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1.
Biosens Bioelectron ; 169: 112592, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32942143

RESUMO

Global health and food security constantly face the challenge of emerging human and plant diseases caused by bacteria, viruses, fungi, and other pathogens. Disease outbreaks such as SARS, MERS, Swine Flu, Ebola, and COVID-19 (on-going) have caused suffering, death, and economic losses worldwide. To prevent the spread of disease and protect human populations, rapid point-of-care (POC) molecular diagnosis of human and plant diseases play an increasingly crucial role. Nucleic acid-based molecular diagnosis reveals valuable information at the genomic level about the identity of the disease-causing pathogens and their pathogenesis, which help researchers, healthcare professionals, and patients to detect the presence of pathogens, track the spread of disease, and guide treatment more efficiently. A typical nucleic acid-based diagnostic test consists of three major steps: nucleic acid extraction, amplification, and amplicon detection. Among these steps, nucleic acid extraction is the first step of sample preparation, which remains one of the main challenges when converting laboratory molecular assays into POC tests. Sample preparation from human and plant specimens is a time-consuming and multi-step process, which requires well-equipped laboratories and skilled lab personnel. To perform rapid molecular diagnosis in resource-limited settings, simpler and instrument-free nucleic acid extraction techniques are required to improve the speed of field detection with minimal human intervention. This review summarizes the recent advances in POC nucleic acid extraction technologies. In particular, this review focuses on novel devices or methods that have demonstrated applicability and robustness for the isolation of high-quality nucleic acid from complex raw samples, such as human blood, saliva, sputum, nasal swabs, urine, and plant tissues. The integration of these rapid nucleic acid preparation methods with miniaturized assay and sensor technologies would pave the road for the "sample-in-result-out" diagnosis of human and plant diseases, especially in remote or resource-limited settings.


Assuntos
Doenças Transmissíveis/diagnóstico , Dispositivos Lab-On-A-Chip , Ácidos Nucleicos/isolamento & purificação , Doenças das Plantas , Sistemas Automatizados de Assistência Junto ao Leito , Betacoronavirus/isolamento & purificação , Fracionamento Químico/instrumentação , Fracionamento Químico/métodos , Doenças Transmissíveis/microbiologia , Doenças Transmissíveis/parasitologia , Doenças Transmissíveis/virologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Desenho de Equipamento , Humanos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/sangue , Ácidos Nucleicos/urina , Pandemias , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia
2.
PLoS Pathog ; 16(8): e1008801, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866183

RESUMO

Rice stripe virus (RSV) is one of the most destructive viral diseases affecting rice production. However, so far, only one RSV resistance gene has been cloned, the molecular mechanisms underlying host-RSV interaction are still poorly understood. Here, we show that increasing levels or signaling of brassinosteroids (BR) and jasmonic acid (JA) can significantly enhance the resistance against RSV. On the contrary, plants impaired in BR or JA signaling are more susceptible to RSV. Moreover, the enhancement of RSV resistance conferred by BR is impaired in OsMYC2 (a key positive regulator of JA response) knockout plants, suggesting that BR-mediated RSV resistance requires active JA pathway. In addition, we found that RSV infection suppresses the endogenous BR levels to increase the accumulation of OsGSK2, a key negative regulator of BR signaling. OsGSK2 physically interacts with OsMYC2, resulting in the degradation of OsMYC2 by phosphorylation and reduces JA-mediated defense to facilitate virus infection. These findings not only reveal a novel molecular mechanism mediating the crosstalk between BR and JA in response to virus infection and deepen our understanding about the interaction of virus and plants, but also suggest new effective means of breeding RSV resistant crops using genetic engineering.


