Epsilon Archive for Student Projects

Abstract

RNA interference (RNAi) strategies, especially spray-induced gene silencing (SIGS), provide sustainable alternatives to traditional fungicides for managing plant diseases. However, the mechanisms behind the transport of SIGS-derived small interfering RNAs (siRNAs) from plants to pathogens remain poorly understood although previous studies have demonstrated the role of Extracellular Vesicles (EVs) (a membrane-bound sub-cellular organelle) in transporting small RNAs across species boundaries during infection. The current thesis focuses on the role of EVs and their cargo during SIGS in Nicotiana benthamina-Phytophthora infestans pathosystem.
The EVs, enriched with host RNA-binding proteins (RBPs) A and B and SIGS-derived siRNAs (SDSRs), form complexes that are taken up by P. infestans mycelia. We found that RBPs A and B are transported into the pathogen’s mycelia, delivering SDSRs during SIGS. Overexpression of these RBPs increased resistance against P. infestans, whereas VIGS-mediated knockdown of same intensified the disease severity by reducing the silencing of target genes T and P in N. benthamiana plants treated with double-stranded RNAs. These findings suggest that RBPs A and B are the carriers of SDSRs and promote cross-kingdom RNA interference.
In summary, this study demonstrates the role of EV-associated RBPs in cross-kingdom RNAi and further advances the development of efficient RNAi-based disease management technologies in agriculture.