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1.
Arch Virol ; 166(3): 987-990, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33462672

RESUMO

We report the complete nucleotide sequence of the genome of a novel virus in ringspot-diseased common oak (Quercus robur L.). The newly identified pathogen is associated with leaf symptoms such as mottle, chlorotic spots and ringspots on diseased trees. High-throughput sequencing (HTS, Illumina RNASeq) was used to explore the virome of a ringspot-diseased oak that had chlorotic ringspots of suspected viral origin on leaves for several years. Bioinformatic analysis of the HTS dataset followed by RT-PCR enabled us to determine complete sequences of four RNA genome segments of a novel virus. These sequences showed high similarity to members of the genus Emaravirus, which includes segmented negative-stranded RNA viruses of economic importance. To verify the ends of each RNA, we conducted rapid amplification of cDNA ends (RACE). We identified an additional genome segment (RNA 5) by RT-PCR using a genus-specific primer (PDAP213) to the conserved 3´ and 5´termini in order to amplify full-length genome segments. RNA 5 encodes a 21-kDa protein that is homologous to the silencing suppressor P8 of High Plains wheat mosaic virus. The five viral RNAs were consistently detected by RT-PCR in ringspot-diseased oaks in Germany, Sweden, and Norway. We conclude that the virus represents a new member of the genus Emaravirus affecting oaks in Germany and in Scandinavia, and we propose the name "common oak ringspot-associated emaravirus" (CORaV).


Assuntos
Bunyaviridae/classificação , Bunyaviridae/genética , Genoma Viral/genética , Vírus de Plantas/genética , Quercus/virologia , Sequência de Aminoácidos , Sequência de Bases , Bunyaviridae/isolamento & purificação , Alemanha , Sequenciamento de Nucleotídeos em Larga Escala , Noruega , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Vírus de Plantas/classificação , RNA Viral/genética , Alinhamento de Sequência , Suécia
2.
Viruses ; 13(1)2020 12 25.
Artigo em Inglês | MEDLINE | ID: mdl-33375657

RESUMO

Chinese jujube (Ziziphus jujuba Mill.) is a native fruit crop in China. Leaf mottle and dapple fruit disease is prevalent in cultivated jujube plants grown at Aksu in Xinjiang Uygur Autonomous Region of China. Jujube yellow mottle-associated virus (JYMaV), a tentative member in the genus Emaravirus, was recently identified from mottle-diseased jujube plants grown in Liaoning Province in China, but its incidence and genetic diversity in China is unknown. In this study, the genome sequences of three JYMaV isolates from two jujube cultivars and one jujube variant were determined by high-throughput sequencing (HTS) for small RNA and rRNA-depleted RNA coupled with RT-PCR assays. Comparison of these sequences together with sequences of the viral RNA segments derived by primer set 3C/5H-based RT-PCR revealed that genetic diversity was present in the virus populations and high sequence variation occurred at the non-translational regions of each of the viral genomic segments. Field investigation confirmed the close association of the virus with leaf mottle symptoms of jujube plants. Furthermore, this study revealed that P5 encoded in the viral RNA5 displayed a nuclear localization feature differing from the plasmodesma (PD) subcellular localization of the virus movement protein (P4), and the two proteins could interact with each other in the BiFC assays. Our study provides a snapshot of JYMaV genetic diversity in its natural hosts.


Assuntos
Bunyaviridae/classificação , Bunyaviridae/genética , Ziziphus/virologia , Bunyaviridae/isolamento & purificação , Bunyaviridae/ultraestrutura , China , Variação Genética , Genoma Viral , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , Fenótipo , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Vírus de RNA/genética , RNA Viral , Análise de Sequência de RNA
3.
Arch Virol ; 165(10): 2349-2353, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32743696

RESUMO

The complete nucleotide sequence of a new member of the family Potyviridae, which we propose to name "Arachis virus Y" (ArVY), is reported from forage peanut plants (Arachis pintoi) exhibiting virus-like symptoms. The ArVY positive-sense RNA genome is 9,213 nucleotides long and encodes a polyprotein with 2,947 amino acids that is predicted to be cleaved into 10 mature proteins. The complete single open reading frame (ORF) of ArVY shares 47% and 34% nucleotide and amino acid sequence identity, respectively, with the closest related virus, soybean yellow shoot virus. Electron microscopic analysis revealed elongated viral particles typical of those found in plant cells infected with potyviruses.


