Current Review: hrp Genes of Phytopathogenic Bacteria. David K. Willis. U.S. Department of Agriculture, Agricultural Research Service, Plant Disease Resistance Research Unit, and Department of Plant Pathology, University of Wisconsin, Madison, WI 53706 U.S.A. Jessica J. Rich(2), and Estelle M. Hrabak(2). (2)Department of Plant Pathology, University of Wisconsin, Madison, WI 53706 U.S.A. MPMI 4:132-138. Accepted 8 January 1991. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1991.