• 식물병연구
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• 제22권2호
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• pp.65-71
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• 2016

Cymbidium mosaic virus (CymMV) is a major virus infecting orchid plants and causing economic loss. In this study, the incidence of viral infection in Calanthe spp. at the Korean Institute of Calanthe was investigated using reverse transcription polymerase chain reaction. The CymMV infection rate was 42%, and the two viruses Odontoglossum ringspot virus and Cucumber mosaic virus had frequencies of 8% and 2%, respectively. Additionally, we characterized an isolate of CymMV, CymMV-GW, using biological tests and examined the nucleotide sequence properties of its complete genome. CymMV-GW induced chlorotic ringspots and chlorotic spot symptoms in inoculated leaves of Chenopodium amaranticolor and Nicotiana benthamiana, respectively. In this study, we have for the first complete genome sequence of CymMV-GW in Korea. The CymMV-GW genome was 6,225 nucleotides in length, excluding the poly-(A) tail, and showed whole-genome nucleotide and amino acid sequence identities of 97.7% and 100%, respectively, with the NJ-1 isolate of CymMV. Here, we report the complete genome sequence of the CymMV-GW isolate and viral infection rates for Calanthe spp. in Korea.

• The Plant Pathology Journal
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• 제38권6호
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• pp.665-672
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• 2022

Cymbidium mosaic virus (CymMV) is one of economically important viruses that cause significant losses of orchids in the world. In the present study, a reverse transcription recombinase polymerase amplification (RT-RPA) assay combined with a lateral flow immunostrip (LFI) assay was developed for the detection of CymMV in orchid plants. A pair of primers containing fluorescent probes at each terminus that amplifies highly specifically a part of the coat protein gene of CymMV was determined for RT-RPA assay. The RT-RPA assay involved incubation at an isothermal temperature (39℃) and could be performed rapidly within 30 min. In addition, no cross-reactivity was observed to occur with odontoglossum ringspot virus and cymbidium chlorotic mosaic virus. The RT-RPA with LFI assay (RT-RPA-LFI) for CymMV showed 100 times more sensitivity than conventional reverse transcription polymerase chain reaction (RT-PCR). Furthermore, the RT-PCR-LFI assay demonstrated the simplicity and the rapidity of CymMV detection since the assay did not require any equipment, by comparing results with those of conventional RT-PCR. On-site application of the RT-RPA-LFI assay was validated for the detection of CymMV in field-collected orchids, indicating a simple, rapid, sensitive, and reliable method for detecting CymMV in orchids.

• The Plant Pathology Journal
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• 제17권6호
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• pp.325-328
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• 2001

Gelatin particle agglutination test (GPAT) was used to detect Cymbidum mosaic virus (CymMV) in Cattleya plants. Gelatin particles were coated with purified anti-CymMV immunoglobulin of 25-100 $\mu\textrm{g}$/ml and were subjected to several different concentrations of purified CyMfV as well as varying dilutions of orchid leaf extracts. The GPAT detected purified CymMV up to a minimum concentration of 10 $\mu\textrm{g}$/ml. CymMV was detected from crude sap extract of infected Cattleya leaves and roots up to 1:51,200 and 1:25,600 dilutions, respectively. However, the optimum range of leaf and root sap dilutions was between 50-100. Non-specific reactions were not encountered from any of the healthy orchid plants tested. The entire GPAT process was completed within 2-3 hours. This test was found to be very useful for the detection of CymMV in orchids because it is sensitive, economical, and easy to perform.

• The Plant Pathology Journal
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• 제26권2호
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• pp.194-197
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• 2010

Most orchids are propagated by tissue culture. To survey the viral infection of tissue cultured Orchids, total RNA was extracted from in vitro Cymbridium and Phalaenopsis spp. collected from companies producing tissue-cultured orchids, and RT-PCR analysis was conducted with primer pairs specific to Cymbidium mosaic virus (CymMV) and Odontoglossum ring spot virus(ORSV), which are infecting wide range of orchid genera. The bulb size of Cymbidium infected with CymMV and ORSV was compared with healthy one at 10 months after planting in vitro orchids in the glasshouse. The CymMV or ORSV infection in 97 Cymbidium and 55 Phalaenopsis plants was 84.5 and 89.1 %, respectively. Mixed infection was found in 52.6 and 47.3% of Cymbidium and Phalaenopsis tested, whereas virus-free orchids were 15.5 and 10.9%, respectively. The CymMV and ORSV reduced the bulb size by 2.7-50% depending on the cultivars of Cymbidium. The both viruses caused yellowing, mottle and mosaic with or without necrosis in 4 Cymbidium cultivars.

