Nanotubes Effectively Deliver siRNA to Intact Plant Cells and Protect siRNA Against Nuclease Degradation

Abstract

Post-transcriptional gene silencing (PTGS) is a powerful tool to understand and control plant metabolic pathways, which is central to plant biotechnology. PTGS is accomplished through delivery of small interfering RNA (siRNA) into cells, which has been optimized for mammalian systems but remains a significant challenge for plants due to the plant cell wall. Standard plant siRNA delivery methods (Agrobacterium and viruses) involve coding siRNA into DNA vectors, and are only tractable for certain plant species. Herein, we develop a nanotube-based platform for direct delivery of siRNA, and show high silencing efficiency in intact plant leaves. We demonstrate that nanotubes successfully deliver siRNA and silence endogenous genes owing to effective intracellular delivery and nanotube-induced protection of siRNA from nuclease degradation. This study establishes that nanotubes, which are below the size exclusion limit of the plant cell wall, could enable a myriad of plant biotechnology applications that rely on RNA delivery.