Abstract: A method is provided for introducing a foreign gene into a plant cell by means of an Olpidium zoospore vector having associated with it a reassembled nucleoprotein complex comprising the foreign gene and reassociated coat protein of a zoospore-transmissable virus. The plant cell is contacted with the zoospore under conditions suitable for transmission of the nucleoprotein complex into the cell. The method can be conducted under nonsterile conditions, is applicable to all nucleic acids regardless of size, and is useful for introducing foreign genes into cells of both monocots and dicots.