• The Korean Journal of Mycology
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• v.51 no.4
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• pp.505-510
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• 2023

In June 2023, at the oat field on Kongju National University's Yesan Campus, flies infected with an entomopathogenic fungus were discovered. The flies were hanging with their wings folded backward. Fungal mycelia had sprouted on the abdomens of the flies. An analysis of the 28S ribosomal RNA sequence confirmed that the fungus was Entomophthora muscae. Moreover, cytochrome oxidase sequence analysis of the host insect identified it as Delia platura.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.153-158
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• 1998

The internal structures of Arabidopsis thaliana infected with beet curly top virus (BCTV) were studied by light microscopy. Hyperplasia was observed in the inflorescence stems of Arabidopsis thaliana ecotype Sei-O at 2 weeks after BCTV-Logan inoculation and callus was induced on symptomatic tissues at 4 weeks after virus inoculation. The infection processes were revealed as follows: hyperplasia of phloem tissue, necrosis of hyperplastic phloems, lacuna formation of necrotic tissues, elongation and enlargement of cortex and epidermal cells surrounding the lacuna formed phloem tissues, induction of cell division in the enlarged cortex and epidermal cells, and induction of callus tissue. Callus formation on Arabidopsis was caused by the virus infection, and virus inclusion body was observed in both phloem and callus tissue by azure-A staining.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.348-352
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• 2007

Inflammation is a complex process resulting from a variety of mechanisms. Combined inhibition of the activities of enzymes involved in the process may therefore be considered more important in anti-inflammatory property of plant extracts than any single contribution. In this study, the inhibitory effects of the ethanol extracts of thirty plant foods on the activities of secretory phospholipase $A_{2}$ ($sPLA_{2}$), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and 12-lipoxygenase (12-LOX) were examined. Several legumes, mungbean sprout and some leaf vegetables inhibited the activity of $sPLA_2$, upstream enzyme of inflammation pathway. Only soybean sprout and mungbean sprout significantly inhibited 12-LOX activity. Although most of extracts inhibited the activities of both COX-1 and COX-2, water dropwort and amaranth showed selectivity for the inhibition of COX-2 over COX-1. Especially, mungbean showed anti-inflammatory property at both upstream and downstream of inflammation pathway with relatively low $IC_{50}$ values for $sPLA_{2}$ and COX-2 enzymes. Mungbean sprout exhibited inhibitory effects on all enzymes related to early and late inflammation and soybean sprout suppressed 12-LOX and COX-2 simultaneously, although the activities of these plants were showed at relatively high concentration. Therefore, mungbean, mungbean sprout, and soybean sprout appear to exhibit anti-inflammatory effects by combined inhibition of inflammatory enzymes.

• Journal of Life Science
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• v.21 no.2
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• pp.227-234
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• 2011

The hrp gene cluster in the plant pathogen Pseudomonas syringae is a key determinant of pathogenicity. Recent studies have demonstrated that specific host cell induction of the Ralstonia solanacearum hrp gene cluster is controlled by the PrhA (plant regulator of hrp) receptor. To characterize the role that P. syringae PrhA plays in the virulence of plant cells, a prhA homolog was isolated from P. syringae pv. tabaci and a $\Delta$prhA mutant was constructed by allelic exchange. The $\Delta$prhA mutant had reduced virulence in the host plant, and co-culture of P. syringae pv. tabaci and plant cell suspensions induced a much higher level of hrpA gene transcription than culture in hrp-inducing minimal medium. These results indicate that PrhA of P. syringae is a putative pathogen-plant cell contact sensor, therefore, we used a hrpA-gfp reporter fusion to monitor the in situ expression of PrhA. The results of this study demonstrated that PrhA induces hrp gene expression in P. syringae pv. tabaci in the presence of plant cells.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.24-30
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• 2003

Aqueous extracts from eleven species of Korean medicinal plants were screened for antiviral activity against transmissble gastroenteritis virus (TGEV) and porcine epidemic diarrhae virus (PEDV). Seven of eleven plant extracts were found to have cytotoxicity for ST cells at the concentration of 1mg/ml, and ten extracts except Ephedra sinica were found to have non-cytotoxicity for Vero cells at the same concentration, Extracts of Zanthoxylum piperium, Cudrina tricuspidata, Clerodendron trichomum, Sophora flavescens, effectively inhibited TGEV, respectively. There were the antiviral activity against TGEV in the extracts of Glesdistsia sinensis, Euonymus alatus, Ficus carica, Solanum nigrum, Ephedra sinica, Xanthium strumarium, Acanthopanax seeliflorus in spite of their cytotoxicities. Nine extracts except Xanthium strumarium and Acanthopanax seeliflorus were found to have the antiviral activitity against PEDV. Extracts of Zanthoxylum piperium, Sophora flavescens was shown to have antiviral activities against both TGEV and PEDV.

• Journal of Plant Biology
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• v.33 no.2
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• pp.97-104
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• 1990

In order to investigate the host range of Agrobacterium tumefaciens KU12 containing pTi-12, 28 species of dicotyledonous plants were infected with KU12, A136 without Ti plasmid and A348 containing pTi A6, respectively. KU12 and A348 induced tumor in 20 species and 14 species, respectively. This results showed that KU12 has a wide host range. Therefore, it was confirmed that KU12 and pTi-12 are very useful for developing plant vector system having a broad host range.

