Virus-induced gene silencing (VIGS) uses recombinant viruses to knock down the expression of endogenous plant genes, allowing for rapid functional analysis without generating stable transgenic plants. The Tobacco rattle virus (TRV) is a popular vector for VIGS because it has a wide host range that includes Petunia × hybrida (petunia), and it induces minimal viral symptoms. Using reporter genes like chalcone synthase (CHS) in tandem with a gene of interest (GOI; pTRV2-PhCHS-GOI), it is possible to visually identify silenced flowers so that phenotyping is more accurate. Inoculation methods and environmental conditions need to be optimized for each host plant-virus interaction to maximize silencing efficiency. This chapter will provide detailed protocols for VIGS in petunia, with an emphasis on the investigation of flower phenotypes.
Broderick, S. R., Chapin, L. J., & Jones, M. L. (2020). Virus-induced gene silencing for functional analysis of flower traits in petunia. In Methods in Molecular Biology (Vol. 2172, pp. 199–222). Humana Press Inc. https://doi.org/10.1007/978-1-0716-0751-0_15