• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.75.1-75
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• 2003

Barely yellow mosaic(BaYMV) and barely mild mosaic (BaMMV) bymoviruses are both transmitted by the soil-inhabiting fungus Polymyxa gramnis, and are responsible for economic losses in barley crops in Asia and Europe. Because chemical control of the vector is ineffective, the losses can only be prevented by growing resistant barley cultivars. The objective of this study is to produce resistant barley plants by transformation with viral coat protein(cp) genes. Resistance tests of T1 plants transformed with the BaYMV CP gene showed that at least four independent lines had clear resistance to BaYMV but two other lines were highly susceptible with severe symptoms. The CP gene was detected in all resistant T1 plants by genomic PCR. Most of T2 progenies derived from the resistant T1 lines also showed resistance. In contrast, only one out of 21 independent T2 lines transformed with the BAMMV CP gene tested showed clear resistance to BaMMV, and others were very susceptible. Further analyses of resistance and CP gene expression are in progress.

• 식물조직배양학회지
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• 제22권3호
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• pp.149-155
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• 1995

국내에서 분리 동정한 오이모자이크 바이러스(CMV)로부터 외피단백질(CP) 유전자를 분리하였고 이의 염기서열을 결정한 결과 129번째 아미노산이 proline으로서 mosaic symptom을 보이고 염기 및 아미노산 서열의 유사성을 비교한 결과 subgroup I (type I)에 속한다는 것을 확인하였다. 분리한 CP 유전자를 식물형질전환용 운반체에 삽입하여 담배 재배종인 NC82와 바이러스 증식용인 Samsun에 잎절편을 통하여 형질전환시켰다. 형질전환된 담배의 DNA를 분리하여 Southern blotting과 PCR을 수행한 결과 대부분의 형질전환체에 CP 유전자가 삽입되였음을 확인하였고 T$_1$ 종자를 kanamycin이 첨가된 배지에서 후대 항생제 저항성 검정을 실시한 결과 1개의 CP 유전자가 삽입된 경우가 50%에 달했고 2개와 3개의 유전자가 삽입된 경우도 각각 39%와 11%에 달했다.

• The Plant Pathology Journal
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• 제16권1호
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• pp.48-51
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• 2000

Citrus tristeza virus (CTV) was identified form CTV-infected early satsuma mandarin (Citus unshiu) and yuzu (C.junos) by RT-PCR. The total RNAs were isolated from citrus bark and seaf tissues infected with CTV and reverse transcription was followed with primers designed for amplifying CTV coat protein gene. DNA fragments 738 bp were amplified by RT-PCR and these products were colned for sequence analysis. Based on the sequence analysis, this PCR product has 97% sequence homology to CTV (T-385) CP gene isolated from USA. RT-PCR assay for CTV detection was more sensitivity than ELISA assay which was done with anti-CTV CP antibody. This is the frist report about CTV identification in Cheju island Korea.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.145.1-145
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• 2003

This study was conducted to designing conserved regions of molecules for virus-derived resistance to transgenic Phlaenopsis orchids to protect against two major orchid viruses, Cymbidum mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV). Infected leaf samples of Phalaenopsis were randomly screened by the RT-PCR with specific primers to both of viruses. RT-PCR products of the viruses were cloned and their nucleotide sequences were determined. Multiple alignments of coat protein (CP) genes of the viruses revealed that over the 88 ％ and 94 ％ identities with CymMV and ORSV, respectively, were observed. These data can be useful for selection of highly conserved regions of CP gene of the viruses for transgenic orchid experiments.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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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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• 제22권2호
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• pp.125-130
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• 2006

An isolate of Peanut stunt virus (PSV) isolated from black locust tree (Robinia pseudo-acacia L.) showing severe mosaic and malformation symptoms, was designated as PSV-Rp. PSV-Rp was characterized by the tests of host range, physical properties, RNA and coat protein composition and RT-PCR analysis. Nucleotide sequences of the cucumoviruses CP genes were also used for identification and differentiation of PSV-Rp. Six plant species were used in the host range test of PSV-Rp. PSV-Rp could be differentiated from each Cucumovirus strain used as a control by symptoms of the plants. The physical properties of PSV-Rp virus were TIP $65^{\circ}C$, DEP $10^{-3}$, and LIP $2{\sim}3$ days. In dsRNA analysis, PSV-Rp consisted of four dsRNAs, but satellite RNA was not detected. Analysis of the coat proteins by SDS-PAGE showed one major protein band of about 31 kDa. RT-PCR using a part of Cucumovirus RNA3 specific primer amplified ${\sim}950bp$ DNA fragments from the crude sap of virus-infected black locust leaves. RFLP analysis of the RT-PCR product could differential PSV-RP from CMV The nucleotide sequence identity between the PSV-Rp CP and the TAV-P CP genes and the PS-V-RP CP and CMV-Y CP genes were 61.6% and 40.5%, respectively. On the other hand, the nucleotide sequence identity of the PSV-Rp CP gene was $70.9%{\sim}73.4%$ in comparison with those of PSV subgroup I (PSV-ER and PSV-J) and 67.3% with that of PSV subgroup II(PSV-W). Especially, the nucleotide sequence identity of PSV-Rp CP gene and that of PSV-Mi that was proposed recently as the type member of a novel PSV subgroup III was 92.4%.

