Principles of plant virology: genome, pathogenicity, virus ecology.

THE VIRUS, THE CELL AND THE PLANT Viral Structures * Architecture of the virion * Viral nucleic acids * Viral information: a protected message Infection of the Cell: Synthesis of Viral Proteins * Entry of viral genetic information into the cell * Translation of the viral messenger Infection of the Cell: Replication of the Viral Nucleic Acid * Replication of positive-sense RNA viruses * Replication of negative-sense RNA viruses * Replication of single-stranded DNA viruses: Geminiviridae and Nanoviridae * Replication of double-stranded DNA viruses: Caulimoviridae * Conclusion Plant Virus Movement * TMV movement: a model system * The movement of other viruses * Another form of cell-to-cell movement: the viral particle * Virus movement: a paradigm for macromolecular trafficking within plants * Concluding remarks The defence reaction of the infected plant * Recovery from viral infection is due to an RNA silencing mechanism similar to post-transcriptional gene silencing (PTGS) * Viruses can suppress RNA silencing * Concluding remarks: RNA silencing, the tip of the iceberg? Resistance with Hypersensitivity Reaction and Extreme Resistance * Description of resistance * Induction of resistance * Translation of the signal * The expression of resistance * Conclusion Subviral Pathogenic RNAs: Satellites and Viroids * Satellite viruses and satellite RNAs * Viroids. THE VIRUS IN THE AGRO-ENVIRONMENT Virus Dissemination * To be transmitted or to disappear * Specific molecular interactions between viruses and vectors * The epidemiology of viral diseases Diagnostic Methods * Symptoms observed on the plant * Symptoms observed at the cellular level * Diagnosis through biological means * Serological diagnostics * Towards plant virus diagnosis in the fields * Contribution of electron microscopy * Detection of viral nucleic acids * Towards efficient use of diagnostic methods Control of Plant Viral Diseases: Prophylactic Measures * Virus-free seeds and vegetative propagules * Preventing and reducing virus dissemination Controlling Plant Viral Diseases: Breeding for Resistant Varieties * Search for and characterization of virus resistances * Diversity of resistance mechanisms * Durability of resistance genes Control of Plant Viral Diseases: Genetic Engineering for Protection * Gene transfer * How is a transgenic plant obtained? * Transgenic protection against plant viruses * Potential environmental impact of virus-resistant transgenic plants EVOLUTION AND CLASSIFICATION OF VIRUSES Evolution of Viruses * Mutation * Recombination * Viral sequences are integrated in plant DNA * Viral quasi-species * Vectors, a field that is constantly explored by viruses * New viral diseases and emerging viruses * Molecular phylogenies * Origin of viruses and viral genes: modular evolution * A phylum: positive-sense RNA viruses * A provisional conclusion: How is a virus produced? Classification of Plant Viruses * Species * Genera * Families * Orders Viral Genera * Positive-sense single-stranded RNA viruses One isometric particle * Positive-sense single-stranded RNA viruses bipartite genome, isometric particles * Positive-sense single-stranded RNA viruses tripartite genome, isometric particles * Positive-sense single stranded RNA viruses helical rod-shaped particles * Positive-sense single stranded RNA viruses helical filamentous particles * Negative-sense single stranded RNA viruses * Double-stranded RNA viruses * Single-stranded RNA viruses * Double-stranded DNA reverse-transcribing viruses Glossary.