• The Plant Pathology Journal
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• v.37 no.2
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• pp.162-172
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• 2021

Soybean mosaic virus (SMV) is the predominant viral pathogen that affects the yield and quality of soybean. The natural host range for SMV is very narrow, and generally limited to Leguminosae. However, we found that SMV can naturally infect Pinellia ternata and Atractylodes macrocephala. In order to clarify the molecular mechanisms underlying the cross-family infection of SMV, we used double-stranded RNA extraction, rapid amplification of cDNA ends polymerase chain reaction and Gibson assembly techniques to carry out SMV full-length genome amplification from susceptible soybeans and constructed an infectious cDNA clone for SMV. The genome of the SMV Shanxi isolate (SMV-SX) consists of 9,587 nt and encodes a polyprotein consisting of 3,067 aa. SMV-SX and SMV-XFQ008 had the highest nucleotide and amino acid sequence identities of 97.03% and 98.50%, respectively. A phylogenetic tree indicated that SMV-SX and SMV-XFQ018 were clustered together, sharing the closest relationship. We then constructed a pSMV-SX infectious cDNA clone by Gibson assembly technology and used this clone to inoculate soybean and Ailanthus altissima; the symptoms of these hosts were similar to those caused by the virus isolated from natural infected plant tissue. This method of construction not only makes up for the time-consuming and laborious defect of traditional methods used to construct infectious cDNA clones, but also avoids the toxicity of the Potyvirus special sequence to Escherichia coli, thus providing a useful cloning strategy for the construction of infectious cDNA clones for other viruses and laying down a foundation for the further investigation of SMV cross-family infection mechanisms.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.137.2-138
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• 2003

The commercial cultivars of red pepper were screened against Tobacco mosaic virus (TMV), Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) by seedling test. Tn single infection of TMV or PMMoV, mosaic symptom was produced on the cultivars of 'Cheongyang'and 'Wangshilgun'. However, in cultivars of 'Manilla'and 'Bugang', symptoms were not occurred. In single infection of PepMoV, symptoms of mottle and malformation were produced on the tested cultivars of 'Manilla', 'Bugang', 'Cheongyang'and 'Wangshilgun' In the cultivars of 'Cheongyang'and 'Wangshilgun', synergistic symptoms of stunt and lethal death were induced by mixed infections in the two combinations of TMV+PepMoV and PMMoV+PepMoV. However, in cultivars of 'Manilla'and 'Bugang', synergistic symptom was not occurred as mottle which was milder than that of single infection. Cells were single infected with TMV and PMMoV the cultivars of 'Cheongyang'and 'Wangshilgun', respectively, had typical ultrastructures of tobamovirus as the stacked-band structure and multiple spiral aggregate (SA). Ultrastructures of cell and tissues infected with PepMoV on the cultivars of 'Cheongyang', 'Wangshilgun', 'Manilla'and 'Bugang', the potyvirus inclusions of pinwhills, scrolls, lamminated aggregates and amorphous inclusion were observed. Infected cells with a combination of TMV+PepMoV and PMMoV+PepMoV, the virus particles and inclusions of the two different viruses were found only mixed infection in the same cytoplasm and the amounts of viruses in mixed infections were abundant than in single infection. The angled-layer aggregates (ALA) was observed in the cells infected mixedly with TMV and PepMoV

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.141.2-142
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• 2003

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing green mosaic and puckering symptoms at Anseong, Korea. Based on the biological tests, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the isolate was identified as Papaya ringspot virus type Watermelon (PRSV-W). In the biological test, host range of PRSV-W was limited in the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucurmis lanatus, Cucurmis sativus, Cucurbita pepo, and Citrullus lanatus, responded to mechanical inoculation by PRSV-W that induce green mosaic, malformation, puckering, and narrow laminae. The local lesion symptoms were produced on the inoculated leaves of Chenopodium maranticolor and C. quinoa PRSV specific primers which amplifies the part of the coat protein (CP) genes, generated a 648 bp product from 6 isolates of PRSV-W, but no amplification had been detected in other viruses including CMV, CGMMV, KGMMV, ZYMV and WMV. In electron microscopy, PRSV particles were flexuous, approximately 780 nm in length and 12 nm in width. PRSV-W is one of the worldwide viruses which has the great economic importance in cucumber, melon, squash, watermelon, and other cultivated cucurbits with ZYMV and WMV. This is the first report of PRSV-W on cucurbits in Korea.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.467-477
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• 2017

