• The Plant Pathology Journal
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• 제33권3호
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• pp.345-349
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• 2017

Tomato chlorosis virus (ToCV), a member of the genus Crinivirus, has caused an epidemic disease in tomato worldwide. ToCV is phloem-limited and transmitted by whiteflies in a semi-persistent manner, but not by mechanical inoculation. Experimental propagation of ToCV has been performed primarily by using whitefly-mediated inoculation. To develop a simple and convenient method for transmission of ToCV, we investigated grafting single-leaflets from tomato plants infected with ToCV to recipient tomato seedlings. Forty-one of 46 tomato seedlings tested were grafted successfully with single-leaflets infected with ToCV. Among them, 36 seedlings (87.8%) were systemically infected with ToCV and developed typical symptoms. Our results demonstrated that single-leaflet grafting could provide a sufficient amount of inoculum for the transmission of ToCV to the grafted seedlings.

• 농업과학연구
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• 제45권1호
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• pp.38-42
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• 2018

Demand for tomatoes has been increasing every year as people desire more healthy food. In Korea, tomatoes are mainly grown in the Chungnam, Chunnam and Kyungnam provinces. Recently, reports of whitefly-transmitted viral diseases have increased due to newly emerging whitefly pressures caused by climate change in Korea. Specifically, in 2017, the main tomato growing areas, Buyeo and Nonsan in Chungnam, showed damage typical of viral infection; therefore, we investigated viral diseases in these areas. We collected samples with virus-like symptoms and found that not only whitefly transmitted Tomato yellow leaf curl virus (TYLCV) and Tomato chlorosis virus (ToCV) were detected but also Tomato mosaic virus (ToMV, for which no specific vector is known) and Tomato spotted wilt virus (TSWV, transmitted by thrips). The ToMV-infected samples were mostly co-infected with either TYLCV or ToCV. Mixed infections of different combinations of TYLCV, ToCV and ToMV were detected with the mixed infection of two whitefly-transmitted viruses (TYLCV and ToCV) causing the most severe symptoms. According to the CP sequence of each virus, the 100% identities were shown to be Mexico/ABG73017.1 (TYLCV), Greece/CDG34553.1 (ToCV), China/AKN79752 (TSWV), and Australia/NP078449.1 (ToMV). Based on the sequence data, we presumed that these tomato infecting viruses were transmitted through insects and seeds introduced from neighboring countries.

• The Plant Pathology Journal
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• 제34권3호
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• pp.199-207
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• 2018

Tomato chlorosis virus (ToCV) is a whitefly-transmitted and phloem-limited crinivirus. In 2013, severe interveinal chlorosis and bronzing on tomato leaves, known symptoms of ToCV infection, were observed in greenhouses in Korea. To identify ToCV infection in symptomatic tomato plants, RT-PCR with ToCV-specific primers was performed on leaf samples collected from 11 tomato cultivating areas where ToCV-like symptoms were observed in 2013 and 2014. About half of samples (45.18%) were confirmed as ToCV-infected, and the complete genome of 10 different isolates were characterized. This is the first report of ToCV occurring in Korea. The phylogenetic relationship and genetic variation among ToCV isolates from Korea and other countries were also analysed. When RNA1 and RNA2 are analysed separately, ToCV isolates were clustered into three groups in phylogenetic trees, and ToCV Korean isolates were confirmed to belong to two groups, which were geographically separated. These results suggested that Korean ToCV isolates originated from two independent origins. However, the RNA1 and RNA2 sequences of the Yeonggwang isolate were confirmed to belong to different groups, which indicated that ToCV RNA1 and RNA2 originated from two different origins and were reassorted in Yeonggwang, which is the intermediate point of two geographically separated groups.

• The Plant Pathology Journal
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• 제39권5호
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• pp.466-485
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• 2023

Crop productivity can be obstructed by various biotic and abiotic stresses and thus these stresses are a threat to universal food security. The information on the use of viruses providing efficacy to plants facing growth challenges owing to stress is lacking. The role of induction of pathogen-related genes by microbes is also colossal in drought-endurance acquisition. Studies put forward the importance of viruses as sustainable means for defending plants against dual stress. A fundamental part of research focuses on a positive interplay between viruses and plants. Notably, the tomato yellow leaf curl virus (TYLCV) and tomato chlorosis virus (ToCV) possess the capacity to safeguard tomato host plants against severe drought conditions. This study aims to explore the combined effects of TYLCV, ToCV, and drought stress on two tomato cultivars, Money Maker (MK, UK) and Shalala (SH, Azerbaijan). The expression of pathogen-related four cellulose synthase gene families (CesA/Csl) which have been implicated in drought and virus resistance based on gene expression analysis, was assessed using the quantitative real-time polymerase chain reaction method. The molecular tests revealed significant upregulation of Ces-A2, Csl-D3,2, and Csl-D3,1 genes in TYLCV and ToCV-infected tomato plants. CesA/Csl genes, responsible for biosynthesis within the MK and SH tomato cultivars, play a role in defending against TYLCV and ToCV. Additionally, physiological parameters such as "relative water content," "specific leaf weight," "leaf area," and "dry biomass" were measured in dual-stressed tomatoes. Using these features, it might be possible to cultivate TYLCV-resistant plants during seasons characterized by water scarcity.

