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1.
Viruses ; 14(2)2022 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-35215892

RESUMO

Reverse transcription PCR (RT-PCR) is a popular method for detecting RNA viruses in plants. RT-PCR is usually performed in a classical two-step procedure: in the first step, cDNA is synthesized by reverse transcriptase (RT), followed by PCR amplification by a thermostable polymerase in a separate tube in the second step. However, one-step kits containing multiple enzymes optimized for RT and PCR amplification in a single tube can also be used. Here, we describe an RT-PCR single-enzyme assay based on an RTX DNA polymerase that has both RT and polymerase activities. The expression plasmid pET_RTX_(exo-) was transferred to various E. coli genotypes that either compensated for codon bias (Rosetta-gami 2) or contained additional chaperones to promote solubility (BL21 (DE3) with plasmids pKJE8 or pTf2). The RTX enzyme was then purified and used for the RT-PCR assay. Several purified plant viruses (TMV, PVX, and PVY) were used to determine the efficiency of the assay compared to a commercial one-step RT-PCR kit. The RT-PCR assay with the RTX enzyme was validated for the detection of viruses from different genera using both total RNA and crude sap from infected plants. The detection endpoint of RTX-PCR for purified TMV was estimated to be approximately 0.01 pg of the whole virus per 25 µL reaction, corresponding to 6 virus particles/µL. Interestingly, the endpoint for detection of TMV from crude sap was also 0.01 pg per reaction in simulated crude plant extracts. The longest RNA fragment that could be amplified in a one-tube arrangement was 2379 bp long. The longest DNA fragment that could be amplified during a 10s extension was 6899 bp long. In total, we were able to detect 13 viruses from 11 genera using RTX-PCR. For each virus, two to three specific fragments were amplified. The RT-PCR assay using the RTX enzyme described here is a very robust, inexpensive, rapid, easy to perform, and sensitive single-enzyme assay for the detection of plant viruses.


Assuntos
Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Vírus de RNA/isolamento & purificação , Produtos Agrícolas/virologia , DNA Polimerase Dirigida por DNA/metabolismo , Filogenia , Vírus de Plantas/classificação , Vírus de Plantas/genética , Reação em Cadeia da Polimerase/instrumentação , Vírus de RNA/classificação , Vírus de RNA/genética , Sensibilidade e Especificidade
2.
Viruses ; 12(10)2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003342

RESUMO

Yam (Dioscorea spp.) is an important crop in tropical and subtropical regions. Many viruses have been recently identified in yam, hampering genetic conservation and safe international exchanges of yam germplasm. We report on the implementation of reliable and cost-effective PCR-based detection tools targeting eight different yam-infecting viruses. Viral indexing of the in vitro yam collection maintained by the Biological Resources Center for Tropical Plants (BRC-TP) in Guadeloupe (French West Indies) unveiled a high prevalence of potyviruses, badnaviruses, Dioscorea mosaic associated virus (DMaV) and yam asymptomatic virus 1 (YaV1) and a high level of coinfections. Infected yam accessions were subjected to a combination of thermotherapy and meristem culture. Sanitation levels were monitored using PCR-based and high-throughput sequencing-based diagnosis, confirming the efficacy and reliability of PCR-based detection tools. Sanitation rates were highly variable depending on viruses. Sixteen accessions were successfully sanitized, paving the way to safe yam germplasm exchanges and the implementation of clean seed production programs worldwide.


Assuntos
Dioscorea/virologia , Patologia Molecular/métodos , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Saneamento/métodos , Badnavirus/genética , Badnavirus/isolamento & purificação , Vírus de Plantas/genética , Reação em Cadeia da Polimerase/métodos , Potexvirus/genética , Potexvirus/isolamento & purificação , Reprodutibilidade dos Testes , Índias Ocidentais
3.
Mol Cell Probes ; 53: 101627, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32622961

RESUMO

Reverse transcription recombinase polymerase amplification (RT-RPA), an isothermal nucleic acid amplification and detection method, was developed to detect peach latent mosaic viroid (PLMVd) in pollen and peach leaves. Results showed that this RT-RPA detection method can be performed at 42 °C and completed in approximately 5 min, and there was no cross-reactivity with other common peach viruses. A sensitivity assay showed that the RT-RPA assay was 1000-fold more sensitive than a regular RT-PCR. Moreover, the method was successfully applied to test field-collected samples. The newly developed RT-RPA assay is rapid, sensitive, and reliable method for detection of PLMVd in peach pollen and leaves and can be utilized as an effective technique in quarantine and viroid-free certification processes.


