Plant expression vector pBI 121 containing the gene encoding coat protein of Plum Pox Virus of the Skierniewice isolate (CP PPV-S) was prepared (clone pCMl). The construct was used for transformation of Nicotiana tabacum plants using an Agrobacterium tumefaciens based system. About 82% of kanamycin resistant plant lines contained a transgene (the sequence of CP PPV-S) but only 81% of them actively expressed the PPV-S coat protein gene as measured by RT-PCR.