• The Plant Pathology Journal
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• v.25 no.2
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• pp.157-164
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• 2009

The complete nucleotide sequences of both RNA of an isolated Barley mild mosaic virus (BaMMV) from Iksan, Korea, have been determined. RNA1 was 7273 nucleotides long and encodes for a polyprotein of 2261 amino acids, which contains the eight putative functional proteins. RNA2 was 3520 nucleotides long and encodes for a polyprotein of 894 amino acids, which contains two functional proteins. Results of multiple sequence alignment showed 92.9% similarity with Na1 isolate, followed by Sil, UK(F), Asl1, Remis M and UK(M) isolates, respectively. Comparison of the BaMMV-Iks polyproteins with the corresponding proteins of BaMMV-Na1 isolates showed 95% amino acid sequence identity. The phylogenetic analysis revealed that Iks isolate was closely related to Na1 strain and have a common origin.

• The Plant Pathology Journal
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• v.19 no.4
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• pp.217-220
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• 2003

Zucchini squash (Cucurbita pepo cv. Black Beauty) plants infected with A strain of Zucchini yellow mosaic virus (ZYMV-A) isolated from a hollyhock plant showed systemically severe mosaic symptom, similar to previously established Cu strain of ZYMV. However, initial symptom of squash infected by ZYMV-A strain was generally more severe than those infected by ZYMV-Cu. Using leaf-detachment assay, examination of kinetics of accumulation of the coat protein (CP) in systemic loaves of squash plants showed that CPs of ZYMV-A appeared earlier than those of ZYMV-Cu. However, both ZYMV-A and ZYMV-Cu showed similar kinetics of CP accumulation 7 days post-inoculation. These results indicate that different rates and initial severity of systemic symptom development were due to differences in the rate of movement rather than vims replication.

• The Plant Pathology Journal
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• v.18 no.5
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• pp.237-243
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• 2002

A survey of virus infection in garlic plants cultivated in Korea was conducted for three years. Most virus-infected garlic plants (Allium sativum) showed typical symptoms on the leaves such as yellow mosaic, stripes, and distortion. Through immunosorbent electron micro-scopy and RT-PCR analysis, the complex mixtures of viruses including garlic viruses of the genus Allerivirus, gaylic strain of Leek yellow stripe virus of the genus Potyvirus, and Garlic latent virus of the genus Carlavirus were identified in the virus-infected garlic plants. Among these viruses, Allexivirus was the most frequently detect-ed in the regions surveyed. Using sets of differential primers for Allexivirus genomes, two members of the genus were amplified and sequenced from the purified viruses. The deduced amino acid sequences for the coat proteins and the nucleic acid binding proteins of two viruses showed high homologies to Garlic virus A (CarV-A) and Garlic virus D (GarV-D) of Allekivirus. This is the first report of GarV-A and GarV-D in Korea. This suggests that Allexivirus in gavlic plants in Korea was mixed and varied. Phylogenetic analyses showed that the genus Allexivirus was diversi(ied by the processes of accumulation and evolution of viruses in garlic plants due to the long period of repeated vegetative propagation.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.630-635
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• 1998

Tobacco mosaic tobamovirus (TMV), cucumber mosaic cucumovirus (CMV), cucumber green mottle mosaic tobamovirus (CGMMV) and zucchini yellow mosaic potyvirus (ZYMV) from individual fruits and seeds of hot pepper and cucumber were detected by the reverse transcription-polymerase chain reaction (RT-PCR). The dilution end-points for RT-PCR in curde sap from TMV. and CMV - infected hot pepper leaves and CMV - and CGMMV-infected cucumber leaves were 10-5. However, the amount of PCR product obtained from preparation of ZYMV-infected cucumber leaf was 10-fold lower than those of CMV or CGMMV-infected cucumber leaves. In hot pepper, both TMV and CMV were detected in all parts of the fruit wall tissue, but the yields of PCR products in the fruit stalk and its surrounding tissues were higher than those of the end parts of the fruit. On the other hand, in cucumber fruit infected with CMV, CGMMV or ZYMV, the fruit wall tissue and seed located in both stalk and end parts showed higher yields of PCR products than those of intermediate parts. Of five viruses that were analysed, only TMV in hot pepper seed, and CGMMV and CMV in cucumber seed were detected in testa parts.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.625-629
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• 1998

