LOCALIZATION OF THE P1 PROTEIN OF POTATO Y-POTYVIRUS IN ASSOCIATION WITH CYTOPLASMIC INCLUSION-BODIES AND IN THE CYTOPLASM OF INFECTED-CELLS

The N-terminal P1 proteinase of potato virus Y (ordinary strain group isolate PVY-O) was expressed in E, coli. Antiserum was raised against the expressed protein and used to detect the viral proteins in infecte d tobacco leaf tissue by Western blotting and by electron microscopy w ith immunogold labelling. In the immunogold localization studies P1 pr otein was detected in association with the cytoplasmic inclusion bodie s characteristic of PVY infections and in the cytoplasm of the infecte d plant cells. No significant P1 antibody binding with other plant cel l organelles, or with the cell wall and plasmodesmata, was detected by immunogold labelling.