Assuntos
Vírus de Plantas/isolamento & purificação , Recombinases/metabolismo , Vírus de Plantas/genética , Pólen/virologia , Prunus persica , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fatores de Tempo
4.
Viruses ; 12(6)2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32531939

RESUMO

"Rhizomania" of sugar beet is a soilborne disease complex comprised of beet necrotic yellow vein virus (BNYVV) and its plasmodiophorid vector, Polymyxa betae. Although BNYVV is considered the causal agent of rhizomania, additional viruses frequently accompany BNYVV in diseased roots. In an effort to better understand the virus cohort present in sugar beet roots exhibiting rhizomania disease symptoms, five independent RNA samples prepared from diseased beet seedlings reared in a greenhouse or from field-grown adult sugar beet plants and enriched for virus particles were subjected to RNAseq. In all but a healthy control sample, the technique was successful at identifying BNYVV and provided sequence reads of sufficient quantity and overlap to assemble > 98% of the published genome of the virus. Utilizing the derived consensus sequence of BNYVV, infectious RNA was produced from cDNA clones of RNAs 1 and 2. The approach also enabled the detection of beet soilborne mosaic virus (BSBMV), beet soilborne virus (BSBV), beet black scorch virus (BBSV), and beet virus Q (BVQ), with near-complete genome assembly afforded to BSBMV and BBSV. In one field sample, a novel virus sequence of 3682 nt was assembled with significant sequence similarity and open reading frame (ORF) organization to members within the subgenus Alphanecrovirus (genus Necrovirus; family Tombusviridae). Construction of a DNA clone based on this sequence led to the production of the novel RNA genome in vitro that was capable of inducing local lesion formation on leaves of Chenopodium quinoa. Additionally, two previously unreported satellite viruses were revealed in the study; one possessing weak similarity to satellite maize white line mosaic virus and a second possessing moderate similarity to satellite tobacco necrosis virus C. Taken together, the approach provides an efficient pipeline to characterize variation in the BNYVV genome and to document the presence of other viruses potentially associated with disease severity or the ability to overcome resistance genes used for sugar beet rhizomania disease management.


Assuntos
Genoma Viral , Doenças das Plantas/parasitologia , Doenças das Plantas/virologia , Vírus de Plantas/genética , Plasmodioforídeos/virologia , Vírus Satélites/genética , Beta vulgaris/parasitologia , Beta vulgaris/virologia , Filogenia , Raízes de Plantas/parasitologia , Raízes de Plantas/virologia , Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Vírus Satélites/classificação , Vírus Satélites/isolamento & purificação , Análise de Sequência de RNA
5.
Acta Virol ; 64(1): 36-43, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32180417

RESUMO

The genome sequence of a novel RNA virus, Trichosanthes associated rhabdovirus 1 (TrARV1), was identified in a transcriptome dataset isolated from a root sample of Trichosanthes kirilowii, which is a flowering plant belonging to the family Cucurbitaceae. The fruits, seeds, and root tubers of T. kirilowii have been used clinically in traditional Chinese medicine. The TrARV1 genome sequence was predicted to have six open reading frames (ORFs) encoding five canonical structural proteins of the family Rhabdoviridae (N ORF for nucleocapsid, P ORF for phosphoprotein, M ORF for matrix protein, G ORF for glycoprotein, and L ORF for polymerase), and an accessory protein. Sequence comparisons and phylogenetic analyses based on L and N proteins confirmed that TrARV1 is a novel member of the genus Cytorhabdovirus of the family Rhabdoviridae. TrARV1 is most closely related to Wuhan insect virus 5 and persimmon virus A. The putative cis-regulatory elements involved in transcription termination and polyadenylation, commonly found in the gene junction regions of rhabdoviruses, were also identified in the TrARV1 genome having the consensus sequence 3'- ACUAAAUUAUUUUGAUCUUU-5'. The genome sequence of TrARV1 may be useful to study the evolution and molecular biology of cytorhabdoviruses. Keywords: Trichosanthes associated rhabdovirus 1; Cytorhabdovirus; Rhabdoviridae; Trichosanthes kirilowii.


