Structural Analysis and Activation by Fungal Infection of a Gene Encoding a Pathogenesis-related Protein in Potato. Janet L. Taylor, Karl-Heinrich Fritzemeier, Isolde Häuser, Erich Kombrink, Frauke Rohwer, Martin Schröder, Günter Strittmatter, and Klaus Hahlbrock. Max Planck Institut für Züchtungsforschung, Abteilung Biochemie, D-500 Köln 30, Federal Republic of Germany. MPMI 3:72-77. Accepted 20 October 1989. Copyright 1990 The American Phytopathological Society.

The structure, genomic organization, and temporal pattern of activation of a gene encoding a pathogenesis-related protein (PR1) in potato (Solanum tuberosum) have been analyzed.  The gene is rapidly activated in leaves from the potato cultivar Datura, containing the resistance gene R1, in both compatible and incompatible interactions with appropriate races of the late-blight fungus Phytophthora infestans.  Activation is also observed in leaves treated with fungal elicitor.  The gene occurs in multiple very similar copies and encodes a polypeptide (M_r = 25,054; pI = 5.5) that is classified as a PR portein by several criteria.  Small fragments with great sequence similarity to portions of the two exons were found closely linked to the expressed gene, which altogether represents a simple case of genome organization in potato.  The coding sequence of the prp1 gene and the deduced amino-acid sequence are strikingly similar to the corresponding sequences of a 26-kDa heat-shock protein from soybean.