• 한국식물병리학회지
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• 제14권6호
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• pp.606-611
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• 1998

An antagonistic bacterium, Pseudomonas flurorescens MC07 inhibited the mycelial growth of Rhizoctonia solani, Pythium ultimum, Fusarium oxysporum, and Phytophthora capsici in on potato dextrose agan (PDA) and other media. The strain MC07 conlonizes various plant roots and possesses antifungal activity. To determine the role of antifungal activity of the bacterium in disease suppression, a mutant Okm3-4 which lost its activity was isolated after screening 2,500 colonies generated by Omegon-Km insertions. The mutant Okm3-4 showed diminished growth inhibition of R. solani, P. ultimum, F. oxysporum, and Ph. capsici in vitro and had reduced suppressive effects on sesame damping.-off compared to the parental strain. In soils, accumulation of the pathogens by continuous cropping, 90% of sesame plants were killed by natural infection of damping-off whereas, only 29% of plants grown from seeds treated with MC07 were killed. On the other hand, 85% of plants died when sesame seeds were treated with the Okm3-4 cells. This indicated that antifungal activity of MC07 in vitro is directly responsible for the suppression of damping-off disease. Emergence rates of sesame seeds in pots containing diseased soil were 33%. However, MC07 treatments on seeds significantly improved emergence rates, which has similar effects of Benomyl treatment. The mutant Okm3-4 exhibited 53% of emergence rate. This indicated that antifungal activity of MC07 also affects the emergence rate of sesame seeds.

• IMMUNE NETWORK
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• 제1권3호
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• pp.221-229
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• 2001

Background: Inactivation of tumor suppressor genes is believed to be important in the development of many human malignancies. Recently, several lines of evidence have indicated that the wild type p53 gene located at 17p13.3, may function as a tumor suppressor gene and that a mutant p53 gene could promote transformation by inactivating normal p53 function in a dominant negative fashion. These broad spectrum of p53 mutation in human cancers provide that mutant p53 and their protein may be potential targets of tumor diagnostic and therapeutic interventions. Method: Colony formation was performed to investigate growth suppressional ability. p53 expression pattern was examined by western blot and p53-mediated transactivation ability was assessed by CAT activity. SNU C2A cells were observed in apoptotic aspects induced by etoposide and $H_2O_2$ treatment, detecting sensitivity on agent, DNA fragmentation through agarose gel, chromatin condensation by fluorescence microscope, and cell cycle distribution by FACS. Result: 1) p53 mutant his179arg ($histidine{\rightarrow}arginine$) detected in SNU C2A cells lost transcriptional activity and growth suppression ability, showing dominant negative effect on its wild type p53. 2) Etoposide-treated SNU C2A cells induced apoptosis, exhibiting dramatic reduction of cell growth, DNA fragmentation, nuclear condensation formation of apoptotic body and increment of sub-G1 cell fraction. 3) Etoposide and $H_2O_2$-treated SNU C2A cells have no high increase of p53 expression and overexpressed p53 protein changed localization, from cytoplasm to nucleus. Also, p53-mediated transcriptional activity was increased by agents-treatment. Conclusion: SNU C2A cells coexpress wild-type and mutant p53 protein induced apoptosis in the condition on DNA damage, through localizational shift from cytoplasm to nucleus of p53 protein rather than the induction of p53 protein. SNU C2A cells derived mutant p53 his179arg abrogated both the growth supression ability and transactivational activity, showing inhibition effect on transcriptional activity of wild type p53, but did not repress the activity of wild type p53 in SNU C2A cells owing to dominant activity of wild type. These cell condition may provide new gene therapeutic implications leading effective antiproliferation of cell when mutant and wild-type p53 protein were co-expressed in cell.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.95.1-95
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• 2003

Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varying levels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytopkhora capsici and increased plant growth promotion in red pepper. PGPR isolates further analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia Iyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytopkhora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.286-297
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• 1996

