An object of the present invention is to provide a method for transforming a plant by grafting of a rootstock and a scion, and using siRNA for initiating transcriptional gene silencing. The method for transforming a plant by grafting of a rootstock and a scion of the present invention as a means for resolution is characterized in that siRNA for initiating transcriptional gene silencing is produced in a scion, the siRNA produced in the scion is transported to a rootstock by grafting, and the rootstock is transformed by initiating transcriptional gene silencing therein.
