• Applied Microscopy
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• v.5 no.1
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• pp.9-19
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• 1975

In order to clarify the mecahnism of histological barriers to pathogens of witches' broom diseased in sweet potatoes, this experiment has been conducted to observe the relationship between pathological characters and the transfer of mycoplasmae in the shoot apex. The material used the experiment is the sweet potato (Ipomoea batatas (L.) Lamm. Suwon 147). In the experiment regarding of mycoplasmae, the upper limit zone of transfer of mycoplasmae is examined by way of the process of free stock and the shoot apex of a infected part in nature, observed in the culture of each part of the diseased plant which is cut to a certain length. The pathological change pattern of tissues infected with mycoplasmae has been observed under the light and electron microscopes. As a result of this experiment, the following conclusion was arrived at. 1. It has been ascertained that the mycoplasmae are not existent in a promeristem and primary meristem zone from the meristem dome, and is existent in the lower part of the vascular differentiation zone, after which differential tissues the mycoplasmae become progressively enlarged, and before which undifferential tissues it become progressively immatured and diminished in size. 2. It can be suggested that mycoplasmae may not be existed in the shoot meristem, be cause the passing structures such as sieve area and plasmodesma which can be pass ed immatured mycoplasmae is undifferentiated. 3. In the tissue culture, free stock can be obtained in the zone between 1.0-1.5mm of the shoot apex, while it cannot in the 2.0-3.0mm zone, because of infection by mycoplasmae. It is suggested that immature mycoplasmae may be diffused according to temperature ($28{\pm}1^{\circ}C$) in tissue culture process.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.194-200
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• 2014

Monodehydroascorbate reductase (MDHAR) is an important enzyme that plays a role in the detoxification of reactive oxygen species (ROS) by maintaining reduced pool of ascorbate through recycling the oxidized form of ascorbate. In this study, we isolated a PagMDHAR1 gene from Populus alba ${\times}$ P. glandulosa, and investigated its expression characteristics. The PagMDHAR1 cDNA encodes a putative 434 amino acids containing FAD- and NAD(P)H-binding domains. Southern blot analysis indicated that a single nuclear gene encodes this enzyme. Northern hybridization analysis revealed that PagMDHAR1 is highly expressed in both suspension cells and flower tissues, while its expression levels were enhanced by drought, salt, cold, wounding and ABA. Therefore, PagMDHAR1 might be expressed in response to abiotic stress through the ABA-mediated signaling pathway in this poplar species, suggesting that the PagMDHAR1 plays an important role in the defense mechanisms against oxidative stress.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.172-178
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• 2010

This study was carried out to investigate abiotic and biotic environmental factors affecting homoharringtonine (HHT) contents of Cephalotaxus koreana, whereby, to provide basic information of high value-added industry production of HHT as a promising anti-cancer agent. For correlation between abiotic environmental factors (soil moisture, soil pH, habitat density and temperature) and HHT contents, the contents were highly correlated with soil moisture (0.77) and soil pH (-0.68). For multiple regression analysis of relationship between abiotic environmental factors (soil moisture and soil pH) and HHT contents, soil moisture appeared to be strongly affecting the contents relatively due to being significant at only its regression coefficient ($26.48^{***}$). For the effect of biotic environmental factors (damage index) affecting HHT contents, the contents was quadratic with equation of $H=278.23+1242D-398.87D^2$, also, damage index had strong effect on the contents. Finally, for the result of the most influencing an environmental factor on HHT contents, both damage index and soil moisture were suitable in second polynomial regression, also, damage index ($R^2=0.73^{***}$) was turned out to be more influencing factor than soil moisture ($R^2=0.67^{**}$) on HHT contents relatively. Therefore, we predict that HHT contents in the trees of Cephalotaxus koreana is produced as a chemical defense mechanism triggered by a stress-related damage of fungi or insects.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.165-171
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• 2010

Oxidative stress induced by reactive oxygen intermediates has been implicated in a variety of human diseases including neurodegenerative disorders, cancer, cardiovascular and respiratory diseases, and mode of action of environmental toxicants. Tert-butylhydroperoxide (t-BHP) is an organic lipid hydroperoxide analogue, which is commonly used as a pro-oxidant for evaluating mechanisms involving oxidative stress in cells and tissues. In this study, the underlying mechanisms involved in the protective effects of Hwabuk 94 kiwifruit (Actinidia deliciosa cv. 'Hwabuk 94'), which is cultivated in Jeju, on the t-BHP-induced cytotoxicity in PC12 cell. The pretreatment of rat pheochromocytoma cell line PC12 with Hwabuk 94 extract ($1-100\;{\mu}g/ml$) resulted in a significant recovery from t-BHP-induced cell death and increased Bcl-2 and procaspase-3 expression, whereas the expression of Bax and cleaved PARP were decreased in a dose-dependent manner compared to the control. Furthermore, Hwabuk 94 inhibited the t-BHP-induced p38 MAP kinase and extracellular signal-regulated kinase 1/2, but not c-Jun N-terminal kinase activations. Finally, these findings suggest that Hwabuk 94 kiwifruit might attenuate t-BHP-induced PC12 cell cytotoxicity, at least in part, through the inhibition of signaling pathways mediated by the ERK1/2 and p38 MAP kinase.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.36-36
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• 2022