A nationwide survey was performed to investigate the current incidence of viral diseases in Korean sweet potatoes for germplasm and growing fields from 2011 to 2014. A total of 83.8% of the germplasm in Korea was infected with viruses in 2011. Commercial cultivars that were used to supply growing fields were infected at a rate of 62.1% in 2012. Among surveyed viruses, the incidence of five Potyvirus species that infect sweet potato decreased between 2012 and 2013, and then increased again in 2014. Representatively, the incidence of Sweet potato feathery mottle virus (SPFMV) was 87.0% in 2012, 20.7% in 2013 and then increased to 35.3% in 2014. Unlike RNA viruses, DNA viruses were shown to decrease continuously. The incidence of Sweet potato leaf curl virus (SPLCV) was 5.5% in 2003, 59.5% in 2011, and 47.4% in 2012. It then decreased continuously year by year to 33.2% in 2013, and then 25.6% in 2014. While the infection rate of each virus species showed a tendency to decline, the virus infection status was more variable in 2013 and 2014. Nevertheless, the high rate of single infections and mixed infection combinations were more variable than the survey results from 2012. As shown in the results from 2013, the most prevalent virus infection was a single infection at 27.6%, with the highest rate of infection belonging to sweet potato symptomless virus-1 (SPSMV-1) (12.9%). Compared to 2013, infection combinations were more varied in 2014, with a total of 122 kinds of mixed infection.

• Research in Plant Disease
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• v.20 no.4
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• pp.307-313
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• 2014

In May 2013, an angel's trumpet leaves showing mosaic and malformation symptoms were collected from Suwon city, Gyeonggi-do. An analysis of the collected sample by transmission electron microscopy observation showed filamentous rod particles of 720-800 nm in length. On the basis of the these observations, we performed PCR against three reported Potyviruses (Brugmansia mosaic virus, Colombian datura virus and Brugmansia suaveolens mottle virus), and the sample was positive for BruMV. Pathogenicity and host range test of BruMV was determined by mechanical inoculation. Solanaceae (tobacco, tomato and eggplant) and Amaranthaceae (ground cherry) appeared typical virus symptoms. To determine coat protein of this virus, we designed specific primer pairs, and performed PCR amplification, cloning, and sequencing. Phylogenetic analysis showed that BruMV-SW was most closely related to BruMV isolate SK. Comparison of the BruMV-SW coat protein nucleotide sequences showed 92% to 99% identities to the other BruMV isolates.

• Research in Plant Disease
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• v.19 no.4
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• pp.331-337
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• 2013

A disease, supposedly caused by a virus, was observed from Insam (Panax ginseng) fields of Punggi in year 2006. It has long believed to be a physiological disorder. However, the incidence of the disease has increased every year. When several samples were observed under electron microscope, filamentous virus-like particles were observed. The nucleotide sequences of the virus were analyzed by RT-PCR with specific primer sets derived from the results of DNA chip. The results indicated that the disease was caused by Watermelon mosaic virus (WMV). It revealed that the result of the biological assay by the virus was different from that of WMV previously found in other crops. Therefore, this is the first report that WMV causes the disease in P. ginseng and the virus is named to be WMV-Insam.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.117-122
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• 2003

Six isolates of Turnip mosaic Potyvirus (TuMV) namely, TuMV-CA7 from oriental cabbage, TuMV-TU and TuMV-TU2 from turnip, TuMV-RA from rape, TUMV-ST from stock, and TuMV-R9 from radish, and Ribgrass mosaic Tobamovirus (RMV-FG22) from oriental cabbage were isolated. Three kinds of characteristics of the six TuMV isolates were sorted by bioassay: TuMV-CA7 and TuMV-TU isolates infected mostly oriental cabbages; TuMV-ST, TuMV-TU2, and TuMV-R9 infected radishes; and TuMV-RA infected both oriental cabbages and radishes. Mixed infections of crucifers were RMV-FG22+TuMV-CA7, RMV-FG22+TuMV-TU, RMV-FG22+TuMV-RA, RMV-FG22+TuMV-ST, RMV-FG22 +TuMV-TU2 and RMV-FG22+TuMV-R9. Crops used were 'Tambok' cultivar resistant to TuMV, 'SSD63' susceptible inbred line of oriental cabbage, pure line of leaf mustard and 'Daeburyungyeorum' cultivar of radish. New specific ultrastructures of nonagon-like ring (NLR) and spiral aggregates (SA) by mixed infection with TuMV and RMV were formed in cells of crucifer plants. The NLR was made by a TuMV surrounded loosely by nine RMV particles, and the SA was formed spirally by full mixed of two virus particles. The SA had some NLR in its center, which was observed from cross sectioned SA. Host plants with specific ultrastructures expressed synergistic symptoms. Specific ultrastructures of NLR and SA were formed in combinations of RMV-FG22 and in TuMV-CA7, TuMV-TU, or TuMV-RA that could infect oriental cabbages. How-ever, no specific ultrastructures and mixing of the two virions in the same cell were observed in combinations of RMV-FG22, and TuMV-57, TuMV-TU2, or TuMV-R9 isolates haying virulence in radishes.

