• Journal of Plant Biotechnology
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• 제32권2호
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• pp.129-134
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• 2005

체세포배 유도를 통해 두릅나무 역병 저항성 개체인 '자오'의 효율적인 재분화가 가능하였다. 절편에 따라 배발생 캘러스에 요구되는 생장조절제의 종류가 다르게 나타났다. 잎의 경우 MS 배지에 2,4-D와 TDZ, L-glutamine이 처리된 배지에서 캘러스와 체세포배의 유도가 양호하였으며, 엽병과 뿌리는 2,4-D 단독처리 시 가장 좋은 결과를 얻을 수 있었다. 적정 배양조건하에서 배발생캘러스 유도율은 잎, 엽병, 뿌리로부터 각각 75%, 67% 및 83%를 나타냈다. 삼투압제 처리에 따른 체세포배의 발아율은 sucrose, glucose, maltose모두 90% 이상의 발아율을 보였으나, 식물체 형성은 2% sucrose에서 72%로 가장 좋았다. 어린 식물체는 생장조절제를 첨가하지 않은 1/2MS 배지에서 정상 식물체로 생장하였고, 인공상토에 이식하여 95% 이상 순화하였다. 본 실험결과는 두릅나무 역병 저항성 개체 '자오'의 체세포 배발생을 통한 기내 대량증식이 가능함을 보여주었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.96.1-96
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• 2003

Serratia plymuthim A21-4 strongly inhibits the mycelial growth, zoospore formation, and cystospore germination of Phytophthor spp and Pythium species. The bacterial isolate produced antifungal substance and chitinase. The bacteria also enhanced to plant growth remarkably in low nutritional condition. The application of cell suspension of A21-4 to pepper seedlings in greenhouse experiments and soil drenching in farmer's field was proved successfully to control the phythophthora blight of pepper. For the effective control, however, relatively high density of cell number(10$\^$9/cfu/$m\ell$) is required. Density effect was similar in plant growth promoting activity of A21-4. Though this investigation we improved the problem with changes of culture condition of bacteria and some nutritional amendment.

• 한국식물병리학회지
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• 제11권1호
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• pp.47-52
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• 1995

One hundred and thirty bacterial isolates with high chitinolytic activity on chitin agar media were isolated and identified. Most of the isolates were Aeromonas hydrophila (110 isolates), and the others were Serratia marcescens (11 isolates), Aeromonas caviae (3 isolates), Chromobacterium violaceum strain C-61 (2 isolates), Chromobacterium violaceum strain C-72 (1 isolate) and unknown species (3 isolates). Among them, C. violaceum strain C-61 had highest chitinolytic activity and fungal growth inhibition on PDA. This bacterium also inhibited the growth of Rhizoctonia solani, Sclerotinia scelrotiorum, Phytophthora capsici and Pythium ultimum, but it didn't inhibit the growth of Fusarium oxysprum and Fusarium solani. C. violaceum strain C-61 suppressed damping-off of eggplant caused by R. solani. Populations of the chitinolytic bacteria such as Aeromonas hydrophila, Serratia marcescens, Aeromonas caviae, Chromobacterium violaceum strain C-61 and Chromobacterium violaceum strain C-72 introduced into R. solani-infested soil were continuously decreased until 20 days after treatment, but their populations except A. caviae were not changed significantly and maintained over 5$\times$104 CFU per g of soil thereafter.

• 한국미생물·생명공학회지
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• 제29권3호
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• pp.142-148
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• 2001

경주 인근 지역의 토양으로부터 식물병원성 진균 Fusarium oxysprum과 phytophthora capsici를 동시에 길항할수있는 항진균성 항생물질 생산성 생물방제균을 분리하고, 성분을 함유한 병원진균의 세포벽을 분해하는 chitinase 생산성이 우수한 균주를 분리하고자 하였다. 분리된 생물방제균의 형태학적, 생화학적 및 배양학적으로 동정하여 잠정적으로 Bacillus amyloliquefaciens 7079로 동정하였다. 이 생물방제균이 생산하는 chitinase 생산의 최적 조건을 검토하여 본 결과 Chitin-yeast extract 배지(0.7% $K_2$$HPO_4$ 0.2% $KH_2$$PO_4$ 0.1%($NH_4$)$_2$$SO_4$ 0.05% sodium citrate 0.01% MgSO$_4$$7H_2$O 0.1% yeast extract, 0.1% coloida chitin)에서 pH는 7.0 배양온도는 3$0^{\circ}C$였고 배양한 후 3일 이 되었을 때 가장 많은 chitinase를 생산하였다. 또한 0.1% colloida chitin을 탄소원으로 하여 배양하였을 때 chitinase 생산성이 가장 좋았으며 0.15% proteose peptone NO .3 또는 0.1% tryptone 을 질소원으로 하여 배양하였을 때 효소 생산이 높게 나타났다. 선발된 생물방제균의 고추를 기주식물로한 in vivo pot 시험 결과 고추역병균 Phytophthora capsici에 좋은 길항력을 확인할 수 있었다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.41-41
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• 2015

