Plant Carbohydrates I: Intracellular Carbohydrates

ISBN-13: 9783642682773 / Angielski / Miękka / 2011 / 918 str.

F. a. Loewus; W. Tanner

Opis

The essential features of constitution, configuration, and conformation in carbo hydrate chemistry, so well established in the . first half of this century, had yet to be exploited by those concerned with biochemical and physiological processes in plants when the original Encyclopedia appeared. Two outstanding developments, discovery of sugar nucleotides and the advent of chromatography, brought together the insight and a means of probing complexities inherent in plant carbohydrates. These advances, combined with a modern knowledge of enzymes and cellular metabolism, have provided new horizons of investigation for the student of plant physiology. This volume and its companion (Vol. 13B) present a comprehensive assess ment of the current viewpoint in plant carbohydrates with emphasis on those aspects which impinge on physiological processes of growth and development. To accommodate the extensive amount of information to be presented, subject matter has been divided, somewhat arbitrarily, into intracellular and extracellular carbohydrates, with the latter defined as carbohydrates occurring in space out side the plasma membrane (plasmalemma). This classification is not exclusive; rather it is intended to lend a degree of flexibility to the way in which subject matter is arranged between volumes. The first section of this volume addresses the occurrence, metabolism, and function of monomeric and higher saccharides of fungi, algae, and higher plants."

Spis treści

I. Monomeric and Oligomeric Sugars and Sugar Derivatives — Occurrence, Metabolism, Function.- 1 Aldo (and Keto) Hexoses and Uronic Acids.- 1 Introduction.- 1.1 Historical.- 1.2 Sugar Nucleotides and Carbohydrate Interconversions in Plants.- 1.3 Sugar Nucleotides Isolated from Plants to Date.- 2 Phosphorylation of Free Sugars.- 2.1 Hexokinase.- 2.2 d-Galactokinase and L-Arabinokinase.- 2.3 d-Glucuronokinase.- 2.4 d-Galacturonokinase.- 3 Formation of Nucleotide Sugars (Pyrophosphorylases).- 3.1 UDP-d-Glucose Pyrophosphorylase.- 3.2 ADP-d-Glucose Pyrophosphorylase.- 3.3 GDP-d-Glucose Pyrophosphorylase.- 3.4 TDP-d-Glucose Pyrophosphorylase.- 3.5 Utilization of ?-d-Galactopyranosyl Phosphate.- 3.6 GDP-d-Mannose Pyrophosphorylase.- 3.7 UDP-N-Acetyl-d-Glucosamine Pyrophosphorylase.- 3.8 ADP-N-Acetyl-d-Glucosamine Pyrophosphorylase.- 3.9 GDP-l-Fucose Pyrophosphorylase.- 3.10 UDP-d-Glucuronate Pyrophosphorylase.- 3.11 UDP-d-Galacturonate Pyrophosphorylase.- 3.12 Nucleoside Diphosphate Pentose Pyrophosphorylases.- 3.13 Other Nucleotide Sugar Pyrophosphorylase Activities.- 3.14 Other Transglycosylation Reactions Responsible for the Formation of Nucleotide Sugars.- 3.15 Degradation of Nucleotide Sugars.