Assuntos
Brassinosteroides/metabolismo , Ciclopentanos/metabolismo , Oryza , Oxilipinas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais , Tenuivirus , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Oryza/genética , Oryza/metabolismo , Oryza/virologia , Doenças das Plantas/genética , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/virologia , Tenuivirus/genética , Tenuivirus/metabolismo
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.
Arch Virol ; 165(10): 2379-2384, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32761427

RESUMO

In this study, we determined the complete genome sequence of a new blunervirus isolated from tomato plants grown in an open field in Italy in the fall of 2018. Like other blunerviruses, the RNA genome of this virus is quadripartite, positive-sense, and single-stranded. Excluding the polyA tail present in each segment, the RNAs 1 and 2 are 5790 nucleotides (nt) and 3621 nt in size, respectively, and each contains a single open reading frame (ORF). The RNAs 3 and 4 are 2842 and 1924 nt long and encode five and two ORFs, respectively. BLASTp analysis of the predicted products of RNA1 and RNA2 ORF1 showed the highest sequence identity (31% and 42%) to tea plant necrotic ring blotch virus (TPNRBV), while the protein encoded by RNA 4 ORF2 had the highest sequence identity (38%) to blueberry necrotic ring blotch virus (BNRBV). These are the only two recognized members in the genus Blunervirus. When the RNA3 ORF3 and ORF5 products were compared with the blunerviruses-encoded proteins, they had the highest sequence identity (30% and 32%) to their TPNRBV-encoded homologs; however, general comparisons showed stronger matches to two different proteins from Acinetobacter baumannii. The proteins encoded by ORFs 1, 2 and 4 of RNA3 and ORF 1 of RNA4 showed no significant BLASTp hits to any known proteins in the databases. Given the limited genetic similarity of this virus to those currently available in the databases, we suggest that this is a new virus, for which we propose the name "tomato fruit blotch virus" (ToFBV). A distinct isolate of the same virus was also detected in Australia.


Assuntos
Genoma Viral , Lycopersicon esculentum/virologia , Filogenia , Vírus de RNA/genética , Proteínas Virais/genética , Austrália , Sequência de Bases , Produtos Agrícolas/virologia , Itália , Fases de Leitura Aberta , Doenças das Plantas/virologia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA Viral/genética , Alinhamento de Sequência
5.
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
6.
PLoS One ; 15(8): e0236674, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756600

RESUMO

In Sub-Saharan Africa cassava (Manihot esculenta Crantz) is one of the most important food crops where more than 40% of the population relies on it as their staple carbohydrate source. Biotic constraints such as viral diseases, mainly Cassava Mosaic Disease (CMD) and Cassava Brown Streak Disease (CBSD), and arthropod pests, particularly Cassava Green Mite (CGM), are major constraints to the realization of cassava's full production potential in Africa. To address these problems, we aimed to map the quantitative trait loci (QTL) associated with resistance to CBSD foliar and root necrosis symptoms, foliar CMD and CGM symptoms in a full-sib mapping population derived from the genotypes AR40-6 and Albert. A high-density linkage map was constructed with 2,125 SNP markers using a genotyping-by-sequencing approach. For phenotyping, clonal evaluation trials were conducted with 120 F1 individuals for two consecutive field seasons using an alpha-lattice design at Chambezi and Naliendele, Tanzania. Previously identified QTL for resistance to CBSD foliar symptoms were corroborated, and a new putative QTL for CBSD root necrosis identified (qCBSDRNc14AR) from AR40-6. Two QTL were identified within the region of the previously recognized CMD2 locus from this population in which both parents are thought to possess the CMD2 locus. Interestingly, a minor but consistent QTL, qCGM18AR, for CGM resistance at 3 months after planting stage was also detected and co-localized with a previously identified SSR marker, NS346, linked with CGM resistance. Markers underlying these QTL may be used to increase efficiencies in cassava breeding programs.


Assuntos
Resistência à Doença/genética , Manihot/genética , Doenças das Plantas/genética , Locos de Características Quantitativas/genética , Cruzamento , Testes Genéticos , Genótipo , Manihot/fisiologia , Manihot/virologia , Doenças das Plantas/virologia , Potyviridae/genética , Potyviridae/patogenicidade , Estresse Fisiológico/genética , Tanzânia
7.
PLoS Pathog ; 16(8): e1008710, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817722

