SIMPLE HAND-HELD DEVICES FOR THE EFFICIENT INFECTION OF PLANTS WITH VIRAL-ENCODING CONSTRUCTS BY PARTICLE BOMBARDMENT

An efficient method for infection of plants with a cloned potyvirus by particle bombardment has been described (Gal-On et al., 1995). A simp lified method is described now whereby a vacuum chamber and helium pro pulsive gas are not required to achieve a high efficiency of infection . The new device-the 'HandGun'-is hand-held, and easily constructed fr om readily available materials. With this technique it is possible to bombard soft plants and seedlings that do not survive particle bombard ment by other devices. Bombardment of C. pepo plants with a full lengt h clone of zucchini yellow mosaic potyvirus results in approximately 1 00% infection at 100 pg cDNA per plant using air or helium to propel t he microprojectiles. The HandGun is 10(5)-fold more efficient than mec hanical inoculation. Tungsten and gold were found to be the most effic ient materials tested for use as microprojectiles. Crude extracts of p lasmids from E. coli were found to be effective, as well as column-pur ified cDNA. A functional, simple version of the HandGun-'the Blowpipe' -was also constructed, which does not require an electrically controll ed valve. Plants can be inoculated with plant viruses from sap with th e HandGun. Copyright (C) 1997 Elsevier Science B.V.