous

414 Photoperiodism 415 Photoperiodic Response may be characterized by a variety of response types

415 Critical Day Length Defines Short-Day and Long -Day Response

417 Plants Actually measure the Length of the Dark Period

418 Phytochrome and Cryptochrome are the Photoreceptors for Photoperiodism

419 The Photoperiodic Signal is perceived by the leaves

420 Control of Flowering by Photoperiod Requires a transmissible Signal

421 Photoperiodism normally Requires a period of High Fluence Light Before or After the Dark Period

423 The Biological Clock

423 Clock Driven Rhythms persist Under Constant Conditions

423 Light Roots the Biological Clock on a daily basis

426 The Circadian Clock is temperature Compensated

427 The Circadian Clock is a Significant Component in Photoperiodic Time Measurement

428 Daylength Measurement Involves an Interaction Between an External Light Signal and a Circadian Rhythm

429 The Circadian Clock is a Negative Feedback loop

430 Photoperiodism in Nature

431 Summary

432 Chapter Review

432 Further Reading

414 Historical Perspectives: The Discovery of Photoperiodism

422 Historical Perspectives The Biological Clock

433 Flowering and Fruit Development

433 Flowering Initiation and Developments Involves Sequential Action of three Sets of Genes

434 Flowering -Time Genes Influence the Duration of Vegetative Growth

436 Floral -Identity Genes and Organ-Identity Genes Overlap in Time and Function

437 Temperature can Alter the Flowering Response to Photoperiod

438 Vernalization Occurs most Commonly in Winter Animals and Biennials

439 The Effective Temperature for Vernalization is Variable

440 The Vernalization Treatment is Perceived by the Shoots Apex

440 The Vernalized State is Transmissible

440 Gibberellin and Vernalization Operate Through Independent Genetic Pathways

441 Three Genes Determines the Vernalization Requirements in Cereals

442 Fruits set and Developments is Regulated by Hormones

442 The Development of Fleshy Fruits can be Divided into Five Phase

442 Fruits set is Triggered by Auxin

444 Ripening is Triggered by Ethylene in Climacteric Fruits

445 Summary

445 Chapter Review

446

445 Ethylene its a Gas

447 Temperature : Plant Development and Distribution

447 Temperature in the Plant Environment

449 Bud Dormancy 450 Bud Dormancy is Induced by Photoperiod

451 A Period of LOW temperature IS required

451 Seed Dormancy

451 Numerous Factors Influence Seed Dormancy

453 Temperature has a Significant Impact on Seed Dormancy

454 Thermotropism is a Response to Alternating Temperature

454 Temperature Influence Plant Distribution

457 Summary

457 Chapter Review

457 Further Reading

450 Bulbs and Corns

459 Secondary Metabolites

459 Secondary Metabolites A.K.A Natural Products

460 Terpenes

460 The Terpenes are a Chemically and Functionally Diverse Group of Molecules

460 Terpenes are Constituents of Essentials Oils

462 Steroids and Sterols are Tetracyclic Triterpenoids

463 Glycosides

464 Saponins are Terpenes Glycosides With Detergents Properties

465 Cardiac Glycosides are Highly Toxic Steroids Glycosides

Cyanogenic glycosides are A Natural Source of Hydrogen Cyanide

467 Glucosinolates are Sulfur Containing Precursors to Mustard Oils

462 Polyterpenes Includes the Carotenoids Pigments and Naturals Rubber

463 Glycosides

464 Saponins are Terpenes Glycosides with Detergents Properties

466 Cyanogenic Glycosides are A Natural Source of Hydrogen Cyanide

466 Glucosinolates are Sulphur-Containing Precursors to Mustard Oils

467 Phenylpropanoids

468 Shikimic Acid is a Key InIntermediate in the Synthesis of Both Aromatic Amino Acids and Phynylpropanoids

the Simplest Phenolic Molecules are Essentially deaminated Versions of the Corresponding Amino Acids

Coumarin and Coumarin Derivatives Function as Anticoagulant s 468

Lignin is a Major Structural Component of Secondary Cell Wall 470

Flavonoid and Stilbenes have parallel Biosynthesis Pathway 471

Tannins Denature Proteins and Add an Astringent Taste to Foods 472

Secondary Metabolites are Active Against Insect5s and Disease 474

Some Terpenes and Isoflavones Have Insecticidal and Anti-Microbial and Anti-Microbial Activity 474

Recognizing Potential Pathogens 475

Salicylic Acids Shikimic Acid Derivative Triggers Systemic Acquired Resistance 473

Jasmonates are Limited to Ubiquitin-Related Protein Degradation 476

Alkaloids are a Large Famiy of Chemically Unrelated Molecules 476

Alkaloids are noted Primarily for their Pharmacological Properties and Medical Applications 476

Like Many other Secondary Metabolites Alkaloids Serves as Preformed Chemical Defense ,molecules 479

Summary 479

Chapter Review 480

Further Reading 480

Building Block: Lipids Proteins and Carbohydrates 481

Lipids 481

Proteins 483

Carbohydrates 485

Monosaccharides 485

polysaccharides 486

Index/Glossary 489