• The Plant Pathology Journal
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• 제33권3호
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• pp.296-306
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• 2017

Sugarcane mosaic virus (SCMV) is one of the most damaging viruses infecting sugarcane, maize and some other graminaceous species around the world. To investigate the genetic diversity of SCMV in Iran, the coat protein (CP) gene sequences of 23 SCMV isolates from different hosts were determined. The nucleotide sequence identity among Iranian isolates was more than 96%. They shared nucleotide identities of 75.5-99.9% with those of other SCMV isolates available in GenBank, the highest with the Egyptian isolate EGY7-1 (97.5-99.9%). The results of phylogenetic analysis suggested five divergent evolutionary lineages that did not completely reflect the geographical origin or host plant of the isolates. Population genetic analysis revealed greater between-group than within-group evolutionary divergence values, further supporting the results of the phylogenetic analysis. Our results indicated that natural selection might have contributed to the evolution of isolates belonging to the five identified SCMV groups, with infrequent genetic exchanges occurring between them. Phylogenetic analyses and the estimation of genetic distance indicated that Iranian isolates have low genetic diversity. No recombination was found in the CP cistron of Iranian isolates and the CP gene was under negative selection. These findings provide a comprehensive analysis of the population structure and driving forces for the evolution of SCMV with implications for global exchange of sugarcane germplasm. Gene flow, selection and somehow homologous recombination were found to be the important evolutionary factors shaping the genetic structure of SCMV populations.

• The Plant Pathology Journal
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• 제29권3호
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• pp.260-273
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• 2013

The incidence and distribution of Tobacco mosaic virus (TMV) and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP) gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100%) among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each subgroup was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

• The Plant Pathology Journal
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• 제19권2호
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• pp.123-127
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• 2003

A severe disease of muskmelon (Cucumis melo cv. Alsnight) grown on rockwool in a plastic house was characterized by leaf and stem necrosis followed by death of the plants. In 2001, an isolate of Melon necrotic spot virus-MN (MNSV-MN) of the genus Camovirus was identified as the causal agent of the disease on the basis of biological reactions and nucleotide sequence analyses of coat protein (CP) gene. MNSV-MN induced necrotic local lesions on mechanically inoculated leaves and systemic necrotic spots on the upper leaves of melon cvs. Alsnight, Rui III, Party, Imperial, and Seolhang. However, the inoculated leaves of watermelon and cucumber showed only necrotic lesions. DsRNAs extracted from the melon infected with MNSV-MN were separated into three components. Molecular sizes of the dsRNAs were estimated at approximately 4.5, 1.8, and 1.6 kbp. The amplified cDNA products of CP gene for MNSV-MN by RT-PCR showed approximately 1.2 kbp. The amplified DNA was digested to three fragments by MspI treatment. The cDNA of the genomic RNA of MNSV-MN was cloned and the region deduced to encode the CP was sequenced. The CP coding region, located near 3' end of the genome, consisted of 1,170 nucleotides and had the potential to encode a 390 amino acid protein. The nucleotide and amino acid sequences of MNSV-MN CP gene were 84.0-94.6% and 90.8-94.9% identical with other MNSV isolates found in the GeneBank database, respectively. This is the first report on the occurrence of MNSV in Korea.

• The Plant Pathology Journal
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• 제16권1호
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• pp.43-47
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• 2000

Citrus tristeza virus (CTV) is the causal agent of one of the most important diseases of citrus. Recently, CTV has been detected in Cheju Island by ELISA. The coat protein (CP) gene of CTV isolated form Cheju Island was cloned by RT-PCR and the nucleotide was analyzed in this study. Citrus leaves were collected from trees showing decline symptoms from various region of Cheju Island in the summer of 1998 and 1999. The CP gene open reading frame is composed of 670 nucleotides and encodes a polypeptide of 223 amono acids. Sequence analysis the CP gene revealed that two CTV strains present in Cheju Island. Viruses collected form Sogwipo area and Cheju City area in 1999 ahowed 91-93% nucleotide sequence homology with CTV T36 strain. Viruses collected form Cheju City area in 1999 and Sogwipo City in 1998 showed 94-98% nucleotide sequence homology with CTV SY568 strain. A efficient viral RNA extraction methods was developed by modifying procedure for animal virus RNA purification methods and PCR product was detected form one tenth of RNA purified from as small as 45 mg fresh or frozen tissue.