• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.57-62
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• 2022

Excessive activation and aggregation of platelets is a major cause of cardiovascular disease. Therefore, inhibition of platelet activation and aggregation is considered an attractive therapeutic target in preventing and treating cardiovascular diseases. In particular, strong platelet activation and aggregation by collagen secreted from the vascular endothelium are characteristic of vascular diseases. Artesunate is a compound extracted from the plant roots of Artemisia or Scopolia species, and has been reported to be effective in anticancer and Alzheimer's disease fields. However, the effect and mechanism of artesunate on collagen-induced platelet activation and aggregation have not been elucidated. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artesunate was clarified. Artesunate inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artesunate decreased TXA₂ production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artesunate strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC₅₀ of 106.41 µM. These results suggest that artesunate has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.395-412
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• 2023

The morphology and whole genome sequence of Hyphantria cunea nucleopolyhedrovirus W1 (HycuNPV-W1) isolated in Korea were analyzed for the use as an eco-friendly control agent against H. cunea. The HycuNPV-W1 had irregular tetrahedral polyhedra with a size of 1.5-2.2 ㎛ which is similar to that of previously reported HycuNPV isolated in Korea. As a result of whole viral genome analysis, HycuNPV-W1 was composed of 131,353 bp, which is 1,606 bp shorter than that of the previously reported HycuNPV. The G+C content was 45% and six of the homologous repeated regions were found, so there was no significant difference from the previous report. As a result of ORF analysis, HycuNPV-W1 contains total of 145 ORFs which is three ORFs less than the previous report, while two ORFs were exclusively found in HycuNPV-W1. The functions of these ORFs remains unclear and are not considered to have a significant influence on the characteristics of the HycuNPV. The genome vista analysis showed that the overall sequence identity between HycuNPV-W1 and the previously reported HycuNPV was very high. The whole genome of HycuNPV-W1 analyzed was found to be similar to those of the previously reported HycuNPV, however, it is supposed to be a novel resource in Korea with different isolate.

• Food Science and Preservation
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• v.30 no.3
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• pp.483-491
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• 2023

This study aimed to compare the bioactive compounds in Centella asiatica (C. asiatica) cultivated in a smart farm and a field and their effects on human keratinocyte cells. C. asiatica was collected in Jeju-do, Korea, and cultured in a smart farm and a field. The main bioactive compounds in the two differentially cultured C. asiatica were identified, and their activation in keratinocytes were assessed. Amplification and sequencing of the internal transcribed spacer (ITS) DNA in the nucleus and psbA-H DNA in the chloroplast were performed for species analysis. A comparison of DNA of plants reported in the NCBI GenBank was performed. The ITS DNA and psbA-H DNA sequences of C. asiatica cultivated in a smart farm and a field were consistent with No. MH768338.1 and No. JQ425422.1, respectively. Analysis of the triterpenes was performed using high performance liquid chromatography (HPLC) and as a result, C. asiatica cultured in a smart farm had more triterpenes than those cultured in a field. The effects of C. asiatica grown in a smart farm on cell proliferation and scratch recovery in HaCaT cells were greater than those grown in a field. These results suggest that C. asiatica cultivated in a smart farm can be effectively utilized as a health functional food.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.402-407
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• 2023

The regulation of platelet aggregation is crucial for maintaining normal hemostasis, but abnormal or excessive platelet aggregation can contribute to cardiovascular disorders such as stroke, atherosclerosis, and thrombosis. Therefore, identifying substances that can control or suppress platelet aggregation is a promising approach for the prevention and treatment of these conditions. Artemisinin, a compound derived from Artemisia or Scopolia plants, has shown potential in various areas such as anticancer and Alzheimer's disease research. However, the specific role and mechanisms by which artemisinin influences platelet activation and thrombus formation are not yet fully understood. This study investigated the effects of artemisinin on platelet activation and thrombus formation. As a result, cAMP production were increased significantly by artemisinin, as well as phosphorylated VASP and IP₃R which are substrates to cAMP-dependent kinase by artemisinin in a significant manner. The Ca²⁺ normally mobilized from the dense tubular system was inhibited due to IP₃R phosphorylation from artemisinin, and phosphorylated VASP by artemisinin aided in inhibiting platelet activity via αIIb/β3 platelet membrane inactivation and inhibiting fibrinogen binding. Finally, artemisinin inhibited thrombin-induced thrombus formation. Therefore, we suggest that artemisinin has importance with cardiovascular diseases stemming from the abnormal platelets activation and thrombus formation by acting as an effective prophylactic and therapeutic agent.

