| Recent applications of techniques in plant molecular biology and biotechnology to the study of host-pathogen interactions have resulted in the identification and cloning of numerous genes involved in the defense responses of plants following pathogen infection. These genes that express proteins, peptides, or antimicrobial compounds are directly toxic to pathogens or reduce their growth in situ; directly inhibit pathogen virulence products or enhance plant structural defense genes, directly or indirectly activate general plant defense responses; and improve resistance genes involved in the hypersensitive response and in the interactions with avirulence factors. The introduction and expression of these genes in a range of transgenic plant species have shown that the development of fungal pathogens can be significantly reduced. Induced defense responses have the potential to provide useful broad-spectrum disease resistance. |