• 생약학회지
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• 제42권2호
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• pp.175-181
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• 2011

Oxidative stress or accumulation of reactive oxygen species (ROS) leads neuronal cellular death and dysfunction, and it contributes to neuronal degenerative disease such as Alzheimer's disease, Parkinson's disease and stroke. Glutamate is one of the major excitatory neurotransmitter in the central nervous system (CNS). Glutamate contributes to fast synaptic transmission, neuronal plasticity, outgrowth and survival, behavior, learning and memory. In spite of these physiological functions, high concentration of glutamate causes neuronal cell damage, acute insults and chronic neuronal neurodegenerative diseases. Heme oxygenase-1 (HO-1) enzyme plays an important role of cellular antioxidant system against oxidant injury. NNMBS020, the water-insoluble fraction of the 70% EtOH extract of root barks of Dictamnus dasycarpus, showed dominant neuroprotective effects on glutamate-induced neurotoxicity in mouse hippocampal HT22 cells by induced the expression of HO-1 and increased HO activity. In mouse hippocampal HT22 cells, NNMBS020 makes the nuclear accumulation of Nrf2 and stimulates extracellular signal-regulated kinase (ERK) pathway. The ERK MAPK pathway inhibitor significantly reduced NNMBS020-induced HO-1 expression, whereas the JNK and p38 inhibitors did not. In conclusion, the water-insoluble fraction of the 70% EtOH extract of root barks of D. dasycarpus (NNMBS020) significantly protect glutamate-induced oxidative damage by induction of HO-1 via Nrf2 and ERK pathway in mouse hippocampal HT22 cells.

• The Plant Pathology Journal
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• 제23권4호
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• pp.239-244
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• 2007

MicroTom is a miniature tomato plants with various properties that make it as a model system for experiments in plant molecular biology. To extend its utility as a model plant to study a plant - bacterial wilt system, we investigated the potential of the MicroTom as a host plant of bacterial wilt caused by Ralstonia solanacearum. We compared the disease progress on standard tomato and MicroTom by two inoculation methods, root dipping and soil drenching, using a race 1 strain GMI1000. Both methods caused the severe wilting on MicroTom comparable to commercial tomato plant, although initial disease development was faster in root dipping. From the diseased MicroTom plants, the same bacteria were successfully reisolated using semiselective media to fulfill Koch's postulates. Race specific and isolate specific virulence were investigated by root dipping with 10 isolates of R. solanacearum isolated from tomato and potato plants. All of the tested isolates caused the typical wilt symptom on MicroTom. Disease severities by isolates of race 3 was below 50 % until 15 days after inoculation, while those by isolates of race 1 reached over 50% to death until 15 days. This result suggested that MicroTom can be a model host plant to study R. solanacearum - plant interaction.

• The Plant Pathology Journal
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• 제33권4호
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• pp.410-423
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• 2017

Pathological interrelations of two soil-borne diseases in cucurbits (watermelon, oriental melon, shintosa and cucumber) caused by Fusarium isolates (FI) and the root-knot nematode (RKN), Meloidogyne incognita were characterized by the fusarium disease severity index (DI), RKN gall index (GI) and eggmass index (EI) in inoculation tests using FI and RKN. Virulence of FI as determined by DI at 4 weeks after inoculation was mostly in the higher order of Fusarium proliferatum F6, F5 and Fusarium oxysporum f. sp. melonis or Fusarium oxysporum f. sp. niveum with no significant differential interactions among the cucurbits and RKN co-infection. Significant increases of DI due to RKN coinfection were noticed in watermelon and oriental melon infected with F. proliferatum isolates, suggesting the DI increase due to RKN coinfection may depend upon the virulence of FI relative to aggressiveness of RKN on the cucurbits. For the coinfection of FI and RKN, GI and EI were mostly reduced logarithmically with the increase of DI, largely more in EI than GI, in all cucurbits except for shintosa. Microscopic examination of the root tissues showed histopathological features characteristic to infection types; formation of fungal hyphae and/or spores and plant defense structures (tyloses and mucilage) in variable degrees and formation of giant cells at variable developmental stages and with variable cytoplasmic depletion or degeneration which were visualized in relations with the values of DI, GI and EI. These findings will be helpful to develop control strategies of the soil-borne disease complex based on their pathological characteristics.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.551-560
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• 2018

Bellflower root (Platycodon grandiflorum), which belongs to the Campanulaceae family, is a perennial grass that grows naturally in Korea, northeastern China, and Japan. Bellflower is widely consumed as both food and medicine owing to its high nutritional value and potential therapeutic effects. Since foodborne disease outbreaks often come from vegetables, understanding the public health risk of microorganisms on fresh vegetables is pivotal to predict and prevent foodborne disease outbreaks. We investigated the microbial communities on the bellflower root (n = 10). 16S rRNA gene amplicon sequencing targeting the V6-V9 regions of 16S rRNA genes was conducted via the 454-Titanium platform. The sequence quality was checked and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using the weighted Fast UniFrac distance. The average number of sequence reads generated per sample was 67,192 sequences. At the phylum level, bacterial communities from the bellflower root were composed primarily of Proteobacteria, Firmicutes, and Actinobacteria in March and September samples. Genera Serratia, Pseudomonas, and Pantoea comprised more than 54% of the total bellflower root bacteria. Principal coordinate analysis plots demonstrated that the microbial community of bellflower root in March samples was different from those in September samples. Potential pathogenic genera, such as Pantoea, were detected in bellflower root samples. Even though further studies will be required to determine if these species are associated with foodborne illness, our results indicate that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria on fresh vegetables.

