Activation of induced systemic resistance (ISR) is associated with gene priming, in which plant defense genes are expressed more rapidly and strongly after pathogen attack (Conrath et al., 2006). In monocotyledonous plants, transcripts related to signaling pathways for ethylene and/or jasmonic acid have been induced or primed after treatment with beneficial fungi, bacteria, and insects associated with ISR. Recently, a new organic compound, PC1, developed by Petro- Canada, was found to affect turfgrass diseases in the field (Hsiang et al. 2009). PC1 is a mixture of food-grade synthetic isoparaffins and food-grade emulsifiers. It is a clear, colorless liquid at room temperature. Preliminary studies showed that PC1 does not have a direct effect on fungal pathogens, suggesting that PC1 might be involved in induced resistance. The purpose of this work was to evaluate the interaction between Agrostis stolonifera (creeping bentgrass) treated with PC1, and the fungal pathogens Microdochium nivale (causal agent of pink snow mold), Rhizoctonia solani (causal agent of brown patch) or Sclerotinia homoeocarpa (causal agent of dollar spot). The effect of PC1 on disease inhibition was assessed, and expression of ISR-related marker genes in A. stolonifera was assessed after treatment with PC1 and subsequent inoculation by M. nivale.