- 3.15.1 ADP-d-Glucose Phosphorylase.- 3.15.2 Hydrolysis of Nucleotide Sugars by Phosphodiesterase.- 4 Nucleotide Sugar Epimerases.- 4.1 UDP-d-Glucose-4-Epimerase.- 4.2 UDP-d-Xylose-4-Epimerase.- 4.2.1 Possible Origin of L-Arabinofuranosyl Moieties.- 4.3 UDP-d-Glucuronate-4-Epimerase.- 4.4 Biosynthesis of l-Galactose in Plants (GDP-D-Mannose-3,5-Epimerase).- 4.5 GDP-d-Glucose-2-Epimerase.- 5 Biosynthesis of Deoxysugars in Plants.- 5.1 l-Rhamnose and L-Fucose.- 5.2 UDP-Digitoxose.- 6 Biosynthesis of Uronic Acid in Plants (d-Glucuronic Acid).- 6.1 UDP-d-Glucose Dehydrogenase.- 7 De Novo Synthesis of UDP-d-Xylose; UDP-d-Glucuronate Decarboxylase.- 7.1 UDP-d-Glucuronate Decarboxylase.- 8 Miscellaneous Topics (Not Treated Above).- 8.1 Nucleotide Sugars Involving d-Fructose and d-Ribose.- 8.1.1 UDP-d-Fructose.- 8.1.2 ADP-d-Ribose (5).- 8.2 Control of Nucleotide Sugar Synthesis and Utilization.- 9 Possible Evolutionary Significance of Carbohydrate Interconversion Pathways.- References.- 2 Polyhydroxy Acids: Relation to Hexose Phosphate Metabolism.- 1 Introduction.- 2 Overview of the Role of Hexoses, Pentoses and Polyhydroxy Acids in Metabolic Systems of Plants.- 3 Reactions and Functions of the Oxidative Pentose Phosphate Pathway, and Properties of Glucose 6-Phosphate and 6-Phosphogluconate Dehydrogenases.- 4 Glucose 6-Phosphate-myo-Inositol Glucuronate Pathway and Metabolism of Phytic Acid.- 5 Biosynthesis, Metabolic Reactions and Proposed Metabolic Functions of L-Ascorbate.- 6 l-(+)-Tartaric Acid and Oxalic Acid Metabolism.- 7 Concluding Remarks.- References.- 3 Amino Sugars — Plants and Fungi.- 1 Introduction.- 2 Nomenclature.- 3 Methods of Detection.- 4 Occurrence.- 4.1 Amino Sugars in Fungal Cell Walls.- 4.2 Mannans.- 4.3 Amino Sugars in Algal Cell Walls.- 4.4 Glycoproteins.- 4.4.1 Fungi.- 4.4.2 Higher Plants.- 4.4.3 Membrane Glycoproteins in Higher Plants.- 5 Glycolipids.- 5.1 Lipid Intermediates in Glycoprotein Biosynthesis.- 5.2 Glycosphingolipids.- 6 Amino Sugar Biosynthesis.- 6.1 Glucosamine 6-Phosphate.- 6.1.1 Hexokinases.- 6.2 Formation of N-Acetylglucosamine-6-Phosphate.- 6.3 Conversion of GlcNAc-6-Phosphate to GlcNAc-1-Phosphate.- 6.4 Amino Sugar Nucleotides.- 7 Galactosamine.- 8 Glycosidases.- 8.1 Higher Plants.- 8.2 Fungi.- References.- 4 Branched-Chain Sugars.- 1 Introduction.- 2 Branched-Chain Monosaccharides of Green Plants.- 2.1 d-Hamamelose.- 2.1.1 Elucidation of the Structure.- 2.1.2 Occurrence of Free d-Hamamelose.- 2.1.3 Biosynthesis of d-Hamamelose.- 2.1.4 Natural Derivatives of d-Hamamelose.- 2.1.5 Biological Degradation of d-Hamamelose.- 2.2 d-Apiose (3-C-Hydroxymethyl)-d-Glycero-Aldotetrose).- 2.2.1 Elucidation of the Structure.- 2.2.2 d-Apio d-Furanose as Glycosidic Component of Plant Cell Wall Polysaccharides and of Phenolic Plant Constituents.- 2.2.3 Biosynthesis of UDP-d-Apiose.