RESUMO

Rice stripe virus (RSV, genus Tenuivirus, family Phenuiviridae) is the causal agent of rice stripe disease transmitted by the small brown planthopper (SBPH, Laodelphax striatellus) in a persistent propagative manner. The midgut and salivary glands of SBPH are the first and last barriers to the viral circulation and transmission processes, respectively; however, the precise mechanisms used by RSV to cross these organs and transmit to rice plants have not been fully elucidated. We obtained the full-length cDNA sequence of L. striatellus α-tubulin 2 (LsTUB) and found that RSV infection increased the level of LsTUB in vivo. Furthermore, LsTUB was shown to co-localize with RSV nonstructural protein 3 (NS3) in vivo and bound NS3 at positions 74-76 and 80-82 in vitro. Transient gene silencing of LsTUB expression caused a significant reduction in detectable RSV loads and viral NS3 expression levels, but had no effect on NS3 silencing suppressor activity and viral replication in insect cells. However, suppression of LsTUB attenuated viral spread in the bodies of SBPHs and decreased RSV transmission rates to rice plants. Electrical penetration graphs (EPG) showed that LsTUB knockdown by RNAi did not impact SBPH feeding; therefore, the reduction in RSV transmission rates was likely caused by a decrease in viral loads inside the planthopper. These findings suggest that LsTUB mediates the passage of RSV through midgut and salivary glands and leads to successful horizontal transmission.


Assuntos
Hemípteros/metabolismo , Proteínas de Insetos/metabolismo , Insetos Vetores/metabolismo , Oryza/virologia , Doenças das Plantas/virologia , Tenuivirus/fisiologia , Tubulina (Proteína)/metabolismo , Animais , Sistema Digestório/metabolismo , Sistema Digestório/virologia , Hemípteros/genética , Hemípteros/virologia , Proteínas de Insetos/genética , Insetos Vetores/genética , Insetos Vetores/virologia , Glândulas Salivares/metabolismo , Glândulas Salivares/virologia , Tubulina (Proteína)/genética
8.
Arch Virol ; 165(9): 2123-2126, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32617763

RESUMO

In this study, we report the complete genome sequence of a novel luteovirus detected in almond using high-throughput sequencing. The genome of the new luteovirus comprises 5,047 nucleotides, and its genomic organization is similar to that of the recently described nectarine stem pitting associated virus (NSPaV), with only four open reading frames, encoding replication-related proteins, the coat protein (CP), and a CP readthrough protein involved in the aphid transmission of luteovirids. Phylogenic and pairwise distance analyses showed that this virus shares 79% and 57.8% amino acid identity in the P1-P2 fusion protein and the P3-P5 protein, respectively, with the most closely related luteovirus, NSPaV, suggesting that it represents a novel species, for which the name "Almond associated luteovirus 1" is proposed. To our knowledge, this is the first report of an almond-infecting luteovirus.


Assuntos
Genoma Viral , Luteovirus/genética , Doenças das Plantas/virologia , Prunus dulcis/virologia , Sequência de Aminoácidos , Sequência de Bases , Luteovirus/classificação , Luteovirus/isolamento & purificação , Fases de Leitura Aberta , Filogenia , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genética , Sequenciamento Completo do Genoma
9.
Arch Virol ; 165(9): 2073-2078, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32621153

RESUMO

Complete RNA1 and RNA2 sequences of two and nearly complete genome sequences of six new variants of grapevine fabavirus found in Japan were compared to those of previously reported variants. Negative selection pressure was suggested, and no recombination events were detected in either RNA1 or RNA2. The first 18 nucleotides in both RNAs were predicted to form a stem-loop structure. The variants could be genetically divided into four groups based on RNA1 and two based on RNA2. A broad-spectrum reverse transcription polymerase chain reaction assay using a primer pair designed based on an RNA2 consensus sequence was able to detect all of the known variants.


