• The Plant Pathology Journal
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• 제37권4호
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• pp.389-395
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• 2021

Soil is the major source of plant-associated microbes. Several fungal and bacterial species live within plant tissues. Actinomycetes are well known for producing a variety of antibiotics, and they contribute to improving plant health. In our previous report, Streptomyces globisporus SP6C4 colonized plant tissues and was able to move to other tissues from the initially colonized ones. This strain has excellent antifungal and antibacterial activities and provides a suppressive effect upon various plant diseases. Here, we report the genome-wide analysis of antibiotic producing genes in S. globisporus SP6C4. A total of 15 secondary metabolite biosynthetic gene clusters were predicted using antiSMASH. We used the CRISPR/Cas9 mutagenesis system, and each biosynthetic gene was predicted via protein basic local alignment search tool (BLAST) and rapid annotation using subsystems technology (RAST) server. Three gene clusters were shown to exhibit antifungal or antibacterial activity, viz. cluster 16 (lasso peptide), cluster 17 (thiopeptide-lantipeptide), and cluster 20 (lantipeptide). The results of the current study showed that SP6C4 has a variety of antimicrobial activities, and this strain is beneficial in agriculture.

• Mycobiology
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• 제51권2호
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• pp.94-108
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• 2023

Termitomyces sp. that grow in symbiosis with fungus-farming Termites have medicinal properties. However, they are rare in nature, and their artificial culture is challenging. The expression of AXL receptor tyrosine kinase and immune checkpoint molecules favor the growth of cancer cells. The study evaluated the optimal conditions for the artificial culture of Termitomyces and their inhibitory activity on AXL and immune checkpoint molecules in lung adenocarcinoma and melanoma cell lines. The culture of 45 strains of Termitomyces was compared. Five strains with marked growth rates were selected. Four of the selected strains form a single cluster by sequence analysis. The mycelium of 4 selected strains produces more fungal mass in potato dextrose broth than in a mixed media. The bark was the most appropriate solid substrate for Termitomyces mycelia culture. The mycelium of all five selected strains showed a higher growth rate under normal CO₂ conditions. The culture broth, methanol, and ethyl acetate of one selected strain (T-120) inhibited the mRNA relative expression of AXL receptor tyrosine kinase and immune checkpoint molecules in cancer cell lines. Overall, these results suggest the potential usefulness of Termitomyces extracts as a coadjuvant therapy in malignant diseases.

• 농업과학연구
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• 제50권4호
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• pp.759-771
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• 2023

Plant growth-promoting rhizobacteria (PGPR) are naturally occurring bacteria that intensively colonize plant roots and are crucial in promoting the crop growth. These beneficial microorganisms have garnered considerable attention as potential bio-inoculants for sustainable agriculture. PGPR directly interacts with plants by providing essential nutrients through nitrogen fixation and phosphate solubilization and accelerating the accessibility of other trace elements such as Cu, Zn, and Fe. Additionally, they produce plant growth-promoting phytohormones, such as indole acetic acids (IAA), indole butyric acids (IBA), gibberellins, and cytokinins.PGPR interacts with plants indirectly by protecting them from diseases and infections by producing antibiotics, siderophores, hydrogen cyanide, and fungal cell wall-degrading enzymes such as glucanases, chitinases, and proteases. Furthermore, PGPR protects plants against abiotic stresses such as drought and salinity by producing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and modulating plant stress markers. Bacteria belonging to genera such as Bacillus, Pseudomonas, Burkholderia, Pantoa, and Enterobacter exhibit multiple plant growth-promoting traits, that can enhance plant growth directly, indirectly, or through synergetic effects. This comprehensive review emphasizes how PGPR influences plant growth promotion and presents promising prospects for its application in sustainable agriculture.