- 2.2.4 Transfer of the d-Apiosyl-Residue.- 2.2.5 Metabolism of d-Apiose.- 3 Branched-Chain Monosaccharides of Microorganisms.- 3.1 Methyl-Branched Monosaccharides.- 3.1.1 CDP-l-Vinelose (Cytidine-6-Deoxy-3-C-(Methyl)-2-O-Methyl-l-Talose).- 3.1.2 l-Noviose (6-Deoxy-3-O-Carbonyl-5-C-Methyl-4-O-Methyl-l-Lyxohexose).- 3.1.3 l-Mycarose (2,6-Dideoxy-3-C-Methyl-l-Ribohexose).- 3.1.4 l-Cladinose (2,6-Dideoxy-3-C-Methyl-3-O-Methyl-l-Ribohexose.- 3.2 C-(Hydroxyethyl)-and C-(Oxoethyl)-Branched Monosaccharides.- 3.2.1 d-Aldgarose.- 3.2.2 The Branched-Chain Sugars of the Quinocycline Antibiotics.- 3.3 C-Hydroxymethyl-and C-Formyl-Branched Monosaccharides: The Sugars of the l-Streptose Family.- 4 Conclusion: Physiological Problems Originating from the Branched Carbon Skeleton.- References.- 5 Sugar Alcohols.- 1 Introduction.- 1.1 General Comments on Polyols.- 1.2 Summary of Earlier Reviews.- 2 Occurrence.- 2.1 General Information.- 2.2 Mannitol.- 2.3 Sorbitol.- 2.4 Other Hexitols.- 2.5 The Tetritols and Pentitols.- 2.6 The Heptitols and Octitols.- 2.7 Other Polyols.- 2.8 The Heterosides.- 2.9 Phosphate Esters.- 3 Methods of Study.- 3.1 General.- 3.2 Preparations of Extracts.- 3.3 Fractionation of the Extract.- 3.4 Use of Chromatographic and Electrophoretic Procedures.- 3.5 Methods of Estimation.- 4 Metabolism of Polyols.- 4.1 General.- 4.2 Photosynthetic Production of Polyols.- 4.3 Metabolism of Polyols and Sugars.- 4.4 Enzymes of Polyol Metabolism.- 4.5 Uptake of Polyols.- 5 Physiology and Role in Nature.- 5.1 Sugar Interconversion.- 5.2 Polyols as Redox Agents.- 5.3 Osmoregulation.- 5.4 Cryoprotection.- 5.5 Transport and Storage.- 6 Future Directions of Research.- 7 Conclusion.- References.- 6 Cyclitols.- 1 Introduction.- 2 Nomenclature and Stereochemistry.- 3 Occurrence.- 4 Formation.- 5 Metabolic Processes.- 6 Physiological Roles.- 7 Concluding Remarks.- References.- 7 Sucrose and Other Disaccharides.- 1 Introduction.- 2 Sucrose.- 2.1 Introduction.- 2.2 Enzymes of Sucrose Biosynthesis.- 2.2.1 General.- 2.2.2 Sucrose Synthase.- 2.2.3 Sucrose Phosphate Synthase.- 2.2.4 Sucrose Phosphatase.- 2.2.5 Assay of Sucrose-Synthesizing Enzymes.- 2.3 Sucrose Hydrolases (Invertases).- 2.3.1 General.- 2.3.2 The Enzymes.- 2.3.3 Level and Location of Invertase in Tissues.- 2.3.4 Invertase Inhibitors.- 2.3.5 Sucrose and the Synthesis of ?-Fructofuranans.- 2.4 Subcellular Site of Sucrose Synthesis.- 2.4.1 The Compartment.- 2.4.2 Carbon Fluxes in Leaves.- 2.4.3 Carbon Fluxes in Storage Tissues.- 2.5 Source of Carbon for Sucrose Synthesis.- 2.5.1 Gluconeogenesis from Phosphoglycerate.- 2.5.2 Photorespiration Intermediates.- 2.5.3 Pyruvate and Related Intermediates.- 2.5.4 Utilization of Storage Reserves.- 2.5.5 Metabolic Controls.- 2.5.6 13C-Discrimination.- 2.6 Sucrose Translocation.- 2.7 Intracellular Compartmentation of Sucrose.