Assuntos
Fabavirus/isolamento & purificação , Variação Genética , Doenças das Plantas/virologia , Vitis/virologia , Fabavirus/classificação , Fabavirus/genética , Genoma Viral , Filogenia , RNA Viral/genética
10.
Arch Virol ; 165(9): 2127-2131, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32632824

RESUMO

The complete genome sequence of a putative novel potyvirus, tentatively named "Polygonatum kingianum virus 1" (PKgV1), infecting Polygonatum kingianum in China was determined (GenBank accession no. MK427056). PKgV1 has a genome organization that is typical of potyviruses, with a single large open reading frame (nt 123-9236) that encodes a 3037-aa polyprotein that is predicted to be cleaved into 10 mature proteins by virus-encoded proteases. Nine cleavage sites and several conserved motifs were identified in PKgV1 by comparative sequence analysis. Pairwise comparisons revealed that the PKgV1 polyprotein shares 52.0-56.2% nucleotide and 49.2-52.8% amino acid sequence identity with members of the genus Potyvirus. Phylogenetic analysis indicated that PKgV1 clustered with members of the genus Potyvirus and that it is closely related to but distinct from lettuce mosaic virus (LMV, accession no. KJ161186). These results suggest that Polygonatum kingianum virus 1 (PKgV1) is a new member of the genus Potyvirus of the family Potyviridae.


Assuntos
Genoma Viral , Doenças das Plantas/virologia , Polygonatum/virologia , Potyvirus/genética , Potyvirus/isolamento & purificação , Sequência de Aminoácidos , Sequência de Bases , Fases de Leitura Aberta , Filogenia , Proteínas de Plantas/genética , Potyvirus/classificação
11.
Cytogenet Genome Res ; 160(6): 329-334, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32683370

RESUMO

Rubus yellow net virus (RYNV) infects Rubus spp., causing a severe decline when present in mixed infections with other viruses. RYNV belongs to the family Caulimoviridae, also known as plant pararetroviruses, which can exist as episomal or integrated elements (endogenous). Most of integrated pararetroviruses are noninfectious; however, a few cases have been reported where they excised from the plant genome and formed infectious particles. Graft transmission onto indicator plants R. occidentalis "Munger" has been the standard test method for RYNV detection in certification programs. Previously, it was noticed that some RYNV PCR-positive plants did not induce symptoms on "Munger", suggesting an integration event. In this study, bio-indexing and different molecular techniques were employed to differentiate between integrated and episomal RYNV sequences. Reverse transcription-PCR using RYNV-specific oligonucleotides after DNase treatment generated positive results for the virus in graft transmissible isolates (episomal) only. To confirm these results, rolling circle amplification on DNA preparations from the same samples resulted in amplicons identified as RYNV only from plants with graft transmissible RYNV. High-throughput sequencing was used to identify the RYNV-like sequences present in the host DNA. These results indicate the integration of RYNV into the red raspberry genome and highlight the necessity to recognize this phenomenon (integration) in future Rubus quarantine and certification programs.


Assuntos
Caulimoviridae/genética , Genoma de Planta/genética , Vírus de Plantas/genética , Rubus/genética , Rubus/virologia , Integração Viral/genética , Caulimoviridae/isolamento & purificação , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Plasmídeos/genética
12.
Arch Virol ; 165(10): 2385-2388, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32647930

RESUMO

Spartina mottle virus (SpMV), an unassigned member of the family Potyviridae, has been known since 1980, when it was first described in England and Wales in symptomatic plants of the genus Spartina. In infected cells, flexuous particles and pinwheel inclusion bodies were found that resemble those of potyvirids. To date, the NCBI database contains only two partial sequences of a German (Nessmersiel) and an Italian (Assisi) isolate, suggesting that SpMV could be the first member of a new genus, called "Sparmovirus", in the family Potyviridae. In this study, the first complete genome sequence of the German SpMV isolate (SpMV Ger) was determined. The genome of SpMV is a single-stranded, monopartite, polyadenylated RNA consisting of 9376 nucleotides. Sequence analysis revealed a genome organization similar to that of classical potyviruses, including many conserved features. In phylogenetic analysis, SpMV could not be assigned to any of the known genera, but it showed the closest relationship to rymoviruses and common reed chlorotic stripe virus (CRCSV, unassigned). Sequence comparisons confirmed that a new genus should be established containing SpMV, CRCSV, and three Bermuda grass mosaic virus isolates, which are considered divergent strains of SpMV.


