Tobacco veinal necrosis determinants are unlikely to be located within the 5' and 3' terminal sequences of the potato virus Y genome.
Three potato virus Y isolates, representatives of distinct PVY groups, identified in potato fields in northern Poland were submitted to biological and molecular analysis. Phenotypically, two isolates, PVYN-Ny and PVYN-Wi, belong to the necrotic strain and the third one (PVYO-LW) to the common strain. PVYN-Wi, however, did not react with monoclonal antibodies directed against the necrotic strain isolates which recognise PVYN-Ny. To characterise the isolates, coat protein genes were sequenced and compared with sequences from databases. The necrotic PVYN-Wi isolate showed 99% amino acid homology with the common one-PVYO-LW and significantly differed from the second necrotic isolate (PVYN-Ny). Sequence based homology matrix and phylogenetic analysis lead to classification of PVYN-Ny into group I, encompassing solely necrotic strain isolates, whereas PVYN-Wi falls into a phenotypically heterogeneous group II. The sequence analysis allowed for identification of putative group I-specific epitopes. 3'NTR (non-translated region) sequences were identical for PVYN-Wi and PVYO-LW. The 5'NTR, P1 gene, coat protein gene and 3'NTR sequences of the common (PVYO-LW) and the necrotic (PVYN-Wi) isolates are 99-100% homologous. This suggests that tobacco veinal necrosis determinants are located outside the 3' and 5' terminal sequences of the PVY genome.
Chachulska
A M
AM
Institute of Biochemistry and Biophysics, PAS. Warsaw, Poland.
Chrzanowska
M
M
Robaglia
C
C
Zagórski
W
W
D000595:Amino Acid Sequence; D001483:Base Sequence; D002213:Capsid / Q000737:chemistry / Q000235:genetics; D016679:Genome, Viral; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics*; D010947:Plants, Toxic; D017800:Potyvirus / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana / Q000821:virology*