• The Plant Pathology Journal
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• v.20 no.3
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• pp.212-219
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• 2004

Three isolates of Cucumber mosaic virus (CMV) from lily plants showing mosaic and distortion symptoms were detected by reverse-transcriptase polymerase chain reaction (RT-PCR) using primers specific to Cucumovirus genus namely, LK-CMV, LK4-CMV, and LKS-CMV. Restriction enzymes patterns of the RT-PCR products revealed that the lily isolates belonged to subgroup IA of CMV. In terms of biological properties, the lily isolates have highly similar but distinct pathogenicity as reported in other lily strains and ordinary strains of CMV. To characterize the molecular properties, cDNAs containing coat protein (CP) gene and 3' non-coding region (NCR) of RNA3 for the isolates were cloned and their nucleotide sequences were determined. The CP similarity (218 amino acids) was highly homologous (>97％) with that of subgroup I CMV strains. However, an additional 20-nulcleotide long segment was only present in 3' NCR of lily isolates, which form an additional stem-loop RNA structure. By using chimeric construct exchange cDNA containing 3'NCR of LK-CMV into the full-length cDNA clone of RNA3 of Fny-CMV, this additional segment may prove to be significant in the identification and fitness of the virus in lily plants. The pathology of zucchini squash infected by F1F2L3-CMV, a pseudorecombinant virus was showed to change drastically the severe mosaic and stunting symptom into a mild chlorotic spot on systemic leave, compared with Fny-CMV. To delimit the sequence of RNA3 affected the pathology, various RNA3 chimeras were constructed between two strains of CMV. The symptom determinants of F1F2L3-CMV were mapped to the positions amino acid 234, 239, and 250 in 3a movement protein (MP). RNA3 chimeras changed the sequences encoding three amino acids were resulted in alteration of systemic symptom.

• The Plant Pathology Journal
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• v.18 no.2
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• pp.85-92
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• 2002

A new isolate of Cucumber mosaic virus (CMV), identified as Li-CMV was isolated from a diseased Korean native lily (Lithium tsingtauense Gilg). Biological and serological properties of Li-CMV were characterized, and reverse transcription-polymerase chain reaction (RT-PCR) analysis, restriction enzyme profiling of RT-PCR products, and nucleotide sequence analysis of RNA3 of the virus were performed in this study. Remarkable differences in symptoms between Li-CMV and ordinary CMV strains were found in tobacco plants and Datura stramonium. Li-CMV-infected tobacco plants (cv. Xanthi-nc and cv. Samsun) induced chlorotic ringspots on uninoculated upper leaves, and the symptom expression was delayed or faint whereas, ordinary CMV strains induced green mosaic symptoms on the plant. Systemic infections were observed on Nicotiana benthamiana with severe mosaic symptom. Restriction mapping analysis of RT-PCR products using MspI showed that Li-CMV belonged to CMV subgroup I. A full-length CDNA copy of RNA3 for the virus was amplified by RT-PCR, cloned, and its complete nucleotide sequence was determined. The RNA3 of Li-CMV was 2, 232 nucleotides long, and consisted of two open reading frames of 843 and 657 bases encoding 3a protein (movement protein) and coat protein, respectively. Results of this study indicate that Li-CMV is a novel strain and belongs to subgroup I of CMV in the genus Cucumovirus.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.142-148
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• 2005

Whereas most of isolates of Cucumber mosaic virus(CMV) can induce green mosaic systemic symptoms on zucchini squash, foliar symptoms of a pepper isolate of CMV (Pf-CMV)-infected zucchini squash revealed systemic chlorotic spots. To assess this biological property, infectious full-length cDNA clones of Pf-CMV were constructed using long-template RT-PCR. The complete nucleotide sequences of RNA2 and RNA3 of Pf-CMV were determined from the infectious fulllength cDNA clones, respectively. RNA 2 and RNA3 of Pf-CMV contain 3,070 nucleotides and 2,213 nucleotides, respectively. Overall sequence homology of two RNAs revealed high similarity (90%) between CMV strains, and 60% similarity to those of Tomato aspermy virus and Peanut stunt virus strains. By sequence analysis with known representative strains of CMV, Pf- CMV belongs to a typical member of CMV subgroup IA. The virus has high evolutionary relationship with Fny-CMV, but the pathology of Pf-CMV in zucchini squash was quite different from that of Fny-CMV. The pesudorecombinant virus, F1P2P3, induced chlorotic spot leaf symptom and timing of systemic symptom in squash plants, similar to the plants infected by Pf-CMV. No systemic symptoms were observed when Pf-CMVinoculated cotyledons were removed at 5 days postinoculation (dpi) while Fny-CMV showed systemic symptom at 2 dpi. These results suggest that the pepper isolate of CMV possesses unique pathological properties distinguishable to other isolates of CMVs in zucchini squash.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.115-125
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• 1991