• 식물병연구
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• 제28권1호
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• pp.39-45
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• 2022

경기 광주시 완숙토마토 시설재배단지에서 가루이가 매개하는 바이러스 2종 tomato yellow leaf curl virus (TYLCV)와 tomato chlorosis virus (ToCV)의 발생양상을 조사하였다. 2020년 여름재배 작형에서 TYLCV와 ToCV의 감염률은 수확기에 급격히 증가하였고, 단독 감염률은 각각 30.9%, 5.0%였고, 복합감염률은 52.2%로 TYLCV 단독감염과 2종 바이러스 복합감염이 83.1%로 대부분을 차지하였다. 2종 바이러스를 매개하는 가루이의 발생분포 및 보독률을 조사한 결과, 작물 재배기간 내내 담배가루이가 높은 비율로 발생하였고, 조사한 담배가루이는 모두 Mediterranean (MED)으로 확인되었다. 담배가루이 MED는 TYLCV를 단독으로 보독하거나 ToCV와 복합 보독하는 경우가 48.5%로 많았으며, ToCV의 보독률은 29.1%로 온실가루이(7.2%)에 비해 높았다. 담배가루이 MED의 2종 바이러스 보독률이 토마토 정식 전부터 47.2%로 높았고, 이후 계속 증가하여 수확기에는 73.8%로 가장 높았다. 수확기 토마토 재배포장별 2종 바이러스의 감염률에 따라 수확량을 비교 분석해본 결과, TYLCV와 ToCV의 복합감염률 증가가 수확량을 감소시키는 것을 확인하였고, 복합감염률이 10% 증가함에 따라 405.4 kg/10a 수량감소를 보였다.

• 식물병연구
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• 제23권2호
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• pp.193-201
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• 2017

국내의 토마토에서 발생하는 주요 바이러스는 Tomato chlorosis virus (ToCV), Tomato spotted wilt virus (TSWV), Cucumber mosaic virus (CMV), Pepper mottle virus (PepMoV), Tomato mosaic virus (ToMV)이다. 이들 바이러스를 진단하기 위해 프라이머 세트와 반응액을 포함하는 역전사중합반응(RT-PCR)법의 조건을 조사하였다. 공시한 바이러스에 특이적인 염기서열로부터 모두 46개 프라이머 세트를 설계하고, 이를 이용해 주형을 넣지 않은 RT-PCR에서 비특이 반응을 조사하였다. 이들 가운데 16개 조합을 건전한 토마토 RNA에 적용한 결과 프라이머 세트와 RT-PCR 반응액 간의 친화성이 비특이 반응 감소에 영향을 주었다. cDNA 합성과 관련된 인자와 RT-PCR 반응액 사이의 조합을 근거로 ToCV 진단을 위한 두 종류의 반응액을 선발하였다. ToCV 진단 시 수립된 조건을 나머지 바이러스 진단에 적용했을 때, 특이성이 높은 프라이머 세트 C029 (ToCV), C072 (TSWV), C070 (CMV), C048 (PepMoV), C065 (ToMV)를 선발할 수 있었다. 이들 프라이머 세트는 공시한 바이러스를 특이적으로 진단하는 데 유용할 것으로 판단된다.

• 농업과학연구
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• 제46권3호
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• pp.507-517
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• 2019

To follow up on a 2017 survey of tomato virus diseases, samples with virus-like symptoms were collected from the same areas (Buyeo-gun, Chungchungnam-Do and Daejeon, Korea) in 2018. While in 2017 mixed infections of Tomato mosaic virus with either Tomato yellow leaf curl virus (TYLCV) or Tomato chlorosis virus were detected, only TYLCV was detected in symptomatic samples in 2018. TYLCV amplicons of c.777 bp representing the coat protein (CP) coding region were cloned from the TYLCV positive samples, and the sequence data showed a 97.17% to 98.84% nucleotide and 98.45% to 99.22% amino acid identity with the 2017 Buyeo-gun isolate (MG787542), which had the highest amino acid (aa) sequence identity of up to 99.2% with four 2018 Buyeo-gun sequences (MK521830, MK521833, MK521834, and MK521835). The lowest aa sequence identity of 98.45% was found in a 2018 Daejeon isolate (MK521836); the distance between Buyeo-gun and Daejeon is about 45 km. Phylogenetic analysis indicated that the currently reported CP sequences are most closely related to Korean sequences from Masan (HM130912), Goseong (JN680149), Busan (GQ141873), Boseong (GU325634), and the 2017 isolate TYLCV-N (MG787543) in the 'Japan' cluster of TYLCV isolates and distinct from the 'China' cluster isolates from Nonsan (GU325632), Jeonju (HM130913) and Jeju (GU325633, HM130914). Our survey data from 2017 and 2018 suggest that TYLCV has become established in Korea and may be spread by whitefly vectors from weed reservoirs within the farm environment.

