Portal de Periódicos da CAPES

Genetic Diversity of the Ordinary Strain of Potato virus Y (PVY) and Origin of Recombinant PVY Strains

2011; American Phytopathological Society; Volume: 101; Issue: 7 Linguagem: Inglês

10.1094/phyto-10-10-0284

1943-7684

Alexander V. Karasev, Xiaojun Hu, Celeste J. Brown, Camille Kerlan, O. V. Nikolaeva, James M. Crosslin, Stewart M. Gray,

Plant Pathogenic Bacteria Studies

The ordinary strain of Potato virus Y (PVY), PVY O , causes mild mosaic in tobacco and induces necrosis and severe stunting in potato cultivars carrying the Ny gene. A novel substrain of PVY O was recently reported, PVY O -O5, which is spreading in the United States and is distinguished from other PVY O isolates serologically (i.e., reacting to the otherwise PVY N -specific monoclonal antibody 1F5). To characterize this new PVY O -O5 subgroup and address possible reasons for its continued spread, we conducted a molecular study of PVY O and PVY O -O5 isolates from a North American collection of PVY through whole-genome sequencing and phylogenetic analysis. In all, 44 PVY O isolates were sequenced, including 31 from the previously defined PVY O -O5 group, and subjected to whole-genome analysis. PVY O -O5 isolates formed a separate lineage within the PVY O genome cluster in the whole-genome phylogenetic tree and represented a novel evolutionary lineage of PVY from potato. On the other hand, the PVY O sequences separated into at least two distinct lineages on the whole-genome phylogenetic tree. To shed light on the origin of the three most common PVY recombinants, a more detailed phylogenetic analysis of a sequence fragment, nucleotides 2,406 to 5,821, that is present in all recombinant and nonrecombinant PVY O genomes was conducted. The analysis revealed that PVY N:O and PVY N-Wi recombinants acquired their PVY O segments from two separate PVY O lineages, whereas the PVY NTN recombinant acquired its PVY O segment from the same lineage as PVY N:O . These data suggest that PVY N:O and PVY N-Wi recombinants originated from two separate recombination events involving two different PVY O parental genomes, whereas the PVY NTN recombinants likely originated from the PVY N:O genome via additional recombination events.