• Horticultural Science & Technology
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• v.31 no.2
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• pp.246-254
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• 2013

Five isolates of Tomato yellow leaf curl virus (TYLCV) collected from various regions of Korea were amplified using PCR and determined the sequences of full-length genome, respectively. The PCR-amplified DNA of each TYLCV isolate was introduced into a binary vector to construct infectious clone containing 1.9 copies of the corresponding viral genome. Various cultivars and breeding lines of tomato were inoculated with Agrobacterium tumefaciens harboring infectious clone of each TYLCV isolate to assess resistance against TYLCV. Susceptible cultivar 'Super-sunread' revealed typical yellowing and narrowing of the upper leaves. In contrast, breeding linesTY12, GC9, GC171, and GC173, which contained the TY-1 and/or TY-3 genes that confer resistance against TYLCV in nature, were completely symptomless, suggesting that the lines were resistant to challenging TYLCV isolates. Symptoms of TYLCV in susceptible tomato cultivars are significantly different from those of TYLCV in the resistant tomato cultivars at 30 days after agroinfiltration. Although genomic DNAs of TYLCV were detected from the breeding lines TY12, GC9, GC171, and GC173 using real-time PCR analysis with specific primers, levels of TYLCV DNA accumulation in the resistant breeding lines were much lower than those of TYLCV DNA accumulation in susceptible tomato cultivars. Similar symptom severity and levels of TYLCV DNA accumulation were observed from TYLCV infections mediated by Bemisia tabaci in the resistant and susceptible tomato cultivars. Concentration of agrobacterium did not affect the response of tomato cultivars against TYLCV inoculation. Taken together, these results suggest that TYLCV inoculation via agroinfiltration is as effective as inoculation through Bemisia tabaci and is useful for breeding programs of TYLCV-resistant tomato.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.424-428
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• 2017

Tomato yellow leaf curl virus (TYLCV) infection of the common bean (Phaseolus vulgaris) has been reported, but soybean (Glycine max) has not previously been identified as a TYLCV host. Five cultivars of white soybean were agro-inoculated using an infectious TYLCV clone. At 30 days post-inoculation, they showed infection rates of 25% to 100%. Typical TYLCV symptoms were not observed in any inoculated plants. To examine whether TYLCV was transmitted in soybean seeds, DNA was isolated from bundles of five randomly selected seeds from TYLCV-inoculated soybean plants and amplified with a TYLCV-specific primer set. With the exception of one bundle, all bundles of seeds were verified to be TYLCV-infected. Virus dissemination was also confirmed in three of the 14 bunches. Viral replication was also identified in seeds and seedlings. This is the first report demonstrating that soybean is a TYLCV host, and that TYLCV is a seed-transmissible virus in white soybean.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.378-384
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• 2011

Tomato yellow leaf curl virus (TYLCV), a member of genus Begomovirus, was isolated in Korea in 2008. We sequenced and analyzed the DNA-A of 51 TYLCV isolates from Korea, and 13 of the TYLCV isolates were selected as type representatives of TYLCV from six Korean provinces. The 13 TYLCV isolates were classified into Korea Group 1 (KG1, nine isolates) and Korea Group 2 (KG2, four isolates) based on the results of phylogenetic analysis and genome size (2774 and 2781 nucleotides, respectively). A recombination detection program 3 (RDP3) revealed two recombinations between the TYLCV Korea isolates and other TYLCV isolates [Thailand (AF206674), Iran (AJ132711), and Israel (X76319)]. TYLCV Jeju isolate was characterized by two recombination events (E1 and E2) caused by the presence of E1 in ORF V1 and C3, which may seem to be the mutations of the high nucleotide transversion and transition rate. Collectively, our results suggest that the occurrence of nucleotide transversions and transitions in TYLCV DNA-A might have induced novel recombination events within the TYLCV Korea isolates.

