• Korean Journal of Microbiology
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• v.22 no.1
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• pp.19-28
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• 1984

The nematode-trapping process by Arthrobotrys conoides was investigated with the aid of scanning and transmission electron microscopy. 1. A. conoides captures nematode by means of three-dimensional network. 2. The wall of trap cell was thicker than that of vegetative hypha and the trap cell was more rich in cell organelles such as endoplasmic reticulum, mitochondria and electrondense granule. 3. The electron-dense granule, which could be found only in trap organs, gradually disappeared during its penetration into nematode cuticle. 4. The osmiophilic area was found at adhering site between the trap organ and nematode cuticle. 5. In some cases, any appressorium was not found at the site of penetration. 6. When the fungal-nematode culture was conserved for 2~3 weeks, numerous young nematodes were found to be adhered to spores, resulting in death.

• Biomedical Science Letters
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• v.10 no.1
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• pp.9-13
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• 2004

We have investigated the effects of hypha-water extracts (HWE), fruit body-water extracts (FWE) and cordycepin from Cordyceps militaris on serotonin release out of human platelets and human platelet aggregation. HWE and FWE inhibited the release of [$^3H$]-serotonin from human platelet stimulated by thrombin (2 U/ml) or collagen (20$\mu$g/ml) in a dose-dependent manner. Furthermore, cordycepin, a major component of Cordyceps militaris, inhibited the human platelet aggregation induced by collagen (10$\mu$g/ml) in a dose-dependent manner. These results suggest that cordycepin containing in HWE and FWE may inhibit the serotonin release by suppressing the collagen-induced human platelet aggregation. Accordingly, our data demonstrate that HWE and FWE containing much cordycepin might have antithrombotic and antimigrainous functions.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.435-441
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• 2009

In the present study, we analyzed the defensin protein deduced from Korean radish (Raphanus sativus L.) seeds.To express the genes in E. coli, we constructed a recombinant expression vector with a defensin gene, named rKRs-AFP gene isolated from Korean radish seeds. Over expressed rKRs-AFP proteins was separated by SDS-PAGE to determine the purity, and protein concentration was determined by the Bradford method. Antifungal activity was assessed by disk assay method against the tested fungi. As a result, when 500 mL of cell culture were disrupted by sonicator, 32.5 mg total proteins were obtained. The purified protein showed a single band on SDS-PAGE with estimated molecular weight about 6 KDa, consistent with the molecular mass calculated from the deduced amino acid sequence. The purified rKRs-AFP protein showed remarkable antifungal activities against several fungi including Aspergillus niger, Botrytis cinerea causing the gray mold disease, and Candida albicans. In field tests using the purified rKRs-AFP protein, the protein showed the reducing activity of disease spot and the mitigating effect of spreading of disease like agrichemicals. The immuno-assay of rKRs-AFP protein showed that the purified protein entirely accumulated at B. cinerea cytoplasm through the hyphal septa shown by fluorescence imaging. There was no fluorescence inside the cell, when the hypha was incubated without the protein. These all results indicate that the recombinant rKRs-AFP proteins can be utilized as a potential antifungal drug to control harmful plant fungal pathogens.

• Fisheries and Aquatic Sciences
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• v.20 no.10
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• pp.25.1-25.5
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• 2017

An economic marine alga, which is considered to be an important source of carrageenan, was collected from Jindo of the southern coast of Korea. This species shares the vegetative and female reproductive features of Ahnfeltiopsis and is characterized mostly by its small size (up to 8 cm), terete to subterete thalli at the lower portion, cartilaginous in texture, dichotomous branches, rarely produced proliferations, and an absence of hypha-like filaments in the medulla. It is distinguished from other Korean species within the genus by the thallus feature. In a phylogenetic tree based on the molecular data, this alga nests in the same clade with A. concinna from Japan but forms a sister clade to A. concinna from Mexico and Hawaii (type locality). However, the genetic distance among those sequences was calculated as 0.1-1.3% for rbcL and 1.1% for COI sequences, considered to be intraspecific variation within the genus. Based on the morphology and molecular analysis, this alga is identified as A. concinna originally described from Hawaii. This is the first record of the species in the Korean marine algal flora.

