Viral pathogens seriously decrease the yield of potato (
Solanum tuberosum
L.) –an important agricultural crop. Therefore, there is a demand for potato cultivars resistant to multiple viruses. Ribonucleases (RNases) are supposed to be engaged to antiviral response in plants. Heterologous RNase gene expression provides a tool for production of cultivars with multiple resistance to viruses and viroids. Transgenic potato cultivars Luhivs’ka and Lasynak with heterologous genes
bov
and
ZRNase II
of apoplastic RNases from
Bos taurus
and
Zinnia
elegans
respectively were obtained via
Agrobacterium
-mediated transformation. The presence of
bov
and
ZRNase II
transgenes was confirmed by PCR analysis. RNase activity was examined by modified Oleshko method. Plants with heterologous ribonuclease genes had higher level of RNase activity compared to nontransgenic ones. Transgenic plants inoculated with
Potato virus Y
, PVY (genus
Potyvirus
, family Potyviridae) demonstrated delayed and less severe symptoms of viral infection. DAS-ELISA confirmed the presence of viral antigens both in transformed and control plants. Visual manifestations of viral infection in transgenic potatoes were milder than in control plants and their development was delayed, but complete elimination of the virus did not occur.