SOME PROPERTIES OF PLUM POX VIRUS AND ITS NUCLEIC ACID AND PROTEIN COMPONENTS

Some properties of plum pox virus and its components were studied with a strain from peach trees. This strain, purified by single lesion isolation on Chenopodium foetidum, was propagated in Pisumsativum. The methods previously reported in the litterature failed to produce purified virus suspensions. We were successful in purifying the virus using a very simple method we have recently described.

Antiserum to this strain was prepared and its properties were investigated by different techniques : microprecipitin test, gel double diffusion, electroimmunodiffusion. Immunization and serological tests were carried out using formaldehyde treated antigens.

Nucleic acid was obtained by treating purified virus suspensions with sodium dodecylsulfate in different media. Purified by ultracentrifugation on sucrose gradients or electrophoresis on polyacrylamide gels, plum pox nucleic acid appears to be a single infective molecule with an estimated Mol. wt. of 3.5 x 10⁶.

Coat protein was extracted by heating virus suspension with SDS in the presence of mercaptoethanol and urea. The resulting solution, analysed on polyacrylamide gels, gives three bands as has been observed with some viruses of the Potyvirus group. The estimated Mol. wt. of these three polypeptides are 27,000 ; 29,000 and 43,500.