Assuntos
Filogenia , Vírus de Plantas/classificação , Rhabdoviridae/classificação , Transcriptoma , Trichosanthes/virologia , Genoma Viral , Fases de Leitura Aberta , Vírus de Plantas/isolamento & purificação , Rhabdoviridae/isolamento & purificação , Proteínas Virais/genética
6.
Cienc. tecnol. salud ; 7(2): 205-217, 2020. il 27 c
Artigo em Espanhol | LILACS, DIGIUSAC, LIGCSA | ID: biblio-1348154

RESUMO

La punta morada es una enfermedad que afecta la producción de algunas especies de solanáceas como la papa y el tomate, causando enrollamiento en las puntas de las hojas con una marcada coloración morada, decaimiento temprano de la planta y en la papa se observa tuberización aérea. Como patógenos asociados a la enfermedad se consideran al fitoplasma BLTVA y la bacteria Candidatus Liberibacter solanacearum. Dada la similitud en la sin-tomatología foliar que generan ambos patógenos, es difícil precisar cuál de ellos está implicado en la enfermedad. En Guatemala, existen reportes de la sintomatología típica de punta morada en las principales zonas productoras de papa y tomate, desconociéndose el agente asociado. La investigación determinó cuál de los dos patógenos reportados está asociados a la enfermedad en 12 municipios productores de papa y/o tomate en el país. Se realizaron ampli-ficaciones de ADN con cebadores específicos para cada patógeno asociado a la enfermedad. Por la alta incidencia del fitoplasma BLTVA en las muestras de papa (73.9%), en comparación a C. Liberibacter solanacearum (26%), este es considerado como el patógeno asociado más importante en papa. En las muestras de tomate, la incidencia del fitoplasma BLTVA (29.8%) y C. Liberibacter solanacearum del (27.6%) fue similar. Además, sobresale el primer reporte de la detección del fitoplasma BLTVA afectando el cultivo de tomate en Guatemala. Se sugiere un monitoreo constante, mediante métodos moleculares, para un diagnóstico certero y establecer medidas de manejo de la enfermedad para evitar su diseminación hacia zonas aún no afectadas.


The potato purple top is a disease that affects the production of some solanaceous species such as potatoes and tomatoes, causing curl at the tips of the leaves with a marked purple coloration, early decay of the plant, and aerial tuberization is observed in the potato. BLTVA phytoplasma and Candidatus Liberibacter solanacearum are considered as pathogens associated with the disease. Given the similarity in foliar symptoms generated by both pathogens, it is difficult to determine which one is involved in the disease. There are reports of the typical potato purple top symptoms in the main potato and tomato producing areas in Guatemala, being unknown the associated agent. The research determined which of the two reported pathogens is associated with the disease in 12 potatoes and/or tomato producing areas in the country. We performed DNA amplification with specific primers for each disease-associated pathogen. Due to the high incidence of BLTVA phytoplasma in potato samples (73.9%), com-pared to C. liberibacter solanacearum (26%), this is considered the most important associated pathogen in potatoes. In tomato samples, the incidence of BLTVA phytoplasma (29.8%) and C. liberibacter solanacearum (27.6%) was similar. Besides, the first report of the detection of the BLTVA phytoplasma affecting tomato cultivation in Gua-temala stands out. Using molecular methods, constant monitoring is suggested for an accurate diagnosis and to establish management measures for the disease to prevent its spread to areas not yet affected.


