Diseases of plants are a major problem for agriculture world wide. Understanding the mechanisms employed by plants to defend themselves against pathogens may lead to novel strategies to enhance disease resistance in crop plants. Much of the research in this area has been conducted with Arabidopsis as a model system, and this review focuses on how relevant the knowledge generated from this model system will be for increasing resistance in crop plants. In addition, the progress made using other model plant species is discussed. While there appears to be substantial similarity between the defence responses of Arabidopsis and other plants, there are also areas where significant differences are evident. For this reason it is also necessary to increase our understanding of the specific aspects of the defence response that cannot be studied using Arabidopsis as a model.