• Research in Plant Disease
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• v.18 no.4
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• pp.317-323
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• 2012

The study aims to identify the pathogenicity of Phytophthora. capsici isolates in major pepper-producing areas in Korea and the inherit genetic pattern of phytophthora blight resistance by inocula. With five kinds of testing materials including 'Kataguma (Sakata Korea)' peppers, a disease-susceptible material, '#308', a phytophthora blight resistance material, 'CM334', and their $F_1$ and $F_2$, respective isolates of P. capsici obtained from Icheon, Eumseong, Buan, Imsil and Yeongyang regions together with six kinds of peppers' inoculum including PA-159 (KACC No.40482) received from Korean Agricultural Culture Collection were used for inoculation. The disease-susceptible material '#308', the resistant material 'CM334' and the non-segregating generation of $F_1$ represented 4.94-5.00, 1.00-1.07, and 1.01-1.08 phytophthora blight incidence respectively in the group comparison by isolate. This result means that the phytophthora blight resistance was clearly distinguished among testing materials in the group comparison by P. capsici isolate. Moreover, $F_2$ segregating generation showed 1.79-2.31 phytophthora blight incidence which turned out to be identical in the group comparison by the six isolates of P. capsici isolate and with similarity between both the resistant and susceptible materials. Thus, the result proved that using the six isolates of P. capsici tested as inocula was suitable to investigate the phytophthora blight resistance. When it comes to group comparison of $F_2$ segregation generation, however, isolates were divided with PA-159 isolate being the center: a group consisting of isolates from Icheon, Buan, and Imsil and a group consisting of Yeongyang and Eumseong isolates with higher pathogenicity. The expected segregation ratio of the phytophthora blight resistance in $F_2$ generation by isolate was analyzed. PA-159 isolate showed 3:1 or 9:3:3:1, indicating that one to two genes were involved. On the other hand, results also proved that there is an interaction of genes since both Eumseong and Yeongyang isolates showed a segregation ratio of 11:5 while the Icheon isolate represented 12:3:1.

• Research in Plant Disease
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• v.17 no.3
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• pp.280-287
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• 2011

This investigation was undertaken to survey toxigenic fungal contamination of various rice samples in 93 rice processing complexes (RPC) in Korea. Rice was grown in 2009 and the samples were collected in 2010. Seven types of rice samples such as unhusked, brown, blue-tinged, discolored, polished, half-crushed, and rice husks were obtained from each RPC. One-hundred and five grains of each sample were placed on PDA plates after surface disinfection. The incidence of fungal contaminants was 26.8%. Aspergillus spp. was the most dominant fungal contaminants and Fusarium spp. was the most frequently occurred in samples. The heaviest Fusarium contamination was found in unhusked grain, rice husks, and bare blue-tinged rice and followed by colored rice whereas broken rice was the least contaminated. Regional difference of fungal contamination was distinctive. Fusarium incidence in the rice samples from southern region of Korea including Jeolla and Gyeongsang Provinces was higher than those from central region including Chungcheong, Gyeonggi, and Gangwon Provinces. In contrast to Fusarium spp., Aspergillus spp. and Penicillium spp. were dominated in brown and polished rice samples and their incidences were more severe in central region than southern region. The major contaminants shown more than 1% of kernels infected were Aspergillus (5.0%), Fusarium (2.0%), Alternaria (1.4%), Dreschlera (1.3%), Penicillium spp. (1.3%), and Nigrospora spp. (1.0%). Collectotrichum, Pyricularia, Myrothecium, Epicoccum, Cladosporium, Moniliella, Gloeocercospora, Chaeto- mium, Curvularia, Phialopora, Acremonium, Gliomastix, Trichoderma, Rhizopus, Phomopsis, Paecilomyces, Genicularia, Geotrichum, Acremoniella, Rhizoctonia, Phoma, Oidiodendran, and Candida spp. were among the rest observed at low incidence. The major contaminants of rice samples were well-known as toxigenic fungal genera so toxin producibility of these fungal isolates is necessary to be examined in future. It is also needed to study Myrothecium spp. on species level as it was detected for the first time in rice.

• Research in Plant Disease
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• v.16 no.3
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• pp.274-278
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• 2010

Potato late blight caused by Phytophthora infestans was the most constrain disease at potato cultivation areas. The mating type distribution and fungicides response of P. infestans were investigated to elucidate the changes of pathogen from Gangwon province. On the fungal isolates in 2006, 58.7% were A1 mating type and 41.3% were A2 mating type. In 2007, A1 mating type isolates increased to 93.3% and A2 mating type isolates were collected from Jinbu areas as much as 6.7%. About 234 isolates analysed for metalaxyl response, the results was resistance 73.7%, intermediate 18.8% and sensitive 7.5% in 2006. And it was resistance 59.4%, intermediate 4.0% and sensitive 36.6% in 2007. It meant that mating type distribution and fungicide response were very different over the collection sites. Minimal inhibition concentration (MIC) of dimethomorph examined with 126 isolates in 2006 and 106 isolates in 2007. MIC over $1.0\;{\mu}g/ml$ was 56.3% in 2006 and it was 3.8% in 2007. The average $EC_{50}$ value of P. infestans was $0.37\;{\mu}g/ml$ in 2006, but it decreased to $0.12\;{\mu}g/ml$ in 2007. Fungicides response and pathogenesis of P. infestans should be monitored continuously to enhance the chemical efficacy at potato fields.