• Applied Microscopy
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• v.15 no.2
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• pp.1-9
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• 1985

The portion of Cuscuta japonica haustorium which lies internal to the host tissues, the endophyte, was examined at the ultrastructural level. The endophyte consisted of mainly small parenchymatous cells and large, slightly elongate cells at the tip. The tip cells were characterized by the presence of large and lobed nucleus, several small vacuoles, dense cytoplasm, abundant rough endoplasmic reticulum, dictyosomes, and mitochondria, and thus suggested to have a high metabolic activity. The shape, arrangement, and cytological characteristics of the parenchymatous and tip cells consisting the endophyte were very similar to those of the dividing cells and idioblasts, respectively, which appeared in the endophyte primordium of the upper haustorium. The tip cells with the thickened-apical wall were observed to grow intrusively through the host cell walls and to engulf the remnants of the degenerated host cells. In the former case intrusive growing cell was regarded to develop into the filamentous cell, the hypha. Plasmodesmata through the cell wall were not observed between host and parasite cells. Some host cells that in contact with the penetrating tip cells of the endophyte, showed the degenerating features such as a loss of cytoplasm, a beaded fashion of small vesicles, and deformation of chloroplasts.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.60-70
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• 2015

In this study, we investigated the effects of cordycepin-enriched (CE)-WIB801C, a n-butanol extract of Cordyceps militaris-hypha on collagen-stimulated platelet aggregation. CE-WIB801C dose dependently inhibited collagen-induced platelet aggregation, and had a synergistic effect together with cordycepin (W-cordycepin) from CE-WIB801C on the inhibition of collagen-induced platelet aggregation. CE-WIB801C and cordycepin stimulated the phosphorylation of VASP ($Ser^{157}$) and the dephosphorylation of PI3K and Akt, and inhibited the binding of fibrinogen to glycoprotein IIb/IIIa (${\alpha}IIb/{\beta}3$) and the release of ATP and serotonin in collagen-induced platelet aggregation. A-kinase inhibitor Rp-8-Br-cAMPS reduced CE-WIB801C-, and cordycepin-increased VASP ($Ser^{157}$) phosphorylation, and increased CE-WIB801C-, and cordycepin-inhibited the fibrinogen binding to ${\alpha}IIb/{\beta}3$. Therefore, we demonstrate that CE-WIB801C-, and cordycepin-inhibited fibrinogen binding to ${\alpha}IIb/{\beta}3$are due to stimulation of cAMP-dependent phosphorylation of VASP ($Ser^{157}$), and inhibition of PI3K/Akt phosphorylation. These results strongly indicate that CE-WIB801C and cordycepin may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

• Mycobiology
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• v.46 no.2
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• pp.129-137
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• 2018

Black rot disease in orchids is caused by the water mold Phytophthora palmivora. To gain better biocontrol performance, several factors affecting growth and antifungal substance production by Pseudomonas aeruginosa RS1 were verified. These factors include type and pH of media, temperature, and time for antifungal production. The results showed that the best conditions for P. aeruginosa RS1 to produce the active compounds was cultivating the bacteria in Luria-Bertani medium at pH 7.0 for 21 h at $37^{\circ}C$. The culture filtrate was subjected to stepwise ammonium sulfate precipitation. The precipitated proteins from the 40% to 80% fraction showed antifungal activity and were further purified by column chromatography. The eluted proteins from fractions 9-10 and 33-34 had the highest antifungal activity at about 75% and 82% inhibition, respectively. SDS-PAGE revealed that the 9-10 fraction contained mixed proteins with molecular weights of 54 kDa, 32 kDa, and 20 kDa, while the 33-34 fraction contained mixed proteins with molecular weights of 40 kDa, 32 kDa, and 29 kDa. Each band of the proteins was analyzed by LC/MS to identify the protein. The result from Spectrum Modeler indicated that these proteins were closed similarly to three groups of the following proteins; catalase, chitin binding protein, and protease. Morphological study under scanning electron microscopy demonstrated that the partially purified proteins from P. aeruginosa RS1 caused abnormal growth and hypha elongation in P. palmivora. The bacteria and/or these proteins may be useful for controlling black rot disease caused by P. palmivora in orchid orchards.