• 한국환경농학회지
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• 제31권1호
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• pp.60-67
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• 2012

옻나무 주성분인 조추출액의 고추 탄저병균에 대한 항진균활성을 조사한 결과 1.0 mg urushiol/mL PDA 농도에서 18.3-39.5%의 억제효과가 있었으며, 푸른 고추에 병원성이 강한 것으로 조사된 GC계열의 균주보다는 DC계열의 균주에 대한 효과가 높았다. Urushiol의 농도가 1.0 mg/mL 일 경우 약 70% 정도의 포자가 발아한 PDB 용액에서보다 공시 모든 균주의 포자발아는 50% 이상 억제되었다. 동일한 농도에서 균사생장억제 효과 보다는 포자발아에 대한 억제 효과가 다소 높은 경향을 보였다. 푸른 고추와 붉은 고추에 옻 추출액을 처리하고 공시 탄저병균을 접종한 후 병 발생 억제효과를 in vitro에서 검정한 결과 붉은 고추에 DC 균주를 접종하였을 경우 1.0 mg/mL 농도 처리에서는 75.0%, 0.1 mg/mL 농도 처리에서는 58.0% 로 나타났으며, 푸른고추에 병원성이 강한 GC 균주를 접종하였을 경우에는 각각 68.1% 및 28.3% 탄저병 발생이 억제되었다. 비닐하우스에서 관행재배방법에 의해 고추를 재배하면서 고추 탄저병이 자연발생하기 시작한 8월 21부터 옻 추출액을 1주일 간격으로 3회 살포하고 최종 살포일 7일 후에 전체 고추 열매 중 이병 열매를 조사하여 옻 추출액의 병 발생 억제정도를 구한 결과 1차 조사한 9월 11일에는 무처리 대조구에 비해 옻 조 추출액을 1.0 mg/mL 처리한 시험구에서는 85.0% 탄저병 발생 억제효과를 보였으나, 0.01 mg/mL 처리구에서는 9.8%의 낮은 억제효과를 보였다. 9월 11일 조사 후 이병 열매를 모두 제거한 다음 동일한 방법으로 옻 추출액을 계속처리하고 10월 2일에 조사한 결과 1차 조사 시기보다 대조구의 이병과율이 훨씬 낮은 7.0% 였으며, 옻 추출액 처리효과는 공시 처리 농도별로 각각 60.0, 54.3 및 10.0%로 조사되었다.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1223-1229
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• 2009

To construct a new recombinant strain of Bacillus velezensis that has antifungal and insecticidal activity via the expression of the insecticidal Bacillus thuringiensis crystal protein, a B. thuringiensis expression vector (pHT1K-1Ac) was generated that contained the B. thuringiensis cry1Ac gene under the control of its endogenous promoter in a minimal E. coli-B. thuringiensis shuttle vector (pHT1K). This vector was introduced into a B. velezensis isolate that showed high antifungal activities against several plant diseases, including rice blast (Magnaporthe grisea), rice sheath blight (Rhizotonia solani), tomato gray mold (Botrytis cinerea), tomato late blight (Phytophthora infestans), and wheat leaf rust (Puccinia recondita), by electroporation. The recombinant B. velezensis strain was confirmed by PCR using cry1Ac-specific primers. Additionally, the recombinant strain produced a protein approximately 130 kDa in size and parasporal inclusion bodies similar to B. thuringiensis. The in vivo antifungal activity assay demonstrated that the activity of the recombinant B. velezensis strain was maintained at the same level as that of wild-type B. velezensis. Furthermore, it exhibited high insecticidal activity against a lepidopteran pest, Plutella xylostella, although its activity was lower than that of a recombinant B. thuringiensis strain, whereas wild-type B. velezensis strain did not show any insecticidal activity. These results suggest that this recombinant B. velezensis strain can be used to control harmful insect pests and fungal diseases simultaneously in one crop.

