Host Range Evolution of Potyviruses: A Global Phylogenetic Analysis

Area of Science:

• Virology
• Evolutionary Biology
• Plant Pathology

Background:

• Virus host range influences disease emergence and control.
• Factors driving host range evolution in plant viruses remain largely unknown.
• The genus Potyvirus offers a model for studying host range evolution due to its diversity and recent radiation.

Purpose of the Study:

• To investigate the evolutionary history of host range in the genus Potyvirus.
• To identify patterns and potential drivers of host range expansion and contraction.
• To understand the genetic and ecological factors shaping plant virus host specificity.

Main Methods:

• Phylogenetic analysis of 59 Potyvirus genomes and host range data.
• Maximum likelihood inference to reconstruct host range changes.
• Analysis of host gain and loss events across the Potyvirus phylogeny.

Main Results:

• Potyviruses exhibit frequent host range alterations, averaging 4.6 changes per plant species.
• Host gains (3.1) are more common than host losses (1.5).
• Most host range changes (74%) are recent, occurring on terminal branches, and show correlated gains across different lineages.

Conclusions:

• Potyvirus host range evolution is dynamic and recent, coinciding with agricultural intensification.
• Correlated host gains suggest recurring molecular or ecological mechanisms facilitate adaptation to new plant species.
• Further research is needed to elucidate the specific mechanisms underlying Potyvirus host adaptation.