Assuntos
Solanum tuberosum/virologia , Solanaceae/virologia , Doenças por Fitoplasmas/microbiologia , Vírus de Plantas/isolamento & purificação , Produção Agrícola , DNA de Plantas/análise , Liberibacter/patogenicidade
7.
Mol Cell Probes ; 47: 101438, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31422073

RESUMO

In this study, a new SYBR Green qPCR (qRT-PCR) and a nested RT-PCR (nRT-PCR) were developed to detect Potato mop-top virus (PMTV) in potato tuber tissues. The SYBR Green qRT-PCR and nRT-PCR assays were approximately 104- and 103- fold more sensitive than the conventional RT-PCR assay. The progeny tubers derived from PMTV-infected potato tubers were tested by conventional RT-PCR, SYBR Green qRT-PCR and nRT-PCR assays. Of the 17 samples, 9 (52.9%) were positive for PMTV by conventional RT-PCR, 11 (64.7%) were positive by nRT-PCR, and 17 (100%) were positive by SYBR Green qRT-PCR. Compared to nRT-PCR, SYBR Green qRT-PCR was showed to be more sensitive. The progeny plants exhibited foliar symptoms including chlorosis and reduction in leaf size when the PMTV-positive tubers were planted in a growth chamber at 20-22 °C. These findings suggest that PMTV has been passed on to the progeny plants and tubers.


Assuntos
Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Solanum tuberosum/crescimento & desenvolvimento , Tamanho do Órgão , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/virologia , Vírus de Plantas/genética , RNA Viral/genética , Sensibilidade e Especificidade , Solanum tuberosum/virologia
8.
J Virol Methods ; 271: 113673, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31170470

RESUMO

Pollen transmitted viruses require accurate detection and identification to minimize the risk of spread through the global import and export of pollen. Therefore in this study we developed RT-qPCR assays for the detection of Cherry leaf roll virus (CLRV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV), and Cherry virus A (CVA), four viruses that infect pollen of Prunus species. Assays were designed against alignments of extant sequences, optimized, and specificity was tested against known positive, negative, and non-target controls. An examination of assay sensitivity showed that detection of virus at concentrations as low as 101 copies was possible, although 102 copies was more consistent. Furthermore, comparison against extant assays showed that in both pollen and plant samples, the newly developed RT-qPCR assays were more sensitive and could detect a greater range of isolates than extant endpoint RT-PCR and ELISA assays. Use of updated assays will improve biosecurity protocols as well as the study of viruses infecting pollen.


Assuntos
Abastecimento de Alimentos , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Pólen/virologia , Prunus/virologia , Primers do DNA/genética , Ensaio de Imunoadsorção Enzimática , Flexiviridae/genética , Flexiviridae/isolamento & purificação , Ilarvirus/genética , Ilarvirus/isolamento & purificação , Nepovirus/genética , Nepovirus/isolamento & purificação , Doenças das Plantas/virologia , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Análise de Sequência de DNA
9.
Viruses ; 11(6)2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167478

RESUMO

Banana trees, citrus fruit trees, pome fruit trees, grapevines, mango trees, and stone fruit trees are major fruit trees cultured worldwide and correspond to nearly 90% of the global production of woody fruit trees. In light of the above, the present manuscript summarizes the viruses that infect the major fruit trees, including their taxonomy and morphology, and highlights selected viruses that significantly affect fruit production, including their genomic and biological features. The results showed that a total of 163 viruses, belonging to 45 genera classified into 23 families have been reported to infect the major woody fruit trees. It is clear that there is higher accumulation of viruses in grapevine (80/163) compared to the other fruit trees (each corresponding to less than 35/163), while only one virus species has been reported infecting mango. Most of the viruses (over 70%) infecting woody fruit trees are positive-sense single-stranded RNA (+ssRNA), and the remainder belong to the -ssRNA, ssRNA-RT, dsRNA, ssDNA and dsDNA-RT groups (each corresponding to less than 8%). Most of the viruses are icosahedral or isometric (79/163), and their diameter ranges from 16 to 80 nm with the majority being 25-30 nm. Cross-infection has occurred in a high frequency among pome and stone fruit trees, whereas no or little cross-infection has occurred among banana, citrus and grapevine. The viruses infecting woody fruit trees are mostly transmitted by vegetative propagation, grafting, and root grafting in orchards and are usually vectored by mealybug, soft scale, aphids, mites or thrips. These viruses cause adverse effects in their fruit tree hosts, inducing a wide range of symptoms and significant damage, such as reduced yield, quality, vigor and longevity.


