Distribution of Rhizosphere and Endosphere Fungi on the First-Class Endangered Plant Cypripedium japonicum

( Geun-hye Gang ),( Gyeongjun Cho ),( Youn-sig Kwak ),( Eun-hee Park ) 한국균학회 2017 Mycobiology Vol.45 No.2

Endangered native plant habitats and populations are rapidly disappearing because of climate and environmental changes. As a representative, the abundance of the first-class endangered wild plant, Cypripedium japonicum, has been rapidly decreasing in Korea. The purpose of this study was to evaluate the distribution of rhizosphere and endophytic fungi on C. japonicum in its native habitat. A total of 440 rhizosphere and 79 endosphere fungi isolates were isolated and identified on the basis of their molecular characteristics. Sixty-five genera and 119 fungi species were identified in this study. The genus Trichoderma showed the highest abundance among both rhizosphere and endosphere fungi. Mortierella, Hypocrea, and Penicillium spp. were also relatively dominant species on C. japonicum. The community structures of rhizosphere and endosphere fungi were similar, but endosphere fungi showed greater diversity.

Analysis of Fungicide Sensitivity and Genetic Diversity among Colletotrichum Species in Sweet Persimmon

Gang, Geun-Hye,Cho, Hyun Ji,Kim, Hye Sun,Kwack, Yong-Bum,Kwak, Youn-Sig The Korean Society of Plant Pathology 2015 Plant Pathology Journal Vol.31 No.2

Anthracnose, caused by Colletotrichum gloeosporioides (C. gloeosporioides; Teleomorph: Glomerella cingulata), is the most destructive disease that affects sweet persimmon production worldwide. However, the biology, ecology, and genetic variations of C. gloeosporioides remain largely unknown. Therefore, in this study, the development of fungicide resistance and genetic diversity among an anthracnose pathogen population with different geographical origins and the exposure of this population to different cultivation strategies were investigated. A total of 150 pathogen isolates were tested in fungicide sensitivity assays. Five of the tested fungicides suppressed mycelial pathogen growth effectively. However, there were significant differences in the sensitivities exhibited by the pathogen isolates examined. Interestingly, the isolates obtained from practical management orchards versus organic cultivation orchards showed no differences in sensitivity to the same fungicide. PCR-restriction fragment length polymorphism (RFLP) analyses were performed to detect internal transcribed spacer regions and the ${\beta}$-tubulin and glutamine synthetase genes of the pathogens examined. Both the glutamine synthetase and ${\beta}$-tubulin genes contained a complex set of polymorphisms. Based on these results, the pathogens isolated from organic cultivation orchards were found to have more diversity than the isolates obtained from the practical management orchards.

Revealed the Status of Microbial Diversity and Structure in Soil and Rhizosphere of Endangered Plant Species Cypripedium japonicum

Hye Sun Kim,Geun-Hye Gang,Eun-Hee Park,Youn-Sig Kwak 경상대학교 농업생명과학연구원 2017 농업생명과학연구 Vol.51 No.5

The Cypripedium japonicum is a species of orchid, distributed mainly in the temperate regions of the Northern Hemisphere. In Korea, C. japonicum is an extremely rare species and class I endangered plant. However, little is known about the plant-microbe interaction and its ecology, especially rhizosphere bacterial communities in terms of structure and diversity in C. japonicum. In this study, the diversity of bacterial communities was investigated in C. japonicum rhizosphere and bulk soil. Proteobacteria, Acidobacteria and Actinobacteria were the most abundant groups in both rhizosphere and bulk soil. Significantly Proteobacteria and Actinobacteria abundantly inhabited in the rhizosphere when compared with the bulk soil. Conversely, significantly more unclassified bacteria were detected in the rhizosphere soil than in the bulk soil. This work increases our understanding of the rhizosphere bacterial diversity on class I endangered plant, C. japonicum.

Anti-inflammatory Effect of Indirubin-3'-Monoxime-5-Sulphonic Acid on Lipopolysaccharide-stimulated Murine Macrophage

Gang Baek Park,Hyun Jin Kim,Hye Seon Heo,Geun-Mook Park,Kyung Woo Park,Jin-Kyung Kim 대한의생명과학회 2011 Biomedical Science Letters Vol.17 No.3

Indirubin is the active ingredient of Danggui Longhui Wan, a mixture of plants that is used in traditional Chinese medicine to treat chronic diseases. In this study we investigated the anti-inflammatory effects of an indirubin derivative, indirubin-3'-monoxime-5-sulphonic acid (I3M-5S, C₁₆H₁₁N₃O₅S). We found that I3M-5S inhibits the production of various inflammatory mediators such as nitric oxide (NO) and prostaglandin E₂ (PGE₂) as well as inflammatory cytokines, tumor necrosis factor-α and interleukin-6 in lipopolysaccharide (LPS) stimulated murine macrophage, RAW264.7 cells. In addition, the expression of inducible nitric oxide synthase and cyclooxygenase-2, which are essential enzymes to produce NO and PGE₂, respectively, was blocked by I3M-5S treatment in LPS-stimulated RAW264.7 cells. Present data suggest that I3M-5S exhibits potent anti-inflammatory activity in cultured macrophages and merit further study as potential therapeutic agents for inflammatory disorders.

