• The Plant Pathology Journal
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• v.40 no.1
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• pp.59-72
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• 2024

A comprehensive survey of mungbean-growing areas was conducted to observe leaf spot disease caused by Alternaria alternata. Alternaria leaf spot symptoms were observed on the leaves. Diversity of 50 genotypes of mungbean was assessed against A. alternata and data on pathological traits was subjected to cluster analysis. The results showed that genotypes of mungbean were grouped into four clusters based on resistance parameters under the influence of disease. The principal component biplot demonstrated that all the disease-related parameters (% disease incidence, % disease intensity, lesion area, and % of infection) were strongly correlated with each other. Alt a 1 gene that is precisely found in Alternaria species and is responsible for virulence and pathogenicity. Alt a 1 gene was amplified using gene specific primers. The isolated pathogen produced similar symptoms when inoculated on mungbean and tobacco. The sequence analysis of the internal transcribed spacer (ITS) region, a 600 bp fragment amplified using specific primers, ITS1 and ITS2 showed 100% identity with A. alternata. Potato virus X (PVX) -based silencing vector expressing Alt a 1 gene was constructed to control this pathogen through RNA interference in tobacco. Out of 50 inoculated plants, 9 showed delayed onset of disease. Furthermore, to confirm our findings at molecular level semi-quantitative reverse transcriptase polymerase chain reaction was used. Both phenotypic and molecular investigation indicated that RNAi induced through the VIGS vector was efficacious in resisting the pathogen in the model host, Tobacco (Nicotiana tabacum). To the best of our knowledge, this study has been reported for the first time.

• Food Science and Preservation
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• v.21 no.5
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• pp.735-739
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• 2014

Ephedra sinica Stapf, known as a medicinal plant, inhibited not only syncytium formation, but also trafficking of viral glycoprotein, hemagglutinin-neuramidase (HN) to the cell-surface. Trafficking of viral glycoprotein to the surface of infected-cells results in syncytium formation in Newcastle disease virus (NDV)-infected baby hamster kidney (BHK) cells. Viral glycoprotein in the infected-cell is processed within the endoplasmic reticulum during routing into surface. The processing of viral glycoprotein like a N-linked oligosaccharide trimming by ${\alpha}$-glucosidase in cell is necessary for virus infection. Methanol extracts showed inhibitory activities ($IC_{50}$ $15{\mu}g/mL$) against ${\alpha}$-glucosidase. This suggested that E. sinica extracts inhibited the cell-surface expression of NDV-HN glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.30.1-30.15
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• 2021

Background: New-generation adjuvants for foot-and-mouth disease virus (FMDV) vaccines can improve the efficacy of existing vaccines. Chinese medicinal herb polysaccharide possesses better promoting effects. Objectives: In this study, the aqueous extract from Artemisia rupestris L. (AEAR), an immunoregulatory crude polysaccharide, was utilized as the adjuvant of inactivated FMDV vaccine to explore their immune regulation roles. Methods: The mice in each group were subcutaneously injected with different vaccine formulations containing inactivated FMDV antigen adjuvanted with three doses (low, medium, and high) of AEAR or AEAR with ISA-206 adjuvant for 2 times respectively in 1 and 14 days. The variations of antibody level, lymphocyte count, and cytokine secretion in 14 to 42 days after first vaccination were monitored. Then cytotoxic T lymphocyte (CTL) response and antibody duration were measured after the second vaccination. Results: AEAR significantly induced FMDV-specific antibody titers and lymphocyte activation. AEAR at a medium dose stimulated Th1/Th2-type response through interleukin-4 and interferon-γ secreted by CD4⁺ T cells. Effective T lymphocyte counts were significantly elevated by AEAR. Importantly, the efficient CTL response was remarkably provoked by AEAR. Furthermore, AEAR at a low dose and ISA-206 adjuvant also synergistically promoted immune responses more significantly in immunized mice than those injected with only ISA-206 adjuvant and the stable antibody duration without body weight loss was 6 months. Conclusions: These findings suggested that AEAR had potential utility as a polysaccharide adjuvant for FMDV vaccines.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.451-454
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• 2020

Sericulture is a main insect industry in Sangju (Kyungpook, Korea). This study reports an occurrence of a viral disease in the sericulture farms in 2020. More than 20% silkworm larvae (Bombyx mori) suffered diarrhea and melted tissues with pathogenic lethality at 4th or 5th instars. PCR diagnosis showed a positive response against B. mori nucleopolyhedrosis virus (BmNPV) infection. Tissue extract of the infected larvae was applied to healthy larvae by a leaf-dipping method and exhibited the same viral symptoms. The viral extract was used to be overlaid on Sf9 cells. The infected Sf9 cells showed polyhedra in the cytoplasm. These results indicate that the silkworm larvae reared in the sericulture farms in Sangju were infected with BmNPV.

• Molecules and Cells
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• v.26 no.3
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• pp.258-264
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• 2008

A rice diacylglycerol kinase (DGK) gene, OsBIDK1, which encodes a 499-amino acid protein, was cloned and characterized. OsBIDK1 contains a conserved DGK domain, consisting of a diacylglycerol kinase catalytic subdomain and a diacylglycerol kinase accessory subdomain. Expression of OsBIDK1 in rice seedlings was induced by treatment with benzothiadiazole (BTH), a chemical activator of the plant defense response, and by infection with Magnaporthe grisea, causal agent of blast disease. In BTH-treated rice seedlings, expression of OsBIDK1 was induced earlier and at a higher level than in water-treated control seedlings after inoculation with M. grisea. Transgenic tobacco plants that constitutively express the OsBIDK1 gene were generated and disease resistance assays showed that overexpression of OsBIDK1 in transgenic tobacco plants resulted in enhanced resistance against infection by tobacco mosaic virus and Phytophthora parasitica var. nicotianae. These results suggest that OsBIDK1 may play a role in disease resistance responses.