Assuntos
Frutas/virologia , Vírus de Plantas , Árvores/virologia , Citrus/virologia , Classificação , Genes Virais , Genoma Viral , Malus/virologia , Mangifera/virologia , Musa/virologia , Filogenia , Doenças das Plantas/virologia , Vírus de Plantas/classificação , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Vírus de Plantas/ultraestrutura , Prunus avium/virologia , Prunus domestica/virologia , Vitis/virologia
10.
Arch Virol ; 164(7): 1863-1868, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31065853

RESUMO

Extraction and electrophoretic analysis of viral dsRNA from plants has been used successfully to detect infections by RNA viruses. We used this approach as an initial tool to test non-cultivated plant species for the presence of endornaviruses. Foliar samples were collected from symptomless plants in various locations within East Baton Rouge Parish, Louisiana, USA, and tested for viral dsRNA. After testing 208 plant species belonging to 74 families, five (Geranium carolinianum, Hydrocotyle umbellata, H. prolifera, Sorghum halepense, and Sisyrinchium atlanticum) yielded dsRNAs similar in size to the dsRNAs of members of the family Endornaviridae. The endornavirus nature of the dsRNAs was confirmed by reverse-transcription PCR (RT-PCR) and sequencing the RT-PCR products. Sequence data were used to determine relationships of the putative endornaviruses to members of the family Endornaviridae. The putative endornaviruses were detected in both native and introduced plants species. This is the first survey on the occurrence of endornaviruses in non-cultivated plant species.


Assuntos
Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA de Cadeia Dupla/genética , RNA Viral/genética , Centella/virologia , Genoma Viral/genética , Geranium/virologia , Iridaceae/virologia , Louisiana , Vírus de Plantas/genética , Vírus de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sorghum/virologia
11.
PLoS One ; 14(5): e0216713, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31071169

RESUMO

Virus discovery based on high-throughput sequencing relies on enrichment for virus sequences prior to library preparation to achieve a sufficient number of viral reads. In general, preparations of double-stranded RNA or total RNA preparations treated to remove rRNA are used for sequence enrichment. We used virus-specific antibodies to immunocapture virions from plant sap to conduct cDNA synthesis, followed by library preparation and HTS. For the four potato viruses PLRV, PVY, PVA and PYV, template preparation by virion immunocapture provided a simpler and less expensive method than the enrichment of total RNA by ribosomal depletion. Specific enrichment of viral sequences without an intermediate amplification step was achieved, and this high coverage of sequences across the viral genomes was important to identify rare sequence variations. Using this approach, the first complete genome sequence of a potato yellowing virus isolate (PYV, DSMZ PV-0706) was determined in this study. PYV can be confidently assigned as a distinct species in the genus Ilarvirus.


Assuntos
Anticorpos Antivirais , Vírus de Plantas/genética , Vírus de Plantas/imunologia , Vírion/genética , Vírion/imunologia , Animais , Especificidade de Anticorpos , Carlavirus/genética , Carlavirus/imunologia , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Luteoviridae/genética , Luteoviridae/imunologia , Filogenia , Vírus de Plantas/isolamento & purificação , Potyvirus/genética , Potyvirus/imunologia , RNA Viral/genética , Análise de Sequência de RNA , Solanum tuberosum/virologia , Vírion/isolamento & purificação
12.
Talanta ; 195: 739-744, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625610

