• The Plant Pathology Journal
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• v.31 no.4
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• pp.371-378
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• 2015

Surveys of yellowing viruses in plastic tunnels and in open field crops of melon (Cucumis melo cultivar catalupo), oriental melon (C. melo cultivar oriental melon), and cucumber (C. sativus) were carried out in two melon-growing areas in 2014, Korea. Severe yellowing symptoms on older leaves of melon and chlorotic spots on younger leaves of melon were observed in the plastic tunnels. The symptoms were widespread and included initial chlorotic lesions followed by yellowing of whole leaves and thickening of older leaves. RT-PCR analysis using total RNA extracted from diseased leaves did not show any synthesized products for four cucurbit-infecting viruses; Beet pseudo-yellows virus, Cucumber mosaic virus, Cucurbit yellows stunting disorder virus, and Melon necrotic spot virus. Virus identification using RT-PCR showed Cucurbit aphid-borne yellows Virus (CABYV) was largely distributed in melon, oriental melon and cucumber. This result was verified by aphid (Aphis gossypii) transmission of CABYV. The complete coat protein (CP) gene amplified from melon was cloned and sequenced. The CP gene nucleotide and the deduced amino acid sequence comparisons as well as phylogenetic tree analysis of CABYV CPs showed that the CABYV isolates were undivided into subgroups. Although the low incidence of CABYV in infections to cucurbit crops in this survey, CABYV may become an important treat for cucurbit crops in many different regions in Korea, suggesting that CABYV should be taken into account in disease control of cucurbit crops in Korea.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.121-128
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• 2022

Fusarium wilt disease caused by Fusarium species is a major problem affecting cultivated cucurbit plants worldwide. Fusarium species are well-known soil-borne pathogenic fungi that cause Fusarium wilt disease in several cucurbit plants. In this study, we aimed to identify and classify pathogenic Fusarium species from cultivated Korean cucurbit plants, specifically watermelon and cucumber. Thirty-six Fusarium isolates from different regions of Korea were obtained from the National Institute of Horticulture and Herbal Science Germplasm collection. Each isolate was morphologically and molecularly identified using an internal transcribed spacer of ribosomal DNA, elongation factor-1α, and the beta-tubulin gene marker sequence. Fusarium species that infect the cucurbit plant family could be divided into three groups: Fusarium oxysporum (F. oxysporum), Fusarium solani (F. solani), and Fusarium equiseti (F. equieti). Among the 36 isolates examined, six were non-pathogenic (F. equiseti: 15-127, F. oxysporum: 14-129, 17-557, 17-559, 18-369, F. solani: 12-155), whereas 30 isolates were pathogenic. Five of the F. solani isolates (11-117, 14-130, 17-554, 17-555, 17-556) were found to be highly pathogenic to both watermelon and cucumber plants, posing a great threat to cucurbit production in Korea. The identification of several isolates of F. equiseti and F. oxysporum, which are both highly pathogenic to bottle gourd, may indicate waning resistance to Fusarium species infection.

• Research in Plant Disease
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• v.29 no.1
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• pp.52-59
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• 2023

Cucurbit chlorotic yellows virus (CCYV) is a plant virus that causes damage to cucurbit crops such as watermelon and cucumber, and is transmitted by an insect vector known as the whitefly. Since CCYV was first detected on cucumber in Chungbuk in 2018, it has been reported in other areas including Gyeongsang in Korea. In 2020, we performed field surveys of yellowing diseases in the greenhouses growing melon and watermelon in Chungbuk (Jincheon and Eumseong). Reverse transcription-polymerase chain reaction analysis of 79 collected samples including melon, watermelon, and weeds resulted in detection of CCYV in 4 samples: Three samples were singly infected with CCYV and one samples was mixed infected with CCYV, Cucurbit aphid borne yellows virus, and Watermelon mosaic virus. The complete genome sequences of the four collected CCYV melon isolates (ES 1-ES 4) were determined and genetically compared with those of previously reported CCYV isolates retrieved from GenBank. Phylogenetic analyses of RNA 1 and 2 sequences revealed that four ES isolates were clustered in one group and closely related to the CCYV isolates from China. The analysis also revealed very low genetic diversity among the CCYV ES isolates. In general, CCYV isolates showed little genetic diversity, regardless of host or geographic origins. CCYV has the potential to pose a serious threat to melon, watermelon, and cucumber production in Korea. Further studies are needed to examine the pathogenicity and transmissibility of CCYV in weeds and other cucurbits including watermelon.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.150.1-150
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• 2003

A single-step multiplex reverse transcription polymerase chain reaction (RT-PCR) assay was developed for the simultaneous detection of five cucurbit-infecting viruses： cucumber mosaic virus (CMV), watermelon mosaic virus 2 (WMV2), zucchini yellow mosaic virus (ZYMV), cucumber green mottle mosaic virus (CGMMV), and kyuri green mottle mosaic virus (KGMMV). The multiplex RT-PCR provides a simple and rapid method for detecting various viruses in cucurbit plants, which will help diagnose many cucurbit plants at a time.

