Hormonal Regulation of Development I

This is the first of the set of three volumes in the Encyclopedia of Plant Physiology, New Series, that will cover the area of the hormonal regulation of plant growth and development. The overall plan for the set assumes that this area of plant physiology is sufficiently mature for a review of current knowledge to be organized in terms of unifying principles and processes. Reviews in the past have generally treated each class of hormone individually, but this set of volumes is subdivided according to the properties common to all classes. Such an organization permits the examination of the hypothesis that differing classes of hormones, acting according to common principles, are determinants of processes and phases in plant development. Also in keeping with this theme, a plant hormone is defined as a compound with the properties held in common by the native members of the recognized classes of hormone. Current knowledge of the hormonal regulation of plant development is grouped so that the three volumes consider advancing levels of organizational complexity, viz: molecular and subcellular; cells, tissues, organs, and the plant as an organized whole; and the plant in relation to its environment. The present volume treats the molecular and subcellular aspects of hormones and the processes they regulate. Although it deals with chemically distinct classes of hormone, this volume stresses properties and modes of studying them, that are common to all classes.

1 Plant Hormones and Other Growth Substances ― Their Background, Structures and Occurrence (With 10 figures).- 1.1 Introduction.- 1.2 Ethylene.- 1.3 Auxins.- 1.4 Gibberellins.- 1.5 Cytokinins.- 1.6 Abscisic Acid and Related Compounds.- 1.7 Other Plant Constituents Which Affect Plant Growth.- a) Aromatic Compounds.- b) Nitrogen-Containing Compounds.- c) Terpenoid Compounds.- d) Aliphatic Compounds.- e) Other Compounds.- References.- 2 Extraction, Purification, and Identification (With 38 figures).- 2.1 Methods of Extraction, Purification, and Isolation.- 2.1.1 Extraction of Active Principles from Plant Materials.- a) General Remarks.- b) Auxins.- c) Gibberellins.- d) Cytokinins.- e) Abscisic Acid and Related Compounds.- 2.1.2 Fractionation Based on Solvent Partitioning and Ion Exchange Resin.- a) General Remarks.- b) Auxins.- c) Gibberellins.- d) Cytokinins.- e) Abscisic Acid and Related Compounds.- 2.1.3 Column Chromatography and Other Purification Techniques.- a) General Remarks.- b) Adsorption Column Chromatography.- c) Partition Column Chromatography.- d) Sephadex Column and Gel Permeation Column Chromatography.- e) Insoluble Polyvinylpyrrolidone Column Chromatography.- f) Countercurrent Distribution.- g) Other Techniques.- 2.1.4 Examples of Purification of Plant Hormones.- a) Isolation of Auxins from Young Citrus Fruits.- b) Isolation of Indole-3-Ethanol from Cucumber Seedlings.- c) Isolation of Gibberellins A1? A5, A6, and A8 from Immature Phaseolus Seeds.- d) Isolation of Gibberellins and Gibberellin Conjugates from Mature Phaseolus Seeds.- e) Isolation of Cytokinins from Immature Sweet Corn.- f) Isolation of Glucosylzeatin and Glucosyl Ribosylzeatin from Vinca rosea Crown Gall.- g) Isolation of Abscisic Acid from Young Cotton Fruits.- 2.2 Identification Without Isolation.- 2.2.1 Criteria of Identification and Reliability.- 2.2.2 Paper and Thin-Layer Chromatography.- a) General Remarks.- b) Identification of Plant Hormones by Paper and Thin-Layer Chromatography.- 2.2.3 Gas-Liquid Chromatography.- a) General Remarks.- b) Identification of Plant Hormones by Gas-Liquid Chromatography.- 2.2.4 High Performance (Pressure) Liquid Chromatography.- a) General Remarks.- b) Identification of Plant Hormones by High Performance Liquid Chromatography.- 2.2.5 Combined Gas-Liquid Chromatography-Mass Spectrometry.- a) General Remarks.- b) Identification of Plant Hormones by GC-MS.- c) Selected Ion Monitoring.- 2.2.6 Optical Rotatory Dispersion and Circular Dichroism.- References.- 3 Quantitative Analysis of Plant Hormones.- 3.1 Introduction.- 3.2 Theoretical Considerations.- 3.2.1 Basic Analytical Errors - Accuracy and Precision.- 3.2.2 Analysis of Samples from Open-Ended Systems.- 3.2.2.1 Open Versus Closed Systems.- 3.2.2.2 Accuracy as a Probability Term.- 3.2.2.3 Verification of Accuracy.- a) Successive Approximation.- b) Information Content.- c) Some General Considerations.- 3.3 Assays.- 3.3.1 Bioassays.- 3.3.2 Immunological Assays.- 3.3.3 Physicochemical Detectors.- 3.4 Chromatographic Procedures.