RESUMO

This study presents new type of the lateral flow immunoassay (LFIA) for multi-target analysis. A test, named alarm-LFIA, has an essentially new function that consists in notice (signaling the danger) about the presence at least one target from the controlled list without identification. The design of the alarm-LFIA assumes one test zone, which contains a mixture of antibodies, and multi-specific conjugate that binds the several targets. The alarm test is based on the novel conjugate with broaden specificity due to the immobilisation of a mix of antibodies, specific to several structurally different targets, on the surface of gold nanoparticles. For proof of concept, multi-specific conjugate to five important potato viruses (potato virus X, -M, -S, -Y and potato leaf roll virus) was fabricated using five antibodies with different specificity. The alarm-LFIA was developed for rapid detection of the total infection caused by up to five viruses. Detection limits of the viruses in potato leaf extracts are from 10 to 30 ng/mL. The alarm-LFIA was successfully used for viruses' detection in potato leaves; results were confirmed by enzyme-linked immunosorbent assay. The proposed approach of alarm-LFIA shows great potential for the various cases when different targets of interest can occur simultaneously or separately in samples.


Assuntos
Extratos Vegetais/análise , Folhas de Planta/virologia , Vírus de Plantas/isolamento & purificação , Solanum tuberosum/virologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Ouro/química , Imunoensaio , Nanopartículas Metálicas/química , Vírus de Plantas/imunologia
13.
C R Biol ; 341(6): 343-348, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30032780

RESUMO

Rhizomania is one of serious threat to sugar beet production in Morocco and in several parts of the world. This disease led to a statistically significant decrease in the quality and yield of sugar beet plantations. Therefore, this study aimed at comparing the efficacy of six commonly used RNA extraction methods for the detection, recovery of RNA of beet necrotic yellow vein virus (BNYVV) and removal of amplification inhibitors by reverse transcription-polymerase chain reaction (RT-PCR). The efficiency of these extraction methods was then compared to that of a commercial isolation kit with high content of phenolic compounds. The results showed that the extraction with the lithium chloride technique, the commercial kit, and direct and membrane spotting crude extract methods were found effective in yielding a higher purity and a higher concentration of RNA when compared to the other tested methods. Extraction with the lithium chloride technique and the Qiagen kit (RNeasy Plant Mini Kit) allowed the most intense band, whereas the CTAB method has generated the least intense band. Furthermore, the silica capture extraction method did not yield any RNA after extraction and electrophoresis. Consequently, it was concluded that, of these six methods, the lithium chloride technique and the Qiagen kit are the most appropriate for the extraction of viral RNA from sugar beet samples prior to RT-PCR for detecting BNYVV.


Assuntos
Beta vulgaris/virologia , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Vírus de RNA/isolamento & purificação , Marrocos , Raízes de Plantas , RNA/isolamento & purificação
14.
Virus Genes ; 54(1): 124-129, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28942579

RESUMO

Vertical and horizontal pollen transmission is important for efficient infection by viroids. Vertical pollen transmission of viroids is attributed to the infection by viroid in the embryo sac through infected pollen. To identify the viroid infection in pollen and pollen tubes elongating through the transmitting tract, we used in situ hybridization to histochemically analyze the distribution of Tomato planta macho viroid (TPMVd) in pollen grains, the stigma, and style of petunia plants. TPMVd was present in the generative nucleus and vegetative nucleus of mature infected pollen grains and germinating pollen grains. During pollen tube growth, TPMVd was present in the vegetative nucleus and two sperm nuclei, which were generated by division of the generative nucleus in the style transmitting tract. These findings indicated that viroid infection in sperm nuclei is responsible for vertical pollen transmission of viroids. TPMVd infection from TPMVd-infected pollen tubes to the transmitting tract was not observed. In addition, TPMVd signals were not confirmed in the stigma and transmitting tract of TPMVd-infected petunia plants, suggesting that viroids may not replicate in these tissues at the stage of mature style. Therefore, TPMVd may leak from the pollen tube somewhere in the ovary, except in the transmitting tract, during the horizontal transmission of TPMVd.