• Journal of the Korean Chemical Society
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• v.49 no.1
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• pp.112-116
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• 2005

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.486-495
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• 2020

We surveyed disease outbreak status that has recently become a problem in organic tomatoes and cucurbit in plastic greenhouse that were grown without spraying pesticides during the plastic greenhouse growing season of 2015 to 2019. It was found that the incidence of leaf mold, tomato spotted wilt virus, and tomato chlorosis virus disease was severe in tomato, and disease incidence of powdery mildew and zucchini yellow mosaic virus were severe in Cucurbit. The disease outbreak was found to be faster and more severe in crops grown in pesticide-free cultivation plastic greenhouses than in plastic greenhouses that are cultivated in general using pesticides. In particular, the occurrence of viral diseases mediated by thrips and aphids was found to be severely damaged. Therefore, in order to produce good organic products, it is important to effectively control pests, and in order to minimize the damage caused by disease, sanitation and physical blocking, and comprehensively utilize organic materials or microorganisms to prevent them.

• Mass Spectrometry Letters
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• v.7 no.1
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• pp.16-20
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• 2016

Characterization of intact protein structures in the gas phase using electrospray ionization combined with ion mobility mass spectrometry has become an important tool of research. However, the biophysical properties that govern the structures of protein ions in the gas phase remain to be understood. Here, we investigated the impact of host-guest complexation of ubiquitin (Ubq) with macrocyclic host molecules, cucurbit[n]urils (CB[n]s, n = 6, 7), on its structure in the gas phase. We found that CB[n] complexation induces the formation of compact Ubq ions. Both CB[6] and CB[7] exhibited similar effects despite differences in their binding properties in solution. In addition, CB[n] attachment prevented Ubq from unfolding by collisional activation. Based on the experimental results, we suggest that CB[n]s prevent unfolding of Ubq during transfer to the gas phase to promote the formation of compact protein ions. Furthermore, interaction with positively charged residues per se is suggested to be the most important factor for the host-guest complexation effect.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.514-521
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• 2022

We report the effect of pH on the supramolecular complexation of two biothiols, viz., homocysteine (Hcy) and cysteine (Cys), with cucurbit[7]uril (CB[7]). Under basic pH conditions, Cys did not complex with CB[7], whereas Hcy efficiently complexed with CB[7], as confirmed by ¹H NMR spectroscopy and Ellman's reagent (5,5'-dithio-bis(2-nitrobenzoic acid), DTNB) assay. ¹H NMR and Raman spectroscopic studies revealed that, in the absence of CB[7], Hcy auto-oxidized slowly (~36 h) to homocystine (HSSH) under basic pH conditions. However, the rate of Hcy oxidation increased by up to 150 fold in the presence of CB[7], as suggested by the DTNB assay. Thus, supramolecular complexation under basic pH conditions led to the formation of a HSSH-CB[7] complex, and not Hcy-CB[7]. The results indicate that Hcy is rapidly oxidized to HSSH under the catalysis of CB[7], which acts as a reaction chamber, in basic pH conditions. Our studies suggest that Hcy concentration, a risk factor for cardiovascular disease, can be selectively and more easily quantified by supramolecular complexation with CB [7].

• The Plant Pathology Journal
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• v.38 no.4
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• pp.296-303
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• 2022

The cucurbit powdery mildew (CPM) caused by different fungal species is a major concern for cucurbit crops around the world. In Argentina CPM constitutes the most common and damaging disease for cucurbits, especially for squash crops (Cucurbita moschata). The present study displays initial insights into the knowledge of the disease in western Argentina, including the determination of the prevalent species causing CPM, as well as the evaluation of the resistance of squash cultivars and breeding lines. Fungal colonies were isolated from samples collected in Mendoza province, Argentina. A field trial was also performed to assess the resistance of five squash accessions, including commercial cultivars and breeding lines. The severity of CPM was analyzed and epidemiological models were built based on empirical data. The morphological determinations and analysis with specific molecular markers confirmed Podosphaera xanthi as the prevalent causal agent of CPM in Mendoza. The results od the field trial showed differences in the resistance trait among the squash accessions. The advanced breeding line BL717/1 showed promising results as source of CPM resistance for the future development of open pollinated resistant cultivars, a crucial tool for an integrative control of the disease.

• Proceedings of the Korea Crystallographic Association Conference
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• 2001.11a
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• pp.19-19
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• 2001