• The Plant Pathology Journal
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• 제32권3호
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• pp.273-280
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• 2016

Most biocontrol agents for plant diseases have been isolated from sources such as soils and plants. As an alternative source, we examined the feces of tertiary larvae of the herbivorous rhino beetle, Allomyrina dichotoma for presence of biocontrol-active microbes. The initial screen was performed to detect antifungal activity against two common fungal plant pathogens. The strain with strongest antifungal activity was identified as Bacillus amyloliquefaciens KB3. The inhibitory activity of this strain correlated with lipopeptide productions, including iturin A and surfactin. Production of these surfactants in the KB3 isolate varied with the culture phase and growth medium used. In planta biocontrol activities of cell-free culture filtrates of KB3 were similar to those of the commercial biocontrol agent, B. subtilis QST-713. These results support the presence of microbes with the potential to inhibit fungal growth, such as plant pathogens, in diverse ecological niches.

• Natural Product Sciences
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• 제15권2호
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• pp.60-65
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• 2009

Berberis is an important medicinal plant, of the family Berberidaceae. Different Berberis species and their parts are very common in herbal drug markets of India and world over as an adulterant/substitute to 'Daruharidra' i.e. B. aristata DC. Antimicrobial activity of 50% hydroalcoholic extracts of stem of four Berberis species viz. B. aristata DC., B. asiatica Roxb. ex DC., B. chitria Lindl. and B. lycium Royle and the isolated alkaloid berberine were tested against eleven bacterial and eight fungal strains. The extracts with the strongest antibacterial activity was obtained from B. lycium followed by B. aristata, B. asiatica and B. chitria. Based on these results it is possible to conclude that the hydroalcoholic extract and alkaloid (berberine) has stronger and broader spectrum against bacterial strains as compared to fungal strains. The result obtained in the present study authenticates and support the use of these plants in folklore medicine for treatment of various infectious diseases caused by the bacterial pathogens. However, an attempt has been made to explore the possibilities of utilizing stem part rather than roots of these species with the aim to conserve this species which is over exploited due to diverse use of its root. These findings will stimulate the search for novel, natural products as new antibacterial/antifungal agents which may be useful to pharmaceutical industries.

• The Plant Pathology Journal
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• 제18권5호
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• pp.284-287
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• 2002

The antifungal activity of super reductive water (SRW) against plant pathogenic fungi was examined to extend its application to integrated pest management (IPM) for plant diseases. Diluted solutions ($\times$1/10, $\times$1/25, and $\times$1/50) of SRW inhibited fungal growth of kiwifruit soft rot pathogen, Diaporthe actinidiae, in a concentration dependent manner, When kiwifruits were inoculated on wounds with mycelium blocks, stock and diluted solutions successfully inhibited the disease development. In addition to the high pH of the SRW, fungistatic activity was also considered as the cause of the antifungal effect against the pathogen. Whereas conidial germination of Magnaporthe grisea was not affected by the diluted SRW solutions, appressorium formation was significantly inhibited in a concentration dependent manner, With little harmfulness to human health and environment SRW could be used to control plant pathogenic fungi, particularly appressorium-forming fungal pathogens.

• The Plant Pathology Journal
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• 제27권1호
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• pp.20-25
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• 2011

Gibberella zeae (anamorph: Fusarium graminearum), a homothallic (self-ferile) ascomycete with ubiquitous geographic distribution, causes serious diseases in several cereal crops. Ascospores (sexual spores) produced by this fungal pathogen have been suggested as the main source of primary inoculum in disease development. Here, we report the function of a gene designated GzRUM1, which is essential for ascospore formation in G. zeae. The deduced product of GzRUM1 showed significant similarities to the human retinoblastoma (tumor suppressor) binding protein 2 and a transcriptional repressor, Rum1 in the corn smut fungus (Ustilago maydis). The transcript of GzRUM1 was detected during the both vegetative and sexual stages, but was more highly accumulated during the latter stage. In addition, no GzRUM1 transcript was detected in a G. zeae strain lacking a mating-type gene (MAT1-2), a master regulator for sexual development in G. zeae. Targeted deletion of GzRUM1 caused no dramatic changes in several traits except ascospore formation. The ${\Delta}$GzRUM1 strain produced perithecia (sexual fruit bodies) but not asci nor ascospores within them. This specific defect leading to an arrest in ascospore development suggests that GzRUM1, as Rum1 in U. maydis, functions as a transcriptional regulator during sexual reproduction in G. zeae.

• The Plant Pathology Journal
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• 제35권2호
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• pp.156-163
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• 2019

Our study investigated the available chlorine content, contact time and difference among strains of each pathogen for sodium hypochlorite (NaOCl) to control chemically against soil-borne fungal pathogens, such as Phytophthora rot by Phytophthora cactorum, violet root rot by Helicobasidium mompa, and white root rot by Rosellinia necatrix, causing die-back symptom on apple trees. As a result, the colony growth of Phytophthora cactorum was inhibited completely by soaking over 5 s in 31.25 ml/l available chlorine content of NaOCl. Those of H. mompa and R. necatrix were inhibited entirely by soaking over 160 s in 62.5 and 125 ml/l available chlorine content in NaOCl, respectively. Also, inhibition effect on available chlorine in NaOCl among strains of each soil-borne pathogen showed no significant difference and was similar to or better than that of fungicides.