Assuntos
Arachis/virologia , Genoma Viral , Filogenia , Potyviridae/genética , RNA Viral/genética , Proteínas Virais/genética , Brasil , Fases de Leitura Aberta , Doenças das Plantas/virologia , Folhas de Planta/virologia , Potyviridae/classificação , Potyviridae/isolamento & purificação , Potyviridae/ultraestrutura , Vírion/genética , Vírion/isolamento & purificação , Vírion/ultraestrutura
4.
Virology ; 548: 192-199, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32758716

RESUMO

Plum pox virus (PPV) is a worldwide threat to stone fruit production. Its woody perennial hosts provide a dynamic environment for virus evolution over multiple growing seasons. To investigate the impact seasonal host development plays in PPV population structure, next generation sequencing of ribosome associated viral genomes, termed translatome, was used to assess PPV variants derived from phloem or whole leaf tissues over a range of plum leaf and bud developmental stages. Results show that translatome PPV variants occur at proportionately higher levels in bud and newly developing leaf tissues that have low infection levels while more mature tissues with high infection levels display proportionately lower numbers of viral variants. Additional variant analysis identified distinct groups based on population frequency as well as sets of phloem and whole tissue specific variants. Combined, these results indicate PPV population dynamics are impacted by the tissue type and developmental stage of their host.


Assuntos
Doenças das Plantas/virologia , Vírus Eruptivo da Ameixa/fisiologia , Prunus domestica/virologia , Frutas/virologia , Genoma Viral , Floema/virologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/virologia , Vírus Eruptivo da Ameixa/genética , Vírus Eruptivo da Ameixa/crescimento & desenvolvimento , Prunus domestica/crescimento & desenvolvimento
5.
Arch Virol ; 165(10): 2229-2239, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32676682

RESUMO

A reexamination of proteins with conserved cysteines and basic amino acids encoded by the 3'-proximal gene of the positive-sense single-stranded RNA of some monopartite filamentous plant viruses has been carried out. The cysteines are involved in a putative Zn-finger domain, which, together with the basic amino acids, form part of the nuclear or nucleolar localization signals. An in-depth study of one of these proteins, p15 from grapevine B virus (GVB), has shown: (i) a three-dimensional structure with four α-helices predicted by two independent in silico approaches, (ii) the nucleolus as the main accumulation site by applying confocal laser microscopy to a fusion between p15 and the green fluorescent protein, (iii) the involvement of the basic amino acids and the putative Zn-finger domain, mapping at the N-terminal region of p15, in the nucleolar localization signal, as revealed by the effect of six alanine substitution mutations, (iv) the p15 suppressor function of sense-mediated RNA silencing as revealed by agroinfiltration in a transgenic line of Nicotiana benthamiana, and (v) the enhancer activity of p15 on viral pathogenicity in N. benthamiana when expressed from a potato virus X vector. In addition, we elaborate on an evolutionary scenario for these filamentous viruses, invoking takeover by a common ancestor(s) of viral or host genes coding for those cysteine-rich proteins, followed by divergence, which would also explain why they are encoded in the 3'-proximal gene of the genomic single-stranded viral RNA.


Assuntos
Flexiviridae/genética , Fases de Leitura Aberta , RNA Viral/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Clonagem Molecular , Evolução Molecular , Flexiviridae/metabolismo , Expressão Gênica , Modelos Moleculares , Filogenia , Células Vegetais/virologia , Folhas de Planta/virologia , Conformação Proteica em alfa-Hélice , Domínios Proteicos , RNA Viral/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Tabaco/virologia , Proteínas Virais/química , Proteínas Virais/metabolismo
6.
PLoS Pathog ; 16(6): e1008608, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32574227

