Wheat Gene Expression Differences 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. Six races of leaf rust were evaluated on a single variety of wheat in a time course study to determine if different rust races utilize different pathways in wheat. RNA was sequenced and sixty-three wheat genes were identified that showed varying expression in response to different races. Of the sixty-three, fifty wheat genes have been characterized for timing of expression and whether expression is necessary for rust infection. Race specific expression was found. RNAi is now being used to silence select wheat genes to further understand their role in leaf rust infection.