The proliferation of bone marrow stem cell compartment is thought to be under both positive and negative controls by cytokines and colony stimulation factors. Macrophage inflammatory $protein-1{\alpha}(MIP-1{\alpha})$ has been assessed for its potential to protect hematopoietic stem cells from cytotoxic effects of a cycle-specific antineoplastic agents. We have tested the ability of $MIP-1{\alpha}$ to suppress the proliferation of stem cell line Du.528.101 in variety of active status by using $[^{3}H]-thymidine$ incorporation test. The results were as follows. 1. The effect of $MIP-1{\alpha}$ on steady-state Du.528.101 cell represented the cell growth suppression at the concentration of 10, 50, 100nM of $MIP-1{\alpha}$(P<0.001). 2. $MIP-1{\alpha}$ stimulated the proliferation of Du.528.101 cells previously treated with IL-1 at the concentration of 5, 50nM of $MIP-1{\alpha}$(P<0.01). 3. The suppression effect of MIP-1 on Du.528.101 cells at the concentration of 5, 50nM was shown when cells were treated with $MIP-1{\alpha}$ before activation with $IL-1{\beta}(P<0.01)$. 4. The growth rate of synchronized cells were slower than that of non-synchronized ones, and $MIP-1{\alpha}$ represented the similar suppression effect on both synchronized and non-synchronized cells.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 제10차 국제학술회의 및 추계정기 학술발표회
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• pp.47-47
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• 2003

Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varyinglevels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytophthora capsici and increased plant growth promotion in red pepper. PGPR isolatesfurther analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia lyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytophthora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

• 원예과학기술지
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• 제34권2호
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• pp.242-248
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• 2016

This research was conducted to determine the effects of four different substrates, expanded rice hulls (ERH), commercial substrates for strawberries (CSS), clay sand (CS), and loamy sand (LS), on the inhibition of anthracnose crown rot (ACR) in strawberry. Mother plants of 'Seolhyang' strawberry were transplanted into an elevated bed in March, 2013 and March, 2014 and the runners connecting mother plants and daughter plants were cut in early August of both years. After separation, growth characteristics of the daughter plants were measured and then each daughter plant was inoculated with conidial suspensions of Colletotrichum fructicola, one of several species of Colletotrichum that causes ACR in strawberries. The incidence of ACR as influenced by the different substrates was investigated in both years. The daughter plants grown on CSS had the highest values for shoot height, leaf area, and fresh weight. Those grown on ERH and LS substrates also displayed good above-ground growth characteristics except for fresh weight, but the daughter plants grown on CS had the poorest above-ground growth characteristics. The ERH and CS treatments resulted in the highest number of primary roots and the greatest root weight. The CSS-grown daughter plants had the highest ACR disease index, followed by the CS and LS treatments, but there were no significant differences among the three substrates. However, the ERH-grown daughter plants had a markedly lower ACR disease index on October 11, 2013 and October 7, 2014. The CSS-grown daughter plants had high nitrogen and potassium contents and low calcium content, whereas the ERH-grown daughter plants had low nitrogen levels and high silicon levels. The results of this study provide basic information on the ability of the different substrates tested to provide disease suppression of ACR in the propagation of strawberry transplants.

• The Plant Pathology Journal
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• 제18권4호
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• pp.216-220
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• 2002

Seed decay of soybean caused by Diaporthe phaseolorum, Colletotrichum truncatum and Cercospora kikuchii is a serious disease when soybean is harvested under warm and wet weather conditions. Benomyl has been used for controlling the disease, however, benomyl application may be limited due to common occurrence of resistance. The efficacy of 21 fungicides against the pathogens was evaluated in vitro. Among the fungicides tested, benomyl, carbendazim, fluazinam, iprodione+propineb, thiophanate-methyl, and triflumizole were found effective and were evaluated for their ability to control the seed pathogens. Fluazinam completely inhibited mycelial growth at a concentration of 100 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for D. phaseolorum; and at a concentration of 500 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for C. truncatum and C. kikuchii. $EC_90$ values of fluazinam were similar to that of benomyl. Because fluazinam, iprodione+propineb, and triflumizole were found effective against the seed pathogens, these were subjected for field-testing. Suppression of pod and seed infection by fluazinam and iprodione+propineb was as high as that of benomyl without any reduction in agronomic characters of soybean. This study shows that fluazinam and iprodione+propineb may be used in combination with benomyl to control seed pathogens, manage resistance, and ensure production of high quality soybean seeds.