- 2.8 Sucrose-Starch Transformation.- 2.8.1 General Considerations.- 2.8.2 Photosynthetic Tissues.- 2.8.3 Rice.- 2.8.4 Maize.- 2.8.5 Wheat, Barley and Sorghum.- 2.8.6 Potato Tubers.- 2.9 Sucrose as a Source of Nucleoside Diphosphate Glycosyls.- 2.10 Utilization of Exogenous Sucrose.- 2.11 Sucrose and Environmental Stress.- 2.11.1 Water Stress.- 2.11.2 Illumination and Irradiance.- 2.11.3 Frost.- 2.11.4 High Temperature.- 2.11.5 NH4+.- 2.11.6 Metal Toxicity.- 2.11.7 Potassium Deficiency.- 2.11.8 CO2 and SO2.- 2.11.9 Salt and Ion Concentration.- 2.11.10 Infection and Symbiosis.- 2.11.11 Low O2.- 2.11.12 Boron.- 3 ?,?-Trehalose (O-?-d-Glucopyranosyl-?-O-d-Glucopyranoside).- 3.1 Occurrence.- 3.2 Metabolism.- 3.2.1 Synthesis.- 3.2.2 Degradation.- 3.2.3 Metabolic Pattern.- 4 Other Nonreducing Disaccharides and Related Glycosides.- 4.1 Disaccharides.- 4.2 Monoglycosides of Polyhydroxy Alcohols and Acids.- 4.2.1 Monoglycoside-Alditols.- 4.2.2 Glycosyl Glyceric Acids.- 4.2.3 Glycoside-Cyclitols.- 5 Maltose.- 5.1 General.- 5.2 Occurrence.- 5.3 Mechanism of Formation.- 5.4 Mechanism of Utilization.- 5.5 Patterns of Metabolism in Leaves.- 5.6 Utilization of Maltose as an External Source of Carbohydrate.- 6 Reducing Disaccharides.- 6.1 Introduction.- 6.2 Disaccharides from Storage Oligosaccharides.- 6.2.1 Melibiose.- 6.2.2 Isomelibiose (Umbelliferobiose).- 6.2.3 Planteobiose.- 6.2.4 Isolychnobiose.- 6.2.5 Turanose.- 6.2.6 Gentiobiose.- 6.3 Disaccharides as Products of Polysaccharide Degradation.- 6.3.1 ?-Glucosides.- 6.3.2 Mannosides.- 6.3.3 Galactosides.- 6.3.4 Lactose.- 6.3.5 Arabinosides.- 6.3.6 Xylosides.- 6.3.7 Fructobioses.- 6.3.8 Hexuronides.- 6.3.9 Chitobiose.- 6.4 Reducing Disaccharides Produced by Glycoside Hydrolase-Catalyzed Transglycosylations.- 6.4.1 d-Glucosides.- 6.4.2 d-Galactosides.- 6.4.3 ?-Fructofuranosides.- 6.5 Disaccharides in Plant Glycosides.- References.- 8 Oligosaccharides Based on Sucrose (Sucrosyl Oligosaccharides).- 1 Introduction.- 2 Extraction, Isolation and Identification of Sucrosyl Oligosaccharides.- 3 Occurrence of Sucrosyl Oligosaccharides and Their Distribution in Higher Plants.- 3.1 Raffinose Series.- 3.2 Lolium Trisaccharide.- 3.3 Umbelliferose.- 3.4 Lychnose and Isolychnose Series.- 3.5 Planteose Series.- 3.6 Kestoses (Fructosylsucroses) Series (Fructan).- 3.7 Gentianose.- 4 Biosynthesis of Sucrosyl Oligosaccharides.- 4.1 The Biosynthesis of the Raffinose Series.- 4.2 Biosynthesis of Lolium Trisaccharide.- 4.3 Biosynthesis of Umbelliferose.- 4.4 Biosynthesis of the Lychnose and Isolychnose Series.- 4.5 Biosynthesis of the Planteose Series.- 4.6 Biosynthesis of the Kestoses (Fructosylsucroses) Series (Fructan).- 4.7 Biosynthesis of Gentianose.- 5 Degradation of Sucrosyl Oligosaccharides.- 6 Function of Sucrosyl Oligosaccharides.- 6.1 Storage.