RESUMO

Transmission is a crucial part of a viral life cycle and transmission mode can have an important impact on virus biology. It was demonstrated that transmission mode can influence the virulence and evolution of a virus; however, few empirical data are available to describe the direct underlying changes in virus population structure dynamics within the host. Potato virus Y (PVY) is an RNA virus and one of the most damaging pathogens of potato. It comprises several genetically variable strains that are transmitted between plants via different transmission modes. To investigate how transmission modes affect the within-plant viral population structure, we have used a deep sequencing approach to examine the changes in the genetic structure of populations (in leaves and tubers) of three PVY strains after successive passages by horizontal (aphid and mechanical) and vertical (via tubers) transmission modes. Nucleotide diversities of viral populations were significantly influenced by transmission modes; lineages transmitted by aphids were the least diverse, whereas lineages transmitted by tubers were the most diverse. Differences in nucleotide diversities of viral populations between leaves and tubers were transmission mode-dependent, with higher diversities in tubers than in leaves for aphid and mechanically transmitted lineages. Furthermore, aphid and tuber transmissions were shown to impose stronger genetic bottlenecks than mechanical transmission. To better understand the structure of virus populations within the host, transmission mode, movement of the virus within the host, and the number of replication cycles after transmission event need to be considered. Collectively, our results suggest a significant impact of virus transmission modes on the within-plant diversity of virus populations and provide quantitative fundamental data for understanding how transmission can shape virus diversity in the natural ecosystems, where different transmission modes are expected to affect virus population structure and consequently its evolution.


Assuntos
Modelos Biológicos , Doenças das Plantas/virologia , Folhas de Planta , Tubérculos , Potyvirus , Solanum tuberosum , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Tubérculos/metabolismo , Tubérculos/virologia , Potyvirus/metabolismo , Potyvirus/patogenicidade , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia
7.
Proc Natl Acad Sci U S A ; 117(20): 10848-10855, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32371486

RESUMO

Grapevine fanleaf virus (GFLV) is a picorna-like plant virus transmitted by nematodes that affects vineyards worldwide. Nanobody (Nb)-mediated resistance against GFLV has been created recently, and shown to be highly effective in plants, including grapevine, but the underlying mechanism is unknown. Here we present the high-resolution cryo electron microscopy structure of the GFLV-Nb23 complex, which provides the basis for molecular recognition by the Nb. The structure reveals a composite binding site bridging over three domains of one capsid protein (CP) monomer. The structure provides a precise mapping of the Nb23 epitope on the GFLV capsid in which the antigen loop is accommodated through an induced-fit mechanism. Moreover, we uncover and characterize several resistance-breaking GFLV isolates with amino acids mapping within this epitope, including C-terminal extensions of the CP, which would sterically interfere with Nb binding. Escape variants with such extended CP fail to be transmitted by nematodes linking Nb-mediated resistance to vector transmission. Together, these data provide insights into the molecular mechanism of Nb23-mediated recognition of GFLV and of virus resistance loss.


Assuntos
Nepovirus/efeitos dos fármacos , Doenças das Plantas/imunologia , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/farmacologia , Animais , Anticorpos Antivirais/imunologia , Capsídeo/química , Proteínas do Capsídeo/química , Proteínas do Capsídeo/efeitos dos fármacos , Microscopia Crioeletrônica , Epitopos/química , Modelos Moleculares , Nematoides/virologia , Nepovirus/ultraestrutura , Doenças das Plantas/virologia , Folhas de Planta/virologia , Vírus de Plantas/imunologia , Vírus de Plantas/fisiologia , Conformação Proteica , Vitis
8.
Arch Virol ; 165(8): 1877-1881, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32447620

RESUMO

Codiaeum variegatum (common name, garden croton) is an ornamental plant grown for its bright yellow variegated leaf morphology. Two C. variegatum plants with upward leaf curling and vein swelling symptoms were collected in Faisalabad, Pakistan. Sequencing of clones obtained by PCR amplification with specific primers showed one plant infected with the monopartite begomoviruses pedilanthus leaf curl virus (PeLCV) and papaya leaf curl virus (PaLCuV) and the other to be infected with only PeLCV. Both plants also harboured a betasatellite that was distinct from all previously identified betasatellites, for which the name "codiaeum leaf curl betasatellite" (CoLCuB) is proposed. This is the first identification of a begomovirus and an associated betasatellite infecting C. variegatum in Pakistan. Both PeLCV and PaLCuV cause problems in a number of crop plants, and C. variegatum may act as a reservoir for these agriculturally important viruses. The precise impact and geographical distribution of the newly identified CoLCuB will be investigated.


