Sudden Oak Death is killing trees by the millions across California and Oregon. Understanding how the pathogen changes the plants it infects at a molecular level could give us clues as to how the pathogen infects and spreads. We extracted RNA from inoculated and mock-inoculated (control) tanoak leaves and sequenced all of the mRNA. When this is done using infected tissue, RNA from both the tree and the pathogen are sampled- allowing us to compare transcriptomes and to get some clues as to how the host and pathogen are responding to each other. Using a published genome for P. ramorum to sort out tree genes from pathogen genes, we were able to assemble both transcritpomes as the host and pathogens were interacting- a first for both species. We found that the genes that were expressed in the tree were different in infected tissues when compared to the control. This work is part of the Western Transcriptome Survey (http://www.fs.fed.us/pnw/olympia/silv/wfts/index.html).