- 6.2 Translocation.- 6.3 Frosthardiness.- 7 Concluding Remarks.- References.- 9 Glycosylation of Heterosides (Glycosides).- 1 Introduction.- 2 O-Glycosides.- 2.1 Phenolic Glycosides.- 2.1.1 Simple Phenolic Glycosides.- 2.1.2 Flavonoid Glycosides.- 2.1.3 Coumarin Glycosides.- 2.1.4 Anthraquinone Glycosides.- 2.2 Glycosides of Terpenoids.- 2.2.1 Monoterpene Glycosides.- 2.2.2 Steryl Glycosides.- 2.2.3 Cardiac (Digitalis) Glycosides.- 2.2.4 Glycosylated Steroid Alkaloids.- 3 C-Glycosides.- 4 Conclusion.- References.- II. Macromolecular Carbohydrates — Occurrence, Metabolism, Function.- 10 Biosynthesis of Starch and Its Regulation.- 1 Pertinent Enzymatic Reactions.- 1.1 Suggestive Evidence for the Major Route to Starch Formation.- 1.2 Sucrose Conversion to Starch in Reserve Tissues.- 2 Regulation of Starch Synthesis.- 2.1 General Considerations.- 2.2 Regulation of Leaf and Algal ADPglucose Pyrophosphorylases by 3-P-Glycerate and Orthophosphate.- 2.3 Are the Allosteric Phenomena Operative in Vivo?.- 3 Properties of the Starch Biosynthetic Enzymes.- 3.1 ADPglucose Pyrophosphorylase.- 3.1.1 Enzyme from Higher Plants, Green Algae and Blue-Green Bacteria.- 3.1.2 Native and Subunit Molecular Weight of ADPglucose Pyrophosphorylase.- 3.1.3 ADPglucose Pyrophosphorylases of Nonphotosynthetic Plant Tissues.- 3.2 Properties of Starch Synthase (ADPglucose: (1 ? 4)-?-d-Glucan 4-?- Glucosyltransferase).- 3.2.1 Starch Bound and Soluble Starch Synthases.- 3.2.2. Requirements for Activity.- 3.2.3 Multiple Forms of Soluble Starch Synthase.- 4 Branching (Q) Enzyme ((1?4)-?-Glucan 6-Glycosyl Transferase).- 4.1 Mechanism of Action.- 4.2 Multiple Forms of Plant Branching Enzymes.- 4.3 A Possible Function for the Multiple Forms of Starch Synthases and Branching Enzymes.- References.- 11 Reserve Polysaccharides Other Than Starch in Higher Plants.- 1 Introduction.- 2 Cell Wall Storage Polysaccharides in Seeds.- 2.1 Occurrence and Classification.- 2.2 The Mannan Group.- 2.2.1 “Pure” Mannans.- 2.2.2 Glucomannans.- 2.2.3 Galactomannans.- 2.2.4 Other Mannans.- 2.3 The Xyloglucans.- 2.3.1 Distribution.- 2.3.2 Structures.- 2.3.3 Metabolism.- 2.4 The Galactans.- 2.5 Others.- 3 Nonstarch Storage Polysaccharides of Vegetative Tissues.- 3.1 Occurrence and Classification.- 3.2 The Fructan Group.- 3.2.1 Fructans of the Dicotyledons.- 3.2.2 Fructans of the Monocotyledons.- 3.3 The Mannan Group.- 3.3.1 Occurrence and Chemistry.- 3.3.2 Cytology, Deposition, and Mobilization.- 3.4 Other Polysaccharides with a Possible Reserve Function.- 4 Biological Functions.- 4.1 Cell Wall Storage Polysaccharides in Seeds.- 4.2 Nonstarch Storage Polysaccharides in Vegetative Tissue.- References.- 12 Reserve Carbohydrates of Algae, Fungi, and Lichens.- 1 Introduction.- 1.1 Starch and Glycogen-Type Reserve Polysaccharides.- 1.2 (l-3)-?-d-Glucans.