Assuntos
Begomovirus/genética , Euphorbiaceae/virologia , Folhas de Planta/virologia , Vírus Satélites/genética , Carica/virologia , DNA Satélite/genética , DNA Viral/genética , Paquistão , Filogenia , Doenças das Plantas/virologia
9.
Sci Rep ; 10(1): 6510, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32300157

RESUMO

Protein-protein interactions (PPIs) play an essential role in cellular regulatory processes. Despite, in-depth studies to uncover the mystery of PPI-mediated regulations are still lacking. Here, an integrative interactome network (MePPI-Ux) was obtained by incorporating expression data into the improved genome-scale interactome network of cassava (MePPI-U). The MePPI-U, constructed by both interolog- and domain-based approaches, contained 3,638,916 interactions and 24,590 proteins (59% of proteins in the cassava AM560 genome version 6). After incorporating expression data as information of state, the MePPI-U rewired to represent condition-dependent PPIs (MePPI-Ux), enabling us to envisage dynamic PPIs (DPINs) that occur at specific conditions. The MePPI-Ux was exploited to demonstrate timely PPIs of cassava under various conditions, namely drought stress, brown streak virus (CBSV) infection, and starch biosynthesis in leaf/root tissues. MePPI-Uxdrought and MePPI-UxCBSV suggested involved PPIs in response to stress. MePPI-UxSB,leaf and MePPI-UxSB,root suggested the involvement of interactions among transcription factor proteins in modulating how leaf or root starch is synthesized. These findings deepened our knowledge of the regulatory roles of PPIs in cassava and would undeniably assist targeted breeding efforts to improve starch quality and quantity.


Assuntos
Manihot/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Mapas de Interação de Proteínas/genética , Secas , Regulação da Expressão Gênica de Plantas/genética , Interações Hospedeiro-Patógeno/genética , Manihot/virologia , Doenças das Plantas/virologia , Folhas de Planta/genética , Folhas de Planta/virologia , Potyviridae/patogenicidade , RNA Viral/genética
10.
Arch Virol ; 165(5): 1249-1252, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32232672

RESUMO

In this study, the complete genomic sequence of a novel virus was determined by next-generation sequencing of a sample from a symptomatic strawberry plant with severe yellow spots and mosaic on its leaves. Its genomic organization and sequence showed that this virus is related to members of the proposed insect-specific genus "Negevirus". The sample also contained sequences from the geranium aphid Acyrthosiphon malvae. Although the virus was detected repeatedly in the same plant during the three following years, no other positive samples were obtained from the surroundings or more-distant locations. Reverse transcription qPCR analysis revealed the presence of both genomic positive and complementary negative strands of the viral genome in the sample, with a 3- to 30-fold excess of the positive strand, indicating active viral replication. As the virus was not detected in any insect species collected at this location, the virus was provisionally named "Fragaria vesca-associated virus 1" (FVaV-1).


Assuntos
Fragaria/virologia , Genoma Viral , Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Análise de Sequência de DNA , Animais , Afídeos/genética , Biologia Computacional , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Vírus de Plantas/genética , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real
11.
PLoS One ; 15(4): e0229196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32294099

RESUMO

Citrus mosaic virus (CiMV) is one of the causal viruses of citrus mosaic disease in satsuma mandarins (Citrus unshiu). Prompt detection of trees infected with citrus mosaic disease is important for preventing the spread of this disease. Although rabbit monoclonal antibodies (mAbs) exhibit high specificity and affinity, their applicability is limited by technical difficulties associated with the hybridoma-based technology used for raising these mAbs. Here, we demonstrate a feasible CiMV detection system using a specific rabbit mAb against CiMV coat protein. A conserved peptide fragment of the small subunit of CiMV coat protein was designed and used to immunize rabbits. Antigen-specific antibody-producing cells were identified by the immunospot array assay on a chip method. After cloning of variable regions in heavy or light chain by RT-PCR from these cells, a gene set of 33 mAbs was constructed and these mAbs were produced using Expi293F cells. Screening with the AlphaScreen system revealed eight mAbs exhibiting strong interaction with the antigen peptide. From subsequent sequence analysis, they were grouped into three mAbs denoted as No. 4, 9, and 20. Surface plasmon resonance analysis demonstrated that the affinity of these mAbs for the antigen peptide ranged from 8.7 × 10-10 to 5.5 × 10-11 M. In addition to CiMV, mAb No. 9 and 20 could detect CiMV-related viruses in leaf extracts by ELISA. Further, mAb No. 20 showed a high sensitivity to CiMV and CiMV-related viruses, simply by dot blot analysis. The anti-CiMV rabbit mAbs obtained in this study are envisioned to be extremely useful for practical applications of CiMV detection, such as in a virus detection kit.


