• The Plant Pathology Journal
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• v.21 no.4
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• pp.343-348
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• 2005

The partial nucleotide sequences of the genomic dsRNA mycoviruses infecting Pleurotus ostreatus (isolates ASI2596, ASI2597, and Bupyungbokhoe) and Agaricus blazei Murrill were determined and compared with those of the other dsRNA mycoviruses. Partial nucleotide sequences of the purified dsRNA from ASI2596 and ASI2597 revealed RNA-dependent RNA polymerase sequences that are closely related to Oyster mushroom isometric virus 2, while nucleotide sequences and the deduced amino acid sequence from dsRNA mycovirus infecting Agaricus blazei did not show any significant homology to the other dsRNA mycoviruses. Specific primers were designed for RT-PCR detection of these dsRNA viruses and were found to specifically detect each dsRNA virus. Northern blot analysis confirmed the homogeneity of RT-PCR products to each purified dsRNA. Altogether, our results suggest that these virus-specific primer sets can be employed for the specific detection of each dsRNA mycovirus in infected mushrooms.

• BMB Reports
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• v.41 no.10
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• pp.739-744
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• 2008

Turnip yellow mosaic virus (TYMV) is a positive strand RNA virus that infects mainly Cruciferae plants. In this study, the TYMV genome was modified by inserting an extra subgenomic RNA promoter and a multiple cloning site. This modified TYMV was introduced into Nicotiana benthamiana using a Agrobacterium-mediated T-DNA transfer system (agroinfiltration). When a gene encoding $\beta$-glucuronidase or green fluorescent protein was expressed using this modified TYMV as a vector, replication of the recombinant viruses, especially the virus containing $\beta$-glucuronidase gene, was severely inhibited. The suppression of replication was reduced by co-expression of viral silencing suppressor genes, such as tombusviral p19, closteroviral p21 or potyviral HC-Pro. As expected, two subgenomic RNAs were produced from the recombinant TYMV, where the larger one contained the foreign gene. An RNase protection assay revealed that the recombinant subgenomic RNA was encapsidated as efficiently as the genuine subgenomic RNA.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.15-19
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• 2006

RNA interference has been used as a powerful tool in preventing virus proliferation in many species. In this study, we injected the dsRNA in vitro transcripts into Bombyx mori to investigate the resistance to B. mori nuclear polyhedrosis virus (BmNPV). Through vivisectional observation and real-time quantities PCR analysis, we found that these dsRNA can prevent the BmNPV to a certain extent, and delay the viruses' proliferation.

• The Plant Pathology Journal
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• v.33 no.3
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• pp.213-228
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• 2017

Plasmodesmata (PDs) are specialized intercellular channels that facilitate the exchange of various molecules, including sugars, ribonucleoprotein complexes, transcription factors, and mRNA. Their diameters, estimated to be 2.5 nm in the neck region, are too small to transfer viruses or viral genomes. Tobacco mosaic virus and Potexviruses are the most extensively studied viruses. In viruses, the movement protein (MP) is responsible for the PD gating that allows the intercellular movement of viral genomes. Various host factors interact with MP to regulate complicated mechanisms related to PD gating. Virus replication and assembly occur in viral replication complex (VRC) with membrane association, especially in the endoplasmic reticulum. VRC have a highly organized structure and are highly regulated by interactions among the various host factors, proteins encoded by the viral genome, and the viral genome. Virus trafficking requires host machineries, such as the cytoskeleton and the secretory systems. MP facilitates the virus replication and movement process. Despite the current level of understanding of virus movement, there are still many unknown and complex interactions between virus replication and virus movement. While numerous studies have been conducted to understand plant viruses with regards to cell-to-cell movement and replication, there are still many knowledge gaps. To study these interactions, adequate research tools must be used such as molecular, and biochemical techniques. Without such tools, virologists will not be able to gain an accurate or detailed understanding of the virus infection process.

• Korean Journal of Veterinary Research
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• v.63 no.4
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• pp.41.1-41.6
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• 2023

Many viruses can infect different types of birds, with poultry being the most susceptible. These viral diseases have a direct negative impact on the poultry industry, with significant economic losses. This study examined a group of the most important viruses that infect backyard chickens in 2 specific areas of Basrah Governorate, south of Iraq. The study analyzed avian influenza viruses (AIVs), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV). Two hundred and ninety oropharyngeal swabs, 150 from Abu Al-Khasib and 140 from Shatt Al-Arab regions in the Basrah governorate, were obtained from backyard chickens with clear respiratory signs. The samples were subjected to viral RNA extraction, and the viral nucleic acids were detected using a reverse transcriptase polymerase chain reaction technique. The overall rate of viral infections was 74.8%, which varied depending on the type of virus: 15.8%, 31.3%, and 27.5% for AIV, NDV, and IBV, respectively. The NDV and IBV had much higher infection rates than that of AIV. In addition, the prevalence of AIV in the Shatt Al Arab district was significantly higher than in the Abul Khasib district. Moreover, there were no significant differences between the NDV and the IBV distributions in either of the targeted regions in this study.