Assuntos
Genoma Viral , Poaceae/virologia , Poliproteínas/genética , Potyviridae/genética , RNA Viral/genética , Alemanha , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/virologia , Potyviridae/classificação , Potyviridae/isolamento & purificação , Sequenciamento Completo do Genoma
13.
Arch Virol ; 165(10): 2389-2392, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32699979

RESUMO

A novel tobamovirus, brugmansia latent virus (BrLV), was discovered during a study of brugmansia (Brugmansia spp.) in the living collections held at the Royal Botanic Gardens, Kew. Here, we report the complete genome sequence of BrLV, which is 6,397 nucleotides long and contains the four open reading frames (RNA-dependent RNA polymerase, methyltransferase/helicase, movement, and coat proteins) typical of tobamoviruses. The complete genome sequence of BrLV shares 69.7% nucleotide sequence identity with brugmansia mild mottle virus (BrMMV) and 66.7 to 68.7% identity with other tobamoviruses naturally infecting members of the Solanaceae plant family. Phylogenetic analysis of the complete genome nucleotide sequence and the deduced amino acid sequences of the four tobamovirus proteins place BrLV in a subcluster with BrMMV within the Solanaceae-infecting tobamovirus subgroup as a new species.


Assuntos
Brugmansia/virologia , Proteínas do Capsídeo/genética , Genoma Viral , RNA Viral/genética , Tobamovirus/genética , Sequência de Bases , Sequência Conservada , Metiltransferases/genética , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/virologia , RNA Replicase/genética , Alinhamento de Sequência , Tobamovirus/classificação , Tobamovirus/isolamento & purificação , Reino Unido , Sequenciamento Completo do Genoma
14.
PLoS One ; 15(7): e0236340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32692775

RESUMO

Cotton (Gossypium hirsutum L.), being a cash and fiber crop is of high significance in Pakistan. Numerous insect pests and viral diseases in Pakistan and around the world attack cotton crop. Genetically modified cotton (transgenic, resistant to lepidopteran insects), hereafter written as 'Bt-cotton' has been introduced in many regions of the world to combat bollworms. However, cultivars differ in their pest susceptibility, yield response and fiber quality traits. Nonetheless, recent studies have indicated that lepidopteran pests are evolving resistance against 'Bt-cotton'. Several 'Bt-cotton' cultivars have been developed in Pakistan in the past decade; however, limited is known about their pest susceptibility, seed-cotton yield and fiber quality traits. This two-year field study evaluated pest susceptibility, yield and fiber quality traits of thirteen newly developed 'Bt-cotton' cultivars in Pakistan. The cultivars differed in their susceptibility to sucking insects during both years of study. The cultivars 'FH-647', 'SLH-8', 'FH-Lalazar' and 'IUB-013' were more susceptible to jassid, whereas 'BS-52' exhibited higher susceptibility to whitefly during both years of study. Similarly, cultivars 'AGC-999' and 'MNH-992' proved highly susceptible to thrips during each study year. Although 'Bt-cotton' is resistant to bollworms, cultivars 'SLAH-8', 'VH-305' and 'BH-184' were susceptible to spotted bollworm, while 'SLAH-8', 'RH-647' and 'VH-305' were infested by American bollworm. The most susceptible cultivars to cotton leaf curl virus (CLCuV) attack were 'RH-647', 'IR-NIBGE-7' and 'VH-305'. The highest seed-cotton yield was recorded for 'FH-Lalazar' during both years of study. Similarly, the highest ginning out turn was recorded for cultivars 'BS-52', 'VH-305', 'RH-647', 'IUB' and 'AA-919'. The cultivar 'FH-Lalazar' exhibited low pest susceptibility and CLCuV infestation compared to the rest of cultivars. The highest and the lowest gross and net incomes and benefit:cost ratio were noted for 'FH-Lalazar' and 'RH-647, respectively. Keeping in view the low pest susceptibility and high seed-cotton yield, 'FH-Lalazar' could be recommended for higher yield and economic returns in Multan, Pakistan. Nonetheless, regional trials should be conducted for site-specific or region-specific recommendations.


