Comprehensive Virology 11, Softcover reprint of the original 1st ed. 1977 Regulation and Genetics Plant Viruses Comprehensive Virology Series, Vol. 11

The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having passed only recently through its descriptive phase of naming and num­ bering, has probably reached that stage at which relatively few new­ truly new-viruses will be discovered. Triggered by the intellectual probes and techniques of molecular biology, genetics, biochemical cytology, and high resolution microscopy and spectroscopy, the field has experienced a genuine information explosion. Few serious attempts have been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of about 22 volumes, represents a commitment by a large group of active investigators to analyze, digest, and expostulate on the great mass of data relating to viruses, much of which is now amorphous and disjointed, and scattered throughout a wide literature. In this way, we hope to place the entire field in perspective, and to develop an invalu­ able reference and sourcebook for researchers and students at all levels. This series is designed as a continuum that can be entered anywhere, but which also provides a logical progression of developing facts and integrated concepts.

1 Plant Covirus Systems: Three-Component Systems.- 1. Introduction.- 2. Structure and Composition.- 2.1. Isocapsidic Viruses.- 2.2. Heterocapsidic Viruses.- 2.3. Separation Methods.- 3. Infectivity.- 3.1. Dose-Infectivity Curves.- 3.2. Infectivity of Nucleoprotein Components.- 3.3. Infectivity of RNAs.- 3.4. Activity of Coat Protein.- 4. Test-Tube Exchange of Genetic Material.- 4.1. Hybrids.- 4.2. Backcross Experiments.- 4.3. Thermosensitive Mutants.- 5. Translation and Aminoacylation.- 5.1. In Vitro Translation.- 5.2. In Vivo Translation.- 5.3. Aminoacylation.- 6. Replication.- 6.1. Double-Stranded RNAs.- 6.2. Replicase.- 7. Discussion.- 8. References.- 2 Plant Covirus Systems: Two-Component Systems.- 1. Introduction.- 2. Tobraviruses.- 2.1. Serotypes and Particle Dimensions; Separation of Virions.- 2.2. Particle Structural Homologies.- 2.3. Protein and RNA Molecular Weights.- 2.4. Virion Reconstitution Experiments.- 2.5. Conversion of Unstable TRV to Stable TRV.- 2.6. Infectivity as a Function of Virion Concentration.- 2.7. TRV Hybrids.- 2.8. In Vitro Protein Synthesis.- 2.9. Nucleotide Sequence Relationships.- 2.10. Events in TRV Replication.- 2.11. Possible Significance of Other TRV Components.- 3. Comoviruses.- 3.1. Members of the Comovirus Group.- 3.2. Chemical Composition of the Centrifugal Components.- 3.3. Virion Electrophoretic Forms.- 3.4. Capsid Structure.- 3.5. Infectivity of the Components.- 3.6. Hybrid Comoviruses.- 3.7. In Vitro Protein Synthesis.- 3.8. Nucleotide Sequence Relationships.- 3.9. Infection-Associated RNA Polymerase Activity.- 3.10. Events in Replication.- 4. Nepoviruses.- 4.1. Members of the Nepovirus Group.- 4.2. Chemical Composition of Multiple Centrifugal Components.- 4.3. Component and RNA Infectivities; Hybrid Viruses.- 4.4. Nucleotide Sequence Relationships.- 4.5. The Proteins and RNAs of Strawberry Latent Ringspot Virus.- 4.6. Satellite Viruses.- 4.7. Events in Replication.- 5. Other Possible Two-Component Systems.- 6. References.- 3 Defective and Satellite Plant Viruses.- 1. Introduction.- 2. Defective Viruses.- 2.1. Productivity of Virus Infection.- 2.2. Specific Infectivity of the Virus.- 2.3. Defective Particles in Preparations of Normal Viruses.