Assuntos
Anticorpos Monoclonais/biossíntese , Citrus/virologia , Vírus do Mosaico/isolamento & purificação , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Especificidade de Anticorpos/imunologia , Proteínas do Capsídeo/imunologia , Cinética , Folhas de Planta/virologia , Coelhos
12.
Rev Fac Cien Med Univ Nac Cordoba ; 77(1): 15-18, 2020 03 18.
Artigo em Espanhol | MEDLINE | ID: mdl-32238253

RESUMO

Introduction: The Norovirus (NoV) constitute a genus within the viral family Caliciviridae, being the main cause of outbreaks of food origin among humans. Fresh vegetables are susceptible to being contaminated with these pathogens during their cultivation, harvest, transport, processing and handling. So it was intended to determine the frequency of detection of NoV in plant samples of leaves of the City of Córdoba, and adapt a method of viral concentration with polyethylene glycol for the recovery of viral particles from the surface of vegetables and characterize the genogroups of NoV detected. Methods: 19 samples of leafy vegetables were taken between June and December 2012. A viral concentration technique previously validated in the laboratory was applied (elution and precipitation with polyethylene glycol). The viral RNA was extracted to the concentrates of the samples using Trizol and precipitation with isopropyl alcohol. The nucleic acid was amplified by Rt-PCR with specific primers to identify genogroups I (GI) and II (GII). The products of the amplification were revealed by polyacrylamide gel electrophoresis and silver staining. Results: We found 57.89% positive samples. Ten of the detected strains belonged to genogroup I (GI) and one to genogroup II (GII). They were identified throughout the study period, particularly during the months of August, September and November. Conclusion: These pathogens were detected with a prevalence of 57.89%. The strains belonged mainly to the GI, representing a potential risk for the population.


Assuntos
Microbiologia de Alimentos , Norovirus/genética , Norovirus/isolamento & purificação , Folhas de Planta/virologia , RNA Viral/análise , Verduras/virologia , Argentina , Infecções por Caliciviridae/transmissão , Genótipo , Humanos , Reação em Cadeia da Polimerase em Tempo Real
13.
Arch Virol ; 165(6): 1501-1504, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32266551

RESUMO

We provide the complete sequence of a virus tentatively named "Tetranychus urticae-associated picorna-like virus 1PK13" (TuaPV1-PK13) obtained from the high-throughput sequencing of a symptomless apple leaf sample. Although the virus sequence was originally derived from apple leaves, the data suggest that the virus is associated with the two-spotted mite Tetranychus urticae.


Assuntos
Malus/virologia , Picornaviridae/classificação , Folhas de Planta/virologia , Tetranychidae/virologia , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Picornaviridae/isolamento & purificação , Sequenciamento Completo do Genoma
14.
J Virol ; 94(12)2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32269127

RESUMO

Positive-strand RNA [(+)RNA] viruses assemble numerous membrane-bound viral replicase complexes (VRCs) with the help of viral replication proteins and co-opted host proteins within large viral replication compartments in the cytosol of infected cells. In this study, we found that deletion or depletion of Sac1 phosphatidylinositol 4-phosphate [PI(4)P] phosphatase reduced tomato bushy stunt virus (TBSV) replication in yeast (Saccharomyces cerevisiae) and plants. We demonstrate a critical role for Sac1 in TBSV replicase assembly in a cell-free replicase reconstitution assay. The effect of Sac1 seems to be direct, based on its interaction with the TBSV p33 replication protein, its copurification with the tombusvirus replicase, and its presence in the virus-induced membrane contact sites and within the TBSV replication compartment. The proviral functions of Sac1 include manipulation of lipid composition, sterol enrichment within the VRCs, and recruitment of additional host factors into VRCs. Depletion of Sac1 inhibited the recruitment of Rab5 GTPase-positive endosomes and enrichment of phosphatidylethanolamine in the viral replication compartment. We propose that Sac1 might be a component of the assembly hub for VRCs, likely in collaboration with the co-opted the syntaxin18-like Ufe1 SNARE protein within the TBSV replication compartments. This work also led to demonstration of the enrichment of PI(4)P phosphoinositide within the replication compartment. Reduction in the PI(4)P level due to chemical inhibition in plant protoplasts; depletion of two PI(4)P kinases, Stt4p and Pik1p; or sequestration of free PI(4)P via expression of a PI(4)P-binding protein in yeast strongly inhibited TBSV replication. Altogether, Sac1 and PI(4)P play important proviral roles during TBSV replication.IMPORTANCE Replication of positive-strand RNA viruses depends on recruitment of host components into viral replication compartments or organelles. Using TBSV, we uncovered the critical roles of Sac1 PI(4)P phosphatase and its substrate, PI(4)P phosphoinositide, in promoting viral replication. Both Sac1 and PI(4)P are recruited to the site of viral replication to facilitate the assembly of the viral replicase complexes, which perform viral RNA replication. We found that Sac1 affects the recruitment of other host factors and enrichment of phosphatidylethanolamine and sterol lipids within the subverted host membranes to promote optimal viral replication. In summary, this work demonstrates the novel functions of Sac1 and PI(4)P in TBSV replication in the model host yeast and in plants.


