Caracterização de um begomovírus obtido de maracujazeiro (Passiflora edulis f. flavicarpa) e produção de clones infecciosos

• Ano de defesa: 2008
• Autor(a) principal: Ferreira, Sávio de Siqueira
• Orientador(a): Lamêgo, Márcia Rogéria de Almeida
• Banca de defesa: Carvalho, Claudine Márcia , Paula, Sérgio Oliveira de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Bioquímica Agrícola
• Departamento: Bioquímica e Biologia molecular de plantas; Bioquímica e Biologia molecular animal
• País: BR
• Palavras-chave em Português: Begomovírus; Maracujá; Clones
• Palavras-chave em Inglês: Begomovirus; Yellow passionfruit; Clones
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::BIOLOGIA MOLECULAR
• Link de acesso: http://locus.ufv.br/handle/123456789/2397

Begomoviruses (family Geminiviridae) possess a circular, single-stranded DNA genome encapsidate in twinned icosahedral particles. They are vectored by the whitefly Bemisia tabaci and cause economically important diseases in several crops, mainly in tropical and subtropical regions. In Brazil, begomoviruses are major pathogens in common bean and tomato crops, and recent reports have confirmed their presence in yellow passionfruit. In spite of the low incidence, their importance in this crop should not be underestimated, due to the severity of the disease and the plant s inability to recover from the infection. The objective of this work was to carry out the molecular and biological characterization of the begomovirus isolate BR:LNS2:Pas:01, obtained from yellow passionfruit plants in Livramento de Nossa Senhora, Bahia state. The viral genome (DNA-A and DNA-B) was cloned and sequenced. Sequence analysis demonstrated that the BR:LNS2:Pas:01 DNA-A has five ORFs corresponding to the genes cp, rep, trap, ren and ac4, and two additional ORFs with high sequence identity with the AC5 ORF. The DNA-B has two ORFs corresponding to the genes mp and nsp. The DNA-A of isolate BR:LNS2:Pas:01 has the highest nucleotide sequence identity with Tomato chlorotic mottle virus (ToCMoV) (77%), and the DNA-B with Tomato yellow spot virus (ToYSV) (74%). These identity values indicate that this isolate represents a new begomovirus species, for which the name Passion flower severe leaf distortion virus (PSLDV) is proposed. Phylogenetic analysis clustered the PSLDV DNA-A in a monophyletic branch with TGMV, and the DNA-B in a monophyletic branch with ToYSV. Biological characterization consisted in the determination of the isolate s host range, via biolistic inoculation of infectious clones in plants of several species/cultivars. The host range was restricted to species from the Passifloraceae and Solanaceae families. However, in spite of the high sequence identity between PSLDV-[BR:LNS2:Pas: 01] and tomato begomoviruses, the virus was not capable of infecting tomato.