- 1.3 Other Types of Reserve Carbohydrate.- 2 Reserve Carbohydrates of Marine Algae.- 2.1 ?-d-Glucans.- 2.1.1 Floridean Starch.- 2.1.2 Starches.- 2.2 ?-d-Glucans.- 2.2.1 Laminarin.- 2.2.2 Eisenan.- 2.3 Fructans.- 2.4 Xylans.- 2.5 Other Polysaccharides.- 3 Reserve Carbohydrates of Freshwater Algae.- 3.1 ?-d-Glucans.- 3.1.1 Starches.- 3.1.2 Amylopectin and Phytoglycogen Type.- 3.2 ?-d-Glucans.- 3.2.1 Paramylon.- 3.2.2 Leucosin (Chrysolaminarin).- 3.3 Other Polysaccharides.- 4 Reserve Carbohydrates in Fungi.- 4.1 ?-d-Glucans.- 4.1.1 Glycogen Type.- 4.1.2 Other (1?4)- and (1?6)-?-d-Glucans.- 4.1.3 (l?4)-?-d-Glucans.- 4.1.4 (l?3)-?-d-Glucans.- 4.1.5 Nigeran.- 4.2 ?-d-Glucans.- 4.2.1 (1?3)-?-d-Glucans.- 4.3 Other Polysaccharides.- 5 Reserve Carbohydrates of Lichens.- 5.1 ?-d-Glucans.- 5.2 ?-d-Glucans.- References.- 13 Plant Glycoproteins.- 1 Introduction.- 2 Natural Occurrence of Glycoproteins.- 3 Isolation, Fractionation, and Purification.- 3.1 Methods of Extraction: Practical Considerations.- 3.2 Isolation and Purification.- 4 Composition of Glycoproteins.- 5 Structural Studies.- 5.1 Types of Peptide-Carbohydrate Linkages.- 5.2 Structural Studies of the Carbohydrate Groups.- 6 Some of the Better-Defined Glycoproteins and Proteoglycans.- 6.1 Lectins (or Phytoagglutinins).- 6.1.1 Soybean Agglutinin (SBA).- 6.1.2 Lectins from Some Phaseolus vulgaris Species.- 6.1.3 Lima Bean Agglutinin.- 6.1.4 Sainfoin Agglutinin.- 6.1.5 Broad Bean Lectin.- 6.1.6 Potato Lectin.- 6.2 Enzymes.- 6.2.1 Stem Bromelain.- 6.2.2 Ficin.- 6.2.3 Horseradish Peroxidase.- 6.2.4 Invertases.- 6.3 Storage Proteins.- 6.3.1 7S Protein of Soybean.- 6.3.2 Kidney Bean Glycoproteins.- 6.3.3 Vicilin and Legumin.- 6.4 Toxins.- 6.4.1 Ricin D.- 6.5 Intracellular Proteoglycans and Glycoprotein-Polysaccharide Complexes.- 6.5.1 Intracellular Hydroxypyroline-Rich Proteoglycan of Suspension-Cultured Tobacco Cells.- 6.5.2 Glycoproteins and Glycoprotein-Polysaccharide Complexes from the Leaves of Higher Plants.- 6.5.3 Arabinogalactan-Proteins from Higher Plants.- 6.6 Plant Cell Wall Glycoproteins.- 7 Glycoprotein Biosynthesis.- 8 Comparison of Higher Plant Glycoprotein Structure with Those of Microorganisms and Animals.- 8.1 N-Glycosidic Linkages.- 8.2 O-Glycosidic Linkages Through the Hydroxyl Group of Hydroxypyroline or Hydroxylysine.- 8.3 O-Glycosidic Linkage Through the Hydroxyl Group of Serine and Threonine.- 9 Concluding Remarks.- References.- 14 Membrane Glycoproteins.- 1 The Membrane as a Molecular Milieu.- 2 Structure and Mechanisms of Biosynthesis.- 2.1 Structure.- 2.2 Mechanisms of Biosynthesis.- 2.2.1 Use of Model Systems.- 2.2.2 Synthesis of Integral Membrane Proteins.- 2.2.3 Cotranslational Glycosylation.- 2.2.4 Post-Translational Glycosylation.- 2.2.5 Synthesis of Peripheral Membrane Proteins.- 2.2.6 Synthesis of Mitochondrial and Chloroplast Membrane Proteins.