Análise comparativa dos padrões de recombinação de cinco espécies do gênero Potyvirus

Abstract

Plant viruses utilize a range of evolutionary mechanisms to generate genetic variability. Among these mechanisms, recombination can be extremely important, since it accelerates the viral evolution through the emergence of new genomic combinations. The aim of this work was to estimate the recombination frequency in genomes of potyviruses obtained from plants collected in several countries and to identify recombination hot- and coldspots throughout the viral genomes. Nucleotide sequences corresponding to full-length genomes of five distinct species were analyzed: Bean common mosaic virus, Lettuce mosaic virus, Plum pox virus, Sugarcane mosaic virus and Watermelon mosaic virus. Viral genomes were obtained from GenBank by using Taxonomy Browser. The data sets were aligned using the Muscle module contained in the Molecular Evolutionary Genetics Analysis (MEGA) program and recombination events were detected using the Recombination Detection Program version 4 (RDP4). All species datasets showed a high number of recombination events suggesting that this mechanism contributes significantly to the levels of genetic variability observed within and among potyvirus populations. The frequent occurrence of recombination may result in a wider viral host range or even in overcoming plant defenses. In this context, the present study provides relevant information to guide the genetic breeding of potyvirus host plants.