• 한국약용작물학회지
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• 제22권5호
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• pp.391-397
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• 2014

To control the disease of root rot in ginseng nursery, inorganic sulfur solution of 0.1%, 1.0%, and 2.0% were irrigated by amount of $10{\ell}$ per $3.3m^2$ before sowing. On the last ten days of July, Fusarium solani and F. oxysporum were similarly detected by 44.8% and 43.8%, respectively, while Cylindrocarpon destructans was low detected by 4.4% in the diseased seedling. The more sulfur's concentration was increased, the more soil pH was decreased. Soil pH was decreased from 5.87 to 4.59 by the irrigation of sulfur solution of 1.0%. The more sulfur's concentration was increased, the more electrical conductivity (EC) of soil was increased. EC was increased from 0.27 dS/m to 1.28 dS/m by the irrigation of sulfur solution of 1.0%. Irrigation of sulfur solution was effective on the inhibition of damping-off caused by Rhizoctonia solani in ginseng seedling. Control value for damping-off by the irrigation of sulfur solution of 1.0% and 2.0% were 75.7%, and 78.5%, respectively. Growth of leaf was inhibited by the irrigation of sulfur solution of 2.0%. Root weight per $3.3m^2$ showed the peak in sulfur solution of 1.0%, while survived-root ratio and root weight per plant were decreased in the level of 2.0%. Survived-root ratio of seedling in sulfur solution of 1.0% was distinctly increased by 4.7 times compare to the control, but control value for root rot was relatively low as 49.2%. Mycelium growth of C. destructans, F. solani, and R. solani were distinctly inhibited by the increase of sulfur's concentration in vitro culture using PDA medium.

• 한국약용작물학회지
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• 제9권3호
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• pp.211-219
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• 2001

1999년과 2000년 수원 작물시험장 백출 시험재배포장에서 시기별 P. drechsleri에 의한 역병 이병주율을 조사한 결과 파종 후 약 30-45일의 유묘기와 하절기 장마 이후 두 시기에 크게 증가하였다. 유묘기의 역병 발생은 20일간 $15^{\circ}C$ 이상의 평균 기온과 100mm이상의 강우 조건하에서 발생하며, 하절기 장마로 인한 토양 과습 조건에서 다시 증가하는 비슷한 경향을 보였다. 역병 이병주율은 종근 이식재배가 56.0%로 종자파종재배 18.6%보다 역병발생의 피해가 큰 것으로 나타났다. 재배조건 및 포장조건이 다른 5개 포장의 역병 이병주율과 토양내 역병 균밀도를 조사한 결과 객토포장이 연작포장에 비해, 무피복포장이 피복포장에 비해 역병 발생에 의한 피해가 적었으며, 역병 이병주의 확산은 재배방법 및 포장조건에 따라 다르나 토양 내 역병 원인균인 P. drechsleri의 균밀도와 깊은 연관이 있는 것으로 보인다. 종근 파종 후 각각 재배 2년 차와 재배 3년 차인 안동 북부 시험장과 영주 개인농가의 백출 포장의 토양내 역병 균밀도는 수원 작물시험장 백출 재배포장에 비해 비교적 낮았으나, 역병 발생에 의한 피해가 큰 것으로 나타나 백출 재배 시 2년 이상의 연작은 적합치 않은 것으로 나타났다.

• 식물병연구
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• 제24권4호
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• pp.332-338
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• 2018

2011년 8월 경상북도 봉화군 재산면 농가포장 5년생 인삼포장에서 잎이 푸른색을 띈 채 급격하게 마르는 증상이 발견되었다. 잎이 시든 직후 인삼의 뿌리를 채취하였으나, 뿌리나 줄기에서 특별한 병징은 없었으며, 뿌리의 수분이 약간 빠져나간 상태였다. 이러한 증상이 발생된 지 10일이 경과된 뿌리에서는 뿌리가 물러지면서 썩는 증상이 나타났다. 이러한 병징과 건전부의 경계부위에서 세균이 분리되었으며, 이 세균에 의한 뿌리썩음병이 의심되었다. 세균을 배양한 후 건전 인삼에 접종하자, 동일한 썩음 증상이 발현되었으며, 병반으로부터 동일한 세균이 재분리되었다. 이 세균을 BioLog system에 의한 탄소원 이용여부, Vitek 2 system을 이용한 생화학적 반응, GC-MIDI Sherlock system을 이용한 지방산 조성, 16S rRNA 염기서열을 분석한 결과, 모두 Serratia plymuthica로 동정되었다. 이에 따라 인삼 뿌리에 발생하는 이 병을 Serratia plymuthica에 의한 인삼 세균뿌리썩음병으로 명명하여 보고하고자 한다.

