• The Plant Pathology Journal
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• 제31권2호
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• pp.195-201
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• 2015

Plant growth promoting rhizobacteria (PGPR) are known to confer disease resistance to plants. Bacillus sp. JS demonstrated antifungal activities against five fungal pathogens in in vitro assays. To verify whether the volatiles of Bacillus sp. JS confer disease resistance, tobacco leaves pre-treated with the volatiles were damaged by the fungal pathogen, Rhizoctonia solani and oomycete Phytophthora nicotianae. Pre-treated tobacco leaves had smaller lesion than the control plant leaves. In pathogenesis-related (PR) gene expression analysis, volatiles of Bacillus sp. JS caused the up-regulation of PR-2 encoding ${\beta}$-1,3-glucanase and acidic PR-3 encoding chitinase. Expression of acidic PR-4 encoding chitinase and acidic PR-9 encoding peroxidase increased gradually after exposure of the volatiles to Bacillus sp. JS. Basic PR-14 encoding lipid transfer protein was also increased. However, PR-1 genes, as markers of salicylic acid (SA) induced resistance, were not expressed. These results suggested that the volatiles of Bacillus sp. JS confer disease resistance against fungal and oomycete pathogens through PR genes expression.

• Weed & Turfgrass Science
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• 제6권2호
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• pp.157-164
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• 2017

본 연구는 미생물을 이용하여 친환경적인 잔디관리를 위해 계분이나 돈분의 퇴비화 과정에서 얻어진 가축분 퇴비로부터 단백질 및 탄수화물 분해능과 잔디 갈색퍼짐병(large patch), 갈색마름병(brown patch), 그리고 동전마름병(dollar spot) 병원균에 항균활성을 보이는 미생물을 분리하기 위하여 실시하였다. 분리된 미생물은 총 68균주였고, 이들을 대상으로 단백질 분해활성, 탄수화물 분해활성 및 잔디 주요병원균에 대한 항균활성을 조사하여 활성이 높은 미생물 34균주를 선발하였다. 이 중에서 단백질과 탄수화물 분해 및 항균활성을 나타내는 균주인 ASC-14, ASC-18 및 ASC-35를 선발하였다. 이들 선발 균주를 대상으로 16s rRNA 유전자 분석 결과 ASC-14와 ASC-18은 B. amyloliquefaciens로 확인되었고, 반면에 ASC-35는 B. subtilis 세균으로 최종 동정되었다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.28-28
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• 2015

Asexual reproduction or conidiation in aspergilli is a primary mean to produce their progenies that is environmentally and genetically controlled tightly. Previously, intensive researches in the model fungus Aspergillus nidulans disclosed some genes playing important roles in asexual and sexual development. Among them, one gene encoding a putative helix-loop-helix (HLH) transcription factor, named ndrA, has been isolated and characterized as a downstream regulator of developmental master regulator NsdD. By using comparative genome search of A. niduans NdrA protein, its orthologues have been identified in A. fumigatus and A. flavus, respectively (AfudrnA and AfldrnA). Deletion of the ndrA genes in both Aspergillus species made them unable to produce the conidia yet abundant production of sclerotia in A. flavus. Complementation of ndrA deletion strains by intact ndrA ORFs has restored the conidiation as in the control strains. In A. fumigatus, ndrA deletion also resulted in loss of conidiation phenotype. Northern analyses showed that the ndrA genes in both Aspergillus species are highly expressed at the early stage of the conidiation. Interestingly, the ndrA genes were found to be necessary for the proper expression of brlA genes. Antifungal sensitivity test revealed that the ndrA genes might be responsible for the sensitivity or resistance to some antifungal agents. However, ndrA deletion did not greatly influence the growth in both strains. And the A. flavus ndrA gene did not affect the aflatoxin production. Taken together, ndrA genes in Aspergillus species could be an important positive regulator of conidiation under the regulation of the nsdD gene yet upstream of the brlA gene.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.682-685
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• 2008

Among thirteen strains of the genus Bacillus isolated from Shrimp-jeotkal in our laboratory, a strain BA34 showing good antifungal activity against Phytophthora infestans in a previous experiment was tested for the inhibitory effect against Akt, protein kinase B. Since Akt is known to play an important role in controlling apoptosis, its inhibitors can be used as potential apoptosis-inducing agents in the treatment of cancer. Two active compounds were isolated and their structures were determined. They have similar structures, despite showing different inhibitory effects. In order to elucidate the reasons for these different effects, three-dimensional studies were carried out.

• Toxicological Research
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• 제21권4호
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• pp.285-290
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• 2005

We demonstrate that radicicol, a macrocyclic antifungal antibiotic originally isolated from Monosporium bonorden, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Treatment of peritoneal macrophages and RAW 264.7 cells with radicicol inhibited LPS-stimulated nitric oxide production in a dose-related manner. Immunohistochemical staining of iNOS and RTPCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunostaining of p65, EMSA, and reporter gene assay showed that radicicol inhibited $NF-\kappa/Rel$ nuclear translocation. DNA binding, and transcriptional activation, respectively. Collectively, these series of experiments indicate that radicicol inhibits iNOS gene expression by blocking $NF-\kappa/Rel$ nuclear translocation. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of radicicol on iNOS suggest that radicicol may represent a useful anti-inflammatory agent.

