Aberrant mRNA Expression of Maize Rust Resistance Gene in Wheat and Barley

Plant resistance (R) genes involved in gene-for-gene interactions with pathogens tend to undergo co-evolutionary arms races in which plant specificity and pathogen virulence continually adapt in response to each other. Studies in this regard have documented that genes resistant for different plant pathogens—fungi, bacteria, viruses and nematodes—are highly conserved in some motifs among a variety of plant species. Based on these studies, disease resistance genes have been isolated from several plant species. Although originally believed to provide durable resistance, only a few exceptional R genes proved able to control pathogens for an extended period. By exploiting new developments in plant transformation technology, isolated R genes can be transferred from donor species to sexually incompatible recipients. In some instances functional R gene transfer was successful, although in some cases it was limited to members of the same family. In these studies recipient transgenic plants were challenged with the same pathogen or avirulence product that the R gene donor species recognized. These data therefore show that signal transduction molecules that activate a resistance response are conserved among non-sexually compatible plant species. However they do not provide insight into the ability of heterologous R genes to recognize pathogen species that they have not previously encountered. Researchers from CSIRO Plant Industry (Australia), Kansas State University (USA), and the University of Sydney (Australia) studied the function and expression of a maize R gene, Rp1-D, to investigate its potential against related pathogens i