A novel recombinant strain of Potato virus Y suggests a new viral genetic determinant of vein necrosis in tobacco

Potato virus Y: An Evolving Concern for Potato Crops in the United States and Canada

“…The PVY NTN strain has been historically associated with PTNRD, but it is apparent that molecular identification of PVY NTN isolates does not always correlate with the isolate's ability to induce PTNRD (40,101). Similarly, isolates identified by serology or molecular analyses as belonging to strains other than PVY NTN can also induce PTNRD (5).…”

Potato cv. Romano reaction to primary and secondary infection with potato necrotic strain Y virus (PVYNTN)

“…This fact has been confirmed in our research and we found that tubers from infected plants without symptoms were able to transmit infection and produce infected plants. Hu et al (2009) found that only PVY NTN produced PTNR symptoms, while PVY O and PVY N:O did not. Based on the results of our investigation of PVY isolates and their effects on the intensity of symptoms on leaves and tubers of the potato cultivar Romano, the following conclusions can be inferred:…”

Recombinants of PVY Strains Predominate Among Isolates from Potato Crop in Poland

“…Two single-nucleotide polymorphisms A/G 2213 and A/C 2271 that lead to modification of residues K 400 /E 419 (in the necrotic PVY genotype) to residues R 400 /D 419 (in the non-necrotic PVY genotypes) within the HC-Pro protein were initially identified (Tribodet et al 2005). Recently another viral genetic determinant of VN in tobacco has been found; a single nucleotide change (A-1627 to G-1627) resulting in the single amino acid change (D-205 to G-205) in the HC-Pro cistron that correlates with the loss of VN phe-notype of an isolate named L26 (Hu et al 2009b). However, the viral sequences or domains responsible for PTNRD have not yet been determined (Glais et al 2002;Schubert et al 2007;Singh et al 2008).…”

“…The finding that non-recombinant PVY NTN induces PTNRD means that the recombinant structure of the genome is not necessary for the isolate to cause PTNRD (Nie and Singh 2003;Ogawa et al 2008). Moreover, isolate L26's ability to cause PTNRD but not VN in tobacco, provides further evidence that necrosis in potato tubers and tobacco are controlled in the virus by different genetic determinants (Hu et al 2009b). In addition, point mutation in a Syrian PVY isolate (PVY-12) was reported as changing the PVY N serotype into PVY O serotype (Chikh Ali et al 2007) and an American PVY O isolate (PVY O -O5) was recognized by a PVY N -specific monoclonal antibody, 1F5 .…”

“…Point mutation has been shown to be responsible for serotype variation of certain isolates (Chikh Ali et al 2007;Karasev et al 2010). For the recombinant PVY NTN isolate Gr99, two amino acid changes in the viral genetic determinants (K-400 to R-400, E-419 to D-419 in the HC-Pro protein) may be responsible for the loss of VN in tobacco (Hu et al 2009b).…”