Optical Gain in MoS₂ <i>via</i> Coupling with Nanostructured Substrate: Fabry–Perot Interference and Plasmonic Excitation

Jeong, Hye Yun,Kim, Un Jeong,Kim, Hyun,Han, Gang Hee,Lee, Hyangsook,Kim, Min Su,Jin, Youngjo,Ly, Thuc Hue,Lee, Si Young,Roh, Young-Geun,Joo, Won-Jae,Hwang, Sung Woo,Park, Yeonsang,Lee, Young Hee American Chemical Society 2016 ACS NANO Vol.10 No.9

<P>Despite the direct band gap of monolayer transition metal dichalcogenides (TMDs), their optical gain remains limited because of the poor light absorption in atomically thin, layered materials. Most approaches to improve the optical gain of TMDs mainly involve modulation of the active materials or multilayer stacking. Here, we report a method to enhance the optical absorption and emission in MoS2 simply through the design of a nanostructured substrate. The substrate consisted of a dielectric nanofilm spacer (TiO2) and metal film. The overall photoluminescence intensity from monolayer MoS2 on the nanostructured substrate was engineered based on the TiO2 thickness and amplified by Fabry-Perot interference. In addition, the neutral exciton emission was selectively amplified by plasmonic excitations from the local field originating from the surface roughness of the metal film with spacer thicknesses of less than 10 nm. We further demonstrate that the quality factor of the device can also be engineered by selecting a spacer material with a different refractive index.</P>

Exploration of Mycobiota in Cypripedium japonicum , an Endangered Species

Cho Gyeongjun,Gang Geun-Hye,Jung Hee-Young,Kwak Youn-Sig 한국균학회 2022 Mycobiology Vol.50 No.2

Orchids live with mycorrhizal fungi in mutualism. This symbiotic relationship plays an essential role in the overall life cycle of orchids from germination, growth, settlement, and reproduction. Among the 1000 species of the orchid, the Korean lady’s slipper, Cypripedium japonicum, is known as an endangered species. Currently, only five natural habitats of the Korean lady’s slipper remain in South Korea, and the population of Korean lady’s slipper in their natural habitat is not increasing. To prevent extinction, this study was designed to understand the fungal community interacting in the rhizosphere of the Korean lady’s slipper living in the native and artificial habitats. In-depth analyses were performed to discover the vital mycorrhizal fungi contributing to habitat expansion and cultivation of the endangered orchid species. Our results suggested that Lycoperdon nigrescens contributed most to the increase in natural habitats and Russula violeipes as a characteristic of successful cultivation. And the fungi that helped L. nigrescens and R. violeipes to fit into the rhizosphere community in Korean lady’s slipper native place were Paraboeremia selaginellae and Metarhizium anisopliae, respectively. The findings will contribute to restoring and maintaining the endangered orchid population in natural habitats.

Effect of Isomerism on Molecular Packing and Gas Transport Properties of Poly(benzoxazole-<i>co</i>-imide)s

Zhuang, Yongbing,Seong, Jong Geun,Do, Yu Seong,Jo, Hye Jin,Lee, Moon Joo,Wang, Gang,Guiver, Michael D.,Lee, Young Moo American Chemical Society 2014 Macromolecules Vol.47 No.22

<P>A facile approach to synthesize poly(benzoxazole-<I>co</I>-imide)s without thermal rearrangement at high temperature is proposed. Poly(benzoxazole-<I>co</I>-imide)s with improved mechanical and solution-processable properties were prepared through polycondensation of 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with three synthesized novel benzoxazole-containing diamines and a commercial diamine. These poly(benzoxazole-<I>co</I>-imide)s had high tensile strengths of 110.3–122.0 MPa and good elongation at break of 11.9–26.3%, good thermal stability and high glass transition temperatures (<I>T</I><SUB>g</SUB>s) of up 306 °C. The effect of chain isomerism on molecular packing and physical and gas transport properties of the poly(benzoxazole-<I>co</I>-imide)s was investigated. The <I>para</I>-connecting isomers exhibited higher molecular weights (<I>M</I><SUB>w</SUB>s), better mechanical properties, higher <I>T</I><SUB>g</SUB>s, higher chain packing order and better overall performance for CO<SUB>2</SUB>/CH<SUB>4</SUB> and CO<SUB>2</SUB>/N<SUB>2</SUB> separations as compared to the corresponding <I>meta</I>-connecting ones. This study guides molecular architecture to improve particular membrane separation performance by introducing either <I>para</I>- or <I>meta</I>-connections into polymeric main chains.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2014/mamobx.2014.47.issue-22/ma501891m/production/images/medium/ma-2014-01891m_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma501891m'>ACS Electronic Supporting Info</A></P>