Turnip mosaic potyviruses (TuMV) were isolated from Rorippa indica and Armoracia lapathifolia showing mosaic symptoms in field. Identification of the TuMVs were carried out by host reactions of indicator plants, electron micrograph, serological properties and reverse transcription-poly-merase chain reaction (RT-PCR). Both viruses systemically infected Chenopodium quinoa, Nicotiana clevelandii, Brassica rapa, B. campestris subsp. pekinensis, B. juncea and Raphanus sativus, and developed local infection on inoculated leaves of C. quinoa, C. amaranticola, C. album, N. tabacum cv. Xanthi nc and Gomphrena grobosa. However, the viruses did not infect on N. glutinosa, Cucumis sativus and Vigna unguiculata. The filamentous particles, about 720 nm in length, and inclusion bodies were observed from the infected leaf tissues by dipping on electron microscopy. Crude sap of leaf infected with the viruses was reacted positively with an antiserum of TuMV in agar gel double diffusion. For detection of the viruses, RT-PCR was carried out with TuMV--specfic oligonucleotide primer. The RT-PCR products, a 1,092 bp DNA fragment, were obtained from naturally infected leaves of R. indica and A. lapathifolia. In inoculation test to seven cruciferous weeds with TuMV, infection occurred in Arabis glabra, Barbarea orthoceras, Capsella bursa-pastoris, Draba nomorosa var. hebecarpa, Rorippa cantoniensis and Thlaspi arvense.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.245-250
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• 2007

The complete genome sequence of Zucchini yellow mosaic virus stain A (ZYMV-A) isolated from a hollyhock (Althaea rosea) was determined by using RT-PCR with a series of primer sets. The virus genome consisted of 9593 nucleotides (nt), excluding the poly(A) tract at 3' terminus of the virus genome, with 5' and 3' untranslated region of 139 and 211 nt, respectively. The deduced polyprotein of ZYMV-A consisted of 3080 amino acid (aa) residues and was 351 kDa in molecular weight. All proteolytic cleavage sites of the polyprotein of ZYMV-A were compared with those of ZYMV strains, which showed the cleavage sites were conserved among ZYMV strains. The HC-Pro contained the KITC and PTK motifs, and the DAG motif was located at CP ORF of ZYMV-A, suggesting that ZYMV-A is aphid-transmissible. Phylogenetic tree analysis based on the complete genome among ZYMV strains or CP ORFs with other potyviruses showed ZYMV strains formed a distinct group. These results clearly confirmed that ZYMV-A was another distinct strain in ZYMV population at molecular level.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.76.1-76
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• 2003

The coat protein (CP) of Turnip crinkle virus (TCV) is organized into 3 distinct domains, R domain (RNA-binding) connected by an arm, 5 domain and P domain. We have previously shown that the CP of TCV strongly suppresses RNA silencing, and have mapped N-terminal R domain of which is also the elicitor of resistance response in the Arabidopsis ecotype Di-17 carrying the HRT resistance gene. In order to map the region in the TCV CP that is responsible for silencing suppression, a series of CP mutants were constructed, transformed into Agrobacterium, coinfiltrated either with HC-Pro (the helper component proteinase of tobacco etch potyvirus) known as a suppressor of PTGS or GFP constructs into leaves of Nicotiana benthmiana expressing GFP transgenically. In the presence of HC-Pro, all CP mutants were well protected, accumulating mutant CP mRNAs and their proteins even 5 days post-infiltration (DPI). In the presence of GFP, some mutant constructs which showed the accumulation of CP mutants and GFP mRNAs at early stage but eventually degraded at 5 DPI. Only a mutant which carrying 4 amino acid deletion of R domain was tolerable to maintain suppressing activity, suggesting that the suppressing activity is not directly related with the eliciting activity. A transient assay also revealed that the mutants synthesized their proteins, suggesting that a full length of CP sequences and its intact structure are required to stabilize CP, which suppresses the RNA silencing.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.97-102
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• 2006