• Research in Plant Disease
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• v.14 no.3
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• pp.210-213
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• 2008

The occurrence of Rice stripe virus (RSV) has been confirmed in some parts of South Korea. In the current year, this was observed to be limited in the double cropping zones of the southern region. Earlier, RSV occurred largely in the west coast regions of the country, particularly in Gangwha, Gyeonggi-do in 2001; and Buan, Jeollabuk-do and Seocheon, Chungcheongnam-do in 2007. This study was carried out to determine the nationwide extent of RSV occurrence by investigating RSV infestations in different latitudes and altitudes. Result revealed a recent reported occurrence of RSV in the southern region (Milyang, latitude $35^{\circ}$), a reported occurrence in the northern region (Cheolwon, latitude $38^{\circ}$) in 2005, and in the middle northern region of the east coast (Goseon, latitude $38^{\circ}$) as newly confirmed from this investigation. Results also confirmed the occurrence of RSV in a wide range of altitude from the plains (Milyang, 17 m altitude) to the alpine regions (Jinbu, 576 m) including the middle mountains (Sangju, altitude 285 m). The RSV occurrence in Jinbu in the alpine region and at Goseong and most of the northern end regions were confirmed only this year. The results of the present study confirmed that RSV is a fast-spreading disease in rice plant cultivation regions of the entire country.

• Research in Plant Disease
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• v.11 no.2
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• pp.89-92
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• 2005

In 2004, average temperature was higher, and rainfall was less than those of previous year, The diseases of rice, barley, pepper, chinese melon, apple and oriental pear were surveyed. Seedling diseases, leaf blast, sheath blight and bacterial blight of rice, phytophthova blight, virus diseases and anthracnose of pepper, and sudden wilt syndrome and powdery mildew of chinese melon grown in plastic greenhouse were severe. Especially, sheath blight and bacterial blight of rice occurred two times higher than those of previous year, Panicle blight of rice decreased about 4 times, compared with the previous year, presumed that the lower rainy days, rainfall and RH suppressed spread of the fungal pathogens to panicles of rice. Lower rainfall during mid- and late Aug caused three-times less occurrence of phytophtora blight of red-pepper than that of the previous year, Another diseases surveyed occurred similar or less than those of the previous year.

• Research in Plant Disease
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• v.14 no.2
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• pp.134-137
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• 2008

A strain of Cucumber mosaic virus(CMV) was isolated newly from sweet pepper(Capsicum annuum var. angulosum) showing necrosis with large necrotic spots on fruits and vein banding with malformation on leaf at Cheongdo area in Gyeongsangbukdo. The new strain was designated as a CMV-NP and the shape of virus particles was isometric of 26 nm in diameter from the sweet pepper fruit by Dip method. The strain of CMV-NP was identified genetically by VC/RT-PCR. CMV-NP could infect systemically on the 9 indicator plants including Cucumis sativus, but it could infect locally on Chenopodim amaranticolor and C. quinoa. CMV-NP induced the specific symptoms of necrotic rings on the inoculated and the upper leaves of N. rustica and Tetragonia expansa. On Cucumis sativus, the large chlorotic ring and vein chlorosis were produced on the upper leaves. CMV-NP had no virulence on Datura stramonium.

• Research in Plant Disease
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• v.10 no.1
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• pp.53-57
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• 2004

Cucumber green mottle mosaic virus (CGMMV) was a major pathogen of watermelon and had affected seriously to watermelon production in Korea. Rapid and sensitive detection method of CGMMV associated with bottle gourd (Lagenafia siceraria) seeds was developed by using RT-PCR in this study. A pair of primeri Wmfl and Wmrl, specific for CGMMV was designed from coat protein gene sequences of CGMMV-W and used for amplifying 420 bp product in RT-PCR. To simplify the virus extraction procedure and reduce an inhibitor from the extract for the RT-PCR, some methods using ethanol precipitation, double filtration, polyethylene glycol precipitation and phenol/chloroform/isoamyl alcohol extraction procedure were compared and the phenol/chloroform/isoamyl alcohol extraction procedure was selected by its enhanced sensitivity. This detection method using the selected extraction step and the primers for RT-PCR could reliably detect an infected level of one CGMMV-infested seed in 1,000 seeds. This rapid and sensitive RT-PCR assay provides auseful tool for the specific detection of CGMMV in bottle gourd seed samples containing high levels of back-ground inhibitors.

• Research in Plant Disease
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• v.24 no.2
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• pp.170-173
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• 2018

Three isolates of Cucumber mosaic virus isolated from Commelina communis plants showing chlorosis and mosaic were collected in Chungju and Chuncheon, Korea. To confirm genetic variation of these three isolates (CMV-Co, CMV-Co2, and CMV-Co3), we performed PCR-RFLP and sequence analysis. Sequences of coat protein genes of CMV-C0, -Co2 and -Co3 were compared with CMV-Fny and showed 96.3%, 96.3%, and 95.9% similarities, respectively. In host reactions, three CMV-Co isolates induced systemic necrosis in Cucurbita pepo unlike CMV-Fny and CMV-Co, CMV-Co2 and CMV-Co3 observed differential symptoms responses in Physalis angulata and Nicotiana rustica. These results indicated that three isolates of CMV isolated from C. communis have genetic and biological variation.