Graphene Oxide Nanosheets for Delivery of RNAi and Plant Immune Stimulation for Sustained Protection against Plant Viruses.

Given the dearth of effective antiviral drugs, the exogenous delivery of dsRNA for RNAi against plant viral diseases holds great promise. Here, we present an effective delivery approach of dsRNA utilizing graphene oxide nanosheets (GONs) on mature plant leaves via a spray. Our method achieves rapid and sustained gene knockdown, reducing the level of the target gene to 46% by day 2, and continuously releases dsRNA for at least 6 days. The coupling of GONs with specific fragments of coat protein and replicase gene dsRNA exhibited a superior antiviral effect compared to specific fragments of RNA-dependent replicase and movement protein. The coupling of GONs with the specific fragment of the replicase gene even has 87.2% protection against TMV. Moreover, the nanocomplex GONs@dsRNA can also stimulate plant immunity through bursts of reactive oxygen species without harming growth. Overall, our findings present a robust and convenient tool for plant virus control.