The recent recombinant evolution of a major crop pathogen, potato virus Y
Date
2012-11-30
Journal Title
Journal ISSN
Volume Title
Publisher
PLOS
Abstract
Potato virus Y (PVY) is a major agricultural disease that reduces crop yields worldwide. Different strains of PVY are associated
with differing degrees of pathogenicity, of which the most common and economically important are known to be
recombinant. We need to know the evolutionary origins of pathogens to prevent further escalations of diseases, but
putatively reticulate genealogies are challenging to reconstruct with standard phylogenetic approaches. Currently available
phylogenetic hypotheses for PVY are either limited to non-recombinant strains, represent only parts of the genome, and/or
incorrectly assume a strictly bifurcating phylogenetic tree. Despite attempts to date potyviruses in general, no attempt has
been made to date the origins of pathogenic PVY. We test whether diversification of the major strains of PVY and
recombination between them occurred within the time frame of the domestication and modern cultivation of potatoes. In
so doing, we demonstrate a novel extension of a phylogenetic approach for reconstructing reticulate evolutionary
scenarios. We infer a well resolved phylogeny of 44 whole genome sequences of PVY viruses, representative of all known
strains, using recombination detection and phylogenetic inference techniques. Using Bayesian molecular dating we show
that the parental strains of PVY diverged around the time potatoes were first introduced to Europe, that recombination
between them only occurred in the last century, and that the multiple recombination events that led to highly pathogenic
PVYNTN occurred within the last 50 years. Disease causing agents are often transported across the globe by humans, with
disastrous effects for us, our livestock and crops. Our analytical approach is particularly pertinent for the often small
recombinant genomes involved (e.g. HIV/influenza A). In the case of PVY, increased transport of diseased material is likely to
blame for uniting the parents of recombinant pathogenic strains: this process needs to be minimised to prevent further
such occurrences.
Description
The original publication is availbale at www.plos.org
Keywords
Potato virus Y, Pathogenicity, Potatoes -- Diseases and pests, Agricultural pests, Virus diseases of plants
Citation
Visser, J.C., Bellstedt, D.U., Pirie, M.D. 2012. The recent recombinant evolution of a major crop pathogen, potato virus Y. PLoS ONE, 7(11): e50631