A virus causing vein banding, sometimes yellow mosaic and rugose symptoms on peanut was prevalent around Suwon, Korea. A survey conducted in the area found disease incidence, depending on cultivar, to range from 79 to $100\%$. The virus was found to be seed-transmissible in all the five peanut cultivars tested with transmission rates ranging from 2 to $16\%$. Host range analysis failed to differentiate 9 field isolates collected from different peanuts cultivars showing various symptoms. Inclusion bodies such as scroll, pinwheel and long laminated aggregates induced by the virus in host plant cells were similar to those induced by members of the Potyvirus subdivision III. The virus showed < $95\%$ homology with Bean common mosaic virus (BCMV), BCMV-BICMV/AzMV strains and only < $91\%$ with Desmodium mosaic virus. Based on biological characterization, electron microscopy and molecular analyses of a Korean isolate (Daewon 1), the virus was identified as peanut stripe strain of BCMV.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1997.06a
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• pp.5-21
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• 1997

Unique virus-like particles were associated with five eriophyid mite-borne plant diseases of unknown etiology; fig mosaic, redbud yellow ringspot, rose orsette, thistle mosaic, and high plains disease of corn and wheat. Quasi-spherical, double membrane-bound particles (DMPs), 120 - 200 nm in diameter, were observed in the cytoplasm of all cell types in symptomatic leaves of infected plants. No DMPs were observed in symptomless plants. The DMPs in symptomatic thistles were associated with two types of inclusions, electron-dense amorphous material and tubular aggregates. Similar amorphous inclusions were also found in corn and wheat with high plains disease, while tubular inclusions were observed in figs with mosaic symptoms. The particles and inclusions were similar in some aspects to immature particles associated with viroplasms of animal and insect poxviruses and also to the double-enveloped particles of tomato spotted wilt virus associated with viroplasms during early stages of infection, but were unique and unlike any known plant viruses. The DMPs and associated viroplasm-like inclusions in the high plains disease were specifically immunogold labeled in situ with the disease-specific antiserum. Thread-like structures, similar to tenuivirus particles, present in the partially purified virus preparations were also immunogold labeled with the antiserum. It is suggested that the thread-like structures are derived from the DMP. In many cells of symptomatic corn and wheat samples, DMPs occurred together with flexuous rod-shaped particles and cylindrical inclusions of wheat streak mosaic potyvirus (WSMV), suggesting that the disease is caused by a mixed infection of WSMV and the agent represented by the DMPs. Based on cytopathology, symptomatology and mite and/or graft-transmissibility, the five diseases described in this paper are potentially caused by virus(es) and the DMPs associated with these diseases may represent virus particles. If the DMPs are indeed viral in nature, they would comprise a new group of plant viruses.

• Research in Plant Disease
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• v.19 no.4
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• pp.313-318
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• 2013

In March, 2013, twenty symptomatic freesia plants (10 plants of cultivar Shiny Lemon and 10 plants of cultivar Shiny Gold), with striking virus-like symptoms were collected in Cheongju, Korea. The plants showed chlorotic, coalescing, interveinal, whitish, necrotic, mosaic, mottling or dark brown-to-purple necrotic spots on leaves. Freesia crude sap was directly analyzed by transmission electron microscopy, which potyvirus particles as well as long virus-like particles were detected. Total RNA extracts were analyzed for the infection of Freesia sneak virus (FreSV) by reverse transcription (RT)-PCR with primers specific to FreSV coat protein (CP) gene based on the sequences of FreSV isolates (GenBank No. GU071089, FJ807730 and DQ885455), showing 9 of 20 plants were infected. All 1305bp RT-PCR products were cloned and sequenced. Comparisons of nucleotide and deduced amino acid sequences using BLAST and bioinformatics tools resulted in 99 to 100% sequence identity with FreSV isolates FOV, Virginia, and Italy, confirming FreSV in 9 symptomatic freesia plants. Of 9 determined cDNAs of FreSV isolates, sequences of 5 cDNA clones were identical (GenBank No. AB811437) and sequences of 4 cDNA clones were identical (GenBank No. AB811792). To our knowledge, this is the first report of FreSV from Freesia spp. in Korea.