Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2011
Publication Date: June 1, 2011
Citation: Campbell, J.B., Giroux, M.J., Jin, Y., Chen, X., Huang, L. 2011. Novel rust resistance in wheat (Triticum aestivum L.). American Phytopathological Society Annual Meeting. 101:S25. Technical Abstract: The Puccinia fungi that cause wheat rust diseases are among the most globally destructive agricultural pathogens. The most effective and utilized defense against rust is genetic resistance. The vast majority of rust resistance is racespecific conferred by single genes rapidly overcome by the pathogens. From EMS mutagenesis using a soft white spring wheat cultivar ‘Alpowa’, we have identified a mutant, MNs220Alp, expressing broad spectrum, slow-rusting, all plant stage resistance. The mutation is likely to be associated with the change of negative regulation of resistance that is known to suppress either active or passive defense responses. In wheat, negative regulators have been observed to inhibit rust resistance genes. MNs220Alp has enhanced resistance to leaf, stem (including Ug99 and its derivative races), and stripe rusts, as well as powdery mildew. Genetic analysis in several backgrounds demonstrated that the resistance found in MNs220Alp is conferred by a single dominant gene. Gene expression profiling of several pathogenesis-related (PR) genes indicates that MNs220Alp has a rapid and elevated pathogen induced response. The mutant has an indistinguishable phenotype from the wild type in the absence of pathogens allowing for the immediate deployment into breeding programs. Beyond the immediate benefit, continued analysis of the locus will lead to a better understanding of the regulation of defense response network in wheat.