- 2.2.7 Summary of Mechanisms of Biosynthesis.- 3 Intracellular Transport.- 3.1 General Principles.- 3.2 Regulation.- 3.2.1 Secretion Signals.- 3.2.2 Retention Signals.- 4 Plant Membrane Glycoproteins.- 4.1 Distribution.- 4.1.1 Cell Surface.- 4.1.2 Intracellular Membranes: GA, ER and Tonoplast.- 4.1.3 Chloroplasts and Mitochondria.- 4.1.4 Microbodies: Glyoxysomes and Peroxisomes.- 4.1.5 Other Membranes.- 4.2 Structure and Mechanisms of Biosynthesis.- 4.3 Intracellular Transport.- 5 Future Perspectives.- References.- 15. Glycolipids and Other Glycosides.- 1 Introduction.- 2 Methods Used in the Isolation and Purification of Glycolipids.- 3 Glycosyl Diglycerides.- 3.1 Mono- and Digalactosyl Diglycerides.- 3.2 Sulfoquinovosyl Diglyceride.- 4 Cerebrosides.- 5 Phytoglycolipids.- 6 Steryl Glucosides.- 7 Lipid-Linked Saccharides.- References.- 16 Steryl Glycosides.- 1 Introduction.- 2 Presence and Structure of Glycosylated Sterols in Plants.- 3 Organ and Cellular Localization of Steryl Glucosides.- 4 Biosynthesis and Degradation of Steryl Glucosides and Acylated Steryl Glucosides.- 5 The Intracellular Location of UDPGlc: Sterol Glucosyl Transferase and Steryl Glucoside Acylase.- 6 Distribution of Steryl Glucosides and Acylated Steryl Glucosides as a Probe of Functions.- 7 Steryl Glucosides and Acylated Steryl Glucosides in Plant Membranes.- 8 Steryl Glucosides as Intermediary Sugar Carriers.- 9 Miscellaneous Activities of Steryl Glucosides in Plants.- References.- III. Physiological Processes.- 17 Transport of Sugar.- 1 Introduction.- 2 Classification of Sugar Transport Across Membranes.- 2.1 Passive Transport (Diffusion).- 2.2 Mediated Diffusion.- 2.3 Active Transport.- 3 Energy Input for Active Sugar Transport.- 3.1 Equilibrium Shift by Substrate Conversion.- 3.2 Primary Active Transport.- 3.3 Secondary Active Transport.- 3.3.1 Proton-Symport in Plants.- 3.3.2 Proton-Translocating ATPases on Plasmalemma and Tonoplast.- 3.3.3 Sugar Uptake Driven by Sugar Efflux.- 4 Kinetic Properties of Sugar Transport Systems.- 4.1 Sugar Transport at Net and Steady-State Conditions.- 4.2 The Sugar Accumulation Ratio.- 4.3 Effect of Metabolic Inhibitors on Transport Kinetics.- 4.4 Influence of Proton-Gradient and Membrane Potential on Kinetics.- 5 Transport Proteins.- 6 Regulation of Sugar Transport.- 6.1 Induction and Repression.- 6.2 Transport Regulation by Direct Effectors.- 7 Relevance of Sugar Transport Systems for Plant Cells.- 8 Concluding Remarks.- References.- 18 Secretion of Nectar.- 1 Introduction.- 2 Route of Transport.- 2.1 Apoplastic Transport.- 2.2 Symplastic Transport.- 3 Sites of Membrane Transport.- 3.1 At the Phloem.- 3.2 To the Exterior.- 3.2.1 Modifications Increasing the Secreting Surface.- 3.2.2 Protoplast Specialization.- 4 Metabolism.- 4.1 Sugar Interconversion.- 4.2 Energy Metabolism.