Evaluating the Effects of Propiconazole on Hard Fescue (Festuca brevipila) via RNA sequencing and Liquid Chromatography–Mass Spectrometry

Propiconazole is often used to remove fungal endophytes from turfgrass to study the effects of Epichloë endophytes. However, besides a fungicidal effect, propiconazole can bind to the genes in the cytochrome P450 family and affect the biosynthesis of brassinosteroids. For this reason, outside of fungicidal application, propiconazole has also been used as plant growth regulator. In this study, we used a combination of RNA sequencing and liquid chromatography–mass spectrometry (LC-MS) to study how hard fescue ( Festuca brevipila ) responded to the high dose of propiconazole treatment. To test the long-term effect of the heavy use of propiconazole on plants, we inoculated with Microdochium nivale (causal agent of pink snow mold) half year post the last fungicide application. Propiconazole-treated plants showed enhanced pink snow mold resistance. This study suggested that the high dose use of propiconazole fungicide resulted in phenotypic and physiological changes in the plant such as slow growth and change in disease resistance. Genes and pathways affected by propiconazole identified in this study provide turfgrass breeders new information for genetic improvement of hard fescue and also provide turfgrass management new ways to control turfgrass diseases. ### Competing Interest Statement The authors have declared no competing interest.