Higher Plant Cell Respiration

I am honored by the editor's invitation to write a Preface for this volume. As a member of an older generation of plant physiologists, my lineage in plant respiration traces back to F. F. BLACKMAN through the privilege of having M. THOMAS and W. O. JAMES, two of his "students," as my mentors. How the subject has changed in 40 years! In those dark ages B. 14C. most of the information available was hard-won from long-term experiments using the input-output approach. Respiratory changes in response to treatments were measured by laborious gas analysis or by titration of alkali from masses of Pettenkofer tubes; the Warburg respir­ ometer was just beginning to be used for plant studies by pioneers such as TURNER and ROBERTSON. Nevertheless the classical experiments of BLACKMAN with apples had led to important results on the relations between anaerobic and aerobic carbohydrate utilization and on the climacteric, and to the first explicit concept of respiratory control of respiration imposed by the" organiza­ tion resistance" of cell structure. THOMAS extended this approach in his investi­ gations of the Pasteur effect and the induction of aerobic fermentation by poi­ sons such as cyanide and high concentrations of CO , JAMES began a long 2 series of studies of the partial reactions of respiration in extracts from barley and YEMM'S detailed analysis of carbohydrate components in relation to respira­ tory changes added an important new dimension.

Contenu

1 Preparation of Plant Mitochondria, Criteria for Assessement of Mitochondrial Integrity and Purity, Survival in Vitro.- 1 Introduction.- 2 General Considerations for the Isolation of Intact Mitochondria.- 3 Large-Scale Preparation of Washed Mitochondria.- 3.1 Reagents.- 3.2 Procedure for Potato Tuber Mitochondria.- 4 Assessment of Mitochondrial Integrity.- 4.1 Spectrophotometric Assay for Succinate: Cytochrome c Oxidoreductase.- 4.2 KCN-Sensitive-Ascorbate-Cytochrome c-Dependent O2 Uptake.- 5 Control of Mitochondrial Purity.- 6 Purification of Plant Mitochondria.- 6.1 Purification on Sucrose Gradients.- 6.2 Purification on Percoll Gradients.- 6.2.1 Purification of Mitochondria from Potato Tubers.- 6.2.2 Purification of Mitochondria from Pea Leaves.- 6.2.3 Properties of Percoll-Purified Mitochondria.- 7 Concluding Remarks.- References.- 2 Molecular Organization and Expression of the Mitochondrial Genome of Higher Plants.- 1 Introduction.- 2 Physicochemical Characterization.- 2.1 Buoyant Density and Melting Point.- 2.2 Direct Observation of mtDNA Molecules by Electron Microscopy.- 2.3 C0t Curves and Kinetic Complexity.- 2.4 Detection of Discrete Circular mtDNA Molecules by Gel Electrophoresis.- 3 Restriction Analysis and Molecular Cloning.- 3.1 Restriction Patterns.- 3.2 Molecular Cloning.- 3.3 Physical Map(s) of mtDNA.- 4 Identified Mitochondrial Genes.- 4.1 rRNA Genes.- 4.2 tRNA Genes.- 4.3 Protein Genes.- 5 Concluding Remarks.- References.- 3 Plant Mitochondrial Lipids: Structure, Function and Biosynthesis.- 1 Introduction to Lipid Structures.- 2 Composition of Mitochondrial Membranes.- 2.1 Content of Acyl and Other Lipids.- 2.2 Comparison with Other Plant Membranes.- 3 Metabolism.- 3.1 Sources of Precursors for Lipid Synthesis.- 3.2 Mitochondrial Phospholipid Synthesis.- 3.3 Degradative Enzymes.- 4 Functional Aspects of Lipids.- 4.1 Membrane Structure and function.- 4.2 Changes in Mitochondrial Lipids.- 5 Conclusion.- References.- 4 Plant Mitochondrial Cytochromes.- 1 Introduction.- 2 Cytochrome Estimation.- 3 Mitochondrial Cytochromes in Higher Plants.- 3.1 The c Cytochromes.- 3.1.1 Cytochrome c.- 3.1.2 Cytochrome c1.- 3.2 The b Cytochromes.- 3.2.1 The Various Cytochromes b.- 3.2.2 The Cytochrome b-c1 Complex.- 3.2.3 Cytochromes b of the External Mitochondrial Membrane.- 3.3 The a Cytochromes.- 4 Influence of the Membrane Potential on the Redox States of the Mitochondrial Cytochromes.- 5 Miscellany.- 6 Cytochromes in the Respiratory Chain of Higher Plant Mitochondria.