• Journal of Microbiology
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• 제34권1호
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• pp.61-67
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• 1996

Double-stranded RNA (dsRNA) viruses and single-stranded RNA(ssRNA) viruses were detected in a strain of Pleurotus mushroom cultivated in a farm. Those fungal virsus were purified in the pH 6.0 or pH 7.2 using CsCI or Cs$_{2}$SO$_{4}$ buoyant density centrifugation. Each viral particles were not completely separated at any trials. However, mushroom bacili-form virus contains a single major nucleic acid with 0.7 Kb ssRNA, which might code for 20 Kd viral capsid protein. The dsRNAs are encapsidatred into spherical-form viruses, whereas ssRNA viral genomes are encapsidated into two different sizes of bacili-form particles. A healthy-looking mushroom also contained some spherical-form viruses with dsRNAs. Laboratory strains of Pleurotus ostreatus and a cultivated strain of P. sajor-caju did not show any viral particles. Mushrooms with specific disease symptoms. however, contained at least four different sizes of spherical-form viruses. Thus, we concluded that a bacilli-form virus case a severe disease symptoms of adnormal on mushroom development.

• The Plant Pathology Journal
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• 제39권1호
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• pp.28-38
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• 2023

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positivesense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host's machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins' role in replicating plant (+)ss RNA viruses.

• BMB Reports
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• 제32권1호
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• pp.82-85
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• 1999

The movement protein of cucumber mosaic virus (CMV) is required for cell-to-cell movement of viral RNA. The movement of viral RNA occurs through the plant intercellular connection, the plasmodesmata. The viral movement protein was known to be multi-functional. In this work, a series of deletion mutants of CMV movement protein gene were created to identify the functional domains. The mutated movement proteins were produced as inclusion body in E. coli, and purified and renatured. A polyclonal antibody was raised against the CMV-Kor strain (Korean isolate) movement protein expressed in E. coli. The ability of the truncated proteins to bind to ssRNA was assayed by UV cross-linking and gel retardation analyses. The results indicate that the domain between amino acids 118 and 160 of CMV movement protein is essential for ssRNA binding.

• The Plant Pathology Journal
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• 제27권3호
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• pp.291-296
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• 2011

In order to detect quarantine plant viruses, we developed reverse transcription-polymerase chain reaction (RT-PCR) primer pairs for five single-stranded (ss) plant RNA viruses that are not currently reported in Korea but could be potential harmful plant viral pathogens. Three viruses such as Chilli veinal mottle virus (ChiVMV), Colombian datura virus (CDV), and Tobacco etch virus (TEV) belong to the genus Potyvirus while Chrysanthemum stem necrosis virus (CSNV) and Iris yellow spot virus (IYSV) are members of the genus Tospovirus. To design RT-PCR primers, we used reported gene sequences corresponding to the capsid protein and polyprotein for ChiVMV, CDV, and TEV while using nucleocapsid protein regions for CSNV and IYSV. At least two different primer pairs were designed for each virus. Fifteen out of 16 primer pairs were successfully applied in detection of individual quarantine virus with high specificity and efficiency. Taken together, this study provides a rapid and useful protocol for detection of five quarantine viruses.

• 농업과학연구
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• 제42권2호
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• pp.105-109
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• 2015

Andean potato latent virus (APLV)는 Group IV (+) sense ssRNA viruses, Tymovirus속으로 분류되는 식물 병원성 바이러스로, 주로 감자에 감염되며 국내 관리급 검역바이러스로 지정되어 있다. 본 연구에서는 검역현장에서 APLV를 신속 정확하게 진단할 수 있는 2개의 RT-PCR 프라이머 조합[조합 2 (404 bp)와 23 (501 bp)]과 각각의 nested PCR 조합($404{\rightarrow}259bp$ 및 $501{\rightarrow}349bp$)을 선발하였다. 또한, 진단에 양성대조군으로 활용할 수 있는 유전자변형 양성대조구를 개발하여 실험실 오염에 대한 검증이 가능하도록 하였다. 본 연구에서 개발한 PCR 기반 진단시스템은 향후 검역 현장에서 APLV를 검출하여 우리나라 식물검역에 기여할 것이라고 기대된다.

• The Plant Pathology Journal
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• 제21권1호
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• pp.13-20
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• 2005

Chlorella viruses are large icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorellalike green algae. The genomic DNA of over 300 kb contains many useful genes and promoters. Over 40 chlorella viruses have been isolated from fresh water in Korea since 1998. The viruses were amplified initially in chlorella strain NC64A, and pure isolates were obtained by repeated plaque isolation. SDS-PAGE analysis revealed similar but distinct protein patterns, both among the group of purified viruses and in comparison with the prototype chlorella virus PBCV-1. Digestions of the 330- to 350-kb genomic DNAs with 10 restriction enzymes revealed different restriction fragment patterns among the isolates. The tRNA-coding regions of 8 chlorella viruses were cloned and sequenced. These viruses contain 14-16 tRNA genes within a 1.2- to 2-kb region, except for the SS-1 isolate, which has a 1039-bp spacer in a cluster of 11 tRNA genes. Promoter regions of several early genes were isolated and their activities were analyzed in transformed chlorella. Some promoters showed stronger activity than commonly used CaMV 35S promoter and chlorella transformation vectors for heterologous protein are beings constructed using these promoters.