Assuntos
Interações Hospedeiro-Patógeno/genética , Fosfatos de Fosfatidilinositol/metabolismo , Monoéster Fosfórico Hidrolases/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Tombusvirus/genética , Replicação Viral/genética , 1-Fosfatidilinositol 4-Quinase/genética , 1-Fosfatidilinositol 4-Quinase/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/virologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Endossomos/metabolismo , Regulação da Expressão Gênica , Fosfatidiletanolaminas/genética , Fosfatidiletanolaminas/metabolismo , Monoéster Fosfórico Hidrolases/deficiência , Monoéster Fosfórico Hidrolases/metabolismo , Células Vegetais/metabolismo , Células Vegetais/virologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Protoplastos/metabolismo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , /metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/virologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais , Esteróis/metabolismo , Tabaco/genética , Tabaco/metabolismo , Tabaco/virologia , Tombusvirus/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteínas rab5 de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/metabolismo
15.
J Gen Virol ; 101(5): 565-570, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32149597

RESUMO

Pepper mild mottle virus (PMMoV) causes serious economic losses in pepper production in China. In a survey for viral diseases on pepper, two PMMoV isolates (named PMMoV-ZJ1 and PMMoV-ZJ2) were identified with different symptoms in Zhejiang province. Sequence alignment analysis suggested there were only four amino acid differences between the isolates: Val262Gly, Ile629Met and Ala1164Thr in the replicase, and Asp20Asn in the coat protein. Infectious cDNA clones of both isolates were constructed and shown to cause distinctive symptoms. Chlorosis symptoms appeared only on PMMoV-ZJ2-infected plants and the Asp20Asn substitution in the CP was shown to be responsible. Confocal assays revealed that the subcellular localization pattern of the two CPs was different, CP20Asp was mainly located at the cell periphery, whereas most CP20Asn located in the chloroplast. Thus, a single amino acid in the CP determined the chlorosis symptom, accompanied by an altered subcellular localization.


Assuntos
Aminoácidos/genética , Anemia Hipocrômica/virologia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Tobamovirus/genética , Sequência de Aminoácidos , Capsicum/virologia , Proteínas do Capsídeo/genética , China , Cloroplastos/virologia , DNA Complementar/genética , Genoma Viral/genética , Alinhamento de Sequência , Virulência/genética
16.
PLoS One ; 15(3): e0230066, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142559

RESUMO

Sugarcane yellow leaf virus (SCYLV), the causal agent of yellow leaf disease, naturally infects at least three plant species in Florida: sugarcane (Saccharum spp.), the weed Columbus grass (Sorghum almum) and cultivated sorghum (S. bicolor). All three hosts are also colonized by the sugarcane aphid (Melanaphis sacchari), the main vector of SCYLV worldwide. To understand the high incidence of SCYLV observed in sugarcane commercial fields and in germplasm collections, we investigated the transmission efficiency of SCYLV from sugarcane and Columbus grass to sugarcane using the sugarcane aphid and a spider mite (Oligonychus grypus) that also tested positive for SCYLV in Florida. Healthy and SCYLV-infected leaf pieces of sugarcane and Columbus grass carrying viruliferous aphids or spider mites were transferred to virus-free plants of the yellow leaf susceptible sugarcane cultivar CP96-1252. Three- and 6-months post inoculation, the 108 aphid-inoculated plants of Columbus grass and the 90 mite-inoculated plants of sugarcane tested negative for SCYLV by tissue blot immunoassay (TBIA) or reverse transcription polymerase chain reaction (RT-PCR). Similar results were obtained for 162 aphid-inoculated plants of sugarcane, except for two plants that tested positive for SCYLV by TBIA and RT-PCR. In two field experiments planted with SCYLV-free and virus-infected sugarcane (cultivar CP96-1252), only 18-28% of healthy plants became infected during a 24- to 28-month period. SCYLV prevalence in these field experiments did not differ between aphicide treated and untreated plots. Incidence of M. sacchari haplotypes in the Everglades agricultural area also indicated that the predominant haplotype that is currently colonizing sugarcane was not a vector of SCYLV in Florida. Lack of virus transmission by the spider mite suggested that this arthropod only acquired the virus when feeding on infected plants but was unable to transmit SCYLV. The current vector of SCYLV in Florida remains to be identified.


