DETECTION OF THE 3A-PROTEIN OF CUCUMBER MOSAIC-VIRUS IN A CELL-WALL FRACTION FROM INFECTED NICOTIANA-CLEVELANDII PLANTS

The 3a protein of cucumber mosaic virus was-expressed in Escherichia coli and, after purification, used to produce an antiserum. The 3a protein was detected in a cell wall fraction obtained from infected Nicotiana clevelandii leaf tissue by immunoblotting using the 3a antiserum. The 3a protein reached a maximum level 4 days after inoculation and remained at this level for a further 8 days before slowly declining. In contrast, the virus capsid protein, detected in an 80 000 g pellet by immunoblotting using a virus particle antiserum, reached a maximum 5 days after inoculation and remained at this level for at least a further 16 days.