Fast forward genetics based on virus-induced gene silencing

Gene expression in plants can be suppressed in a sequence-specific manner b y infection with virus vectors carrying fragments of host genes, Recent dev elopments have revealed that the mechanism of this gene silencing is based on an RNA-mediated defence against viruses. It has also emerged that a rela ted mechanism is involved in the post-transcriptional silencing that accoun ts for between line variation in transgene expression and cosuppresion of t ransgenes and endogenous genes, The technology of virus-induced gene silenc ing is being refined and adapted as a high throughput procedure for functio nal genomics in plants.