Epsilon Archive for Student Projects

Abstract

Phytophthora infestans, an oomycete pathogen, causes late blight in potatoes, leading to significant crop and economic losses worldwide. Traditional control methods involve breeding for resistance and extensive fungicide use. However, fungicides pose environmental risks and may lead to resistant P. infestans strains. Spray-induced gene silencing (SIGS) is a strategy based on RNA interference (RNAi) which can be utilized to control the disease. SIGS is a non-transgenic approach that uses double-stranded RNA (dsRNA) applied as a foliar spray to target and silence critical pathogen genes, aiming to reduce disease symptoms. dsRNAs can move from host to pathogen and vice versa. This study investigates the role of extracellular vesicles (EVs) in the cross-kingdom trafficking of small RNAs (sRNAs) within the potato (Solanum tuberosum) and Nicotiana benthamiana pathosystems infected by Phytophthora infestans during SIGS. Specific objectives include examining sRNA alterations in potato local and systemic leaf following dsRNA and P. infestans application, optimizing an EV extraction protocol in N. benthamiana and identifying the role of EVs and their associated proteins during sRNA movement. We demonstrate that sRNAs are transported in EVs and optimize an EV extraction protocol for N. benthamiana. Additionally, sRNAs and EV-associated proteins were identified. The findings highlight the potential of EVs as vehicles for RNA interference, offering promising strategies for enhancing plant defence mechanisms.
Keywords: Phytophthora infestans, potato, Nicotiana benthamiana, cross-kingdom RNAi, SIGS, small RNA trafficking, EVs