• Research in Plant Disease
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• v.28 no.1
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• pp.39-45
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• 2022

Patterns of occurrence of tomato yellow leaf curl virus (TYLCV) and tomato chlorosis virus (ToCV) with whitefly on summer-cultivated tomato in Gwangju-si, Gyeonggi Province were surveyed using multiplex reverse transcription-polymerase chain reaction in 2020. In addition, distribution of the whiteflies species and their viral transmission rates were investigated throughout the tomato growing season. The infection rates of TYLCV and ToCV increased sharply during harvest, and the single infection rates were 30.9% and 5.0%, respectively, with a mixed infection rate of the two viruses being the highest at 52.2%. Single infection with TYLCV and double infections with TYLCV and ToCV accounted for the majority with 83.1%. Bemisia tabaci were dominant over Trialeurodes vaporariorum in greenhouse grown plants, and all of the investigated B. tabaci biotypes were identified as Mediterranean (MED, formerly known as Q biotype). The transmission rate of TYLCV, detected in every sampled B. tabaci MED population, was 21.4%, and the mixed transmission rate with ToCV was 35.5%. Viruliferous MED whiteflies with ToCV showed a higher rate than that of T. vaporariorum. In the transplant stage, viruliferous rate of both TYLCV and ToCV of B. tabaci was 42.7%; this rate was highest in the harvest stage. In examination of tomato yield, the increase in the mixed infection rate of TYLCV and ToCV led to complete yield loss. When the mixed infection rate increased by 10%, the yield decreased by 405.4 kg/10a.

• Research in Plant Disease
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• v.21 no.3
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• pp.180-185
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• 2015

In the present work, a pair of primers specific to Tomato yellow leaf curl virus (TYLCV) was designed to allow specific amplification of DNA fragments from any TYLCV isolates using an extensive alignment of the complete genome sequences of TYLCV isolates deposited in the GenBank database. A pair of primers which allows the specific amplification of tomato ${\beta}$-tubulin gene was also analyzed as an internal PCR control. A duplex PCR method with the developed primer sets showed that TYLCV could be directly detected from the leaf crude sap of infected tomato plants. In addition, our developed duplex PCR method could determine PCR errors for TYLCV diagnosis, suggesting that this duplex PCR method with the primer sets is a good tool for specific and sensitive TYLCV diagnosis. The developed duplex PCR method was further verified from tomato samples collected from some farms in Korea, suggesting that this developed PCR method is a simple and reliable tool for rapid and large-scale TYLCV detections in tomato plants.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.377-387
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• 2016

Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, is one of the most important viruses of cultivated tomatoes worldwide, mainly causing yellowing and curling of leaves with stunting in plants. TYLCV causes severe problems in sub-tropical and tropical countries, as well as in Korea. However, the mechanism of TYLCV infection remains unclear, although the function of each viral component has been identified. TYLCV C4 codes for a small protein involved in various cellular functions, including symptom determination, gene silencing, viral movement, and induction of the plant defense response. In this study, through yeast-two hybrid screenings, we identified TYLCV C4-interacting host proteins from both healthy and symptom-exhibiting tomato tissues, to determine the role of TYLCV C4 proteins in the infection processes. Comparative analyses of 28 proteins from healthy tissues and 36 from infected tissues showing interactions with TYLCV C4 indicated that TYLCV C4 mainly interacts with host proteins involved in translation, ubiquitination, and plant defense, and most interacting proteins differed between the two tissues but belong to similar molecular functional categories. Four proteins-two ribosomal proteins, S-adenosyl-L-homocysteine hydrolase, and 14-3-3 family protein-were detected in both tissues. Furthermore, the identified proteins in symptom-exhibiting tissues showed greater involvement in plant defenses. Some are key regulators, such as receptor-like kinases and pathogenesis-related proteins, of plant defenses. Thus, TYLCV C4 may contribute to the suppression of host defense during TYLCV infection and be involved in ubiquitination for viral infection.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.641-651
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• 2021