• Applied Biological Chemistry
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• 제48권1호
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• pp.34-39
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• 2005

시설원예단지의 재배환경은 고온다습으로 많은 병해가 발생하며, 이를 방제하기위해 과다한 농약을 사용하므로 농약 잔류성에 대한 피해가 심각한 우려를 낳고 있다. 미생물을 이용한 생물학적 방제법 개발로 청정 시설원예작물을 생산할 목적으로 길항균을 분리하였다. 잎들깨 재배토양과 식물체로부터 길항세균 18종을 분리하였으며 분리한 길항세균 중에 AK-17이 가장 활성이 뛰어나 이를 이용하여 주요 식물병원균에 대한 항균스펙트럼을 조사하였다. 그 결과 잿빛곰팡이병원균의 Botrytis cinerea와 균핵병원균의 Sclerotinia sclerotiorum 및 줄기썩음병원균인 Rhizoctonia solani에 대한 항균효과가 뛰어났다. 잎들깨의 주요 병에 대한 생물학적 방제실험은 병발생 억제효과와 병 방제효과를 pot 실험으로 실시했다. 그 결과 균핵병은 55%의 병발생 억제호과와 92%의 방제효과가 있었고, 잿빛곰팡이병은 40%의 병발생 억제효과와 78%의 방제효과를 확인할 수 있었다. AK-17의 식물 생육촉진효과는 신장이 120%, 생체중이 164% 증가되었으며, 엽수와 엽면적은 각각 120%와 220%의 증가효과를 보였다. 그리고 AK-17을 생리 생화학적방법과 유전학적 방법으로 동정한 결과, Burkhoderia sp.로 확인되었다.

• 정신신체의학
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• 제8권2호
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• pp.165-171
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• 2000

연구목적 : 스트레스가 밀접하게 관련된 원형탈모증 환자들이 경험하는 생활사건, 이와 관련된 스트레스의 양, 이에 대한 대처방식 및 환자의 성격유형을 알아보아 이들 요소가 질병의 발병과 악화에 어떤 영향을 주는 지를 비교 분석하여 스트레스와 원형탈모증과의 관련성을 평가하고자 하였다. 방법 : 연구 대상은 피부과 외래를 방문한 원형탈모증 환자 43명과 대조군으로 피부진균감염증 환자 36명으로 하였다. 평가 도구로는 생활사건척도(Scale of Life Events), 대처방식척도(Coping Style Checklist)와 Eysenck A-유형성격검사로 세 가지의 설문조사를 실시하였다. 자료 분석은 연령을 보정한 공분산분석(analysis of covariance)을 적용하였다. 결과 : 원형탈모증군에서 생활 사건 수와 생활 사건의 총합이 유의하게 높았으나 대처 방식과 Eysenck A-유형성격에서는 유의미한 차이를 보이지 않았다. 결론 : 생활 사건에 대한 스트레스 양은 원형탈모증 환자군이 대조군에 비해 유의미하게 높은 수치를 보였고 이는 스트레스가 원형탈모증 발생에 기여한다는 기존의 연구들과 일치하는 소견이다. 후 스트레스와 원형탈모증과 보다 직접적인 연관 관계를 명확히 규명하여 궁극적으로 임상적으로 응용이 되어야 한다고 생각한다.

• 한국균학회지
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• 제46권3호
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• pp.333-344
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• 2018

점박이응애와 복숭아혹진딧물 그리고 잿빛곰팡이병균에 대해 우수한 살충 및 항균활성을 지닌 4가지 곤충병원성 곰팡이에 대해 효율적인 배양 배지 선발 및 다른 식물병원균에 대한 항균활성을 검정하였다. 효율적인 배지 선발은 출아포자 생산량과 배양액의 항진균활성 검정을 통해 선발하였으며, 그 결과 Beauveria bassiana 2R-3-3-1, Metarhizium anisopliae 4-2, SD3의 경우 GY배지가, B. bassiana SD15의 경우에는 PDB 배지가 적절한 배지로 선발되었다. 다른 식물병원균에 대한 항균활성 검정 결과, 4개 균주 모두 Colletotrichum acutatum과 Sclerotinia sclerotiorum에 대해서는 항진균 활성을 보였으나, Phytophthora capsici와 Colletotrichum fructicola에 대해서는 M. anisopliae SD3만 P. capsici에 대해 높은 항진균 활성을 나타내었고 다른 균주들의 활성은 미미하였다. Clavibacter michiganensissubsp. michiganensis에 대한 항세균 활성은 Metarhizium속의 2균주는 높은 활성을 보였으나 Beauveria속의 2 균주들은 활성을 보이지 않았다. 이상의 결과로 해충방제에 효과적인 곤충병원성 곰팡이가 다양한 식물병원균에 대해서도 효과적인 방제제로 이용될 수 있음을 확인할 수 있었다.