Assuntos
Fibra de Algodão , Gossypium/parasitologia , Controle Biológico de Vetores , Análise de Variância , Animais , Animais Geneticamente Modificados , Begomovirus/fisiologia , Fibra de Algodão/economia , Comportamento Alimentar , Gossypium/virologia , Insetos , Paquistão , Doenças das Plantas/parasitologia , Doenças das Plantas/virologia , Sementes/crescimento & desenvolvimento , Solo , Tempo (Meteorologia)
15.
Sheng Wu Gong Cheng Xue Bao ; 36(5): 949-958, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32567278

RESUMO

Soybean mosaic virus (SMV), one of the major viral diseases of Pinellia ternata (Thunb.) Breit., has had a serious impact on its yield and quality. The construction of viral infectious clones is a powerful tool for reverse genetics research on viral gene function and interaction between virus and host. To clarify the molecular mechanism of SMV infection in Pinellia ternata, it is particularly important to construct the SMV full-length cDNA infectious clone. Therefore, the infectious clone of Soybean mosaic virus Shanxi Pinellia ternata isolate (SMV-SXBX) was constructed in this study by Gibson in vitro recombination system, and the healthy Pinellia ternata leaves were inoculated by Agrobacterium infiltration, further through mechanical passage and RT-PCR, confirming that the 3' end of the SMV-SXBX infectious clone had a stable infectivity when it contained 56-nt of poly(A) tail. This method is not only convenient and efficient, but also avoids the instability of SMV infectious clones in Escherichia coli. The construction of SMV full-length infectious cDNA clones laid the foundation for further study on the molecular mechanism of SMV replication and pathogenesis.


Assuntos
Pinellia , Potyvirus , DNA Complementar , Pinellia/virologia , Doenças das Plantas/virologia , Potyvirus/isolamento & purificação , Potyvirus/metabolismo
16.
Arch Virol ; 165(8): 1919-1923, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32504394

RESUMO

Mycoviruses are widely distributed in a variety of fungal species. However, few viruses have been reported in basal fungi. A novel non-segmented dsRNA virus was isolated from the basal fungus Conidiobolus sp. of the phylum Zoopagomycota, which has been named "Conidiobolus non-segmented RNA virus 1" (CNRV1). The complete genome sequence of CNRV1 was determined by dsRNA extraction, next-generation sequencing, and RACE. The genome of CNRV1 dsRNA is 3,092 bp in length and contains two open reading frames (ORFs) predicted to encode a subgenomic protein 1 (sgP1) and a putative RNA-dependent RNA polymerase (RdRp). Multiple sequence alignment and phylogenetic analysis based on RdRp sequences from selected dsRNA viruses showed that CNRV1 shared 31.9% sequence identity with Nigrospora oryzae unassigned RNA virus 1 (NoNRV1) and clustered with NoNRV1 and four other mycoviruses. These viruses are unassigned and distant from members of the family Partitiviridae, although they were previously considered partitivirus-like viruses. Thus, CNRV1 is a novel member of proposed genus "Unirnavirus", and is the first dsRNA sequence reported from a member of the phylum Zoopagomycota. This study extends our knowledge about mycoviruses in basal fungi.


Assuntos
Conidiobolus/virologia , Micovírus/genética , Fungos/virologia , Vírus de RNA/genética , RNA de Cadeia Dupla/genética , RNA Viral/genética , Genoma Viral/genética , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/virologia , RNA Replicase/genética , Análise de Sequência de DNA/métodos
17.
Arch Virol ; 165(8): 1915-1918, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32504395

RESUMO

We determined the complete genomic sequence of begonia flower breaking virus (BFBV), a novel putative member of the genus Potyvirus isolated from Begonia bowerae cv. 'Tiger' plants grown in Kunming. The genomic RNA comprises 9540 nucleotides (nt), excluding the 3'-terminal poly(A) tail, and contains a typical open reading frame (ORF) of potyviruses. The ORF consists of 9219 nucleotides and encodes a 3073-amino-acid polyprotein that is predicted to be proteolytically cleaved into 10 mature peptides. Sequence comparison indicated that BFBV shares 43.9-55.12% amino acid sequence identity with known potyviruses and that BFBV shares the highest amino acid sequence identity (55.12%) with beet mosaic virus. The results from the complete genomic sequence analysis further suggest that BFBV is a member of a novel species in the genus Potyvirus.


