Application of virus-induced gene silencing in Pogostemon cablin advances our understanding of patchoulol and sesquiterpene metabolism

In plant species, virus-induced gene silencing (VIGS) effectively enables the transient knock down of target genes for functional analysis. To overcome the bottleneck preventing the functional genomics and biological engineering of Pogostemon cablin (Blanco) Benth. an important medicinal and industrial plant with high-value natural products, the VIGS system was established to enable the fast and efficient functional characterisation of candidate genes. In our study, the effectiveness of phytoene desaturase (PDS) gene silencing by VIGS was monitored by the visual indications in P. cablin and the activation effect spanned several months. VIGS of the PatPTS gene, encoding patchoulol synthase, caused a decline in expression abundance, resulting in a significant decreasing accumulation of patchouli alcohol and other sesquiterpenes. Cosilencing of PatPDS and PatPTS in P. cablin also suppressed the biosynthesis of patchouli alcohol. Negative feedback of the MVA and MEP pathway genes was demonstrated in PatPTS-silenced plants.