• Research in Plant Disease
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• v.20 no.3
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• pp.173-181
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• 2014

The early and accurate detection of plant viruses is an essential component to control those. Because the globalization of trade by free trade agreement (FTA) and the rapid climate change promote the country-to-country transfer of viruses and their hosts and vectors, diagnosis of viral diseases is getting more important. Because symptoms of viral diseases are not distinct with great variety and are confused with those of abiotic stresses, symptomatic diagnosis may not be appropriate. From the last three decades, enzyme-linked immunosorbent assays (ELISAs), developed based on serological principle, have been widely used. However, ELISAs to detect plant viruses decrease due to some limitations such as availability of antibody for target virus, cost to produce antibody, requirement of large volume of sample, and time to complete ELISAs. Many advanced techniques allow overcoming demerits of ELISAs. Since the polymerase chain reaction (PCR) developed as a technique to amplify target DNA, PCR evolved to many variants with greater sensitivity than ELISAs. Many systems of plant virus detection are reviewed here, which includes immunological-based detection system, PCR techniques, and hybridization-based methods such as microarray. Some of techniques have been used in practical, while some are still under developing to get the level of confidence for actual use.

• Research in Plant Disease
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• v.28 no.1
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• pp.32-38
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• 2022

A survey of Barley yellow dwarf virus (BYDV) was conducted in major oat-growing areas of Korea in 2020. BYDV is an economically important pathogen of cereal crops that can be transmitted by aphids. The present study evaluated the genetic composition of BYDV in oat from eight geographical areas in Korea. Multiplex reverse transcription-polymerase chain reaction was used to screen 322 oat leaf samples for six BYDV strains (PAV, MAV, SGV, PAS, RPV, and RMV). The 125 samples (~39%) tested positive for BYDV. BYDV-PAV, BYDV-SGV, BYDV-PAS, and BYDV-RPV were detected from oat in different areas. Most of the BYDV-infected samples were assigned to subgroup I (n=112). The results indicate that BYDV-PAV could be dominant throughout Korea. Also, the phylogenetic analysis of coat protein sequences indicated that 23 BYDV isolates from Korea could be separated into two clades, which exhibited high nucleotide sequence similarity. In conclusion, the present survey provides a BYDV infection assessment for domestic oat varieties in Korea and basic information for the development of BYDV control measures in Korea's oat industry.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.360-363
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• 2006

Efficacy of plant growth promoting rhizobacteria(PGPR) Bacillus vallismortis strain EXTN-1 has been proved in eliciting induced systemic resistance(ISR) in several crops. The present paper described the beneficial effects of EXTN-1 in potato as increase in yield and chlorophyll content, and plant protection against Potato Virus Y and X(PVY & PVX). EXTN-1 induced systemic resistance to the plants resulting in significant disease suppression in the field. Also the plants under treatment with EXTN-1 had higher chlorophyll content. The bacterized plants had significantly higher yields over the untreated control plants. The strain induced activation of defense genes, PR-1a and PDF 1.2 in transgenic tobacco model, which indicated the possible role of both SA, and JA pathways in EXTN-1 mediated plant protection against crop diseases.

• BMB Reports
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• v.46 no.10
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• pp.495-500
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• 2013

Turnip yellow mosaic virus (TYMV) is a positive strand RNA virus. We have modified TYMV coat protein (CP) by inserting a c-Myc epitope peptide at the N- or C-terminus of the CP, and have examined its effect on assembly. We introduced the recombinant CP constructs into Nicotiana benthamiana leaves by agroinfiltration. Examination of the leaf extracts by agarose gel electrophoresis and Western blot analysis showed that the CP modified at the N-terminus produced a band co-migrating with wild-type virions. With C-terminal modification, however, the detected bands moved faster than the wild-type virions. To further examine the effect, TYMV constructs producing the modified CPs were prepared. With N-terminal modification, viral RNAs were protected from RNase A. In contrast, the viral RNAs were not protected with C-terminal modification. Overall, the results suggest that virion assembly and RNA packaging occur properly when the N-terminus of CP is modified, but not when the C-terminus is modified.

• Journal of fish pathology
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• v.22 no.3
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• pp.283-291
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• 2009

This study was conducted to evaluate the effects of a commercial extruded pellet (EP) and raw fish moist pellet (MP) diet on disease prevalence and serum chemistry of olive flounder Paralichthys olivaceus grown in two commercial-scale aquaculture farms from July to December in 2008. The contents of serum GOT, GPT and glucose in fish fed EP diet (EP group) were higher than those of fish fed the MP diet (MP group). There were no distinct differences in survival rates and mean detection rates of fish pathogens among fish group fed the experimental diets. However, the mean detection rate of fish pathogens in MP group was higher than that of EP group from July to October which are high water temperature season. The dominant pathogens isolated in EP group were Dactylogyrus sp., E. tarda and red sea bream iridovirus (RSIV). On the other hand, Trichodina sp., Streptococcus spp., viral nervous necrosis virus (VNNV) were dominant in MP group.

• Journal of Ecology and Environment
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• v.48 no.2
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• pp.163-172
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• 2024

Background: Fruit bats are natural carriers of Nipah virus (NiV). The primary objective of this study is to identify potential reservoir species in a selected geographic regions. It is necessary to determine an accurate species identification of the associated reservoir bat species distributed in a specific region. Results: In this study, we collected 20 different bat specimens from the NiV-prone area of the Kushtia district. Among these, 14 were tissue samples (BT-1-14) and six were fecal samples (BF-1-6). We used the mitochondrial gene cytochrome b, one of the most abundant and frequently used genetic markers, for polymerase chain reaction amplification and sequencing. Out of the 20 samples, 12 tissue samples and 2 fecal samples were successfully amplified and sequenced. However, two tissue samples and four fecal samples yielded chimeric sequences, rendering them unsuitable for annotation. The sequences of the successfully amplified samples were compared to those deposited in the National Center for Biotechnology Information database using basic local alignment search tool to identify the bat specimen collected. The study identified six different bat species using both morphological and genetic data, which may carriers of the NiV. Conclusions: Our results suggest that additional research should be conducted to gather more information on fruit bats from different localities across the country. The study contributes to the establishment of appropriate measures for NiV carrying disease control and management.