• Journal of Pharmaceutical Investigation
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• 제28권4호
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• pp.241-247
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• 1998

Ketoconazole is an imidazole antifungal agent which inhibits the biosynthesis of fungal cellmembrane ergosterol and has immunosuppressive properties in vitro. Biphenyl dimethyl dicarboxylate (PMC) has been utilized for antioxidative action and for liver-protective purposes. Studies were undertaken to investigate effects of biphenyl dimethyl dicarboxylate (PMC) on the immunosuppression of ketoconazole in ICR mice. In the combination of PMC and ketoconazole, as compared with the treatment of ketoconazole alone, there were significant increases in activities of natural killer (NK) cells and phagocytes along with circulation leukocytes. The elevation of serum glutamic-pyruvic transaminase (S-GPT) and total protein levels caused by ketoconazole were reduced by the combination of PMC and ketoconazole. In addition, lower serum albumin and albumin/globulin (A/G) ratio were also increased to normal level.

• 통합자연과학논문집
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• 제1권1호
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• pp.47-53
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• 2008

In a previous study, we showed that Cecropin A (1-8)-Magainin 2 (1-12) hybrid peptide (CA-MA)'s analogue, Anal P5, exhibit broad-spectrum antimicrobial activity. Anal P5, designed by flexible region (positions 9, 10)-substitution, Lys- (positions 4, 8, 14, 15) and Leu- (positions 5, 6, 12, 13, 16, 17, 20) substitutions, showed an enhanced antimicrobial and antitumor activity without hemolysis. The primary objective of the present study was to gain insight into the relevant mechanisms of antimicrobial activities of Anal P5 by using flow cytometric analysis. Anal P5 exhibits strong antifungal activity in a salt concentration independent manner. In addition, Anal P5 causes significant morphological alterations of the bacterial surfaces as shown by scanning electron microscopy, supporting its antibacterial activity. Its potent antibiotic activity suggests that Anal P5 is an excellent candidate as a lead compound for the development of novel antibiotic agents.

• 약학회지
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• 제58권1호
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• pp.47-52
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• 2014

Clematis mandshurica (Ranunculaceae) has traditionally been used as a remedy for antidiuretic, antifungal, rheumatic conditions and alleviate pain. We carried out to evaluate the anti-oxidative effect, anti-inflammatory effect and anti-melanogenic effect of ethanol extract and solvent fractions of Clematis mandshurica. The ethanol extract and the dichloromethane fraction of Clematis mandshurica showed an anti-oxidative effect in DPPH assay, the inhibitory activity of nitric oxide (NO) production in lipopolysaccharide (LPS) activated RAW 264.7 cell, and melanin synthesis and tyrosinase activity of B16F10 melanoma cells. They reduced NO production and melanin content in a dose-dependent manner at concentrations of $2.5{\sim}10{\mu}g/ml$. They also suppressed iNOS and tyrosinase protein and m-RNA expressions dose dependently, assayed by western blot analysis and RT-PCR experiment.

• BMB Reports
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• 제34권1호
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• pp.15-20
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• 2001

One of the innate immune reactions in invertebrates is the pro-phenoloxidase (pro-PO) activation system that is involved in the generation of superoxide, melanin synthesis, and the subsequent sequestration of foreign matter entering the hemocoel of the invertebrates. However, the molecular mechanism of this biological reaction is still obscure. To expand our understanding of the biological roles of the pro-PO activation system in invertebrates, we performed a yeast two-hybrid screening by using three regions of pro-PO as bait and a yeast two-hybrid cDNA library from Tenebrio molitor larvae as prey We isolated a novel partial cDNA clone that encodes a glycine-rich protein that interacted with the active phenoloxidase (termed phenoloxidase interacting protein, POIP). POIP consists of two domains: One is an N-terminal unique domain and the other is a C-terminal glycine-rich domain. The C-terminal glycine-rich domain showed sequential homology with those of insect antifungal proteins. Also, the yeast two-hybrid screen in a reverse orientation (using POIP as bait) yielded PO, suggesting that the PO-POIP interaction is specific. By using a 315 bP PCR fragment of the N-terminal unique region of POIP, we cloned the full-length cDNA of POIP from the Tenebruo cDNA library constructed by using E. coli injected larvae. The interaction analysis between PO, and a truncated fragment lacking the N-terminal unique region of POIP, indicated that the N-terminal unique region is necessary for interaction between PO and POIP. The expression level of the POIP mRNA is increased by bacterial injection into T. molitor larvae. This suggests that POIP might be engaged in the humoral defense reaction.

• The Plant Pathology Journal
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• 제33권3호
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• pp.264-275
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• 2017

The spent mushroom substrate (SMS) of Lentinula edodes that was derived from sawdust bag cultivation was used as materials for controlling Phytophthora blight disease of pepper. Water extract from SMS (WESMS) of L. edodes inhibited mycelial growth of Phytophthora capsici, suppressed Phytophthora blight disease of pepper seedlings by 65% and promoted growth of the plant over 30%. In high performance liquid chromatography (HPLC) analysis, oxalic acid was detected as the main organic acid compound in WESMS and inhibited the fungal mycelium at a minimum concentration of 200 mg/l. In quantitative real-time PCR, the transcriptional expression of CaBPR1 (PR protein 1), CaBGLU (${\beta}$-1,3-glucanase), CaPR-4 (PR protein 4), and CaPR-10 (PR protein 10) were significantly enhanced on WESMS and DL-${\beta}$-aminobutyric acid (BABA) treated pepper leaves. In addition, the salicylic acid content was also increased 4 to 6 folds in the WESMS and BABA treated pepper leaves compared to water treated leaf sample. These findings suggest that WESMS of L. edodes suppress Phytophthora blight disease of pepper through multiple effects including antifungal activity, plant growth promotion, and defense gene induction.