Harnessing RNA Interference to Constrain Ustilago hordei Growth and Barley Infection

Ustilago hordei, a facultative biotrophic fungal pathogen, poses a significant threat to barley (Hordeum vulgare) crops, causing barley smut and leading to substantial economic losses. Traditional chemical fungicides have a high risk of developing resistance in fungal colonies and is able to pose potential health risks on consumers. This research project aims to explore the application of RNA interference (RNAi) to silence genes implicated in barley colonization, aiming to understand its impact on U. hordei growth. Three pivotal genes (UhAvr1, Fly1, GUS) expressed by U. hordei were chosen to be amplified and transformed into dsRNA that contains small interfering RNA (siRNA) regions through in vitro expression in Escherichia coli. These genes were selected due to the roles they play in promoting U. hordei virulence and enhancing U. hordei’s ability to metabolize complex carbohydrates. The impact of dsRNA on U. hordei growth will be assessed at varying concentrations. The application of target gene dsRNA is expected to limit fungal growth and barley colonization. A positive relationship between translational inhibition and dsRNA concentration is hypothesized. Ultimately, this study provides insights into the application of the three potential dsRNAs in Spray-Induced Gene Silencing (SIGS) as a replacement for chemical fungicides with wide agricultural applications.