• Mycobiology
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• 제37권1호
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• pp.69-71
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• 2009

Clubroot symptoms occurred severely on roots of Pak-Choi (Brassica campestris ssp. chinensis) grown in greenhouses in Gwangju city, Gyeonggi province, Korea in September, 2008. The incidence of the disease symptoms reached as high as 90% in three greenhouses investigated. The root galls collected from the greenhouses were sectioned using a scalpel and observed by light microscope. Many resting spores were found in the cells of the root gall tissues. Suspension of resting spores was prepared from the root galls and inoculated to roots of healthy Pak-Choi plants. Each of five resting spore suspensions caused clubroot symptoms on the roots, which were similar to those observed during the greenhouse survey. Resting spores of the pathogen were observed in the cells of the affected roots. The clubroot pathogen was identified as Plasmodiophora brassicae based on its morphological and pathological characteristics. This is the first report that Plasmodiophora brassicae causes clubroot of Pak-Choi.

• International Journal of Industrial Entomology and Biomaterials
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• 제38권1호
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• pp.6-13
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• 2019

In the present study, we investigated the antifungal activity of methanol and ethanol extracts of different parts (leaves, twigs, and root bark) of mulberry plant against Alternaria alternata and Fusarium sp. Among them, the methanol and ethanol extracts of mulberry root bark exerted the highest inhibitory activity against the mycelial growth of A. alternata ($70.6{\pm}1.6$ to $80.8{\pm}6.7%$ and $58.7{\pm}0.0$ to $80.8{\pm}6.7%$, respectively) and Fusarium sp. ($15.5{\pm}2.7$ to $39.3{\pm}3.4%$ and $26.4{\pm}2.7$ to $47.6{\pm}4.8%$, respectively). In contrast, the methanol and ethanol extracts from mulberry leaves and twigs did not suppress the mycelial growth of these fungal species. Importantly, the methanol and ethanol extracts of mulberry leaves tended to even accelerate the mycelial growth of A. alternata and Fusarium sp. Therefore, the results of this study indicate that methanol and ethanol extracts of mulberry root bark can be used as control agents against A. alternata and Fusarium sp.

• 대한소아치과학회지
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• 제45권2호
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• pp.144-153
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• 2018

본 연구는 치근 및 치주조직의 형성과정동안 Sonic Hedgehog (SHH) signaling의 역할에 대해 알아보고자 치성간엽에서 조직특이적으로 Smoothened (Smo)가 활성화 또는 차단되는 mouse를 제작하여 분석하였다. 생후 28일경 Smo 활성화모델에서는 H-E 염색 시 얇은 두께의 치근상아질, 넓어진 치수강, 치주인대공간에 느슨하게 배열되어있는 섬유들이 관찰되었다. 면역조직화학염색 시 Smo 활성화모델은 wild type mouse와 비교하여 백악질, 치주인대 그리고/또는 백악모세포의 표식자인 Bsp, Dmp1, Periostin, Ank 같은 기질 단백질들의 발현이 현저히 감소하였다. 그러나 Smo 차단모델은 wild type mouse와 비교하여 이러한 기질 단백질들의 발현에 차이가 보이지 않았다. 본 연구를 통하여 치근 및 치주조직의 정상적인 형성과정에 낮은 수준으로 조절되는 SHH signaling이 필요하다는 것을 확인할 수 있었다.

• 한국환경복원기술학회지
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• 제7권2호
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• pp.36-45
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• 2004

This study was conducted to formulate management guidelines for monumental old trees in Korea through analysis of growing environments. A total of 20 old trees designated as natural monuments in Seoul, Incheon, and Gyeonggi provinces were surveyed for biological characteristics, surrounding environments, root collar conditions, tree health, and soil characteristics. Relationships among root collar conditions, tree health, and soil characteristics were analyzed by correlation. The old solitary trees designated as natural monuments included Pinus bungeana(4 trees), Juniperus chinensis(3 trees), Ginkgo biloba(3 trees), Poncirus trifoliata(2 trees), Actinidia arguta, Wisteria floribunda, Thuja orientalis, Quercus variabilis, Sophora japonica, Fraxinus rhynchophylla, Zelkova serrata, and Pinus densiflora. The tree height ranged from 3.56 to 67m, and root collar diameter ranged from 1.01 to 15.2m. The monumental old trees were growing on the various sites ranging from gardens, historical sites, open agricultural fields, mountain hills, to near the ocean beaches and streams. The coverage of bald land ranged from 50 to 100%, and depth of filled soil around the root collar ranged from 0 to 50cm. Tree health was expressed as the amount of branch dieback, cavity development, detachment of cambial tissue, infliction by diseases and insects. The branch dieback ranged from 5 to 20%, cavity development ranged from 10 to 100$cm^3$, detachment of cambial tissue ranged from 5 to 45%, and infliction by diseases and insects ranged from 5 to 20%. Soil pH ranged from 5.9 to 8.3, organic matter contents from 12 to 56%, phosphorus contents from 104 to 618ppm, while soil compaction ranged from 7 to 28mm. Results of correlation analysis showed that coverage of bald land was the most serious factor to deteriorate the cavity development and detachment of cambial tissue. In addition, chemical properties of soils seemed to be related to the health of the trees.

