VIEW ARTICLE | DOI: 10.1094/MPMI-6-745
Cultivar-Specific Elicitation of Barley Defense Reactions by the Phytotoxic Peptide NIP1 from Rhynchosporium secalis. Matthias Hahn. Max-Planck-Institut für Züchtungsforschung, Department of Biochemistry, D-50829 Cologne, Germany. Susanne Jüngling, and Wolfgang Knogge. Max-Planck-Institut für Züchtungsforschung, Department of Biochemistry, D-50829 Cologne, Germany.. MPMI 6:745-754. Accepted 26 July 1993. Copyright 1993 The American Phytopathological Society.
Additional Keywords: Hordeum vulgare L., cultivar-specific elicitor.
Resistance of barley to the phytopathogenic fungus, Rhynhosporium secalis race US238.1, was found to be controlled by resistance gene Rrs1, which segregated in a manner characteristic for a codominant gene. PRHv-1, a thaumatin-like pathogenesis-related protein, was shown to be encoded by a gene family on chromosome 1. As part of the barley defense response, significant accumulation of PRHv-1 and peroxidase transcripts was induced early during pathogenesis in two Rrs1 cultivars but not or to a lower level in a near-isogenic, susceptible rrs1 cultivar or a cultivar lacking known resistance genes. R. secalis secretes a small group of necrosis-inducing peptides. One of these, NIP1, which was detected in culture filtrates only of fungal race US238.1, was found to elicit the accumulation of PRHv-1 and peroxidase mRNAs in Rrs1 cultivars with a time course similar to that upon fungal infection. Therefore, NIP1 is a candidate for the product of fungal avirulence gene avrRrs1, which, together with barley resistance gene Rrs1, determines incompatibility of the interaction.