Tomato yellow leaf curl virus (TYLCV) is one of the most important plant viruses belonging to the genus Begomovirus of the family Geminiviridae. To identify natural weed hosts that could act as reservoirs of TYLCV, 100 samples were collected at a TYLCV-affected tomato farm in Iksan from 2013 to 2014. The sample weeds were identified as belonging to 40 species from 18 families. TYLCV was detected in 57 samples belonging to 28 species through polymerase chain reaction using root samples including five species (Eleusine indica, Digitaria ciliaris, Echinochloa crus-galli, Panicum dichotomiflorum, and Setaria faberi) from the family Poaceae. Whitefly Bemisia tabaci-mediated TYLCV transmission from TYLCV-infected E. indica plants to healthy tomatoes was confirmed, and inoculated tomatoes showed typical symptoms, such as leaf curling and yellowing. In addition, TYLCV was detected in leaf and root samples of E. indica plants inoculated by both whitefly-mediated transmission using TYLCV-viruliferous whitefly and agro-inoculation using a TYLCV infectious clone. The majority of mastreviruses infect monocotyledonous plants, but there have also been reports of mastreviruses that can infect dicotyledonous plants, such as the chickpea chlorotic dwarf virus. No exception was reported among begomoviruses known as infecting dicots only. This is the first report of TYLCV as a member of the genus Begomovirus infecting monocotyledonous plants.

• Research in Plant Disease
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• v.18 no.4
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• pp.298-303
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• 2012

Tomato yellow leaf curl virus (TYLCV), transmitted exclusively by the whitefly (Bemisia tabaci) in a circulative manner is one of the most important virus in tomato. Since the first report of TYLCV incidence in Korea in 2008, the virus has rapidly spread nationwide. TYLCV currently causes serious economic losses in tomato production in Korea. Early detection of TYLCV is one of the most important methods to allow rouging of infected tomato plants to minimize the spread of TYLCV disease. We have developed an ultra-rapid and sensitive real-time polymerase chain reaction (PCR) using a new designed real-time PCR system, GenSpectorTM TMC-1000 that is a small and portable real-time PCR machine requiring only a $5{\mu}l$ reaction volume on microchips. The new system provides ultra-high speed reaction (30 cycles in less than 15 minutes) and melting curve analysis for amplified TYLCV products. These results suggest that the short reaction time and ultra sensitivity of the GenSpector$^{TM}$-based real-time PCR technique is suitable for monitoring epidemics and pre-pandemic TYLCV disease. This is the first report for plant virus detection using an ultra-rapid real-time PCR system.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.328-336
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• 2013

This study was conducted to evaluate imported tomato $F_1$ cultivars as breeding materials for the resistance to Tomato yellow leaf curl virus (TYLCV) by molecular markers and bioassay. From marker genotyping and disease evaluation of 40 $F_1$ cultivars, most of the cultivars declared as TYLCV-resistance carried heterozygous marker genotype for the TYLCV resistance genes Ty-1, Ty-3, or Ty-3a, and showed low disease rates. Whereas, 4 of 5 $F_1$ cultivars declared as intermediate resistance showed marker genotype for susceptibility and disease rates ranged 18.1-33.3%. However, the xx cultivars showed inconsistency in marker genotype and disease rate. Characterization of horticultural traits of the $F_1$ cultivars with TYLCV-resistance indicated that large-size fruit cultivars were higher in yield and similar in sugar contents and solid-acid ratio compared to a control cultivar preferred in the domestic market, although hardness remained to be a problem. On the other hand, cherry tomato cultivars showed lower yield and brix, but longer internode compared to a control cultivar, indicating that breeding for TYLCV-resistance using these cultivars will require more efforts and time compared to large-sized.

• 농업기술회보
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• v.50 no.3
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• pp.31-31
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• 2013

최근 국내에 발생해 큰 문제를 일으키는 토마토황화잎말림바이러스(TYLCV)는 매개충인 담배가루이와 함께 토마토의 안정생산을 위협하는 치명적인 바이러스다. 병이 발생하면 악제나 다른 방법으로 방제가 어려우므로 내병성 풍종, 특히 TYLCV 저항성 유전자 Ty-1,2,3(부분우성)의 한 개체 내 집적을 통해 저항성을 높인 품종의 육성이 시급하다. 이런 목적으로 국립원예특작과학원에서는 TYLCV에 저항성 품종인 '티와이썬'을 개발하였다.