• Journal of Ginseng Research
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• 제47권3호
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• pp.469-478
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• 2023

Background: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. Methods: One-year-old P. ginseng seedlings treated with KNO₃ were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. Results: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. Conclusion: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.

• Journal of Ginseng Research
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• 제48권2호
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• pp.220-228
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• 2024

Background: Panax ginseng, one of the valuable perennial medicinal plants, stores numerous pharmacological substrates in its storage roots. Given its perennial growth habit, organ regeneration occurs each year, and cambium stem cell activity is necessary for secondary growth and storage root formation. Cytokinin (CK) is a phytohormone involved in the maintenance of meristematic cells for the development of storage organs; however, its physiological role in storage-root secondary growth remains unknown. Methods: Exogenous CK was repeatedly applied to P. ginseng, and morphological and histological changes were observed. RNA-seq analysis was used to elucidate the transcriptional network of CK that regulates P. ginseng growth and development. The HISTIDINE KINASE 3 (PgHK3) and RESPONSE REGULATOR 2 (PgRR2) genes were cloned in P. ginseng and functionally analyzed in Arabidopsis as a two-component system involved in CK signaling. Results: Phenotypic and histological analyses showed that CK increased cambium activity and dormant axillary bud formation in P. ginseng, thus promoting storage-root secondary growth and bud formation. The evolutionarily conserved two-component signaling pathways in P. ginseng were sufficient to restore CK signaling in the Arabidopsis ahk2/3 double mutant and rescue its growth defects. Finally, RNA-seq analysis of CK-treated P. ginseng roots revealed that plant-type cell wall biogenesis-related genes are tightly connected with mitotic cell division, cytokinesis, and auxin signaling to regulate CK-mediated P. ginseng development. Conclusion: Overall, we identified the CK signaling-related two-component systems and their physiological role in P. ginseng. This scientific information has the potential to significantly improve the field-cultivation and biotechnology-based breeding of ginseng.

• 한국산림과학회지
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• 제90권4호
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• pp.458-464
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• 2001

본 연구는 토양 산성화 정도가 서로 다른 독일가문비나무 임분에서 토양 깊이에 따른 뿌리의 나이테 발달과 분지형태를 분석함으로서, 임분에 따른 뿌리발달을 비교하고자 하였다. 조사된 독일가문비나무 임분에서 뿌리분지구조는 변형된 뿌리와 변형되지 않은 뿌리에 대한 조사임분간의 통계적 유의성이 인정되지 않았지만, 가장 많이 산성화된 Weidenbrunnen 임분에서는 뿌리가 상해를 입음으로 인해 발생되는 포크형, 권총형, 쇠스랑형과 같은 비정상적인 분지구조가 많이 나타났다. 뿌리의 나이테 분석 결과, 수평뿌리의 연평균 길이생장은 Weidenbrunnen 임분과 Barbis 임분이 6.3cm, Eberg$\ddot{o}$tzen 임분이 9.5cm의 길이 생장을 나타내었으며, 수직뿌리의 연평균 길이생장은 Weidenbrunnen 임분이 4.4cm Barbis 임분이 5.4cm, 그리고 Eberg$\ddot{o}$tzen 임분이 6.7cm의 생장을 보였다. 80cm 토양 깊이에서의 뿌리 횡단면 분포는 Eberg$\ddot{o}$tzen 임분이 굵은 뿌리와 가는 뿌리가 고르게 분포하고 있으며, 횡단면의 합계는 $32.6cm^2$ 이었다. Barbis 임분에서는 굵은 뿌리가 가운데 몰려서 분포하고, 가는 뿌리는 비교적 적게 나타났으며, 그 합계는 $29.2cm^2$이었다. Weidenbrunnen 임분에서는 적은 수의 가는 뿌리만 분포하고 그 값은 $10.9cm^2$에 불과하였다. 뿌리고정계수는 Eberg$\ddot{o}$tzen 임분이 1.04로 다른 두 임분 Barbis(0.3), Weidenbrunnen (0.08)과 비교하여 매우 높은 값을 나타내었다. 본 조사 독일가문비나무 임분 중에서 Weidenbrunnen 임분에서 나타난 비정상적인 형태의 변형된 분지구조와 뿌리의 저조한 생장은 토양산 성화 등으로 인하여 정상적인 뿌리가 생장의 장애를 받아 나타난 결과 때문이라 사료된다.

