Evaluation of the anti-viral efficacy of three different dsRNA nanoparticles against potato virus Y using various delivery methods

Nanoparticles (NPs) derived from RNA interference (RNAi) are considered a potentially revolutionary technique in the field of plant protection in the future. However, the application of NPs in RNAi is hindered by the conflict between the high cost of RNA production and the large quantity of materials required for field application. This study aimed to evaluate the antiviral efficacy of commercially available nanomaterials, such as chitosan quaternary ammonium salt (CQAS), amine functionalized silica nano powder (ASNP), and carbon quantum dots (CQD), that carried double-stranded RNA (dsRNA) via various delivery methods, including infiltration, spraying, and root soaking. ASNP-dsRNA NPs are recommended for root soaking, which is considered the most effective method of antiviral compound application. The most effective antiviral compound tested was CQAS-dsRNA NPs delivered by root soaking. Using fluorescence, FITC-CQAS-dsCP-Cy3, and CQD-dsCP-Cy3 NPs demonstrated the uptake and transport pathways of dsRNA NPs in plants when applied to plants in different modes. The duration of protection with NPs applied in various modes was then compared, providing references for evaluating the retention period of various types of NPs. All three types of NPs effectively silenced genes in plants and afforded at least 14 days of protection against viral infection. Particularly, CQD-dsRNA NPs could protect systemic leaves for 21 days following spraying.