Mechanisms of resistance to plant viruses are diverse, and probably involve different types of recognition events. Often, a cascade of changes affecting broader aspects of defence and metabolism is switched on progressively after the initial recognition event. Virulence, i.e. resistence-breaking behaviour of the virus, involves a failure or alteration of recognition or subsequent signalling. Consequences of these recognition events are the ways in which the pathogenic effects on the host are exerted: formation of visible symptoms and control of plant growth. This volume offers a comprehensive...