• Journal of Plant Biology
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• v.34 no.2
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• pp.129-136
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• 1991

Two cell types, tip cells and hyphal cells, were found at the front of Cuscuta australis endophyte growing into the stem parenchyma of the host plant, Trifolium repens. Each tip cell developed into an elongate, filamentous hypha. The cells of both types possessed a dense cytoplasm including abundant organelles and enlarged nuclei with the deeply lobed envelope. The unevenly thick walls were observed in certain tip cells. The wall penetrated through the middle lamellae of the host cells and engulfed the debris of broken host cells. Some front cells had the plasmalemma-wall invaginations, which increased the surface area and would facilitate material uptake from the host No plasmodesmata between the host and parasite cells were found; instead, an apoplastic continuity was established by fused cell walls at the interface of the two partners. The apoplast was thought to be the main route for water and nutrients transport.nsport.

• Biomedical Science Letters
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• v.22 no.4
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• pp.127-139
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• 2016

A species of the fungal genus Cordyceps has been used as an ingredient of traditional Chinese medicine. In this study, we prepared cordycepin-enriched WIB-801CE, an ethanol extract from culture solution of Cordyceps militaris-hypha, and evaluated its antiplatelet effects on human platelet aggregation. WIB-801CE dose-dependently inhibited ADP-, collagen-, and thrombin-induced platelet aggregation. These antiplatelet effects by WIB-801CE were associated with the attenuation of thromboxane $A_2$ ($TXA_2$) production and serotonin release by ADP, collagen, and thrombin. The inhibition of $TXA_2$ production by WIB-801CE was due to the inhibition of cyclooxygenase-1, $TXA_2$ synthase, and cytosolic phospholipase $A_2$ activity. Therefore, these data suggest that WIB-801CE may be a beneficial component against protection from platelet aggregation-mediated thrombotic disease.

• Journal of Mushroom
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• v.15 no.4
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• pp.168-177
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• 2017

To evaluate effects of ligninolytic enzyme type on the mycelial response and ligninolytic enzyme production during interspecific interactions among wood-rotting fungi, 4 fungal strains, Trichophyton rubrum LKY-7, Trichophyton rubrum LSK-27, Pycnoporus cinnabarinus, and Trichoderma viride, were selected. Regarding ligninolytic enzyme production, LKY-7 secreted laccase and manganese peroxidase (MnP), P. cinnabarinus secreted only laccase, and LSK-27 secreted only MnP in glucose-peptone medium, while T. viride did not produce any ligninolytic enzymes. In the co-culture of LKY-7 with P. cinnabarinus, the formation of aerial mycelium was observed and the enhancement of laccase activity owing to interspecific interaction appeared to be very low. In the co-culture of LKY-7 and P. cinnabarinus with LSK-27, a hypha-free clear zone was observed, which resulted in deadlock, and increased laccase or MnP activity was detected at the interaction zone. The interaction responses of LKY-7, P. cinnabarinus, and LSK-27 with T. viride were characterized by the formation of mycelial barrages along the interface. As mycelial barrages were observed at the T. viride territory and no brownish pigment was observed in the mycelial barrages, it is suggested that laccase and MnP are released as part of an offensive response, not as a defensive response. The co-culture of P. cinnabarinus with T. viride lead to the highest enhancement in laccase activity, yielding more than 14-fold increase in laccase activity with respect to the mono-culture of P. cinnabarinus. MnP activities secreted by LKY-7 or LSK-27 was generally low in interspecific interactions.