• 한국식품영양과학회지
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• 제41권8호
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• pp.1158-1167
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• 2012

현재 전처리 농산물 중 소비비율이 높은 세척 근채류(연근, 우엉, 도라지)의 침지액의 효과 및 저장온도에 따른 품질 변화를 연구하였다. 본 연구의 대상인 근채류의 품질변화는 근채류의 종류와 온도, 저장기간에 따라 pH, 색도, 경도 등의 변화에 차이를 보였으며, 특히 $24^{\circ}C$에는 전처리 근채류의 품질변화가 빨라 $10^{\circ}C$에 저장한 근채류보다 품질유지기간이 평균 3~4일 정도 단축되었다. 침지액에 따른 미생물학적 품질변화 결과를 분석해본 결과, ASC 처리에 의하여 근채류의 초기 총균수 및 대장균군수가 가장 유의적으로 감소하여 미생물 억제 효과가 뚜렷이 나타났다. 연근 도라지에 AA, CA, ASC 처리한 처리군은 초기 PPO 활성을 유의적으로 낮추는데 효과적이었지만, 우엉의 경우 ASC 처리에 의한 갈변 억제 효과가 나타나지 않았다. AA 처리한 도라지의 경우 TW 처리군에 비하여 오히려 경도가 빠르게 감소하여 품목에 따른 침지 방법에 차이를 두어야 함을 확인할 수 있었다. 따라서 세척 근채류는 품목에 따라 저장온도와 침지방법이 품질에 영향을 미치므로 적절한 저장온도 및 세척액 사용과 포장방법을 유지한다면 품질의 안전성을 확보하여 품질유지기한을 연장할 수 있을 것이라고 사료된다.

• 대한소아치과학회지
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• 제24권3호
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• pp.710-717
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• 1997

Autotransplantation is the transplantation of embeded, impacted, or unerupted tooth, into extraction socket or surgically prepared socket in the same individual. Clinically, successful autotransplantation must show radiolucent space(periodontal ligament space) between transplanted tooth and supporting bone, lamina dura, no root resorption, no ankylosis, no inflammatory change, and physiologic tooth mobility. It is important that procedure is atraumatic, and the instruments should not contact the root surface during procedure. We performed autotransplantation of impacted mandibular canine that transversely located beneath the apices of the mandibular incisors with uncompletely developed apex. In radiographs and clinical evaluation, this transplant showed successful clinical finding except irregularity of mesial root surface after 14 months. It is conclued that transplantation of canine with $\frac{1}{2}{\sim}\frac{3}{4}$ root development provides a good chance of pulp survival, limited risk of root resorption and ensures sufficient final length, and is thus recommended.

• Journal of Biosystems Engineering
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• 제27권4호
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• pp.301-310
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• 2002

With a purpose to manufacture an onion peeler, the root cutting equipment of the onion could be attached to a prototype onion peeler was developed. Before the experiment, the distribution of the dimensions of the Korean native onion were measured. And some types of the blades to cut and remove the root of the onion were designed and such characteristics as feasible revolution, conveying speed, and power requirement were investigated. From the result of the test, the selected one among the various cutters was the wing type blade with the round blade to cut out the root and with the vertical blade to cut a circular line. The optimum operating conditions of the wing type blade were revealed the revolution with no load was at 630 rpm, and the conveying speed was 0.08 m/s. Under these conditions, the maximum torque was 5.25 kg·m and the power requirement was 33 W, respectively.