Abstract: Virus-induced gene silencing（VIGS）is an RNA-mediated antiviral defense mechanism of
plant，and has been developed as a reverse genetics tool for gene function analysis recently. VIGS has
many advantages compared to commonly used biotechnological tools such as gene transformation，gene
knockout and antisense inhibition. It is rapid with low cost，no need for stable plant transformation，and
allows a large-scale screening of genes. Consequently，the approach has been widely used in many plant
species to characterize genes involved in various plant development processes，disease resistance，stress
resistance，and metabolic regulation. This paper reviewed the mechanism and current improvements of
VIGS，factors affecting VIGS response，and VIGS applications on plant functional genomics. Meanwhile，
the promising application prospect on crop improvement and plant protection were also discussed.

Key words: virus-induced gene silencing（VIGS）, functional genomics, viral vector