• 농업과학연구
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• 제45권1호
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• pp.38-42
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• 2018

Demand for tomatoes has been increasing every year as people desire more healthy food. In Korea, tomatoes are mainly grown in the Chungnam, Chunnam and Kyungnam provinces. Recently, reports of whitefly-transmitted viral diseases have increased due to newly emerging whitefly pressures caused by climate change in Korea. Specifically, in 2017, the main tomato growing areas, Buyeo and Nonsan in Chungnam, showed damage typical of viral infection; therefore, we investigated viral diseases in these areas. We collected samples with virus-like symptoms and found that not only whitefly transmitted Tomato yellow leaf curl virus (TYLCV) and Tomato chlorosis virus (ToCV) were detected but also Tomato mosaic virus (ToMV, for which no specific vector is known) and Tomato spotted wilt virus (TSWV, transmitted by thrips). The ToMV-infected samples were mostly co-infected with either TYLCV or ToCV. Mixed infections of different combinations of TYLCV, ToCV and ToMV were detected with the mixed infection of two whitefly-transmitted viruses (TYLCV and ToCV) causing the most severe symptoms. According to the CP sequence of each virus, the 100% identities were shown to be Mexico/ABG73017.1 (TYLCV), Greece/CDG34553.1 (ToCV), China/AKN79752 (TSWV), and Australia/NP078449.1 (ToMV). Based on the sequence data, we presumed that these tomato infecting viruses were transmitted through insects and seeds introduced from neighboring countries.

• BMB Reports
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• 제47권6호
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• pp.330-335
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• 2014

Turnip yellow mosaic virus (TYMV) is a spherical plant virus that has a single 6.3 kb positive strand RNA as a genome. In this study, RNA1 sequence of Flock house virus (FHV) was inserted into the TYMV genome to test whether TYMV can accommodate and express another viral entity. In the resulting construct, designated TY-FHV, the FHV RNA1 sequence was expressed as a TYMV subgenomic RNA. Northern analysis of the Nicotiana benthamiana leaves agroinfiltrated with the TY-FHV showed that both genomic and subgenomic FHV RNAs were abundantly produced. This indicates that the FHV RNA1 sequence was correctly expressed and translated to produce a functional FHV replicase. Although these FHV RNAs were not encapsidated, the FHV RNA having a TYMV CP sequence at the 3'-end was efficiently encapsidated. When an eGFP gene was inserted into the B2 ORF of the FHV sequence, a fusion protein of B2-eGFP was produced as expected.

• The Plant Pathology Journal
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• 제23권2호
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• pp.103-105
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• 2007

Mechanical transmission of barley seedlings with barley yellow mosaic virus (BaYMV) is generally inefficient and is the major constraint for testing cultivar resistance to the virus. To explore mechanical transmission, BaYMV-infected barley plants were grown at different conditions and used as inoculum sources to seedlings of susceptible barley cultivar Baegdong. Extracts prepared from BaYMV-infected Baegdong plants at 47, 53, 74, and 90 days after symptom appearance (DASA) and grown at 10 and $12^{\circ}C$ gave 10, 30, 68 and 76% infection, respectively on inoculated susceptible barley cv. Baegdong seedlings. While Jinyangbori, another susceptible cultivar obtained 95% infection rate inoculated with extracts from 90 DASA disease source and grown at $10/12^{\circ}C$. However, low infection rates were obtained when the virus sources were grown in a greenhouse at $15-18^{\circ}C$. Our results indicate that longer incubation period and lower temperature are required for virus accumulation and stability.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1110-1114
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• 2005

Six viruses of the genera Carlavirus (Garlic mosaic virus, GarMV, and Garlic latent virus, GarLV), Allexivirus (Garlic virus X, GarV-X, and Garlic mite-borne filamentous virus, GarMbFV) and Potyvirus (Leek yellow stripe virus, LYSV, and Onion yellow dwarf virus, OYDV) from Korean garlic plants with mosaic symptoms were simultaneously detected by multiplex RT-PCR and subsequently sequenced. An immunocapture RT-PCR for the detection of GarLV, LYSV, and OYDV was also performed. The coat protein phylogenetic analysis of the garlic viruses showed that the Korean isolates were most closely related to the isolates from China, Japan, Brazil, and Argentina. This study is the first report for the differentiation of six garlic viruses in Korea by simultaneous detection using multiplex RT-PCR.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1790-1798
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• 2019

