Phloem Transport

I: Anatomy.- 1. Phloem Tissue in Angiosperms and Gymnosperms.- Cell Types: Their Spatial Distribution, Longevity of Sieve Elements, Aging of Phloem.- Discussion.- 2. Structure and Differentiation of Sieve Elements in Angiosperms and Gymnosperms.- Living Sieve Elements, Cytological and Nuclear Changes During Differentiation; Preparatory Artefacts.- Discussion.- Includes discussion paper: “The Distribution of Filaments in Sieve Tubes in Freeze-Etched, Rapidly-Frozen, Intact Translocating Vascular Bundles”.- 3. P-Proteins.- Isolation, Chemistry, Morphology, Formation, Dispersal, Conformational Changes, Enzyme Activity and Functions.- Discussion.- Includes discussion paper: “Biochemistry of Phloem Proteins,”.- 4. Sieve Element Cell Walls.- “Nacre” wall, “Secondary” wall. Structure and Chemical Composition, Development and Final Structure of Sieve Areas Plates.- Discussion.- 5. Companion Cells and Transfer Cells.- Structure, Function, Development of Transfer Cell.- Discussion.- Includes discussion paper: “Development of Transfer Cells in Higher Parasitic Plants”.- 6. Phloem Tissue and Sieve Elements in Algae, Mosses and Ferns.- Discussion.- Includes discussion paper: “The Phloem (Leptome) of Bryophytes,”.- 7. Sieve Element Structure in Relation to Function.- Overview of Fine Structural Differentiation, P-Protein Formation and Biochemical Characterization of Sieve Element Contents.- Discussion.- II: Physiology Of Translocation.- 1. Phloem Loading and Associated Processes.- Definition, Demonstration, Role in Translocation.- Discussion.- Includes discussion paper: “Phloem Loading,”.- 2. Physiological and Structural Ontogeny of the Source Leaf.- Import-Export Transition, Carbon Balance and Sugar Synthesis; Ultrastructure of Minor Veins.- Discussion.- 3. Translocation Kinetics and Photosynthates.- Factors Affecting Tracer Kinetics; Translocation Profiles (Kinetic and Spatial); Autoradiography, Anatomy and Tracer Kinetics.- Discussion.- 4. The Effect of Externally Applied Factors on the Translocation of Sugars in the Phloem.- Water Stress, “Hormone-directed” Transport, Anaerobic Conditions and Metabolic Inhibitors, Temperature, Adaptation to Cold.- Discussion.- 5. Bidirectional Transport.- Historical Survey, Anatomical Aspects and Mechanism.- Discussion.- 6. The Use of Phloem Exudates from Several Representatives of the Agavaceae and Palmaein the Study of Translocation of Assimilates.- Phloem Origin of Exudates, Origin of Water and Sucrose in Exudate and Bleeding Mechanism.- Discussion.- Includes discussion paper: “Exudation from Cuts and Aphid Stylets,”.- III: Biophysics Of Phloem Transport.- 1. Basic Biophysics of Transport.- Passive Permeation of Membranes, Water Transport, Irreversible Thermodynamics, Active Transport.- 2. Horwitz-Type Models of Tracer Distribution during Unidirectional Translocation.- Irreversible Lateral Loss, Loss by Enzyme Kinetics and Reversible Lateral Loss.- 3. Kinetics of Tracer Efflux from Leaves.- Discussion.- 4. Steady State Models of Münch Pressure Flow.- Discussion.- Includes discussion paper: “Time-Dependent Behaviour of Munch Translocation in Sugar Beet and Trees: Theory vs. Experiment,”.- 5. Some Aspects of the Münch Hypothesis.- Discussion.- 6. The Electro-Osmotic Theory.- Presuppositionf History, Physical Model and Evaluation.- 7. Activated Mass Flow: Surface Flow.- 8. Mechanisms: Comparative Behaviour.- Munch Hypothesis, Ionic Relations, Role of P-Protein.- Discussion.- Includes discussion paper: “Discussion of Electro-Osmotic Theories of Phloem Transport,”.- 9. Summary of the Conference.- Participants.