P-335 - The ESCRT-III Pathway is involved in dsRNA-derived siRNA Transfer in Host-Induced Gene Silencing

Monday, July 14, 2025

13:30 - 15:15

Location: Confex Hall 3

RNA on the move: Advances in Cross-Species communiation &Translational Research

Presenting Author(s)

LP

Lara R. Palatinus

PhD student
University of Regensburg
Regensburg, Bayern, Germany

Author(s)

TS

Timo Schlemmer

University of Regensburg
Regensburg, Bayern, Germany
PB

Patrick Barth

University of Regensburg
Regensburg, Bayern, Germany
BW

Berhard Timo Werner

University of Giessen
Giessen, Hessen, Germany
AK

Aline Koch

Institute of Plant Sciences, Plant Cell Biology, Biochemistry and Biotechnology, University of Regensburg
Regensburg, Bayern, Germany

Host-induced gene silencing (HIGS) has emerged as a promising strategy for controlling plant diseases through the expression of double-stranded RNAs (dsRNAs) targeting pathogen genes. However, the mechanisms underlying RNA transfer at the plant-pathogen interface remain largely unexplored. In this study, we investigated the role of the endosomal sorting complex required for transport (ESCRT-III) in the transfer of dsRNA-derived small interfering RNAs (siRNAs) from Arabidopsis thaliana to the fungal pathogen Fusarium graminearum. We used Arabidopsis plants expressing CYP3RNA, a dsRNA construct specifically designed to target the CYP51 genes of F. graminearum. RNA sequencing analysis of extracellular vesicles (EVs) purified from these plants confirmed the presence of CYP3RNA-derived siRNAs. Furthermore, ESCRT-III mutant plants exhibited a loss of HIGS-mediated disease resistance and EVs isolated from these mutants contained significantly reduced levels of CYP3RNA-derived siRNAs. These findings suggest that endosomal vesicle trafficking is essential for the transfer of transgene-derived siRNAs between donor host cells and recipient fungal cells, possibly in an EV-independent manner.