Fig. 6. Virus-induced gene silencing (VIGS) of FCA and FY in Nicotiana benthamiana. (A,B) TRV-FCA (tobacco rattle virus-FCA) infection leads to asymptomatic silencing of FCA. Whole shoot (A) and leaf (B) phenotypes of Nicotiana plants infected with TRV-FCA. (C,D) TRV-FY infection leads to silencing of FY and associated yellowing of leaf tissues. Whole shoot (C) and leaf (D) phenotypes of Nicotiana plants infected with TRV-FY. (E) RNA was extracted from Nicotiana infected with either TRV-FCA, TRV-FY and TRV-00 (empty vector) and used to generate cDNA. The cDNA was then analysed by RT-PCR for expression of endogenous FCA, FY and ACTIN mRNA. The number of PCR cycles used is indicated above the gel and the final lane (–RT) is a minus RT control.