- 3.5 Internal Standards.- 3.6 Analytical Procedures.- 3.6.1 Indole-3-Acetic Acid.- 3.6.2 Gibberellins.- 3.6.3 Cytokinins.- 3.6.4 Abscisic Acid.- 3.7 Summary.- 3.8 List of Symbols.- References.- 4 Biosynthesis and Metabolism of Plant Hormones.- 4.1 Biosynthetic Pathways.- 4.1.1 Auxins.- a) Tryptophan as Primary Precursor.- b) Pathways of IAA Formation from Tryptophan.- c) Indole-3-Pyruvic Acid Pathway.- d) Tryptamine Pathway.- e) Other Possible Pathways.- f) Chlorinated Auxins.- 4.1.2 Cytokinins.- a) Biosynthesis of tRNA-Cytokinins.- b) Biosynthesis of Free Cytokinins.- 4.1.3 Plant Hormones of Terpenoid Origin: General Terpenoid Pathway.- 4.1.4 Abscisic Acid.- a) Mevalonic Acid as Precursor of ABA.- b) Compounds with a Pre-Formed Carbon Skeleton of ABA.- c) Formation of ABA by Degradation of Carotenoids.- 4.1.5 Gibberellins.- a) General View.- b) Enzymic Cyclization of Geranylgeranyl Pyrophosphate to ent-Kaurene.- c) Oxidation of ent-Kaurene.- d) Contraction of Ring B in ent-Kaurene.- e) Conversion of C20-Gibberellins into C19-Gibberellins.- f) Predominant Steps in Regulation of Biosynthesis.- 4.1.6 Ethylene.- a) Ethylene Formation in Model Systems.- b) Synthesis in Vivo - Physiological Pathways.- c) Enzymes - Reaction Mechanisms.- d) Regulation of Ethylene Biosynthesis.- 4.2 Metabolism (Interconversion and Catabolism).- 4.2.1 Auxins.- a) Routes and Products of IAA Catabolism.- b) Enzymes of IAA Catabolism.- c) Physiological Significance of IAA Catabolism.- d) Control of IAA Catabolism in Vivo.- 4.2.2 Cytokinins.- 4.2.3 Abscisic Acid.- a) 6 -Hydroxymethyl ABA.- b) Phaseic Acid.- c) 4’-Dihydrophaseic Acid and Its 4’-Epimer.- 4.2.4 Gibberellins.- a) Interconversion of C19-Gibberellins in the Fungus.- b) Metabolism of Gibberellins in Higher Plants.- c) Catabolism of Gibberellins.- d) Control of Gibberellin Metabolism by Other Plant Hormones and by Environmental Factors.- 4.2.5 Ethylene.- 4.3 Conjugation.- 4.3.1 Auxins.- a) Peptidyl IAA Conjugates.- b) Glycosyl IAA Conjugates.- c) myo-Inositol IAA Conjugates.- 4.3.2 Cytokinins.- a) Metabolic Conjugation Pathways.- b) Enzymic Investigations.- 4.3.3 Abscisic Acid.- 4.3.4 Gibberellins.- a) Endogenous Gibberellin Conjugates.- b) Chemical Synthesis of Gibberellin Conjugates.- c) Metabolism of Gibberellin Conjugates.- d) Enzymatic Hydrolysis and Biological Activity of Gibberellin Conjugates.- e) Biological Function of Gibberellin Conjugates.- 4.4 Localization of Biosynthesis and Metabolism.- 4.4.1 Auxins.- 4.4.2 Cytokinins.- 4.4.3 Abscisic Acid.- 4.4.4 Gibberellins.- 4.4.5 Ethylene.- References.- 5 Molecular and Subcellular Aspects of Hormone Action.- 5.1 Introduction.- 5.1.1 Receptor Characteristics.- 5.1.2 General Methodology of Receptor Studies.- a) Analysis of Binding Data.- b) Acquisition of Binding Data.- 5.2 Auxins.- 5.2.1 Structure-Activity Relationships.- 5.2.2 Potential Location of Auxin Receptors.- 5.2.3 Nuclear and Cytoplasmic Receptors.- a) Auxin Mediator Proteins.- b) Auxin-Binding Proteins.- 5.2.4 Membrane-Bound Receptors.- a) The Corn Coleoptile System.- b) Membrane-Bound Sites in Other Tissues.- 5.3 Cytokinins.- 5.3.1 Structure-Activity Relationships.- 5.3.2 Cytokinins in Transfer RNA (tRNA).- 5.3.3 Cytokinin Binding to Sub-Cellular Components.- 5.4 Gibberellins.- 5.4.1 Structure-Activity Relationships.- 5.4.2 Transcriptional Control: Analogies with Animal Steroid Hormones….- a) Steroid Hormones.- b) Gibberellins.- 5.4.3 Effects on Membrane Organization.- 5.4.4 Action in Artificial Membrane Systems.- 5.4.5 Changes in Cell Extensibility.- 5.5 Abscisic Acid.- 5.6 Ethylene.- 5.6.1 Structure-Activity Relationships.- 5.6.2 Aspects of Molecular Action.- 5.7 Concluding Remarks.- References.- 6 Molecular Effects of Hormone Treatment on Tissue.- 6.1 Introduction.- 6.2 Effects of Hormones on Processes Involved in Growth.- 6.2.1 Effects of Auxins on Cell Extensibility.- a) Kinetic Studies on Cell Extension.- b) Effects on Nucleic Acids and Proteins.- c) The Acid Growth Effect.- d) Effect on Metabolism of the Cell Wall.- 6.2.2 Other Growth Regulators.- a) Gibberellins.- b) Cytokinins.- c) Ethylene.- d) Abscisic Acid.- e) 3-Methyleneoxindole.- f) Fusicoccin.- 6.2.3 Conclusions.- 6.3 Effects of Growth Regulators on Ion Transport and Regulation of Membrane Properties.- 6.3.1 Hormones and Stomata.- 6.3.2 Hormone-Directed Transport.- 6.4 Effects of Hormones on Non-Growing Systems.- 6.4.1 The Aleurone Layer System.- 6.5 Effects of Hormones on Differentiating Systems.- 6.6 Conclusions.- References.- Author Index.