• 대한환경공학회지
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• 제32권11호
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• pp.1063-1068
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• 2010

본 연구는 유효한 분변오염의 지표 미생물로서 제안되고 있는 E.coli와, 병원성 바이러스에 대한 지표 미생물로 추천되는 $Q{\ss}$ 파지의 UV 및 UV/$H_2O_2$에 대한 내성을 비교하였다. 이 결과에 의거, 병원성 바이러스 관리를 위한 E.coli 규제의 유효성을 고찰하였다. 또한, 병원성 바이러스에 대한 대체 지표 미생물로써, $Q{\ss}$ 파지, T4 및 lambda 파지의 실제 하수 2차 처리 수중에서의 UV 불활성화를 비교하였다. 실험결과, $Q{\ss}$ 파지와 E.coli는 UV에 대해 거의 동등한 내성을 보였으나, UV/$H_2O_2$ 공정에 대해서는 E.coli보다 $Q{\ss}$ 파지가 더 높은 내성을 보였다. 이로부터, $Q{\ss}$ 파지가 모든 병원성 바이러스의 UV 또는 UV/$H_2O_2$에 대한 내성을 대표한다고 할 수는 없을지라도, 지표 미생물로써 E.coli의 불활성화 효과에만 의존하는 것은, 소독공정에 따라서는 바이러스류에 대해 충분한 소독효과를 얻지 못할 수도 있음을 알 수 있었다. 한편, T4 및 lambda 등 DNA 파지와 불활성화를 비교하였을 경우, $Q{\ss}$ 파지가 UV에 대해 더 낮은 내성을 보였다. 따라서, 불활성화에 대한 지표 바이러스로써 $Q{\ss}$ 파지의 이용은 낮은 UV 조사량의 도입에 의해 결과적으로 불충분한 소독효과를 초래할 수도 있을 것 같다. 이 결과는, 병원성 바이러스류에 대해 보다 충분한 불활성화를 달성하기 위해서는 RNA 파지인 $Q{\ss}$보다 T4 및 lambda 등 DNA 파지가 지표 바이러스로써 보다 유효할 수 있음을 보여준다.

• 농업과학연구
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• 제41권4호
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• pp.335-339
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• 2014

Cowpea chlorotic mottle virus (CCMV)는 Group IV positive sense single strand RNA virus, Bromoviridae과, Bromovirus속으로 분류하는 식물병원성 바이러스로, 강낭콩(Phaseolus vulgaris), 나비완두(Clitoria ternatea), 담배(Nicotiana tabaccum), 대두(Glycine max), 동부(Vigna unguiculata, Vigna siensis) 및 땅콩(Arachis hypogaea)이 국내로 수입될 경우, 검사를 수행하는 관리급 검역바이러스이다. 본 연구에서는, RT-PCR, nested PCR 및 유전자-삽입 양성대조구를 개발하여, CCMV를 현장에서 신속, 정확하게 진단할 수 있는 정밀검정 시스템을 구현하였다. 본 연구에서 개발한 방법은 지속적으로 현장에서 활용되어 식물검역에 기여할 것이라고 기대된다.

• The Plant Pathology Journal
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• 제18권6호
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• pp.301-307
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• 2002

Graft transmission and cytopathological studies of a severe pear disease, pear black necrotic leafspot（PBNLS), were carried out to determine the causal agent of the disease. No evidence was found that a fungal or bacterial pathogen could be the causal agent of the disease. Attempts to transmit the agent by sap-inoculation to other plants including herbaceous hosts failed. How-ever, the pathogen was readily graft-transmitted from symptomatic diseased pears to healthy pears. Graft transmission of the pathogen was also demonstrated by using an indicator plant, PS-95, developed in the laboratory through various grafting methods. Ultrastructural study of the disease revealed the consistent presence of flexuous rod-shaped virus-like particles (VLP) in the symptomatic leaves of both Niitaka cultivar and indicator pear, PS-95. The particles, approximately 12 nm in diameter with undetermined length, occurred in the cytoplasm of mesophyll parenchyma cells. Cells with VLPs also contained fibril-containing vesicles, which are common in cells infected with plant viruses with ssRNA genome. The vesicles were formed at the tonoplast. Based on the symptomatology, the presence of fibril-containing vesicles, and graft-transmissibility, it is believed that the VLPs that occurred on symptomatic leaves of black necrotic leafspot of pear are viral in nature, possibly those of a capillovirus.

• The Plant Pathology Journal
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• 제15권1호
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• pp.38-43
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• 1999

Mutants of the monopartite geminivirus beet curly top virus (BCTV) have been screened for infectivity, systemic movement, replication and symptom development in Arabidopsis thaliana. As known by coding for coat protein, R1 mutant was not infectious and did not move systemically. R2, R3 and L2/L3 mutants produced milder symptoms compared to wild type BCTV but the infectivity was reduced by 40% to 60%. R2 ORF is thought to be involved in the regulation of ssDNA and dsDNA accumulation because only dsDNA was accumulated on R2-infected organs. Disruption of ORF L4 resulted in reduced infections, but the viral DNA was accumulated in infected organs from roots to shoot tips as much as wild type BCTV on Sei-O. In addition, 4 mutants did not produce callus-like tissues on infected organs, suggesting that L4 ORF may play a role in the induction of host cell divisions by virus infection. This result was supported by the patterns of mRNA expression and promoter analysis of the cell cycle marker gene, cycl, on Arabidopsis. cycl mRNA was accumulated on symptomatic organs by wild type BCTV infections but not by L4 mutant. We conclude that the BCTV L4 ORF is essential for symptom developments, specially callus-like formation on infected organs.