Propriedades moleculares de um isolado brasileiro do Southern bean mosaic virus
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Data
2002-06-01
Autores
MOREIRA, ANDREIA E. [UNESP]
GASPAR, JOSÉ O. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Fitopatologia
Resumo
Um isolado do Southern bean mosaic virus (SBMV), gênero Sobemovirus, encontrado em feijoeiro (Phaseolus vulgaris) no Estado de São Paulo, foi purificado e algumas de suas propriedades moleculares determinadas. As partículas virais apresentam diâmetro de 28-30 nm e proteína capsidial com massa molecular estimada em 30 kDa. Das partículas virais foi extraído RNA de vários tamanhos (4,2 Kb, 3,1 Kb, 2,65 Kb, 2,15 Kb, 1,64 Kb, 1,36 Kb e 1,0 Kb) sendo aquele de 4,2 Kb o RNA genômico e o de 1,0 Kb supostamente um subgenômico que codifica para a proteína capsidial. Ácidos ribonucleicos de mesmo tamanho foram também detectados in vivo, indicando estar associados à replicação viral. Na análise do RNA de fita dupla (dsRNA), somente duas espécies foram detectadas (4,2 Kpb e 1,0 Kpb) correspondendo às formas replicativas do RNA genômico e do subgenômico para proteína capsidial. Os resultados indicam que somente estes dois RNA são replicados por meio de formas replicativas (RFs), enquanto os demais devem ser formados talvez por iniciação interna da fita negativa do RNA genômico. O SBMV-B SP apresentou propriedades moleculares análogas àquelas do SBMV descrito na América do Norte.
An isolateof the Southern bean mosaic virus (SBMV), genus Sobemovirus, found in the State of São Paulo, Brazil, was purified and some of its molecular properties determined. The virus particles are 28-30 nm in diameter and the coat protein has a molecular mass of 30 kDa. A heterogeneous population of RNAs (4.2 Kb, 3.1 Kb, 2.65 Kb, 2.15 Kb, 1.64 Kb, 1.36 Kb and 1.0 Kb) was extracted from virus particles, where those of 4.2 Kb and 1.0 Kb are, respectively, the genomic and the putative subgenomic RNA for coat protein. RNAs of the same size were also extracted from infected common bean (Phaseolus vulgaris) leaves, indicating that they must have some function in the virus replication cycle. Only two species of double-stranded RNAs (dsRNA) were extracted from infected tissues (4.2 Kbp and 1.0 Kbp), corresponding to the replicative forms of the genomic RNA and the subgenomic RNA for coat protein. These results indicate that only these two RNAs replicate by means of replicative forms (RF) while the others are probably synthesized by an internal initiation of the negative strand of the genomic RNA. The SBMV-B SP showed molecular properties analogous to the SBMV described in North America.
An isolateof the Southern bean mosaic virus (SBMV), genus Sobemovirus, found in the State of São Paulo, Brazil, was purified and some of its molecular properties determined. The virus particles are 28-30 nm in diameter and the coat protein has a molecular mass of 30 kDa. A heterogeneous population of RNAs (4.2 Kb, 3.1 Kb, 2.65 Kb, 2.15 Kb, 1.64 Kb, 1.36 Kb and 1.0 Kb) was extracted from virus particles, where those of 4.2 Kb and 1.0 Kb are, respectively, the genomic and the putative subgenomic RNA for coat protein. RNAs of the same size were also extracted from infected common bean (Phaseolus vulgaris) leaves, indicating that they must have some function in the virus replication cycle. Only two species of double-stranded RNAs (dsRNA) were extracted from infected tissues (4.2 Kbp and 1.0 Kbp), corresponding to the replicative forms of the genomic RNA and the subgenomic RNA for coat protein. These results indicate that only these two RNAs replicate by means of replicative forms (RF) while the others are probably synthesized by an internal initiation of the negative strand of the genomic RNA. The SBMV-B SP showed molecular properties analogous to the SBMV described in North America.
Descrição
Palavras-chave
replicação viral, dsRNA, Sobemovirus, Proteína capsidial
Como citar
Fitopatologia Brasileira. Sociedade Brasileira de Fitopatologia, v. 27, n. 3, p. 292-297, 2002.