• The Plant Pathology Journal
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• 제36권4호
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• pp.335-345
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• 2020

Tomato grey mould has been one of the destructive fungal diseases during tomato production. Ten mM of menadione sodium bisulfite (MSB) was applied to tomato plants for eco-friendly control of the grey mould. MSB-reduced tomato grey mould in the 3rd true leaves was prolonged at least 7 days prior to the fungal inoculation of two inoculum densities (2 × 10⁴ and 2 × 10⁵ conidia/ml) of Botrytis cinerea. Protection efficacy was significantly higher in the leaves inoculated with the lower disease pressure of conidial suspension compared to the higher one. MSB-pretreatment was not effective to arrest oxalic acid-triggered necrosis on tomato leaves. Plant cell death and hydrogen peroxide accumulation were restricted in necrotic lesions of the B. cinereainoculated leaves by the MSB-pretreatment. Decreased conidia number and germ-tube elongation of B. cinerea were found at 10 h, and mycelial growth was also impeded at 24 h on the MSB-pretreated leaves. MSB-mediated disease suppressions were found in cotyledons and different positions (1st to 5th) of true leaves inoculated with the lower conidial suspension, but only 1st to 3rd true leaves showed decreases in lesion sizes by the higher inoculum density. Increasing MSB-pretreatment times more efficiently decreased the lesion size by the higher disease pressure. MSB led to inducible expressions of defence-related genes SlPR1a, SlPR1b, SlPIN2, SlACO1, SlChi3, and SlChi9 in tomato leaves prior to B. cinerea infection. These results suggest that MSB pretreatment can be a promising alternative to chemical fungicides for environment-friendly management of tomato grey mould.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.13-13
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• 2014

Species belonging to the genus Fusarium are widely distributed and cause diseases in many plants. Isolation of fungal strains from air or cereals is necessary for disease forecasting, disease diagnosis, and population genetics [1]. Previously we showed that Fusarium species are resistant to toxoflavin produced by the bacterial rice pathogen Burkholderia glumae while other fungal genera are sensitive to the toxin, resulting in the development of a selective medium for Fusarium species using toxoflavin [2]. In this study, we have tried to elucidate the resistant mechanism of F. graminearum against toxoflavin and interaction between the two pathogens in nature. To test whether B. glumae affects the development of F. graminearum, the wild-type F. graminearum strains were incubated with either the bacterial strain or supernatant of the bacterial culture. Both conditions increased the conidial production five times more than when the fungus was incubated alone. While co-incubation resulted in dramatic increase of conidial production, conidia germination delayed by either the bacterial strain or supernatant. These results suggest that certain factors produced by B. glumae induce conidial production and delay conidial germination in F. graminearum. To identify genes related to toxoflavin resistance in F. graminearum, we screened the transcriptional factor mutant library previously generated in F. graminearum [3] and identified one mutant that is sensitive to toxoflavin. We analyzed transcriptomes of the wild-type strain and the mutant strain under either absence or presence of toxoflavin through RNAseq. Expression level of total genes of 13,820 was measured by reads per kilobase per million mapped reads (RPKM). Under the criteria with more than two-fold changes, 1,440 genes were upregulated and 1,267 genes were down-regulated in wild-type strain than mutant strain in response to toxoflavin treatment. A comparison of gene expression profiling between the wild type and mutant through gene ontology analysis showed that genes related to metabolic process and oxidation-reduction process were highly enriched in the mutant strain. The data analyses will focus on elucidating the resistance mechanism of F. graminearum against toxoflavin and the interaction between the two pathogens in rice. Further evolutionary history will be traced through figuring out the gene function in populations and in other filamentous fungi.