Assuntos
Petunia/virologia , Vírus de Plantas/isolamento & purificação , Pólen/virologia , Núcleo Celular/virologia , Hibridização In Situ , Vírus de Plantas/genética
15.
Biosens Bioelectron ; 94: 365-373, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28319904

RESUMO

An efficient electrochemical impedance genosensing platform has been constructed based on graphene/zinc oxide nanocomposite produced via a facile and green approach. Highly pristine graphene was synthesised from graphite through liquid phase sonication and then mixed with zinc acetate hexahydrate for the synthesis of graphene/zinc oxide nanocomposite by solvothermal growth. The as-synthesised graphene/zinc oxide nanocomposite was characterised with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffractometry (XRD) to evaluate its morphology, crystallinity, composition and purity. An amino-modified single stranded DNA oligonucleotide probe synthesised based on complementary Coconut Cadang-Cadang Viroid (CCCVd) RNA sequence, was covalently bonded onto the surface of graphene/zinc oxide nanocomposite by the bio-linker 1-pyrenebutyric acid N-hydroxysuccinimide ester. The hybridisation events were monitored by electrochemical impedance spectroscopy (EIS). Under optimised sensing conditions, the single stranded CCCVd RNA oligonucleotide target could be quantified in a wide range of 1.0×10-11M to 1.0×10-6 with good linearity (R =0.9927), high sensitivity with low detection limit of 4.3×10-12M. Differential pulse voltammetry (DPV) was also performed for the estimation of nucleic acid density on the graphene/zinc oxide nanocomposite-modified sensing platform. The current work demonstrates an important advancement towards the development of a sensitive detection assay for various diseases involving RNA agents such as CCCVd in the future.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/química , Vírus de Plantas/isolamento & purificação , RNA Viral/isolamento & purificação , Sequência de Bases/genética , DNA de Cadeia Simples/genética , Espectroscopia Dielétrica , Grafite/química , Nanocompostos/química , Sondas de Oligonucleotídeos/química , Sondas de Oligonucleotídeos/genética , Vírus de Plantas/genética , RNA Viral/genética , Óxido de Zinco/química
16.
Arch Virol ; 162(6): 1731-1736, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28204895

RESUMO

Solanum nodiflorum mottle virus (SNMoV) was isolated from a small-flowered nightshade (Solanum nodiflorum) in Queensland, Australia. It has been included in the genus Sobemovirus based on virion morphology and serological relationships. Here, we report the sequence of the complete genome of SNMoV. Sequence analysis confirmed that SNMoV has the characteristic genome organization of sobemoviruses. Phylogenetic analysis showed that it clusters most closely with velvet tobacco mottle virus (VTMoV), another sobemovirus native to Australia. Their genomes show 56.8 % sequence identity.


Assuntos
Genoma Viral , Doenças das Plantas/virologia , Vírus de Plantas/genética , Vírus de RNA/genética , Austrália , Sequência de Bases , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA Viral/genética , Solanum/virologia
17.
Arch Virol ; 162(2): 495-500, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27738843

RESUMO

Sugar beet can be infected by many different viruses that can reduce yield; beet necrotic yellow vein virus (BNYVV) is one of the most economically important viruses of this crop plant. This report describes a new reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for identification of BNYVV. In addition, a novel immunocapture (IC) RT-LAMP assay for rapid and easy detection (without RNA extraction) of BNYVV was developed here and compared with DAS-ELISA and RT-LAMP assays. Our results show that the IC-RT-LAMP assay is a highly reliable alternative assay for identification of BNYVV.


