A CAMV 35S PROMOTER DRIVEN CDNA CLONE OF TOBACCO MOSAIC-VIRUS CAN INFECT HOST-PLANT TISSUE DESPITE BEING UNINFECTIOUS WHEN MANUALLY INOCULATED ONTO LEAVES

Leading from the success of inoculating plants with viral RNA transcri bed in vitro from full length cDNA clones, attempts have been made to build cDNA clones which are directly infectious by inoculation. Howeve r, we and others have found that viral cDNA clones driven by the CaMV 35S promoter were able to infect some host plants yet not others, when manually inoculated onto leaves. Alternative methods including microp rojectile bombardment have been used to deliver an infectious TMV cons truct into plant cells resulting in the infection of all TMV host plan ts tested. Lack of infection via manual inoculation may be due to unsu ccessful delivery of a viable construct into the plant cell nucleus.