Gene Expression Differences in Wheat Induced by Six Puccinia triticina Races

Puccinia triticina, the casual agent of wheat leaf rust, is a devastating disease that can cause up to 20% yield loss. During fungal infection, the host plant recognizes proteins, secreted effectors, and other molecules which trigger a host defense response. Changes in the pathogen effectors and strong varietal selection pressure, are responsible for the rapid development of new rust races. The question arises whether different leaf rust races utilize different pathways in wheat. Six races of leaf rust were evaluated on a single variety of wheat in a time course study and the RNA was sequenced. Thirty-four wheat genes were identified with expression variation induced by different races and are currently being characterized for specific timing of expression and whether their expression is necessary for the rust to infect, i.e. are they susceptibility genes?.