• Annals of Clinical Neurophysiology
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• v.14 no.1
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• pp.29-35
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• 2012

Background: Peripheral neuropathy is the most frequent neurological complication in human immunodeficiency virus (HIV) infection, related with diverse etiologies including inflammation, opportunistic infection and side effects of medications. The purpose of the present study was to evaluate characteristics of HIV associated neuropathy according to the stage of HIV infection. Methods: In reviewing the medical records of HIV patients who underwent electrodiagnostic studies between 1997 and 2011, total 11 patients (all males; median age, 47 years; range, 28-71 years) with comorbid neuropathy were enrolled. Stage of HIV infection was categorized according to the Centers for Disease Control and Prevention (CDC) criteria. Classification of peripheral neuropathy was based on clinical and electrophysiological features. Results: Distal symmetric polyneuropathy was observed in 8 patients (72.7%), inflammatory demyelinating polyneuropathy in 2 patients (18.1%), and polyradiculopathy in 1 patient (9.1%). Median CD4+ T cell count was $123/mm^3$ (range, $8-540/mm^3$) and 7 patients (60%) had the most advanced HIV disease stage (CDC-C3). There was no neuropathy caused by CMV infection. Conclusions: Distal symmetric polyneuropathy was the most common type of neuropathy in HIV infection, but various forms of neuropathy such as inflammatory demyelinating polyneuropathy and polyradiculopathy were also present. HIV associated neuropathy is more frequently associated with advancing immunosuppression, although it can occur in all stages of HIV infection.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.133-138
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• 2011

The prevention of porcine respiratory disease complex (PRDC) is very important because of its high infection-rates in the swine farms and the economic impact in swne industry in Korea. To control the prevalence of PRDC, it is important to know about infection patterns of it. Therefore, this study aimed to investigate the infection patterns of PRDC in the northern area of Gyeongsangnam-do. To this end, the infection of porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae (MH), and Swine influenza virus (SIV) were examined using 120 pig lung tissues by PCR analysis. As a result, single pathogen positive specimens were 25.0% and the others (75.0%) were turned out to be PRDC with at least two pathogens. Among PRDCs, 50 specimens (41.7%) was infected with PRRSV, PCV2, MH and SIV. Ten specimens (8.3%) showed triple infections of PRRSV, PCV2 and MH. Double infected specimens for PRRSV and PCV2 were 10 (8.3%), and for PCV2 and APP were 20 (16.7%).

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.401-410
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• 2024

This study was undertaken to elucidate the effects of virus and viroid infections on the growth of trees and the attributes of fruit quality in 'Hongro' apples. Trials were initiated using virus-infected, viroid-infected, combined virus/viroid-infected, and uninfected apple trees in an experimental apple orchard at the National Institute of Horticultural and Herbal Science in 2019. The growth of each tree was measured annually and compared between virus-free and virus/viroid-infected trees. Fruits were harvested from all apple trees, and selected attributes of fruit quality, including yield, weight, firmness, titratable acidity, and anthocyanin content, were determined in September 2021-2022. The results revealed significant differences among virus-free trees and those infected with either virus, viroid, or a combination of virus and viroid. Infection with viral and viroid diseases led to reductions in tree height (14.0%), trunk area (23.1%), fruit yield (65.0%), fruit weight (34.4%), and anthocyanin content (39.8%), while increasing fruit firmness (33.2%) and titratable acidity (39.8%), respectively. We anticipate that our research findings will also be beneficial for apple virus and viroid disease control, as well as apple cultivation management.

• The Plant Pathology Journal
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• v.37 no.4
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• pp.375-388
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• 2021

Rice yellow mottle virus (RYMV) is the most harmful virus that affects irrigated and lowland rice in Africa. The RBe24 isolate of the virus is the most pathogenic strain in Benin. A total of 79 genotypes including susceptible IR64 (Oryza sativa) and the resistant TOG5681 (O. glaberrima) as checks were screened for their reactions to RBe24 isolate of RYMV and the effects of silicon on the response of host plants to the virus investigated. The experiment was a three-factor factorial consisting of genotypes, inoculation level (inoculated vs. non-inoculated), and silicon dose (0, 5, and 10 g/plant) applied as CaSiO₃ with two replications and carried out twice in the screen house. Significant differences were observed among the rice genotypes. Fifteen highly resistant and eight resistant genotypes were identified, and these were mainly O. glaberrima. Silicon application did not affect disease incidence and severity at 21 and 42 days after inoculation (DAI); it, however, significantly increased plant height of inoculated (3.6% for 5 g CaSiO₃/plant and 6.3% for 10 g CaSiO₃/plant) and non-inoculated (1.9% for 5 g CaSiO₃/plant and 4.9% for 10 g CaSiO₃/plant) plants at 42 DAI, with a reduction in the number of tillers (12.3% for both 5 and 10 g CaSiO₃/plant) and leaves (26.8% for 5 g CaSiO₃/plant and 28% for 10 g CaSiO₃/plant) under both inoculation treatments. Our results confirm O. glaberrima germplasm as an important source of resistance to RYMV, and critical in developing a comprehensive strategy for the control of RYMV in West Africa.