• Journal of Life Science
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• v.27 no.6
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• pp.661-672
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• 2017

Endophytic fungi are present in host plants and contribute to resistance to biotic and abiotic stress. Aquatic plants are living in aquatic environment such as saltwater or freshwater and exposed more water stress than other land plants. In this study, we investigated 4 wetlands in Jeju and collected 11 aquatic plants. Exogenous microbes were removed by preprocessing of plants and endophytic fungal strains were isolated from the plants. We isolated 126 fungal strains from Namsaengi-pond, 22 fungal strains from Sujangdong-marsh, 44 fungal strains from Yongsu-reservoir and 32 fungal strains from Gangjeongcheon. The fungal strains were identified using internal transcribed spacer (ITS) region and analyzed the phylogeny and diversity. Endophytic fungi isolated from plants of Namsaengi-pond were classified to 30 genera, 19 families, 12 orders, 7 classes and 4 phyla. Endophytic fungi of Sujangdong-marsh were classified to 11 genera, 11 families, 6 orders, 5 classes and 4 phyla. Endophytic fungi of Yongsu-reservoir were classified to 13 genera, 12 families, 7 orders, 5 classes and 4 phyla. Endophytic fungi isolated from Gangjeongcheon were classified to 9 genera, 7 families, 5 orders, 2 classes and 1 phyla. Overall, they were divided 40 genera and Alternaria, Colletotrichum and Fusarium were isolated from 4 sites in common. By investigating the endophytic fungi in aquatic plants, it is for baseline data that determination of diversity and the ecological distribution of endophytic fungi.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.139-145
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• 2016

To search for habitat characteristics of myrmecochory Melampyrum species, diaspores and related ant species, habitat characteristics, collecting fruits and diaspores of three Melampyrum species, cafeteria experiments, and the related ant species were studied from May 2012 to November 2014. The habitat of Melampyrum species was south-facing open forest edge with slightly acidic soil and relatively shallow soiil layers. Major plants coexisting with Melampyrum species were four woody species including Quercus mongolica and four herbaceous species including Carex siderosticta. These Plants might be host plants of the Melampyrum species. The shape of the diaspore was an oval seed attached to the white cap on one side. Significant differences is proved between three plant species in weight of diaspores, seeds and and elaiosome ratios. Mean values of diaspores weight showed 10.6mg, 8.0mg and 7.2mg in M. setaceum var. nakaianum, M. roseum var. ovalifolium and M. roseum, respectively. The heaviest elaiosome is M. roseum var. ovalifolium with 1.2mg, M. setaceum var. nakaianum has 1.0mg and the lightest elaiosome is M. roseum with 0.8mg. Major ant species frequently transporting the diaspores of Melampyrum species are Myrmicinae four species; Myrmica kotokui, M. excelsa, Myrmecina nipponica and Aphaenogaster japonica. Further studies on Melampyrum species, hemiparasite annual myrmecochorous plant, and related ant species should be needed.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.293-299
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• 1983

Experiments were carried out to elucidate the specific interactions between host plant, Phaseolus vulgaris, and symbiotic bacteria, Rhizobium Phaseoli. Purified P. vulgaris lectins and six species of cultured Rhizobium were subjected to agglutination test. Lectins from bean and R. phaseoli showed relatively high agglutination activity indicating that host plant lectins recognize carbohydrate moieties on the compatible Rhizobium cell surface. The specific carbohydrate receptors for binding of the lectins on the cell surface of R. phaseoli were found as mannose and galactose. The minimum concentration of sugars for the inhibition was 6.25mM. The lectin content of cultured plant roots was measured after germination and was maximum in 5-day seedlings. The nodulation was competitively inhibited by lectins for the plants cultured with Rhizobium cells. By immunochemical studies, there was some relationship in antigenic determinants between R. phaseoli and R. japonicum but no relationships were observed with other Rhizobium species. The results suggest that the infection by rhizobia to the roots of leguminous plants may be caused by the specific interaction of lectins with rhizobia.

• Journal of Life Science
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• v.28 no.3
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• pp.369-375
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• 2018

Mycoplasma genitalium has 367 conserved genes and the smallest genome among mono-culturable prokaryotes. Conservative metabolic pathways were examined among M. genitalium and 14 prokaryotes, one hyperthermophilic exosymbiotic archaeon Nanoarchaeum equitans and 13 intracellular eubacteria of plants or insects, with fewer conserved genes than M. genitalium. They have 11 to 71 metabolic pathways, however complete metabolic pathways ranged from 1 to 24. Totally, metabolic pathway hole is very high due to the lack of 45.8% of the enzymes required for the whole metabolic pathways and it could be suggested that the shared metabolic pathway with the host's enzyme would work or the essential substances are host dependent. The number of genes necessary for mass transfer through the cell membrane is also very low, and it may be considered that the simple diffusion or the protein of the host will function in the cell membrane of these prokaryotes. Although the tRNA charging pathway was distributed in all 15 prokaryotes, each has 5-20 tRNA charging genes. This study would give clues to the understanding of the metabolic pathways of intracellular parasitic bacteria of plant and endosymbiotic bacteria of insects, and could provide basic data for prevention of crop damage, development of insect pests and human medicines.