Synonymous site variation due to recombination explains higher genetic variability in begomovirus populations infecting non-cultivated hosts

• Autor(a) principal: Lima, Alison T. M.
• Data de Publicação: 2013
• Outros Autores: Sobrinho, Roberto R., González-Aguilera, Jorge, Rocha, Carolina S., Silva, Sarah J. C., Xavier, César A. D., Silva, Fábio N., Zerbini, F. Murilo, Duffy, Siobain
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://dx.doi.org/10.1099/vir.0.047241-0; http://www.locus.ufv.br/handle/123456789/13066
• topic: Synonymous site variation; Recombination; Genetic variability; Begomovirus

Begomoviruses are ssDNA plant viruses that cause serious epidemics in economically important crops worldwide. Non-cultivated plants also harbour many begomoviruses, and it is believed that these hosts may act as reservoirs and as mixing vessels where recombination may occur. Begomoviruses are notoriously recombination-prone, and also display nucleotide substitution rates equivalent to those of RNA viruses. In Brazil, several indigenous begomoviruses have been described infecting tomatoes following the introduction of a novel biotype of the whitefly vector in the mid-1990s. More recently, a number of viruses from non-cultivated hosts have also been described. Previous work has suggested that viruses infecting non-cultivated hosts have a higher degree of genetic variability compared with crop-infecting viruses. We intensively sampled cultivated and non-cultivated plants in similarly sized geographical areas known to harbour either the weed-infecting Macroptilium yellow spot virus (MaYSV) or the crop-infecting Tomato severe rugose virus (ToSRV), and compared the molecular evolution and population genetics of these two distantly related begomoviruses. The results reinforce the assertion that infection of non-cultivated plant species leads to higher levels of standing genetic variability, and indicate that recombination, not adaptive selection, explains the higher begomovirus variability in non-cultivated hosts.