Induced disease resistance: how do induced plants stop pathogens?

The phenomenon of induced or acquired resistance to disease in plants has been studied intensively in recent years. This has led to a better understanding of the signaling pathways involved in the expression of systemic resistance as well as the genetic regulation of induced or acquired resistance. Although the induction of resistance to disease results in the expression of less disease in the plant after challenge with pathogens, how the plant is able to restrict the development of the pathogen is not clearly defined. In this paper, some of the defenses expressed in plants with induced resistance will be discussed in relation to how the induced plants may restrict disease development. (C) 1999 Academic Press.