• Parasites, Hosts and Diseases
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• v.53 no.5
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• pp.583-595
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• 2015

DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.24.1-24.10
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• 2022

Background: Small interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia. Objectives: The main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus. Methods: The effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells. Results: The siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene. Conclusions: These findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus.

• Research in Plant Disease
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• v.24 no.1
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• pp.9-25
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• 2018

Plant viruses cause significant yield losses and continuously threaten crop production, representing a serious threat to global food security. Studies on plant-virus interactions have contributed to increase our knowledge on plant immunity mechanism, providing new strategies for crop improvement. The prophylactic managements consist mainly following international legislations, eradication of infected plants, and application of pesticide to decrease the population of vectors. Hence, putting together the pieces of knowledge related to molecular plant immunity to viruses is critical for the control of virus disease in fields. Over the last several decades, the outstanding outcomes of extensive research have been achieved on comprehension of plant immunity to viruses. Although most dominant R genes have been used as natural resistance genes, recessive resistance genes have been deployed in several crops as another efficient strategy to control viruses. In addition, RNA interference also regulates plant immunity and contribute a very efficient antiviral system at the nucleic acid level. This review aims at describing virus disease on crops and summarizes current resistance mechanisms. Furthermore, we will discuss the current biotechnological approaches to control viral diseases and the future questions that are to be addressed to secure crop production against viruses.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.31-39
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• 2014

Norovirus causes acute gastroenteritis in all age groups and its food poisoning outbreaks are rapidly increasing in Korea. Reverse transcription-polymerase chain reaction (RT-PCR) is most widely used for the rapid detection of foodborne viruses due to high sensitivity. However, the false positive results of RT-PCR obtained against already inactivated viruses could be a serious drawbacks in food safety area. In this study, we investigated a method to yield true positive RT-PCR results only with alive viruses. To decompose the RNA genes from dead viruses, the enzymatic treatments composed of proteinse K and Ribonuclease A were applied to the sanitized and inactivated virus particles. Another aim of this study was to quantify the efficiencies of several major sanitizing treatments using real-time RT-PCR. Feline calicivirus (FCV) that belongs to the same Caliciviridae family with norovirus was used as a surrogate model for norovirus. The initial level of virus in control suspension was approximately $10^4$ PFU/mL. Most of inactivated viruses treated with the enzymatic treatment for 30 min at $37^{\circ}C$ were not detected in RT-PCR, Quantification results to verify the inactivation efficiencies of sanitizing treatments using real-time RT-PCR showed no false positive in most cases. We could successfully develope a numerical quantification process for the inactivated viruses after major sanitizing treatments using real-time RT-PCR. The results obtained in this study could provide a novel basis of rapid virus quantification in food safety area.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.533-540
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• 2022

Thunberg fritillary (Fritillaria thunbergii), a perennial used in traditional Chinese herbal medicine, is a members of the family Liliaceae. The degeneration of germplasm is a severe problem in the production of Fritillaria thunbergii var. chekiangensis. However, no information about viral infections of F. thunbergii var. chekiangensis has been reported. In this study, we sequenced the small RNAs of F. thunbergii var. chekiangensis from leaves and bulbs, and viruses were identified using a phylogenetic analysis and BLAST search for sequence. In addition, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) was used to rapidly detect viruses in this variety. Our study first reported that five viruses infected F. thunbergii var. chekiangensis. Among them, fritillary virus Y (FVY), lily mottle virus (LMoV), Thunberg fritillary mosaic virus (TFMV), and hop yellow virus (HYV) had been reported in F. thunbergii, while apple stem grooving virus was first reported in the genus Fritillaria. A multiplex RT-PCR method was developed to rapidly test the four viruses FVY, LMoV, TFMV, and HYV in F. thunbergii var. chekiangensis. Our results provide a better understanding of the infection of F. thunbergii var. chekiangensis by viruses and a basic reference for the better design of suitable control measures.