• 한국자원식물학회지
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• 제32권2호
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• pp.144-152
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• 2019

인삼은 현금작물로 통용되는 약초로 국내에서 매우 중요한 작물 중 하나이다. 인삼의 수확까지 경작 기간은 4~5년으로 이 기간 동안 여러 토양병원균으로부터 피해를 받게되며, 심할 경우에는 폐포로 경제적 손실을 입게된다. 이러한 뿌리썩음병에 의한 피해 현황을 조사하기 위해 충남, 충북, 강원지역의 6 년근 채굴지 25농가를 대상으로 인삼 뿌리썩음병 발생현황, 발병지수 및 병원균을 분석하였다. 당진 D는 발병도가 2.9로 조사지역 중 가장 높았으며, 괴산 C는 가장 낮은 발병도를 보였다. 인삼 뿌리썩음병의 병반으로부터 병원균을 분리한 결과, 625 균주 중 54.4%가 인삼 뿌리썩음병 관련 병원균인 I. radicicola와 F. solani로 분류가 되었으며, 염기서열을 이용하여 이들 병원균의 유전적 다양성을 확인하였다. 특히 I. radicicola 그룹 내에서도 강병원성 균주로 알려진 I. mors-panacis와 상대적으로 병원성이 약한 I. liriodendri, I. robusta, I. cyclaminicola 등이 동정되었다. F. solani의 경우는 두 개의 그룹으로 구분되어 지나, 추후 다양한 마커를 이용한 유전분석과 병원성 연구를 통해 다양성 연구를 진행해야할필요가 있다. 추후 이 결과는 인삼의 뿌리썩음병 진단 및 방제 있어서 기초자료로 활용될 것으로 판단된다.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.719-730
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• 2005

The purpose of this study was to compare the effect of tetracycline HCL, Citric acid and PrefGel applied on the root surfaces that planed with periodontal curret with Roto bur. In this study, 20 extracted teeth with advanced periodontal disease were used. The teeth were root planing with periodontal curette and Roto bur. Following root planing, each agents was burnished on the prepared root surface for 3 minutes to find opened dentinal tubules. And then, each specimens were investigated using scanning electron microscope. Amount of remained cementum by loss of tooth substance index and the number of opened dentinal tubules were evaluated to each specimens The results were as follows. 1. Groups treated with periodontal curette were almost seemed no removed. Other groups treated with Roto bur showed partially opened dentinal tubule orifices. 2. Loss of tooth substance index were compared between groups. There was no statistically difference between periodontal curette groups. Between Roto bur groups was alike. But there were statistically differences between periodontal curette and Roto bur groups. 3. At comparing with various root conditioning agents, Tetracycline HCL group took statistically higher than Citric acid and PrefGel in opened dentinal tubules. On the other hand, there was no statistically difference between Citric acid group and PrefGel group. As a result of this study, groups treated with Roto bur showed more cementum removed than groups treated with periodontal curette. In a treatment for regeneration of periodontal tissue, it was regarded that Roto bur should be used and that Tetracycline HCL would be more effective as chemical root conditioning agent.

• The Plant Pathology Journal
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• 제25권1호
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• pp.62-69
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• 2009

In this study, we characterized the bacterial strain KJ2C12 in relation with its biocontrol activity against Phytophthora capsici on pepper, and identified this strain using morphological, physiological, biochemical, fatty acid methyl ester, and 16S rRNA gene sequence analyses. Strain KJ2C12 significantly (P=0.05) reduced both final disease severity and areas under the disease progress curves of 5-week-old pepper plants inoculated with P. capsici compared to buffer-treated controls. As for the production of antibiotics, biofilms, biosurfactant, extracellular enzyme, HCN, and swarming activity, strain KJ2C12 produced an extracellular enzyme with protease activity, but no other productions or swarming activity. However, Escherichia coli produced weak biofilm only. Strain KJ2C12 could colonize pepper roots more effectively in a gnotobiotic system using sterile quartz sand compared to E. coli over 4 weeks after treatments. However, no bacterial populations were detected in 10 mM $MgSO_4$ buffer-treated controls. Strain KJ2C12 produced significantly higher microbial activity than the $MgSO_4$-treated control or E. coli over 4 weeks after treatments. Bacterial strain KJ2C12 was identified as Bacillus luciferensis based on morphological, physiological, and biochemical characteristics as well as FAME and 16S rRNA gene sequence analyses. In addition, these results suggested that B. luciferensis strain KJ2C12 could reduce Phytophthora blight of pepper by protecting infection courts through enhanced effective root colonization with protease production and an increase of soil microbial activity.