• 한국식물병리학회지
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• 제14권2호
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• pp.130-135
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• 1998

This study was carried out to detect cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) in cultivated orchid plants in Korea. The standard double antibody sandwich enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) were carried out for detection of the viruses in the collected orchid samples. ELISA was suitable for massive-scale diagnostic method for virus detection in orchids. RT-PCR was rapid, time-saving and reliable detective method, and detection limit data showed that RT-PCR was 103 times more sensitive than ELISA. Of the 321 individual orchids representing 5 orchids genera tested by the ELISA, CymMV and ORSV were detected in 15.6% and 22.4%, and mixed infection of the both viruses with 4.9%, respectively. Of the Cymbidium plants tested, cultivated plants showed 52.5% virus infection rate with either CymMV or ORSV and both viruses.

• The Plant Pathology Journal
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• 제35권5호
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• pp.508-520
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• 2019

Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response-related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by real-time reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

• 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 1999년도 정기총회 및 춘계 학술발표회
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• pp.20.2-20
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• 1999

• The Plant Pathology Journal
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• 제26권2호
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• pp.130-138
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• 2010

Orchid fleck virus (OFV) is an unassigned plant virus in the family Rhabdoviridae. OFV was isolated from Cymbidium sp. showing oval necrotic lesions on their leaves in Korea, and designated as OFV-NHHS1. The complete nucleotide sequence of the RNA1 (6,413 nt) (GenBank accession no. AB516442) and RNA2 (6,001 nt) (GenBank accession no. AB516441) was determined in this study. RNA1 and RNA2 contained five and one ORF respectively. RNA1 encodes nucleocapsid (N) of 49 kDa, ORF2 of 26 kDa, ORF3 of 38 kDa, ORF4 of 20 kDa and glycoprotein (G) of 61 kDa proteins, whereas RNA2 encodes a single polymerase of 212 kDa. OFV-NHHS1 shared extremely high similarity of 98.6-100% and 98.9-99.6% in nucleotidle and amino acid sequences with a Japanese isolate, OFV-so, respectively. However, the N, G and L of OFV-NHHS1 revealed 6.9-19.3%, 7.3-12.0%, and 13.4-26.6% identities to those of 29 Rhabdoviruses, respectively. To survey the infection rate of OFV in commercial orchids in Korea, 51 Cymbidium sp., 10 Phalaenopsis sp., 22 Oncidium sp. and 21 Dendrobium sp. plants that showed typical viral symptoms were collected. RT-PCR with specific primers for detection of Cymbidium mosaic virus (CymMV), ORSV and OFV showed high infection rate by ORSV alone and double infection by ORSV and CymMV. One of the orchids tested was infected with OFV. This is the first report of the complete nucleotide sequences of OFV isolated in Korea.

• 원예과학기술지
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• 제18권4호
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• pp.513-517
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• 2000

우리나라 난 재배 농가에서 많이 재배하고 있는 호접란 대만 수입묘의 바이러스 감염 정도를 검정하기 위하여 플라스크묘 상태의 실생 번식 식물체를 공시하여 역전사 중합효소 연쇄반응(RT-PCR) 기술에 의해 CymMV와 ORSV의 감염 여부를 검정하였다. 호접란 식물체의 잎에서 조즙액을 추출하여 RT-PCR을 위한 total RNA로 사용하였다. $42^{\circ}C$에서 45분간 반응시켜 cDNA를 합성하였으며, $96^{\circ}C$에서 2분간 template를 예비 변성시킨 후, $96^{\circ}C$에서 30초간 template 변성, $60^{\circ}C$에서 30초간 primer 부착 및 $72^{\circ}C$에서 1분간 DNA 합성을 1cycle로 하여 총 36cycle을 반응시키고, $72^{\circ}C$에서 10분간 안정화하는 조건으로 one-step RT-PCR을 수행하였다. 바이러스 검정 결과 정도의 차이는 있으나, 40개 시료 모두 CymMV에 감염되어 있었으며, ORSV에 감염된 식물체는 없었다.