ABSTRACT
Disease resistance in crop plants is a major challenge in plant breeding. Within industrialized agriculture, the need for efficient self-protection of cultivated plants is likely to increase in the future. To achieve this goal, diverse strategies will be necessary and compete. Conventional breeding has made great progress in incorporating natural defense genes, but the limitations of this method are also obvious. The progress in plant molecular biology now allows the generation of transgenic plants, thereby exploiting the mechanisms nature has developed to control and to limit the infection of microbial pathogens on plants. An additional benefit of transgenic plants is the possibility to validate the usefulness of endogenous plant genes in defense strategies. Changes in the expression or composition of a desired gene may still be achieved by conventional breeding assisted by the results from transgenic plants.