Assuntos
Beta vulgaris/virologia , Imunoensaio , Técnicas de Amplificação de Ácido Nucleico , Vírus de Plantas/genética , Vírus de RNA/genética , Transcrição Reversa , Sequência de Bases , Primers do DNA/síntese química , Primers do DNA/genética , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Vírus de RNA/isolamento & purificação , Sensibilidade e Especificidade
18.
J Virol Methods ; 237: 14-17, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27542529

RESUMO

Standard molecular methods for plant virus diagnosis require the purification of RNA or DNA extracts from a large number of samples, with sufficient concentration and quality for their use in PCR, RT-PCR, or qPCR analysis. Most methods are laborious and use either hazardous and/or costly chemicals. A previously published protocol for RNA isolation from several plant species yields high amounts of good quality RNA-DNA mixture in a simple, safe and inexpensive manner. In the present work, this method was tested to obtain RNA-DNA extracts from leaves of tomato, potato and three species of citrus, and was compared with two commercial kits. The results demonstrated that this protocol offers at least comparable nucleic acid quality, quantity and purity to those provided by commercial phenol-based or spin column systems and that are suitable to be used in PCR, RT-PCR and qPCR for virus and viroid detection. Because of its easy implementation and the use of safe and inexpensive reagents, it can be easily implemented to work in plant virus and viroid detection in different plant species.


Assuntos
DNA Viral/isolamento & purificação , Folhas de Planta/genética , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Plantas/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Viroides/genética , Viroides/isolamento & purificação , Citrus/genética , Citrus/virologia , DNA de Plantas/isolamento & purificação , DNA Viral/genética , Técnicas de Diagnóstico Molecular/métodos , Folhas de Planta/virologia , Plantas/virologia , RNA de Plantas/isolamento & purificação , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/economia , Reação em Cadeia da Polimerase em Tempo Real/normas , Solanum tuberosum/genética , Solanum tuberosum/virologia
19.
J Virol Methods ; 235: 34-40, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27185564

RESUMO

Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-ß-farnesene (EßF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EßF release on aphid and virus dispersion under laboratory conditions. EßF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals.


Assuntos
Afídeos/virologia , Nicotiana/virologia , Controle Biológico de Vetores/métodos , Doenças das Plantas/virologia , Vírus de Plantas/fisiologia , Sesquiterpenos , Animais , Afídeos/fisiologia , Feromônios/metabolismo , Folhas de Planta/virologia , Vírus de Plantas/isolamento & purificação , Potyvirus/isolamento & purificação , Potyvirus/fisiologia , Sesquiterpenos/metabolismo , Solanum tuberosum/virologia
20.
Anal Bioanal Chem ; 408(22): 6009-17, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27007732

RESUMO

Multiarray on a test strip (MATS) was developed for the detection of eight important potato pathogens. The proposed assay combines the rapidity of immunochromatography with the high throughput of array techniques. The test zone of the immunochromatographic strip comprises ordered rows of spots containing antibodies specific for different potato pathogens. The assay benefits from the simplicity of immunochromatography; colored immune complexes form at the corresponding spots within the test zone. The presence and intensity of the coloration are used for identification of the target pathogens. The MATS was applied to the simultaneous detection of eight priority potato pathogens, characterized by the following limits of detection: 1 ng/mL for potato virus X and the ordinary type of potato virus Y, 10 ng/mL for potato virus M, 20 ng/mL for potato leaf roll virus, 40 ng/mL for necrotic-type potato virus Y, 100 ng/mL for potato virus S, 300 ng/mL for potato virus A, and 10(4) cells/mL for Clavibacter michiganensis subsp. sepedonicus. Analysis time was 15 min. The observed sensitivity of the MATS was comparable to the traditional enzyme-linked immunosorbent assay. The developed technique was tested on potato leaf extracts, and its efficiency for on-site control of the pathogens was confirmed in 100 % by commercial LFIA test strips. Graphical abstract Location of binding zones in the developed multiarray on a test strip (MATS) for simultaneous detection of eight pathogens.


Assuntos
Cromatografia de Afinidade/métodos , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Fitas Reagentes/análise , Solanum tuberosum/virologia , Anticorpos Imobilizados/química , Cromatografia de Afinidade/economia , Cromatografia de Afinidade/instrumentação , Desenho de Equipamento , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Análise Serial de Proteínas/economia , Análise Serial de Proteínas/instrumentação , Análise Serial de Proteínas/métodos
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