Characteristics of a resistance-breaking isolate of potato virus Y causing potato tuber necrotic ringspot disease

Abstract

An Austrian isolate of potato virus yNTN, the causal agent of potato tuber necrotic ringspot disease (PTNRD), was serologically compared with seven Dutch PVY N isolates. Using polyclonal and monoclonal antibodies, it was found indistinguishable from PVY r~. Determination of the nucleotide sequence of the coat protein cistron and comparison of the deduced amino acid sequence with coat protein sequences of other potyviruses revealed a high level of homology with PVY s coat protein sequences. This confirmed the close taxonomic relationship of PVY Nrs with the PVY s subgroup of potato virus Y. PVY m~ is able to overcome all resistance genes known so far in commercial potato cultivars. Remarkably, transgenic PVY-protected tobacco plants are also resistant to PVY N~ infection upon mechanical and aphid-mediated inoculation. These experiments indicate that genetically engineered resistance offers great potential in protection of potato to new aggressive strains of PVY N.

Effect of plant genotype, virus isolate and temperature on the expression of the potato tuber necrotic ringspot disease (PTNRD)

“…Moreover, the possibility, that it might adversely strengthen the pathogenicity that will enable the parasite to match completely the extreme resistance genes should not be ignored. Another strategy has been proposed using the coat proteinmediated protection in transgenic plants (Van Den Heuvel et al, 1994). Although transgenic plants offer great potential in protection against virus infection, undesirable effects such as complementation and/or recombination between viral RNA and transgenic plant transcripts have already been observed (Greene & Allison, 1994).…”

“…Potato tuber necrotic ringspot disease (PTNRD) recently reached epidemic levels in many European countries and in Lebanon (Le Romancer et al, 1994;Van Den Heuvel et al, 1994). In most cases, it was associated with considerable economic damage for three reasons.…”

Molecular characterization of potato virus YN isolates by PCR-RFLP

“…Two subgroups of new widely spread PVY N isolates have been described. The first one, now called PVY NTN (following a decision of the European Association for Potato Research Virology Section) (Le Romancer et al, 1994;Van Den Heuvel et al, 1994) is associated with a very harmful disease on potato, now referred to as << potato tuber necrosis ringspot disease >> (PTNRD) (Beczner et al, 1984). The second group may be classified as having a particular virulence on potato, causing very mild mosaic symptoms on leaves, but no necrosis on tubers (Chrzanowska, 1991).…”

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

“…1 . PVY NTN isolates were originally named for their ability to cause potato tuber necrosis in addition to tobacco veinal necrosis (2,6,48,65,93). They apparently arose from both recombination (32) and mutation events (45,59).…”