Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Plant Pathol ; 21(11): 1421-1435, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32936537

RESUMO

Broad bean wilt virus 1 (BBWV-1, genus Fabavirus, family Secoviridae) is a bipartite, single-stranded positive-sense RNA virus infecting many horticultural and ornamental crops worldwide. RNA1 encodes proteins involved in viral replication whereas RNA2 encodes two coat proteins (the large and small coat proteins) and two putative movement proteins (MPs) of different sizes with overlapping C-terminal regions. In this work, we determined the role played by the small putative BBWV-1 MP (VP37) on virus pathogenicity, host specificity, and suppression of post-transcriptional gene silencing (PTGS). We engineered a BBWV-1 35S-driven full-length cDNA infectious clone corresponding to BBWV-1 RNA1 and RNA2 (pBBWV1-Wt) and generated a mutant knocking out VP37 (pBBWV1-G492C). Agroinfiltration assays showed that pBBWV1-Wt, as the original BBWV-1 isolate, infected broad bean, tomato, pepper, and Nicotiana benthamiana, whereas pBBWV1-G492C did not infect pepper and tomato systemically. Also, pBBWV1-G492C induced milder symptoms in broad bean and N. benthamiana than pBBWV1-Wt. Differential retrotranscription and amplification of the (+) and (-) strands showed that pBBWV1-G492C replicated in the agroinfiltrated leaves of pepper but not in tomato. All this suggests that VP37 is a determinant of pathogenicity and host specificity. Transient expression of VP37 through a potato virus X (PVX) vector enhanced PVX symptoms and induced systemic necrosis associated with programmed cell death in N. benthamiana plants. Finally, VP37 was identified as a viral suppressor of RNA silencing by transient expression in N. benthamiana 16c plants and movement complementation of a viral construct based on turnip crinkle virus (pTCV-GFP).


Assuntos
Fabavirus/patogenicidade , Especificidade de Hospedeiro/genética , Doenças das Plantas/virologia , Interferência de RNA , Vicia faba/virologia , Proteínas Virais/metabolismo , Capsicum/virologia , Fabavirus/genética , Expressão Gênica , Solanum lycopersicum/virologia , RNA Viral/genética , Nicotiana/virologia , Proteínas Virais/genética , Virulência
2.
Virus Res ; 242: 141-145, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28970056

RESUMO

Broad bean wilt virus 2 (BBWV2, genus Fabavirus, family Secoviridae) has a wide host range and infects many economically important crops. Various isolates of BBWV2 have been identified from diverse host plants, and their molecular and biological characteristics have been investigated. In our previous study, we demonstrated that BBWV2 RNA2 contains a symptom determinant(s) capable of enhancing symptom severity by utilizing infectious full-length cDNA clones of two distinct strains of BBWV2, pBBWV2-PAP1 (a severe strain) and pBBWV2-RP1 (a mild strain). In the present study, to identify the symptom determinant(s) of BBWV2, we exploited disease responses of pBBWV2-PAP1- and pBBWV2-RP1-derived chimeric viruses and amino acid substitution mutant viruses in Nicotiana benthamiana and pepper (Capsicum annuum Quarri) and demonstrated that the movement protein (MP) encoded in BBWV RNA2 is the determinant of disease symptom severity in both plants. A single amino acid substitution in the MP was sufficient for changing symptom severity of BBWV2. Our finding provides a role for the MP as a symptom determinant in BBWV2 and increases the understanding of the basis of molecular interactions between host plants and BBWV2.