• Molecules and Cells
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• 제20권2호
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• pp.196-200
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• 2005

The neurofibromatosis type2 (NF2) tumor suppressor gene product, merlin, is structurally related to the ezrin-radixin-moesin (ERM) family of proteins that anchor the actin cytoskeleton to specific membrane proteins and participate in cell signaling. However, the basis of the tumor suppressing activity of merlin is not well understood. Previously, we identified a role of merlin as an inhibitor of the Ras-ERK signaling pathway. Recent studies have suggested that phosphorylation of merlin, as of other ERM proteins, may regulate its function. To determine whether phosphorylation of merlin affects its suppression of Ras-ERK signaling, we generated plasmids expressing full-length merlin with substitutions of serine 518, a potential phosphorylation site. A substitution that mimics constitutive phosphorylation (S518D) abrogated the ability of merlin to suppress effects of the Ras-ERK signaling pathway such as Ras-induced SRE transactivation, Elk-mediated SRE transactivation, Ras-induced ERK phosphorylation and Ras-induced focus formation. On the other hand, an S518A mutant, which mimics nonphosphorylated merlin, acted like wild type merlin. These observations show that mimicking merlin phosphorylation impairs not only growth suppression by merlin but also its inhibitory action on the Ras-ERK signaling pathway.

• 한국응용곤충학회지
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• 제23권1호
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• pp.22-27
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• 1984

오이를 재배했던 비닐하우스 토양에 병원균을 전면 접종하고 1983년 7월 25일부터 8월 25일까지 포리에칠렌 필림을 멀칭하여 태양열소독 효과를 실험하였다. 멀칭처리 기간중 토양의 일중 최고온도는 깊이 5cm에서 $58^{\circ}C$, 15cm는 $45^{\circ}C$, 25cm는 $42^{\circ}C$에 달했다. 태양열처리 한지 32일 경과후 지표로부터 5cm이내의 토양에 있던 병균은 완전히 사멸되었으며 15cm 까지는 $98\%$ 이상 소멸되었으나 25cm 토양은 무처리와 차이가 없었다. 그러나 태양열처리한 토양에서 분리한 균주는 무처리 토양의 균주보다 소형포자 생산량이 현저하게 감소되었다. 멀칭처리에 재배한 오이는 생육이 월등히 좋았는데 특히 5cm 이내의 토양에서 두드러지게 나타났으며 노지재배의 경우도 생장과 수량이 무처리에 비하여 현저히 좋았다. 병원균 F. oxysporum f. sp. cucumerinum은 오이 유균에 외관상 나타나는 병징 이외에도 전염원의 농도가 증가됨에 따라 오이 생육이 비례하여 억제됨을 나타내었다.

• 생명과학회지
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• 제14권1호
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• pp.154-162
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• 2004

암의 성장과 신생혈관 억제인자로 알려진 thrombospondin-1의 생합성은 다양한 외부자극에 대해 전사단계에서 세포 특이적으로 조절된다. 이전의 연구에서 본 연구자들은 PMA가 정상 돼지 대동맥 내피세포(PAE)에서는 TSP-1의 발현을 감소시키는 반면 사람 간암 세포주인 Hep3B에서는 증가시키는 사실을 발견하였다. PMA 처치에 따른 정상 돼지 대동맥 내피세포에서의 TSP-1의 발현 감소현상은 tsp-1 유전자 조절부위의 염기서열 -767과 -723사이에 존재하는 염기서열이 억제 부위임을 밝혀 이러한 결과를 바탕으로 -767에서 -723 염기서열을 서로 부분 중복되도록 세 종류의 올리고 탐식자 (올리고 탐식자 a-1, -767∼-738; 올리고 탐식자 a-2, -759∼-730; 올리고 탐식자 a-3, -752∼723)를 제작하여 -767과 -723 부위의 특정 염기서열과 이에 결합하는 인자를 EMSA을 수행하여 분석하였다. 실험 결과, PMA 처치에 따른 정상 돼지 대동맥 내피세포에서의 TSP-1 감소는 -752에서 -730 사이의 염기서열이 저해 조절인자와 결합함과 더불어 -767에서 -760과 -752에서 -730 사이의 염기서열들에 촉진 조절인자들이 결합하지 못함으로서 기인된다는 실험적 사실을 관찰하였고. 특히, PMA 처치는 정상 돼지 대동맥 내피세포에서 저해 조절인자의 -752에서 -730 부위에 대한 친화력을 향상시켰으며 이러한 친화력은 c-Jun 항체에 의해 영향을 받지 않았다.