VIGS is an RNA-silencing based technique used for the targeted downregulation of a host gene, allowing the analysis of the gene’s function. VIGS is rapid (1-2 weeks from infection to silencing), does not require the development of stable transformants, and is amenable to high throughput forward and reverse genetic screening. We have developed and used an improved Tobacco rattle virus (TRV)-based VIGS system (PMID:12028572; PMID:12220268; PMID:15356389; PMC1557620; PMC2151726; PMC6508541) to study gene function in plants. The TRV system is the most widely used viral vector in plants and its utility has been demonstrated in over 25 plant species including a large number of plants in Solanaceae, as well as in Brassicaceae, Euphorbiaceae, Malvaceae, Papaveraceae and Rosaceae..
The CRISPR/Cas9 system has been used for efficient targeted genome editing in various organisms including plants. To date, most published reports in plants require the generation of transgenic plants to deliver Cas9 and sgRNA. Transgenic plant production is time consuming and some crop plants are recalcitrant to transformation. Therefore, efficient delivery of Cas9 and sgRNA into plant cells is required for rapid crop trait discovery that circumvents the requirement of transformation. Therefore, one of the active research areas in our group is to engineer viral vectors to deliver Cas9 and sgRNA to induce genome editing. We have recently demonstrated in a collaborative project that our TRV-based system could be used to deliver sgRNA into Cas9 expressing plants to induce heritable genome editing at a low frequency (PMID:25749112). Currently, we are modifying TRV vectors and optimizing methods to improve the efficiency of heritable genome editing and to facilitate the generation of non-transgenic genome modification in plants.