Assuntos
Afídeos/fisiologia , Luteoviridae/fisiologia , Ácaros/fisiologia , Doenças das Plantas/virologia , Saccharum/virologia , Sorghum/virologia , Animais , Afídeos/efeitos dos fármacos , Afídeos/virologia , Florida , Genótipo , Haplótipos , Insetos Vetores/virologia , Inseticidas/toxicidade , Luteoviridae/genética , Luteoviridae/isolamento & purificação , Ácaros/efeitos dos fármacos , Ácaros/virologia , Folhas de Planta/virologia , RNA Viral/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Plant Physiol Biochem ; 148: 347-358, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32004918

RESUMO

The replication of positive strand RNA viruses in plant cells is markedly influenced by the desaturation status of fatty acid chains in lipids of intracellular plant membranes. At present, little is known about the role of lipid desaturation in the replication of tobamoviruses. Therefore, we investigated the expression of fatty acid desaturase (FAD) genes and the fatty acid composition of pepper leaves inoculated with two different tobamoviruses. Obuda pepper virus (ObPV) inoculation induced a hypersensitive reaction (incompatible interaction) while Pepper mild mottle virus (PMMoV) inoculation caused a systemic infection (compatible interaction). Changes in the expression of 16 FADs were monitored in pepper leaves following ObPV and PMMoV inoculations. ObPV inoculation rapidly and markedly upregulated seven Δ12-FADs that encode enzymes putatively located in the endoplasmic reticulum membrane. In contrast, PMMoV inoculation resulted in a weaker but rapid upregulation of two Δ12-FADs and a Δ15-FAD. The expression of genes encoding plastidial FADs was not influenced neither by ObPV nor by PMMoV. In accordance with gene expression results, a significant accumulation of linoleic acid was observed by gas chromatography-mass spectrometry in ObPV-, but not in PMMoV-inoculated leaves. ObPV inoculation led to a marked accumulation of H2O2 in the inoculated leaves. Therefore, the effect of H2O2 treatments on the expression of six tobamovirus-inducible FADs was also studied. The expression of these FADs was upregulated to different degrees by H2O2 that correlated with ObPV-inducibility of these FADs. These results underline the importance of further studies on the role of pepper FADs in pepper-tobamovirus interactions.


Assuntos
Capsicum , Ácidos Graxos Dessaturases , Regulação da Expressão Gênica de Plantas , Tobamovirus , Capsicum/enzimologia , Capsicum/virologia , Ácidos Graxos Dessaturases/genética , Peróxido de Hidrogênio/metabolismo , Folhas de Planta/química , Folhas de Planta/enzimologia , Folhas de Planta/virologia , Tobamovirus/fisiologia
18.
Arch Virol ; 165(4): 1023-1026, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32056003

RESUMO

The complete genome sequence of a new virus, provisionally named "balloon flower endornavirus" (BfEV), was determined following virus isolation from leaves of a balloon flower (Platycodon grandiflorum) exhibiting severe leaf shrinkage disease in Anhui Province, China. The 15,180-nucleotide genome sequence of BfEV shares 40.52% amino acid (aa) sequence identity and 98% coverage with the polyprotein of Helianthus annuus endornavirus (HaEV). The open reading frame (ORF) encodes a deduced 4,887-aa polyprotein with RNA-dependent RNA polymerase (RdRp), viral helicase (Hel) and glycosyltransferase (GT) domains. Phylogenetic analysis of the amino acid sequences of RdRp places BfEV alongside members of the genus Alphaendornavirus in the family Endornaviridae. To our knowledge, this is the first report of a complete genome sequence of a novel alphaendornavirus identified in balloon flower.


