A simple and inexpensive particle acceleration apparatus was designed
for direct delivery of DNA to plant cells. The Particle Inflow Gun (PI
G) is based on acceleration of DNA-coated tungsten particles directly
in a helium stream. High levels of transient expression of the beta-gl
ucuronidase gene were obtained following bombardment of embryogenic su
spension cultures of maize and soybean, and leaf tissue of cowpea. Sta
ble transformation of soybean and maize has also been obtained using t
his bombardment apparatus.