• Research in Plant Disease
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• v.20 no.4
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• pp.235-244
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• 2014

Clubroot and Fusarium wilt of cole crops (Brassica oleracea L.) are destructive diseases which for many years has brought a decline in quality and large losses in yields all over the world. The breeding of resistant cultivars is an effective approach to reduce the use of chemical fungicides and minimize crop losses. This study was conducted to evaluate the resistance of 60 cabbage (B. oleracea var. capitata) and 6 broccoli (B. oleracea var. italica) lines provided by The RDA-Genebank Information Center to clubroot and Fusarium wilt. To investigate resistance to clubroot, seedlings of the genetic resources were inoculated with Plasmodiophora brassicae by drenching the roots with a mixed spore suspension (1 : 1) of two isolates. Of the tested genetic resources, four cabbage lines were moderately resistant and 'K166220' represented the highest resistance to P. brassicae. The others were susceptible to clubroot. On the other hand, to select resistant plants to Fusarium wilt, the genetic resources were inoculated with Fusarium oxysporum f. sp. conglutinans by dipping the roots in spore suspension of the fungus. Among them, 17 cabbage and 5 broccoli lines were resistant, 16 cabbage lines were moderately resistant, and the others were susceptible to Fusarium wilt. Especially, three cabbage ('IT227115', 'K161791', 'K173350') and two broccoli ('IT227100', 'IT227099') lines were highly resistant to the fungus. We suggest that the resistant genetic resources can be used as a basic material for resistant B. oleracea breeding system against clubroot and Fusarium wilt.

• Research in Plant Disease
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• v.18 no.3
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• pp.201-209
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• 2012

The multi-function of 18 Bacillus subtilis isolates collected from agricultural extension centers of local government and National Academy of Agricultural Science was investigated by measuring their antifungal activities against five plant pathogens, such as Rhizoctonia solani, Colletotrichum acutatum, Fusarium oxysporum, Magnaporthe oryzae and Phytophthora capsici, phosphorus solubilization ability, production of indole acetic acid (IAA) and siderophore, and nitrogen fixation. The B. subtilis isolates showed antifungal activity against several plant pathogens and nitrogen fixation activity, and produced siderophore and IAA. They could control pepper powdery mildew (Leveillula taurica), but there was no difference in control efficacy among the B. subtilis isolates. In fields, the control efficacy of B. subtilis R2-1 ($10^8$ cells/ml) was compared with two microbial fungicides, Q-pect and Topsid. In 2009, the control efficacy of B. subtilis R2-1 (37.7%) was lower than that of Topsid (47.6%), but higher than that of Q-pect (25.7%). In 2010, the control efficacy of B. subtilis R2-1 (83.3%) was higher than that of Topsid (67.9%). In order to elucidate mode of action of B. subtilis R2-1 for controlling pepper powdery mildew, spore germination rates of pepper powdery mildew pathogen collected on treated leaves was investigated when suspensions of B. subtilis R2-1 and two microbial fungicides (Q-pect and Topsid) were foliar-sprayed. They highly suppressed spore germination of the pathogen with inhibition values of 84.2% for B. subtilis R2-1, 97.9% for Q-pect and 94.7% for Topsid. Further study on the mass-culturing method and formulation is needed for development of a microbial fungicide.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.26-35
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• 2013

This study was conducted to select superior provenances of Scots pine (Pinus sylvestris L.) well adapted to Korean environment for timber production. In 1976, twenty-two provenances of Scots pine were introduced from Sweden and the seeds were sown in seed beds in March. After one year, the seedlings were transplanted to nursery beds. The resulting 1-1 seedlings of 22 provenances were planted at Whaseong in 1978. Randomized complete block design with 3 replications were used for test plantation. Each provenance was planted with 20-tree row plot in each block and at a spacing of $1.8{\times}1.8m$. The growth performance of each provenance was monitored up to 33-years after planting. There were significant differences among provenances in volume growth. F3001 provenance showed the best volume growth of 33-years after planting ($0.160m^3$), which was 2.2 times greater than that of the lowest provenance W2027 ($0.072m^3$). The ranking of provenances was stabilized after 14 years. Comparing to reference tree species, Japanese red pine (Pinus densiflora), all Scots pine provenances showed poor growth performance. In other words, volume growth of Japanese red pine at age 28 and 33 were 2.1 and 3.3 times greater than that of Scots pine, respectively. Moreover, survival rate of Scots pine was lower than that of Japanese red pine. Based on these results, it was suggested that Scots pine was not suitable to Korean environments. The cause of maladaptation of Scots pine and the implications of introduction breeding were discussed.