The molecular understanding of resistance and susceptibility of host plants to scab, a most threatful disease to pome fruit production worldwide, is very limited. Comparing resistant line '93-3-98' to susceptible one 'Sweet Skin' at seven time points of 0, 0.5, 1, 2, 3, 4, 8 days post inoculation, RNA-sequencing data derived from infected and mock-inoculated young leaves were analyzed to evaluate the tolerant response and to mine candidate genes of pear to the scab pathogen Venturia nashicola. Analysis of the mapped reads showed that the infection of V. nashicola led to significant differential expression of 17,827 transcripts with more than 3-fold change in the seven pairs of libraries, of which 9,672 (54%) are up- and 8,155(46%) are down-regulated. These included mainly receptor (NB-ARC domains-containing, CC-NBS-LRR, TIR-NBS-LRR, seven transmembrane MLO family protein) and transcription factor (ethylene responsive element binding, WRKY DNA-binding protein) related gene. An arsenal of defense response of highly resistant pear accessions derived from European pear was probably supposed no sooner had V. nashicola infected its host than host genes related to disease suppression like Polyketide cyclase/dehydrase and lipid transport protein, WRKY family transcription factor, lectin protein kinase, cystein-rich RLK, calcium-dependent phospholipid-binding copine protein were greatly boosted and eradicated cascade reaction induced by pathogen within 24 hours. To identify transcripts specifically expressed in response to V. nashicola, RT-PCRs were conducted and compare to the expression patterns of seven cultivars with a range of highly resistant to highly susceptible symptom. A DEG belonging to the PR protein family genes that were higher expressed in response to V. nashicola suggesting extraordinary role in the resistance response were led to the identification. This study provides the first transcriptional profile by RNA-seq of the host plant during scab disease and insights into the response of tolerant pear plants to V. nashicola.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.82-82
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• 2020

염증 (Inflammation)은 물리적인 상처나 세균감염이 되었을 때 손상된 조직을 재생하고 신체를 방어하기 위해 일어나는 선천성 면역반응으로 알려져 있다. 주로 선천면역을 담당하는 대식세포는 lipopolysaccharide, reactive oxygen species와 cytokine 등에 의해 활성화되어 tumor necrosis factor-α. interleukin-1β, interleukin-6 등 염증인자들의 생성에 관여한다. 특히, 산화질소는 superoxide 음이온과 쉽게 반응하고 peroxynitrite와 같은 독성이 강한 산화제를 생성하여 단백질 및 지질의 과산화를 유도하고 세포독성을 일으키는 것으로 보고되고 있다. 따라서 본 연구에서는 항산화 및 항염증 소재를 탐색하기 위해 오미자 (Schisandra chinensis), 꾸지뽕 (Cudrania tricuspidata)을 이용하여 항산화 활성을 평가하고자 하였으며, 세포주를 활용한 세포독성 및 항염증 활성을 확인하고자 하였다. 본 연구는 전북 순창군에서 재배된 오미자, 꾸지뽕을 열 건조(60℃) 통해 건조한 후 분말화하였다. 최적 추출 조건 선정을 위해 다양한 용매 (열수, 증류수, 주정 20, 40, 60%), 온도 (25, 40, 60, 80℃) 및 시간 (1, 2, 3, 4, 5 h) 조건에서 추출된 추출물의 총 폴리페놀 함량을 비교함으로써 최적 조건을 선정하였다. 오미자와 꾸지뽕의 DPPH 및 ABTS radical 소거 활성, 총 플라보노이드 함량을 확인하여 항산화능 및 기능성 성분 함량을 평가하였다. 또한 대식세포주인 Raw 264.7을 활용하여 MTT assay, 산화질소 생성 억제 활성을 확인하여 세포독성 및 항염증 활성을 평가하였다. 실험 결과, 오미자 및 꾸지뽕은 각각 주정 40%, 60℃ 그리고 증류수, 60℃에서 추출 시 가장 높은 총 폴리페놀 함량 (약 98.3 mg GAE/g 및 88.2 mg GAE/g)을 함유하며, DPPH 라디칼 소거 활성은 약 44.6% 및 24.4%, ABTS 라디칼 소거 활성은 약 30.3% 및 40.8%로 확인되었다. 총 플라보노이드 함량은 약 21.80 mg QE/g 및 35.68 mg QE/g으로 확인되었다. 또한 오미자 및 꾸지뽕 기능성 추출물을 100 ug/mL 처리 시 세포 독성이 나타나지 않는 것으로 확인되었으며, NO 생성량을 약 56.3% 및 21.7% 저감시켜 항염증 효능을 나타내는 것으로 확인되었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.83-83
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• 2020