- 2.4. Peculiarities of Winter Wheat Mosaic Virus Infection.- 2.5. Missense Mutations and Nonfunctionality of the Virus-Coded Products (Defective and Temperature-Sensitive Phenotypes).- 2.6. Defective Viruses and Genome Masking.- 2.7. Unstable Variants of Tobacco Necrosis Virus.- 2.8. Unstable Variants of Tobacco Rattle Virus and Pea Early-Browning Virus.- 3. Satellitism in Plant Viruses.- 3.1. Association between Tobacco Necrosis Virus and Its Satellite: General Description.- 3.2. Strains of TNV and STNV.- 3.3. Physicochemical Properties and Structure of TNV and STNV.- 3.4. Specificity of STNV Activation by TNV.- 3.5. Interference between TNV and STNV.- 3.6. Coding Properties of STNV Genome.- 4. Concluding Remarks.- 5. References.- 4 The Translation of Large Plant Viral RNAs.- 1. Historical Introduction.- 2. Methodology.- 3. Translation of TMV RNA.- 3.1. In Vivo.- 3.2. In Cell-Free Systems.- 3.3. Isolation and Translation of TMV LMC.- 3.4. Cowpea Strain of TMV; LMC Virions.- 3.5. The Genetic Map of TMV.- 4. Translation of Turnip Yellow Mosaic Virus RNA.- 5. Translation of the RNA of Tobacco Necrosis Virus and Its Satellite.- 6. Covirus Genome Translation.- 6.1. Three-Component Coviruses: AMV, BMV.- 6.2. Two-Component Coviruses: TRV, CPMV.- 7. General Aspects of Translation of Plant Viral RNAs.- 7.1. Importance of RNA Structure.- 7.2. Translation of Multiple Products from Large RNAs.- 7.3. Identification of Gene Products, with Particular Reference to RNA Replicase.- 8. References.- 5 Protoplasts in the Study of Plant Virus Replication.- 1. Introduction.- 2. Protoplasts from Leaf Mesophyll.- 2.1. Isolation.- 2.2. Culture.- 3. Infection of Protoplasts.- 3.1. Inoculation Procedure.- 3.2. Levels of Infection.- 3.3. Efficiency of Infection.- 3.4. Number of Virus Particles Involved in Infection.- 3.5. Process of Virus Entry.- 3.6. Inoculation with Viral RNA.- 4. Studies of Plant Virus Replication Using Protoplasts.- 4.1. Tobacco Mosaic Virus.- 4.2. Cowpea Chlorotic Mottle Virus.- 4.3. Brome Mosaic Virus.- 4.4. Cucumber Mosaic Virus.- 4.5. Cowpea Mosaic Virus.- 4.6. Tobacco Rattle Virus.- 4.7. Turnip Yellow Mosaic Virus.- 4.8. Potato Virus X.- 5. Concluding Remarks.- 6. References.- 6 Viroids.- 1. Introduction.- 2. Biological Properties.- 2.1. Propagation Hosts and Environmental Factors.- 2.2. Inoculation Procedures.- 2.3. Bioassay of Viroids.- 2.4. Host Range.- 2.5. Cytopathic Effects.- 2.6. Subcellular Location in Situ.- 3. Evidence for Existence of Viroids.- 3.1. Sedimentation Properties and Nuclease Sensitivity..- 3.2. Absence of Virions.- 3.3. Molecular Weight Estimates of Native Viroids.- 3.4. Identification of Viroids as Physical Entities.- 4. Purification.- 5. Physical and Chemical Properties.- 5.1. Molecular Weight.- 5.2. Thermal Denaturation Properties.- 5.3. Radiation Sensitivity.- 5.4. Electron Microscopy of Viroids.- 5.5. Molecular Structure.- 5.6. Composition and Primary Sequence.- 6. Replication.- 6.1. Messenger RNA Properties.- 6.2. RNA-Directed RNA Synthesis.- 6.3. DNA-Directed RNA Synthesis.- 6.4. De Novo Synthesis of Viroids.- 7. Possible Origin of Viroids.- 8. Conclusions and Speculations.- 9. Appendix: Determination of Viroid Nature of Unknown Pathogen.- 9.1. Criteria for Suspecting Viroid Nature of Pathogen..- 9.2. Sedimentation Properties.- 9.3. Nuclease Sensitivity.- 9.4. Insensitivity to Treatment with Phenol.- 9.5. Electrophoretic Mobility.- 10. References.