Assuntos
Doenças das Plantas/virologia , Platycodon/virologia , Vírus de RNA/isolamento & purificação , Sequência de Bases , China , Genoma Viral , Fases de Leitura Aberta , Folhas de Planta/virologia , Vírus de RNA/classificação , Vírus de RNA/genética , Proteínas Virais/genética
19.
PLoS One ; 15(1): e0227669, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929569

RESUMO

Apple decline in Washington state has been increasing in incidence, particularly on Honeycrisp trees grown on G.935 rootstock. In this disease the trees exhibit dieback with necrosis at the graft union and in the rootstock. The cause of this disease remains unknown. To identify viral candidates, RNA-seq was performed on six trees: four trees exhibiting decline and two healthy trees. Across the samples, eight known viruses and Apple hammerhead viroid were detected, however none appear to be specifically associated with the disease. A BLASTx analysis of the RNA-seq data was performed to identify novel viruses that might be associated with apple decline. Seventeen novel putative viruses were detected, including an ilarvirus, two tombus-like viruses, a barna-like virus, a picorna-like virus, three ourmia-like viruses, three partiti-like viruses, and two narna-like viruses. Four additional viruses could not be classified. Three of the viruses appeared to be missing key genes, suggesting they may be dependent upon helper viruses for their function. Others showed a specific tropism, being detected only in the roots or only in the leaves. While, like the known apple viruses, none were consistently associated with diseased trees, it is possible these viruses may have a synergistic effect when co-infecting that could contribute to disease. Or the presence of these viruses may weaken the trees for some other factor that ultimately causes decline. Additional research will be needed to determine how these novel viruses contribute to apple decline.


Assuntos
Malus/virologia , Produtos Agrícolas/virologia , Genoma Viral , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Raízes de Plantas/virologia , RNA-Seq , Árvores/virologia
20.
J Plant Physiol ; 245: 153110, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31918353

RESUMO

Infection with Cowpea severe mosaic virus (CPSMV) represents one of the main limitations for cowpea (Vigna unguiculata L. Walp.) productivity due to the severity of the disease symptoms, frequency of incidence, and difficulties in dissemination control. This study aimed to identify the proteins and metabolic pathways associated with the susceptibility and resistance of cowpea plants to CPSMV. Therefore, we treated the seeds of a naturally susceptible cowpea genotype (CE-31) with the mutagenic agent ethyl methane sulfonate (EMS) and compared the secondary leaf proteomic profile of the mutagenized resistant plants inoculated with CPSMV (MCPI plant group) to those of the naturally susceptible cowpea genotype CE-31 inoculated (CPI) and noninoculated (CPU) with CPSMV. MCPI responded to CPSMV by accumulating proteins involved in the oxidative burst, increasing H2O2 generation, promoting leaf cell death (LCD), increasing the synthesis of defense proteins, and decreasing host factors important for the establishment of CPSMV infection. In contrast, CPI accumulated several host factors that favor CPSMV infection and did not accumulate H2O2 or present LCD, which allowed CPSMV replication and systemic dissemination. Based on these results, we propose that the differential abundance of defense proteins and proteins involved in the oxidative burst, LCD, and the decrease in cowpea protein factors required for CPSMV replication are associated with the resistance trait acquired by the MCPI plant group.


Assuntos
Comovirus/fisiologia , Resistência à Doença , Peróxido de Hidrogênio/metabolismo , Mutagênese , Folhas de Planta/virologia , Vigna/metabolismo , Vigna/virologia , Morte Celular/genética , Morte Celular/fisiologia , Resistência à Doença/genética , Resistência à Doença/fisiologia , Metanossulfonato de Etila/química , Metanossulfonato de Etila/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/fisiologia , Ontologia Genética , Homeostase/efeitos dos fármacos , Homeostase/genética , Homeostase/fisiologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Mutagênicos/química , Mutagênicos/farmacologia , Oxirredução/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Doenças das Plantas/genética , Doenças das Plantas/virologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Proteínas de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mapas de Interação de Proteínas , Proteoma/efeitos dos fármacos , Proteoma/genética , Proteoma/metabolismo , Proteoma/fisiologia , Vigna/genética , Vigna/fisiologia , Replicação Viral
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