Identification of possible evolutionary pathways of Plum pox virus and predicting amino acid residues of importance to host adaptation
Plum pox virus (PPV) displays significant genetic diversity that has resulted in the identification of several different strains, some that differ in their biological properties and in their geographic distribution. Some strains are limited in their distribution to a single country, while isolates of PPV strain D are found in every country where the virus has been detected. Many questions remain regarding the evolutionary history of PPV: its genetic (strain) diversification, its origin, its dispersal and the distribution of isolates and/or strains. To explore the evolution of PPV, inferred ancestral sequences were reconstructed at various phylogenetic nodes using PAML. Evidence was obtained that indicates that the strains PPV D and PPV M were likely the earliest strains of PPV to evolve. Specifically considered also was the point at which adaptation occurred that allowed infection of Prunus avium and/or Prunus cerasus, sweet cherry and sour cherry, respectively. Eight amino acid sites were identified that appear to have undergone positive selection during this adaptation process. These amino acid sites cluster into two areas, P1 and VPg. These areas of the genome are known to be important for functions such as the control of viral replication rate. In combination with other data, this information sheds light on functionally significant points along the PPV genome and perhaps even characteristics of ancient PPV populations.
Sanderson, D., Fu, J. and James, D. 2017. Identification of possible evolutionary pathways of Plum pox virus and predicting amino acid residues of importance to host adaptation. Acta Hort. (ISHS) 1163:107-116
Plum pox virus, evolution, ancestral sequences, host adaptation