염증은 물리화학적 자극이나 세균 감염과 같은 외부 자극에 대응하기 위한 생체조직의 방어 반응의 하 나이며 조직이나 장기의 손상을 회복시키는 기전으로서 매우 중요한 역할을 하지만 염증반응이 과도해 질 경우 궤양성 대장염, 기관지염, 천식, 대장암 등을 유발하는 원인으로 작용하기 때문에 염증반응을 조 절하는 항염증제 개발은 매우 중요시되고 있다. 국내 염증개선 관련 시장은 현재 약 3조원 규모이며 지속 적인 성장세에 있지만 천연소재의 기능성 중심으로 출시된 제품 중 다수의 제품에서 주로 수입 원료를 사용하고 있어 국내 자생 및 재배하는 천연 소재들의 효능에 대한 검증을 통해 수입 원료 의존도를 낮추 기 위한 연구가 요구되고 있다. 따라서 본 연구에서는 순창에서 재배되는 참두릅 (Aralia elata Seem)과 도라지 (Platycodon grandiflorum)를 이용하여 천연 염증개선 소재화를 목적으로 기능성 증진을 위한 추 출조건 선정과정과 대식세포에 대한 세포독성 및 항염증 효능을 확인하여 천연소재를 이용한 염증개선 소재화를 시도하고자 한다. 본 연구는 전북 순창에서 재배되는 참두릅과 도라지의 추출조건을 선정하기 위해 용매, 온도 및 시간별 추출물의 total polyphenol 함량 평가를 통하여 최적 추출조건 선정을 진행하 였으며, 선정된 추출조건에서 추출된 추출물의 항산화 활성을 측정하기 위하여 DPPH & ABTS radical scavenging activity 및 total flavonoids 함량을 확인하여 항산화 효능을 평가하였다. 또한 대식세포인 Raw 264.7을 사용하여 MTT assay, Nitric oxide (NO) 생성 억제 효능을 확인하여 세포독성 및 항염증 활 성을 평가하였다. 실험결과, Total polyphenol 함량 분석을 통해 최적 추출조건이 선정된 두릅 (주정 40%, 25℃, 3 h), 도라지 (주정 60%, 25℃, 1 h)의 추출물을 이용하여 DPPH & ABTS radical scavenging activity 및 total flavonoids 함량을 분석한 결과, 도라지보다 두릅에서 더 높은 항산화 활성을 나타내었다. 대식세포를 활용한 두릅과 도라지의 세포독성을 측정한 결과, 100 ug/mL 이내의 농도에서 독성활성이 나타내지 않음을 확인되었으며, 항염증 활성을 측정한 결과 100 ug/mL에서 두릅 추출물이 도라지 추출 물보다 약 33% 이상 NO 생성억제 활성이 높게 나타내었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.84-84
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• 2020

염증 (Inflammation)은 병원체, 손상된 세포, 자극물질 등으로 인한 손상에 대해 작용하여 조직이나 장기의 손상을 재생하는 작용으로써 신체 방어 기전들 가운데 매우 중요한 역할을 하는 것으로 알려져 있다. 이러한 염증반응이 과다할 경우 각종 염증성 질환 혹은 암 등을 유발하는 원인으로 발전할 수 있어 항염증제의 개발은 전 세계적으로 중요시되고 있다. 선천적 면역을 담당하는 대식세포는 lipopolysaccharide(LPS), 활성산소 (ROS) 등에 의해 자극되어 염증인자 생성에 관여한다. 따라서 본 연구에서는 항염증 소재 개발을 목표로 하며, 국내 천연소재를 활용한 기능성 항염증 소재로 전북 순창군에서 재배된 초석잠(Stachys Sieboldii MIQ.)과 돼지감자 (Helianthus tuberosus L.)를 이용하여 항산화 활성을 평가하고자 하였으며, 대식세포주를 활용한 세포독성 및 항염증 활성에 대한 효능을 확인하고자 하였다. 본 연구는, 전북 순창 지역에서 재배 된 초석잠과 돼지감자를 사용하여 각 조건의 추출 용매, 온도, 시간별 추출물의 Total polyphenol 함량 평가를 통한 최적 추출조건 선정을 진행하고, 선정된 추출조건의 추출물의 항산화 활성을 측정하기 위해 DPPH & ABTS radical scavenging activity 분석 및 Total flavonoids 함량 분석을 통해 항산화 효능 평가를 진행하였다. 또한 항염증 소재로의 활용을 위해 대식세포인 Raw 264.7을 사용하여 농도별 MTT assay를 진행하여 세포독성 평가를 진행하였고, Nitric oxide (NO) 생성억제 효능을 확인하여 항염증 활성을 평가하였다. 실험 결과, Total polyphenol 함량 분석을 통해 최적 추출조건이 선정된 초석잠 (25℃, 주정 60%, 3 h), 돼지감자 (25℃, 주정 40%, 1 h)은 최적 조건에서 약 58 mg GAE/g 및 158 mg GAE/g의 총 폴리페놀 함량을 보였으며, DPPH & ABTS radical scavenging activity 및 Total flavonoids 함량 분석한 결과, 초석잠이 돼지감자보다 더 높은 항산화 활성을 나타내었다. 대식세포 실험에서의 추출물 처리군의 세포독성 측정 결과, 100 ug/mL 이내의 농도에서 독성활성이 나타나지 않음을 확인하였고, Nitric oxide (NO) 생성 억제활성 측정을 통해 LPS 처리군 대비 접종량 100 ug/mL 기준 각각 초석잠 약 47%, 돼지감자 약 49% 수준의 항염증 활성을 확인하였다.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.411-417
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• 2009