Assuntos
Begoniaceae/virologia , Flores/virologia , Genoma Viral/genética , Potyvirus/genética , Sequência de Aminoácidos , Genômica/métodos , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/virologia , RNA Viral/genética , Análise de Sequência de DNA/métodos , Sequenciamento Completo do Genoma/métodos
18.
Arch Virol ; 165(8): 1925-1928, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32506147

RESUMO

Nine complete nucleotide sequences of geminialphasatellites (subfamily Geminialphasatellitinae, family Alphasatellitidae) recovered from the wild Poaceae Sorghum arundinaceum collected in Reunion are described and analyzed. While the helper geminivirus was identified as an isolate of maize streak virus (genus Mastrevirus, family Geminiviridae), the geminialphasatellite genomes were most closely related to, and shared ~63% identity with, clecrusatellites. Even though the geminialphasatellite molecules lack an adenine rich-region, they have the typical size of geminialphasatellites, encode a replication-associated protein in the virion sense, and have probable stem-loop structures at their virion-strand origins of replication. According to the proposed geminialphasatellite species and genus demarcation thresholds (88% and 70% nucleotide identity, respectively), the genomes identified here represent a new species (within a new genus) for which we propose the name "Sorghum mastrevirus-associated alphasatellite" (genus "Sorgasalphasatellite").


Assuntos
Geminiviridae/genética , Vírus do Listrado do Milho/genética , Poaceae/virologia , Sorghum/virologia , Genoma Viral/genética , Filogenia , Doenças das Plantas/virologia , Reunião , Análise de Sequência de DNA/métodos , Zea mays/virologia
19.
Arch Virol ; 165(9): 2083-2086, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32524261

RESUMO

A new virus with sequence similarities to members of the genus Cavemovirus in the family Caulimoviridae was identified in an Epiphyllum hybrid. The complete genome of the virus, tentatively named "epiphyllum virus 4" (EpV-4), was determined to be 7,296 nucleotides long. Its circular genome organization is typical of cavemoviruses, containing four open reading frames. This virus and the two known cavemoviruses share 67-69% and 72-75% overall nucleotide sequence identity in the replicase gene. Phylogenetic analysis placed EpV-4 in a same cluster with the two recognized cavemoviruses. Thus, EpV-4 should be considered a representative of a third species of the genus Cavemovirus. The virus was transmitted by grafting.


Assuntos
Cactaceae/virologia , Caulimoviridae/isolamento & purificação , Doenças das Plantas/virologia , Caulimoviridae/classificação , Caulimoviridae/genética , Genoma Viral , Fases de Leitura Aberta , Filogenia , Proteínas Virais/genética
20.
Arch Virol ; 165(9): 2091-2094, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32533330

RESUMO

Two contigs with high similarity to partitivirus sequences were identified by de novo assembly of sequences obtained by RNA-Seq from a wild brassicaceous plant, Arabidopsis halleri subsp. gemmifera. Here, we report the complete genome sequence of a putative novel partitivirus. Excluding the poly-A tail, it consists of two RNA genome segments of 1912 and 1769 bp, which are predicted to encode a 585-amino-acid-long putative RNA-dependent RNA polymerase (RdRp) and a 487-amino-acid-long putative capsid protein (CP), respectively. Phylogenetically, this virus belongs to the genus Alphapartitivirus and is most closely related to Raphanus sativus partitivirus 1 from radish. We propose the name "Arabidopsis halleri partitivirus 1" (AhPV1) for this novel virus.


Assuntos
Arabidopsis/virologia , Genoma Viral , Doenças das Plantas/virologia , Vírus de RNA/genética , Sequência de Bases , Filogenia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA Viral/genética , Proteínas Virais/genética , Sequenciamento Completo do Genoma
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