Conferring resistance to geminiviruses with the CRISPR–Cas prokaryotic immune system

To reduce crop losses due to geminivirus infection, we targeted the bean yellow dwarf virus (BeYDV) genome for destruction with the CRISPR–Cas (clustered, regularly interspaced short palindromic repeats–CRISPR-associated proteins) system. Transient assays using BeYDV-based replicons revealed that CRISPR–Cas reagents introduced mutations within the viral genome and reduced virus copy number. Transgenic plants expressing CRISPR–Cas reagents and challenged with BeYDV had reduced virus load and symptoms, thereby demonstrating a novel strategy for engineering resistance to geminiviruses. Transient assays and transgenic experiments demonstrate that sgRNA/Cas9 constructs targeting the bean yellow dwarf virus inhibit the accumulation of the virus and confer resistance in transgenic N. benthamiana plants.