Taphrina populi-salicis Mix (Fungi, Ascomycota, Taphrinomycetes, Taphrinaceae) is a foliar parasite that causes yellow leaf blisters on black cottonwood (Populus trichocarpa) in the US Pacific Northwest and western Canada. The pathogen induces leaf deformities, caused by abnormal cell division (hyperplasia) and enlargement (hypertrophy), via secretion of growth-regulating chemicals, including hormones. Attacks by pathogens represent one of the most important threats to the sustainable growth of bioenergy trees in plantations. Outbreak prevention depends largely on a better understanding of how pathogens infect trees so that resistance can be developed and on early detection, monitoring and surveillance to prevent spread. Since pathogens of poplars and pines tend to track their hosts worldwide, we must do a better job at detection and surveillance. This can be challenging since pathogens can remain dormant or have endophytic stages in the host tissues. The genome sequencing of Taphrina populi-salicis is part of a larger effort, the Pathobiome database for bioenergy trees project, that aims at sequencing the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. By sequencing and comparing the genomes of the most important pathogens of poplars and pines, we plan to create a database that will be used to develop tools for the detection, monitoring, surveillance and rapid response of pathogens in these economically and ecologically important trees.