Project description:We aim to understand the global transcriptional response of hybrid poplar NM6 (Populus nigra x Populus maximoviczii) to infection by two biotrophic Melampsora fungi, M. larici-populina and M. medusae f. sp. deltoidae separately and simultanously. Transcript profilling revealed 699 differentially expressed genes whose expression level was equal or higher than 2-fold between infected and noninfected tissues. In the mixed infection, our results showed an additive response of the two pathogens. Genes regulated as a result of Melampsora infection were generally induced and mainly involved in primary/secondary metabolism that include cell wall reinforcement and lignification, defense-related processes like pathogenesis-related and stress response, signal perception and transduction mechanisms and regulation of transcription. Keywords: Stress response