This research is intended to discover physiological and biochemical defense mechanisms against herbivores of 8 species of the genus Acerby examining the morphological characteristics of the leaf, the structure and number of leaf domatia, herbivores insects and mites feeding on leaves, which were collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Mt. Bangtae, Mt. Taebaek and Wonju City. This research was conducted from May through July, 2009, and the results are as follows. The domatia of A. pseudosieboldianum, A. pictum subsp. mono and A. mandshuricum belongs to tuft type; that of A. palmatum, A. triflorum and A. tschonoskii pocket+tuft type; and that of A. tegmentosum pocket type. The number of domatia per leaf turned out to be the highest in the case of A. tegmentosum(20.2), and the lowest in the case of A. ginnala (4.2). Leaf surface trichomes of A. palmatum, A. pseudosiebotdianum, A. ginnala and A. mandshuricum are covered with villi; those of A. pictum subsp. mono and A. triflorum with soft, pilose type of hair, and those of A. tschonoskii with stiff, strigose hair. The trichome density of lower leaf surface is found to be higher than that of the upper leaf surface. Only in the case of A. palmatum, A. pseudosieboldianum, A. tegmentosum and A. tschonoskii, a small amount of nectar is found to be secreted from the distal vein parts of the leaf margin. The number of mites on each leaf are found to be significantly different among tree species, and average mites number per leaf was the highest in the case of A. tschonoskii (9.2/leaf), and A. mandshuricum, A. pseudosieboldianum, and A. triflorum follow it in decreasing order. Minute insects attacking the leaf of Acer spp. include Periphyllus californiensis, P. viridis, Psylla spp, and gall mites, and the number of these insects are found in Periphyllus californiensis, Psylla spp, P. viridis, and Cicadellidae sp. in decreasing order. The natural enemies of these herbivores insects are predatory mites, such as Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi, Poecilocoris lewisi and its larva, and Poecilocoris lewisi. Lasius japonicus and Formica japonica are symbiotic with aphids, and supports herbivores. Finally, our research confirmed that predatory mites attack Periphyllus californiensis and suck the body fluid of their victim. This proves that mites form a symbiotic relationship with plants through the mediation of leaf domatia. This also indicates that a protective mutualism may be more conspicuous in temperate broad-leaved trees.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.175-183
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• 2016

BACKGROUND: There's a long rainy season during the Summer in Northeast Asia, including Korea. Heavy rainfall during this season causes harm to tree's root, and damped injury in the pear has been continuously reported. Pear Research Institute is breeding damp resistant rootstocks and investigating their mechanisms to relieve damped damages in the pear.METHODS AND RESULTS: Seedlings of Pyrus betulaefolia and P. calleryana were divided into two groups: control and damped, respectively. Damped group was treated by constant irrigation for 77 days and control group was maintained to keep the soil moisture pressure between 0 and -10 kPa. After the treatment, we analysed trees' growth rate, chlorophyll content, amino acids and total phenolic compounds. As a result, P. betulaefolia was sensitive to damped treatment while P. calleryana did not have significant differences between the control and damped treatment. It was observed that total contents for phenolic compounds were dramatically increased in P. betulaefolia while trees' growth rate, chlorophyll b and general amino acid contents were lowered by damping treatment.CONCLUSION: In some pear cultivars, growth habit is suppressed by damped damage. Pyrus calleryana displayed tolerances to damped damage in growth rate and some organic compound contents compared to P. betulaefolia. So we recommend to exploit P. calleryana as a pear rootstock rather than using P. betulaefolia.