The medicinal plants of 33 species with symptoms of mosaic, necrosis, line pattern, malformation (fine leaf), stripe, and ring spot infected by cucumber mosaic virus spontaneously, were collected in Korea and Japan. Among them, 2 mosaic diseases of portulaca oleracea L. and Celocia argentea L., 2 necrotic mosaic diseases of Aristolochia debilis Sieb. and Tetragonia exponsa Murr., 6 mottle diseases of Cassia torosa Cav., Bupleurum falcantum L., Angelica acutioloba Kitagawa, A. keiskei Koidz., Peucedanum japonicum Thunb., and Foeniculum vulgare Mill., and ringspot disease of Basella rubra L., were named newly in these studies.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.159-161
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• 2003

The coat protein (CP) gene of Apple mosaic virus (ApMV), a member of the genus Ilarvirus, was selected for the design of virus-specific primers for amplification and molecular detection of the virus in cultivated apple. A combined assay of reverse transcription and polymerase chain reaction (RT-PCR) was performed with a single pair of ApMV-specific primers and crude nucleic acid extracts from virus-infected apple for rapid detection of the virus. The PCR product was verified by restriction mapping analysis and by sequence determination. The lowest concentration of template viral RNA required for detection was 100 fg. This indicates that the RT-PCR for detection of the virus is a 10$^3$times more sensitive, reproducible and time-saving method than the enzyme-linked immunosorbent assay. The specificity of the primers was verified using other unrelated viral RNAs. No PCR product was observed when Cucumber mosaic virus (Cucumovirus) or a crude extract of healthy apple was used as a template in RT-PCR with the same primers. The PCR product (669 bp) of the CP gene of the virus was cloned into the plasmid vector and result-ant recombinant (pAPCP1) was selected for molecule of apple transformation to breed virus-resistant transgenic apple plants as the next step. This method can be useful for early stage screening of in vitro plantlet and genetic resources of resistant cultivar of apple plants.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.265-270
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• 2006

Cultivated hot pepper crops showing severe mosaic symptom were found in Korea in 2004 and their causal agent was identified as Cucumber mosaic virus (CMV). These pepper crops was resistant to the virus in the filled, and they belonged to pathotype 0 (P0) resistant pepper. Resistance screening of selected pepper plants showed that a pepper isolate of CMV was the P0 resistance-breaking virus. This P0 resistance-breaking isolate of CMV, named as Ca-P1, was isolated from leaves of the virus-infected Capsicum annuum cv. Manidda that showed systemic severe mosaic symptom. Ca-P1-CMV could induce systemic mosaic symptoms on P0-susceptible (P0-S) and P0-resistant (P0-R) cultivars whereas an ordinary strain (Fny-CMV) could not infect P0-R. This result suggests that Ca-P1-CMV can overcome P0 resistant pepper cultivars. To analyze its genome sequence, the complete nucleotide sequence of RNA3 of Ca-P1-CMV was determined from the infectious full-length cDNA clone of the virus. RNA3 of Ca-P1-CMV consisted of 2,219 nucleotides. Overall sequence homology of RNA3-encoded two viral proteins (movement protein and coat protein) revealed high similarity (75.2-97.2%) with the known CMV strains. By sequence analysis with known representative strains of CMV, Ca-P1-CMV belongs to a typical member of CMV subgroup IB. The resistance and resistance-breaking mechanisms of pepper and counterpart CMV, respectively, remain to be investigated, which will enrich the genetic resources and accelerate CMV-resistant pepper breeding programs.