• Mycobiology
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• 제47권1호
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• pp.126-133
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• 2019

Isaria javanica pf185 is an important entomopathogenic fungus with potential for use as an agricultural biocontrol agent. However, the effect of I. javanica pf185 on plant growth is unknown. Enhanced tobacco growth was observed when tobacco roots were exposed to spores, cultures, and fungal cell-free culture supernatants of this fungus. Tobacco seedlings were also exposed to the volatiles of I. javanica pf185 in vitro using I-plates in which the plant and fungus were growing in separate compartments connected only by air space. The length and weight of seedlings, content of leaf chlorophyll, and number of root branches were significantly increased by the fungal volatiles. Heptane, 3-hexanone, 2,4-dimethylhexane, and 2-nonanone were detected, by solid-phase micro-extraction and gas chromatography-mass spectrophotometry, as the key volatile compounds produced by I. javanica pf185. These findings illustrate that I. javanica pf185 can be used to promote plant growth, and also as a biocontrol agent of insect and plant diseases. Further studies are necessary to elucidate the mechanisms by which I. javanica pf185 promotes plant growth.

• Pediatric Infection and Vaccine
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• 제27권3호
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• pp.190-197
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• 2020

소아에서 후두기관지염이 진균에 의해 발생하는 경우는 매우 드물고 주로 선행 요인이 있는 환자에 보고된다. 또한, Aspergillus 감염에 의한 후두기관지염은 초기에 무증상이거나 가슴 X선 사진에서 특이점이 없는 경우가 많아 조기 진단이 어렵다. 저자는 피부증상과 비감염성 발열을 조절하기 위해 장기간 저용량 스테로이드를 사용했던 복용력이 있는 일차성 면역 결핍 질환이 의심되는 환자에서 점진적인 호흡 부전을 보였고 가막성 아르페르길루스증(Pseudomembranous aspergillosis)에 의한 후두기관지염으로 밝혀진 사례를 보고하여 Aspergillus 후두기관지염의 고위험 환자군에서 조기 진단을 통한 치료의 중요성을 알리고자 한다.

• 한국양봉학회지
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• 제34권2호
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• pp.125-129
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• 2019

Honey bees are important pollinators in agriculture, but are threatened by the pathogen Ascosphaera apis, which causes chalkbrood. Despite attempts to control this fungus using synthetic fungicides, none of them have been proven to be completely effective. Among 640 natural compounds that we tested, 4-hydroxyderricin (MIC=3.125, 6.25 mg/L after 24 h and 48 h growth, respectively) exhibited the strongest anti- Ascosphaera apis activity, followed by acetylshikonin (MIC=12.5 mg/L for 24 h and 48 h growth). 4-Hydroxyderricin showed selective growth inhibition of Ascosphaera apis and Rhizopus oryzae among tested fungus strains. Treatment 4-hydroxyderricin with miconazole revealed a synergistic effect (FICI=0.65±0.13 at 48 h incubation). These findings suggest that 4-hydroxyderricin, which has antifungal activity against Ascosphaera apis but few other fungal species, can effectively control infectious fungal diseases. Combined treatment of bees with 4-hydroxyderricin and miconazole could reduce cytotoxicity and improve the cost effectiveness of treatment.

• 대한약침학회지
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• 제24권1호
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• pp.32-40
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• 2021

Objectives: Pathogenic microbes are causal agents for various types of severe and even lethal infectious diseases. Despite of development in medication, bacterial and fungal infections still persist to be a vital problem in health care. Bacteria and several fungal species have shown resistance to antibiotics used in treatment to current medications. Therefore, it is a considerable field of interest in the design and development of novel compounds with antimicrobial activity. Methods: The compounds bearing a heterocyclic ring play an imperative role among other organic compounds with pharmacological activity used as drugs in human for control and cure of various infections. Thiadiazoles containing nitrogen-sulfur atom as part of their cyclic structure which shown wide-ranging application as structural units of biologically active molecules and are very useful intermediates in Medicinal Chemistry. Results: The effectiveness of the thiadiazole nucleus was established by the drugs currently used for the treatment of various infections. 1,3,4-Thiadiazoles and some of their derivatives are widely studied because of their broad spectrum of pharmacological activities. Conclusion: In the present work, a series of 1,3,4-Thiadiazole derivatives were synthesized by cyclization of a group of various benzaldehyde with thiosemicarbazide in the presence of various reagent like FeCl3, HCHO by losing a molecule of water. These derivatives were found to possess prominent antimicrobial activity.

• Journal of Forest and Environmental Science
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• 제37권4호
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• pp.338-340
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• 2021

Morus alba, known as White Mulberry, is one of the most common species of mulberry found in South Korea, along with M. australis, known as Korean Mulberry. During a routine survey to investigate fungal diseases on deciduous broad-leaved trees in 2020, leaf spots were consistently observed on the White Mulberry in Sejong-si (36°30'12.8"N 127°17'34.5"E) and Wonju-si (37°15'29.6"N 128°11'37.9"E), South Korea, with a disease incidence of approximately 70 to 80%. Symptoms included circular, tan or necrotic lesions surrounded by a dark margin on leaves, which, in some cases, the lesions coalesced to form relatively large necrotic regions. The pathogen was successfully isolated from M. alba, and was identified as Cladosporium pseudocladosporioides based on the phylogenetic analysis and morphology. To the best of our knowledge, this is the first report of leaf spot disease on M. alba caused by C. pseudocladosporioides in South Korea.