title: Tomato yellow spot virus, a tomato-infecting begomovirus from Brazil with a closer relationship to viruses from Sida sp., forms pseudorecombinants with begomoviruses from tomato but not from Sida.
abstract: Geminiviruses are characterized by a circular, single-stranded DNA genome and twinned icosahedral particles. Begomoviruses (whitefly-transmitted geminiviruses) are a major constraint to crop production worldwide. In Brazil, tomato-infecting begomoviruses emerged as serious pathogens over the last 10 years, due to the introduction of a new biotype of the insect vector. Tomato yellow spot virus (ToYSV) is a newly described begomovirus originally isolated from tomato, but phylogenetically closer to viruses from Sida sp. A study was performed to determine the viability of pseudorecombinants formed between the DNA components of ToYSV and other weed- and tomato-infecting begomoviruses from Brazil. Despite its closer relationship to weed-infecting viruses, ToYSV was only capable of forming viable pseudorecombinants with tomato viruses. An infectious pseudorecombinant formed between ToYSV DNA-A and tomato crinkle leaf yellows virus (TCrLYV) DNA-B induced severe symptoms in Nicotiana benthamiana. This was attributed, at least in part, to the fact that the origins of replication of both components had identical Rep-binding sequences. However, this was not the case for another infectious pseudorecombinant formed between tomato golden mosaic virus (TGMV) DNA-A and ToYSV DNA-B, which have different Rep-binding sequences. These results reinforce the notion that pseudorecombinant formation cannot be explained solely on the basis of phylogenetic relationships and conserved iteron sequences, and suggest that the TGMV Rep protein may be more versatile in terms of recognizing heterologous DNA components than that of ToYSV.
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Andrade
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: Manhani
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: P F
authors.initials: PF
authors.lastname: Alfenas
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: R F
authors.initials: RF
authors.lastname: Calegario
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: E P B
authors.initials: EPB
authors.lastname: Fontes
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.
authors.forename: F M
authors.initials: FM
authors.lastname: Zerbini
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D053839:Begomovirus / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D001938:Brazil; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D018551:Solanum lycopersicum / Q000821:virology*; D019660:Malvaceae / Q000821:virology*; D050296:Microbial Viability; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D018741:Replication Origin / Q000235:genetics; D017385:Sequence Homology; D014026:Nicotiana / Q000821:virology
chemical_list: D004279:DNA, Viral