- 4.3 Phosphatases.- 4.4 Sugar Transport.- References.- 19 Storage of Sugars in Higher Plants.- 1 Introduction.- 2 Functional Anatomy of Storage Tissues.- 3 Translocation of Sucrose to the Storage Organs.- 4 Storage of Sugars in Fruits.- 5 Storage of Sucrose in Sugarcane.- 6 Storage of Sucrose in Roots and Beets.- 7 Transfer of Sucrose into the Vacuole.- 8 Remobilization of Sugars from the Storage Compartment.- 9 Concluding Remarks.- References.- 20 Storage of Starch.- 1 Introduction.- 2 Occurrence of Starch.- 2.1 Global Data.- 2.2 Measurement of Starch.- 2.2.1 Occurrence — Dry Fruits.- 2.2.2 Occurrence — Fleshy Organs.- 3 Patterns of Accumulation.- 3.1 Temporal.- 3.2 Ontogenetic Patterns.- 3.2.1 Inception.- 3.2.2 Acceleration.- 3.2.3 The Grand Phase of Accumulation.- 3.2.4 Termination.- 4 Distribution of Starch.- 4.1 Within Storage Organs.- 4.1.1 Vegetative Organs.- 4.1.2 Seeds.- 4.2 Between Storage Organs.- 5 Plastids.- 5.1 Origin and Development.- 5.2 Developmental Homologies.- 5.3 Biochemical Attributes of Plastids.- 5.3.1 Nucleic Acids.- 5.3.2 Enzymes.- 5.4 Stability of Amyloplast Membranes.- 6 Granules.- 6.1 Morphology.- 6.2 Initiation of Granules.- 6.3 Growth of Granules.- 6.3.1 Growth and Lamellae.- 6.3.2 Mechanism of Growth.- 6.3.3 Growth and Changes in Composition.- 6.3.4 Granule Size and Composition.- 7 Metabolism of Starch.- 7.1 Substrates and Precursors.- 7.2 Pathways of Synthesis.- 7.3 Degradation of Starch.- 7.4 The Turnover of Starch.- 7.5 Distribution of 14C.- 8 Regulatory Mechanisms.- 8.1 Intracellular Controls.- 8.2 Supply of Substrate.- 8.2.1 The Seed.- 8.2.2 Fruits, Roots, and Tubers.- 8.2.3 Control by Transport of Substrate.- 8.3 Growth of Storage Organs.- 9 Environmental Influence.- 9.1 Irradiance.- 9.2 Temperature.- 9.3 Water Deficit.- 9.4 Mineral Nutrition.- 10 Summary and Conclusions.- References.- 21 Control by External and Internal Factors Over the Mobilization of Reserve Carbohydrates in Higher Plants.- 1 Introduction.- 2 Seeds.- 2.1 Starch in Cereals.- 2.1.1 Gibberellins and ?-Amylase Synthesis by the Barley Aleurone Layer.- 2.1.2 Gibberellins and the Synthesis of Other Carbohydrases in Barley Grains.- 2.1.3 Gibberellin-Induced Enzymes in Other Cereal Grains.- 2.2 Starch in Legumes.- 2.2.1 Control by the Axis.- 2.3 Mannans in Seed Endosperms.- 2.3.1 Legumes.- 2.3.2 Lettuce.- 2.3.3 Umbellifers and Palms.- 2.4 Other Cell Wall Polysaccharides.- 2.5 Raffinose-Oligosaccharides.- 3 Tubers, Roots, and Bulbs.- 3.1 Fructans in Jerusalem Artichoke Tubers, and Other Roots and Bulbs.- 3.2 Starch in Potato Tubers.- 4 Starch in Leaves.- 5 Fleshy Fruits.- 5.1 Starch.- 5.2 Cell Wall Polysaccharides.- 6 Thermogenesis in Aroids.- 7 Changes in Stems, Roots, and Leaves Associated with Environmental Stresses.- 8 Starch in Organogenesis.- References.- Author Index.- Species Index.