- References.- 5 The Outer Membrane of Plant Mitochondria.- 1 Perspective.- 2 Isolation of Mitochondrial Membranes.- 3 Lipid Composition of the Mitochondrial Outer Membrane.- 3.1 Lipid Classes.- 3.2 Fatty Acid Composition: Temperature Modulation.- 3.3 Lipid Phase Transitions.- 4 Enzymes of the Mitochondrial Outer Membrane.- 4.1 The NADH: Cytochrome c Oxidoreductase System.- 4.1.1 Possible Functions of the Outer Membrane Redox Chain.- 5 Channel-Formers of the Outer Mitochondrial Membrane.- 5.1 Structural Evidence for the Existence of Pores.- 5.2 Trypsin-Insensitive Polypeptides of the Plant Membrane.- 5.3 The Pore-Forming Polypeptides.- 5.4 Structure and Function of the Channels.- 5.4.1 Model from X-ray Diffraction.- 5.4.2 Structure from Electron Microscopy.- 5.4.3 Mechanism of Ion Selectivity.- 5.5 Speculation on a Regulatory Role for Outer Membrane Channels.- References.- 6 Organization of the Respiratory Chain and Oxidative Phosphorylation.- 1 Introduction.- 2 Organization of Respiratory Components.- 2.1 The Basic Functional Units.- 2.1.1 Complex I, NADH Dehydrogenase.- 2.1.2 Complex II, Succinate Dehydrogenase.- 2.1.3 Complex III, the Cytochrome bc1 Complex.- 2.1.4 Complex IV, Cytochrome Oxidase.- 2.1.5 The Alternative Oxidase.- 2.1.6 The External NADH Dehydrogenase.- 3 Connection Between the Functional Units.- 3.1 The Sidedness of the Reactions of the Alternative Oxidase, Succinate Dehydrogenase and the External NADH Dehydrogenase.- 3.2 The Role of Ubiquinone as a Mobile Redox "Pool".- 3.2.1 Mobility Between Components.- 3.2.2 The Role of Ubiquinone in Providing Mobility.- 3.2.3 The Relation of the Quinone Pool to Control of Electron Flow Through the Cytochrome and Alternative Oxidases.- 3.3 Some Instances Where Ideal Q-Pool Behaviour Is Not Observed.- 4 Oxidative Phosphorylation.- 4.1 Background.- 4.2 Proton Electrochemical Gradient.- 4.2.1 Steady-State Ion Distribution.- 4.2.2 Spectroscopic Probes.- 4.2.3 Ion-Specific Electrodes.- 4.2.4 Magnitude of ? p and its Response to the Metabolic State.- 4.3 Mechanism for Generating ? p.- 4.3.1 H+/ORatios.- 4.3.2 H+/Site Ratios.- 4.3.3 H+/ATP Ratios.- 4.4 Thermodynamic Competence of ? p.- 4.5 Is ?p an Obligate Intermediate?.- References.- 7 The Oxidation of NADH by Plant Mitochondria.- 1 Introduction.- 2 NADH Dehydrogenases Oxidizing Exogenous NADH.- 2.1 The Outer Membrane NADH Dehydrogenase.- 2.2 The Inner Membrane NADH Dehydrogenase.- 2.2.1 Location of the Dehydrogenase.- 2.2.2 Nature of the Redox Components and Relationship with the Respiratory Chain.- 2.2.3 Inhibitors of the External Dehydrogenase.- 2.2.4 Specificity of the External NADH Dehydrogenase for the Nicotin-amide Adenine Dinucleotide.- 2.2.5 Regulation of Electron Flux Through the External NADH Dehydrogenase.- 2.2.6 The Physiological Significance of Regulation of the NADH Dehydrogenase.- 3 NADH Dehydrogenases Oxidizing Endogenous NADH.- 3.1 Rotenone-Sensitive Oxidation of Endogenous NADH.- 3.1.1 Redox Components Associated with the Dehydrogenase.- 3.1.2 Regulation of Electron Flow Through the Rotenone-Sensitive Dehydrogenase.- 3.2 Rotenone-Resistant Oxidation of Endogenous NADH.- 3.2.1 Relationship to the Terminal Oxidases.- 3.2.2 Relationship to the NAD+-Linked Krebs Cycle Dehydrogenases.- References.- 8 The Cyanide-Resistant Pathway of Plant Mitochondria.- 1 Introduction.- 2 The Measure of Cyanide Resistance.- 3 The Dependence on Respiratory Substrates.- 4 The Inhibition of Electron Transport.- 4.1 Inhibitors of the Flavoprotein Pathway.- 4.2 Inhibitors of the Cytochrome Pathway.- 4.3 Inhibitors of the Alternative Pathway.- 4.4 Interactions Between Inhibitors.- 5 The Link with Energy Transduction.- 5.1 Oxidative Phosphorylation.- 5.2 Membrane Potential and Proton Gradient.- 6 The Structure of the Alternative Pathway.- 6.1 Branch Point of the Alternative Pathway.- 6.2 Other Components.- 7 The Functional Organization of the Alternative Pathway.- 7.1 Topographical Organization.- 7.2 Compartmentation.- 7.2.1 Ubiquinon…