Flock House virus (FHV), an insect RNA virus, has a bipartite genome. FHV RNA1 can be packaged in turnip yellow mosaic virus (TYMV) as long as the FHV RNA has a TYMV sequence at the 3'-end. The encapsidated FHV RNA1 has four additional nucleotides at the 5'-end. We investigated whether the recombinant FHV RNA1 could replicate in mammalian cells. To address this issue, we prepared in vitro transcribed FHV RNAs that mimicked the recombinant FHV RNA1, and introduced them into baby hamster kidney (BHK) cells. The result showed that the recombinant FHV RNA1 was capable of replication. An eGFP gene inserted into the frame with B2 gene of the FHV RNA1 was also successfully expressed. We also observed that eGFP expression at the protein level was strong at 28℃ but weak at 30℃. Sequence analysis showed that the 3'-ends of the RNA1 and RNA3 replication products were identical to those of the authentic FHV RNAs. This indicates that FHV replicase correctly recognized an internally-located replication signal. In contrast, the 5'-ends of recombinant FHV RNA1 frequently had deletions, indicating random initiation of (+)-strand synthesis.

• BMB Reports
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• 제46권10호
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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.

• 한국식물병리학회지
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• 제14권1호
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• pp.62-67
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• 1998

Barley yellow mosaic virus (BaYMV-HN) occurring Haenam area was isolated by mechanical inoculation onto barley cultivars, purification and production of antibody. BaYV-HN were purified from infected plants a filamentous virus with 13 nm in diameter and 250∼300 nm and 500∼650 nm in length. Specific antibody made by injecting the purified virus to the muscle of a rabbit. In gel-diffusion tests antibody to BaYMV-HN did not make spur with tow Japanese BaYMV isolates BaYMV-II-1 or BaYMV-III. BaYMV-HN showed the symptom of yellowing and necrosis in host plants. Mechanical inoculation tests with Japanese barley cultivars showed that BaYMV-HN infected New Golden, Akagi Nijo and Tosan Kawa 73, but did not infect Amagi Nijo, Haruna Nijo, Ishukushirazu (ym3), Misato Golden (Ym1), Kashimamugi, Joshushiro Hadaka and Mokusekko 3 (ym1). In Korean barley cultivars, some of the naked barleys which are Hinssalbori, Kinssalbori, Saessalbori and Saechalssalbori were not infected by BaYMV-HN. However, it infected all the covered barley cultivars and the beer barley cultivars. BaYMV-HN had two RNAs, RNA 1 (7.6 Kb) and RNA 2 (3.5 Kb), and one coat protein (33 KDa).

• The Plant Pathology Journal
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• 제23권4호
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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.

• The Plant Pathology Journal
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• 제32권1호
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• pp.70-76
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• 2016

The infectious full-length cDNA clone of zucchini yellow mosaic virus (ZYMV) isolate PA (pZYMV-PA), which was isolated from pumpkin, was constructed by utilizing viral transcription and processing signals to produce infectious in vivo transcripts. Simple rub-inoculation of plasmid DNAs of pZYMV-PA was successful to cause infection of zucchini plants (Cucurbita pepo L.). We further engineered this infectious cDNA clone of ZYMV as a viral vector for systemic expression of heterologous proteins in cucurbits. We successfully expressed two reporter genes including gfp and bar in zucchini plants by simple rub-inoculation of plasmid DNAs of the ZYMV-based expression constructs. Our method of the ZYMV-based viral vector in association with the simple rub-inoculation provides an easy and rapid approach for introduction and evaluation of heterologous genes in cucurbits.

• The Plant Pathology Journal
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• 제29권3호
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• pp.285-293
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• 2013

Leaf samples of Solanum lycopersicum, Capsicum annuum, Cucurbita moschata, Cucurbita pepo, Sechium edule and Erythrina spp. were collected. All samples were positive for begomoviruses using polymerase chain reaction and degenerate primers. A sequence of ~1,100 bp was obtained from the genomic component DNA-A of 14 samples. In addition, one sequence of ~580 bp corresponding to the coat protein (AV1) was obtained from a chayote (S. edule) leaf sample. The presence of Squash yellow mild mottle virus (SYMMoV) and Pepper golden mosaic virus (PepGMV) were confirmed. The host range reported for SYMMoV includes species of the Cucurbitaceae, Caricaceae and Fabaceae families. This report extends the host range of SYMMoV to include the Solanaceae family, and extends the host range of PepGMV to include C. moschata, C. pepo and the Fabaceae Erythrina spp. This is the first report of a begomovirus (PepGMV) infecting chayote in the Western Hemisphere.