The hypothesis and approach. The work is based on the well-established notions that the TBSV P19 suppressor is needed (solid green arrow) to overcome the antiviral silencing pathway that involves DCL, HEN, and AGO components that otherwise prevent virus accumulation (open red arrow). In this study, we targeted the silencing components individually for gene editing by expressing gRNAs (scissors) using TBSV vector systems (+ or ΔP19) to measure the effect on virus accumulation (as related to GFP expression). The purple question marks indicate our hypothesis that accumulation does occur (dashed green arrows) when targeting silencing components, even in the absence of P19.