• The Plant Pathology Journal
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• 제35권3호
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• pp.257-273
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• 2019

Tomato (Solanum lycopersicum) is one of the most widely grown and economically important vegetable crops in the world. Tomato chlorosis virus (ToCV) is one of the recently emerged viruses of tomato distributed worldwide. ToCV-tomato interaction was investigated at the molecular level for determining changes in the expression of tomato genes in response to ToCV infection in this study. A cDNA library enriched with genes induced in response to ToCV infection were constructed and 240 cDNAs were sequenced from this library. The macroarray analysis of 108 cDNAs revealed that the expression of 92 non-redundant tomato genes was induced by 1.5-fold or greater in response to ToCV infection. The majority of ToCV-induced genes identified in this study were associated with a variety of cellular functions including transcription, defense and defense signaling, metabolism, energy, transport facilitation, protein synthesis and fate and cellular biogenesis. Twenty ToCV-induced genes from different functional groups were selected and induction of 19 of these genes in response to ToCV infection was validated by RT-qPCR assay. Finally, the expression of 6 selected genes was analyzed in different stages of ToCV infection from 0 to 45 dpi. While the expression of three of these genes was only induced by ToCV infection, others were induced both by ToCV infection and wounding. The result showed that ToCV induced the basic defense response and activated the defense signaling in tomato plants at different stages of the infection. Functions of these defense related genes and their potential roles in disease development and resistance to ToCV are also discussed.

• The Plant Pathology Journal
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• 제28권4호
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• pp.390-400
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• 2012

Eight potato-producing provinces of Iran were surveyed during the growing seasons of 2004-2006 to detect the presence of Tomato yellow fruit ring virus (TYFRV), a tentative species in the genus Tospovirus. A total of 1,957 potato leaf samples were collected from plants with tospovirus-like symptoms of chlorotic or necrotic spots, chlorosis and necrosis. The samples were tested by enzyme-linked immunosorbent assay using TYFRV-specific antibodies. Among those tested, 498 samples (25.4%) were found to be infected with the virus. The virus was detected in 72.4% of the potato fields in all provinces surveyed. Thirteen potato isolates of TYFRV were selected for further biological and molecular studies. Based on their reactions on Nicotiana tabacum plants, the isolates were separated into two groups, namely L (local infection) and N (systemic infection). The nucleotide sequences of the nucleoprotein (N) genes of the isolates were determined and compared with the homologous sequences in Genbank. No recombination evidence was found in the isolates using different recombination-detecting programs. In the phylogenetic tree, the potato isolates fell into two major groups: IRN-1 and IRN-2 corresponding to the two biologically separated groups. This study shows for the first time the biological and phylogenetic relationships of geographically distant TYFRV isolates from potatoes in the mid-Eurasian country of Iran.

• 환경생물
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• 제38권3호
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• pp.486-495
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• 2020

토마토와 박과류채소의 유기농산물을 생산하기 위하여 무농약으로 재배하는 시설하우스에서 최근 문제되는 병해를 조사한 결과 토마토 잎곰팡이병과 토마토반점위조바이러스병, 토마토퇴록바이러스병, 박과류 쥬키니황화모자이크바이러스병, 박과류 흰가루병 등의 피해가 심한 것으로 조사되었다. 농약을 사용하여 일반재배를 하는 시설하우스에 비해 무농약재배 하우스에서 재배되는 작물에서 병 발생 시기가 더 빠르고 병 발생도 심한 것으로 나타났으며, 총채벌레와 진딧물 등에 의해 매개되는 바이러스병 피해가 심한 것으로 조사되었다. 따라서 우수한 유기농산물을 생산하기 위해서는 병해충방제를 효율적으로 하는 것이 중요하며, 병 발생 피해를 최소화기 위해서는 포장위생과 물리적 차단, 유기농업자재나 미생물제 등을 종합적으로 활용하여 예방적으로 방제하는 것이 가장 중요하다.