딸기 세균모무늬병(Xanthomonas fragariae)의 방제를 위한 약제 선발

김다란(Da-Ran Kim),강근혜(Geun-Hye Gang),조현지(Hyun ji Cho),명인식(Inn-Shik Myung),윤혜숙(Hae-Suk Yoon),곽연식(Youn-Sig Kwak) 한국농약과학회 2015 농약과학회지 Vol.19 No.3

In Korea, Strawberry bacterial angular leaf spot disease was first reported in 2010. The disease of strawberry caused serious problem for strawberry producers and export. To field test, we applied the bactericides in June and October as nursery stage and cultivation stage, respectively. In nursery stage with high temperature condition, Oxolinic acid (97.2%) showed significant control effect. In cultivation stage with low temperature condition is soil sterilization and soil non- sterilization the control effect. In cultivation stage in soil sterilization stage Validamycin (93.3%) showed reliable control effect against the disease. Also, soil non-sterilization stage with low control effect of Validamycin (80%) showed control effect the lower than a soil sterilization stage.

멸종위기종 구상나무 서식지별 세균 군집 구조 변이 조사

고영민,강근혜,정대호,곽연식,Young Min Ko,Geun-Hye Gang,Dae Ho Jung,Youn-Sig Kwak 한국식물병리학회 2024 식물병연구 Vol.30 No.2

구상나무(Abies koreana)는 한국의 고유종이지만 기후 변화로 인한 심각한 개체수 감소 현상이 일어나고 있다. 구상나무의 보전을 위한 다양한 연구가 기존에 진행되었지만 구상나무와 근권 세균 군집의 상관관계에 대한 연구는 비교적 미진한 편이기 때문에 추가적인 연구 진행이 필요하다. 식물의 근권 미생물 군집을 구성하는 일부 세균은 식물이 수분, 양분 등이 부족한 환경에서 살아남을 수 있게 돕는다. 또한 계절 변화에 의한 급격한 환경 변화에 대한 식물의 적응력을 향상시켜 줄 가능성이 있다. 본 연구에서는 이러한 세균 군집이 구상나무의 근권에 존재하거나 구상나무의 서식지 유형(자생지, 대체서식지, 고사지, 비재배토양)과 계절 변화(4월, 6월, 9월, 11월)에 따른 군집 구조의 차이가 발생하는지 파악하기 위해 세균의 16S rRNA V4 영역을 대상으로 한 metagenome amplicon sequencing을 진행하였다. 그 결과 우리는 구상나무와 매우 특이적으로 상호작용하는 근권 세균 군집이나 특정 분류군은 찾을 수 없었지만 구상나무 비재배토양에 비해서 구상나무 자생지의 근권 세균 군집이 계절 변화에 의한 변동성이 적게 나타난다는 사실을 알아냈다. 이러한 결과는 구상나무의 근권의 환경이 비재배토양에 비해 상대적으로 안정하다는 것을 보여준다. 그러나 구상나무와 명확하게 상호작용하는 세균 군집이나 분류군을 찾을 수 없었기 때문에 세균 군집 이외의 진균과 같은 기타 근권 미생물 군집들에 대한 추가 연구의 필요성이 제시된다. The Korean fir tree (Abies koreana), an endemic species of South Korea, is experiencing a severe decline in population due to climate change. Studies on the conservation of Korean fir have been extensive, yet research regarding its correlation with rhizosphere bacterial communities remains scarce, warranting further investigation. In this study, metagenome amplicon sequencing targeting the 16S rRNA V4 region was conducted to examine the presence of specific bacterial communities in Korean fir and to investigate potential differences based on habitat types (rhizosphere of native or cultivated trees, soil of dead trees, and bulk soil) and seasonal variations (April, June, September, November). Here we show that although we could not identify specific taxa highly specifically with Korean fir, the rhizosphere bacterial community in native trees exhibited less variability in response to seasonal changes compared to that in bulk soils. Suggesting the establishment of relatively stable bacterial populations around the Korean fir natural habitat. Further research on other types of rhizosphere and/or microbes is necessary to investigate the distinct relationship of Korean fir with microbial communities.

도라지와 더덕 뿌리썩음병의 방제 효과에 미치는 재배환경의 영향

김다란(Da-Ran Kim),강근혜(Geun-Hye Gang),정희준(Hee Jun Jung),홍성원(Sung Won Hong),곽연식(Youn-Sig Kwak) 한국농약과학회 2016 농약과학회지 Vol.20 No.2

Platycodon grandiflorum and Codonopsis lanceolata have been considered as cash vegetables and alternative medicine plants in Korea. In a previous survey from 1998 to 2010, repeated cultivation of the plant increased root rot disease incidence and severity. The disease has been recognized as critically limiting factor for crop production. However, control method has not been established for the disease of P. grandiflorum and C. lanceolata. In this study, control efficacy of Tebuconazole EC, Trifloxystroim SC and grapefriut extract was evaluated on the root rot disease of these plants in two different field conditions. Three of different fungicide were non critical effect to the disease severity and the control value, but grapefriut seed extract (GSE) was more ability to control the disease in C. lanceolata. In most things, soil drainage was the most important to decrease the disease severity and to improve the control value.