Assuntos
Capsicum/virologia , Fabavirus/patogenicidade , Interações Hospedeiro-Patógeno , Doenças das Plantas/virologia , Proteínas do Movimento Viral em Plantas/metabolismo , Fatores de Virulência/metabolismo , Mutação , Recombinação Genética , Genética Reversa , Nicotiana/virologia
3.
Virus Res ; 217: 71-5, 2016 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-26951858

RESUMO

Broad bean wilt virus 1 (BBWV-1), genus Fabavirus, has a genome composed of two single-stranded positive-sense RNAs of ∼5.8 (RNA1) and 3.4kb (RNA2). Full-length cDNA clones of both genomic RNAs (pBenR1 and pBenR2) from BBWV-1 isolate Ben were constructed under the control of the T7 promoter. In vitro derived capped transcripts were infectious in Nicotiana benthamiana, Chenopodium quinoa and Vicia faba plants. The biological activity of viral transcripts was not affected by extra bases at the 5'-terminus introduced during in vitro transcription. Virions derived from the infectious cDNA clones displayed similar viral infectivity and accumulation, as well as symptom induction as the wild-type BBWV-1 isolate.


Assuntos
DNA Complementar , DNA Viral , Fabavirus/patogenicidade , Fabavirus/genética , Doenças das Plantas/virologia , RNA Viral , Nicotiana/virologia , Vicia faba/virologia , Vírion/genética , Vírion/patogenicidade
4.
Virus Res ; 211: 25-8, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26428303

RESUMO

Broad bean wilt virus 2 (BBWV2), which belongs to the genus Fabavirus, is a destructive pathogen of many economically important horticultural and ornamental crops. In this study, we constructed infectious full-length cDNA clones of two distinct isolates of BBWV2 under control of the cauliflower mosaic virus 35S promoter. BBWV2-PAP1 isolated from paprika (Capsicum annuum var. gulosum) induces severe disease symptoms in various pepper varieties, whereas BBWV2-RP1 isolated from red pepper (Capsicum annuum L.) causes mild symptoms. Agrobacterium-mediated inoculation of the infectious cDNA clones of BBWV2-PAP1 and RP1 resulted in the same symptoms as the original virus isolates. The infectious cDNA clones of BBWV2-PAP1 and RP1 were used to examine the symptoms induced by pseudorecombinants between the two isolates to localize in which of the two genomic RNAs are the symptom severity determinants in BBWV2. The pseudorecombinant of RP1-RNA1 and PAP1-RNA2 induced severe symptoms, similar to those caused by the parental isolate PAP1, whereas the pseudorecombinant of PAP1-RNA1 and RP1-RNA2 induced mild symptoms, similar to those caused by the parental isolate RP1. Our results suggest that BBWV2 RNA2 contains a symptom determinant(s) capable of enhancing symptom severity.


Assuntos
Fabavirus/genética , Fabavirus/patogenicidade , Doenças das Plantas/virologia , RNA Viral/genética , Capsicum/virologia , Fabavirus/fisiologia , Proteínas Associadas a Pancreatite , RNA Viral/metabolismo , Nicotiana/virologia , Virulência
5.
Virus Res ; 155(1): 42-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20832435

RESUMO

VP37 protein of Broad bean wilt virus 2 (BBWV-2) is a multifunctional protein that binds single-strand nucleic acids, interacts with viral coat protein (CP) and potentiates the virus cell-to-cell movement in its host plant. In this study, tubule-like structures filled with virus-like particles were observed by Electron Microscopy in plasmodesmata in walls of Chenopodium quinoa leaf cells infected with BBWV-2. Immunogold labeling using VP37 protein specific antibody demonstrates that the VP37 is a component of the tubular structures. When VP37 was fused with the green fluorescent protein (VP37-GFP) and expressed in BY-2 protoplasts or in insect Tn cells, green fluorescent tubules of various lengths were produced, protruding from the surface of the expressing cells. These findings suggest that the movement of BBWV-2 between cells is mediated by the tubular structures that contain the VP37 protein, and the VP37 protein itself is capable of inducing these tubule-like structures in cells. Our results also suggest that the plant and insect cell factors involved in the tubule formation have conserved features.


Assuntos
Chenopodium quinoa/virologia , Proteínas do Citoesqueleto/metabolismo , Fabavirus/patogenicidade , Insetos/virologia , Proteínas Virais/metabolismo , Animais , Fusão Gênica Artificial , Parede Celular/virologia , Células Cultivadas , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Eletrônica de Transmissão , Folhas de Planta/virologia , Plasmodesmos/virologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...