• Research in Plant Disease
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• v.26 no.4
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• pp.283-288
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• 2020

In September 2017, vein clearing and yellowing symptoms resembling those caused by viruses were observed on leaves of Malva verticillata in Chungnam, Korea. Nucleic acids were extracted from leaves of five symptomatic plants and tested by reverse transcription polymerase chain reaction using four virus specific primer pairs including malva vein clearing virus (MVCV). Amplicons of the expected size (600 bp) were obtained from total RNA of all samples using the MVCV-specific primers. To confirm the presence of MVCV in symptomatic plants, the DNA fragments from three samples were purified, and directly sequenced. BLAST analysis revealed that it shared the highest nucleotide identity (99%) with a MVCV isolate from tomato (Mexico). The virus isolates obtained from the third re-inoculated Chenopodium was designated as Cm1-5. Tissue from Cm1, Cm3, and Cm5 isolates was mechanically sap inoculated into 23 indicator plants. Cm3 isolate induced chlorotic local and mosaic symptoms in Althaea rosea. Phylogenetic analysis based on coat protein gene of 19 MVCV isolates from 6 different countries and plant species, did not correlated with either the geographical origin of the isolates, or pathogenicity. To our knowledge, this study first reports the natural occurrence of MVCV on M. verticillata in Korea and characterization of three Korean isolates of MVCV.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.55-62
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• 1995

To understand the molecular structure of Korean garlic viruses, cDNA cloning of virus genomic RNA was attempted. Virus particles were isolated from virus-infected garlic leaves and a cDNA library was constructed from garlic virus RNA. One of these clones, S81, selected by random sequencing has been identified as a member of potexvirus group other than potyvirus and carlavirus. The clone is 873 bp long contains most of the coat protein (CP) coding region and 3'-noncoding region including poly(A) tail. A putative polyadenylation signal sequence (AAUAAA) and the hexanucleotide motif (ACUUAA), a replicational cis-acting element conserved in the 3'-noncoding region of potexvirus RNAs are noticed. The clone S81 shows about 30-40% identity in both nucleotide and amino acid sequences with CPs of potexviruses. The genome size of the virus was analysed to be 7.46 knt by Northern blot analysis, which was longer than those of other potexviruses. The open reading frame encoding CP was expressed as a fusion protein (S81CP) in Escherichia coli and the recombinant protein was purified by immobilized metal binding affinity chromatography. Polyclonal antibody was raised against S81CP in rabbit to examine the occurrence of garlic potexvirus in Korean garlic plants by immunoblot analysis. Two virus protein bands of Mr 27,000 and 29,000 from garlic leaf extract of various cultivars reacted with the antibody. It was shown that Mr 27,000 band might not be a degradation product of Mr 29,000 band, suggesting that two types of potexvirus different in size of coat protein could exist in Korean garlic plants.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.298-308
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• 2009

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing as green mosaic and puckering symptoms at Anseong, Korea. Based on the biological analysis, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the virus isolate was identified as Papaya ringspot virus type watermelon (PRSV-W). From biological analysis, the host range of PRSV-W was limited to the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucumis lanatus, Cucumis sativus, Cucurbita pepo, and Citrullus lanatus, showed symptoms of green mosaic, malformation, puckering, and narrow laminae by infection with PRSV-W. The local lesion were showed on the inoculated leaves of both Chenopodium amaranticolor and C. quinoa. Field survey of PRSV, Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV), three major viruses infecting cucurbit, was done during 2001 to 2003 on 173 commercial cucurbit cultivating fields distributed over the three regions of Gyeonggi, Gyeongbuk and Jeonnam Provinces where cucurbits are grown in different environmental conditions and cropping patterns. Typical viral symptoms were observed from 107 cultivating fields, and all three kinds of potyviruses were detected from 206 samples out of the 235 samples using RT-PCR. Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) are the most widely distributed viruses in outdoor and retarding-culture fields, at an infection rating of 48 and 33 percents, respectively. PRSV was detected from 12 percent of 235 samples. The nucleotide and amino acid sequences of coat proteins (CP) of eight PRSV isolates, collected from several areas including Anseong, were determined and sequenced heterogeneity among the isolates was performed. The CP gene of PRSV showed 88.6~97.3 percent homology in nucleotide sequences and 95.1~99.3 percent homology in amino acid sequences with other PRSV isolates worldwide. The phylogenetic analysis indicated that the Korean PRSV isolates belong to the southern-east Asian cluster.