Oomycetes belong to the kingdom Straminipila, a remarkably diverse group which includes brown algae and planktonic diatoms, although they have previously been classified under the kingdom Fungi. These organisms have evolved both saprophytic and pathogenic lifestyles, and more than 60% of the known species are pathogens on plants, the majority of which are classified into the order Peronosporales (includes downy mildews, Phytophthora, and Pythium). Recent phylogenetic investigations based on DNA sequences have revealed that the diversity of oomycetes has been largely underestimated. Although morphology is the most valuable criterion for their identification and diversity, morphological species identification is time-consuming and in some groups very difficult, especially for non-taxonomists. DNA barcoding is a fast and reliable tool for identification of species, enabling us to unravel the diversity and distribution of oomycetes. Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The mitochondrial cox2 gene has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. To determine which out of cox1 or cox2 is best suited as universal oomycete barcode, we compared these two genes in terms of (1) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (2) in terms of sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding type material. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. Including the two barcoding markers, ITS rDNA and cox2 mtDNA, the multi-locus phylogenetic analyses were performed to resolve two complex clades, Bremia lactucae (lettuce downy mildew) and Peronospora effuse (spinach downy mildew) at the species level and to infer evolutionary relationships within them. The approaches discriminated all currently accepted species and revealed several previously unrecognized lineages, which are specific to a host genus or species. The sequence polymorphisms were useful to develop a real-time quantitative PCR (qPCR) assay for detection of airborne inoculum of B. lactucae and P. effusa. Specificity tests revealed that the qPCR assay is specific for detection of each species. This assay is sensitive, enabling detection of very low levels of inoculum that may be present in the field. Early detection of the pathogen, coupled with knowledge of other factors that favor downy mildew outbreaks, may enable disease forecasting for judicious timing of fungicide applications.

• Journal of Plant Biotechnology
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• 제50권
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• pp.45-55
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• 2023

멕시코 유래의 2배체 감자 근연야생종 Solanum cardiophyllum은 감자역병, 감자바이러스Y, 콜로라도감자잎벌레 등과 같은 병원균 및 해충에 대한 저항성을 가지고 있어 감자의 신품종 육성에 이용되고 있다. 재배종 감자에 이러한 형질을 도입하기 위해서는 전통적인 교잡육종에 의해 이루어질 수 있으나, 재배종 감자와 근연야생종과의 서로 다른 EBN에 따라 제한적이며, S. tuberosum과 S. cardiophyllum 간에도 생리적 불화합성이 존재한다. 따라서, 이러한 생리적 장벽의 극복을 위해 체세포융합에 의한 체세포잡종 계통을 육성하고 이를 감자 신품종 육성에 활용할 수 있는데, 분자 마커는 적절한 체세포잡종 계통 선발에 필요하다. 이에, 본 연구에서는 S. cardiophyllum의 전체 엽록체 유전체 정보를 구명하고 8개의 다른 Solanum 종의 전체 엽록체 유전체 정보와 비교하여 S. cardiophyllum 특이적인 분자마커를 개발하였다. S. cardiophyllum의 전체 엽록체 유전체의 길이는 155,570 bp였으며, 그 구조와 유전자 구성은 다른 Solanum 종들과 매우 유사하였고 가지과에 속해 다른 32개의 종들과의 계통수 분석을 통해 예상했던 바와 같이 다른 Solanum 종과 같은 그룹에 속해 있고 S. bulbocastanum과의 가장 근접한 유연관계를 확인하였다. S. cardiophyllum의 전체 엽록체 유전체와 8개 다른 Solanum 종의 전체 엽록체 유전체의 다중 정렬 결과로 총 13개의 S. cardiophyllum 특이적인 SNP 영역을 확인하였으며, 이 정보를 이용하여 4개의 PCR 기반 분자마커를 개발하였다. 본 연구의 결과는 S. cardiophyllum의 진화적 측면에서의 연구와 S. cardiophyllum를 이용한 감자 신품종 육성을 위한 연구에 기여를 할 수 있을 것이다.

• Molecules and Cells
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• 제28권4호
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• pp.321-329
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• 2009

Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.

• Journal of Plant Biotechnology
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• 제48권1호
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• pp.18-25
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• 2021

멕시코로부터 유래한 Solanum demissum은 감자 야생종 중의하나로 감자 역병에 대해 저항성을 가지고 있어 감자 육종에서 중요한 재료로 이용되고 있다. S. demissum의 EBN은 4배 체인 감자와 같은 4로 직접적인 교배로 육종에 활용될 수 있다. 본 연구에서는 NGS 기술에 의해 완성된 S. demissum의 엽록체 전장 유전체(cpDNA)와 이를 다른 Solanum종과의 비교를 통해 개발한 분자마커에 대해 보고하였다. S. demissum의 전체 cpDNA의 크기는 155,558 bp였으며 그 구조는 다른 Solanum종과 매우 유사하였다. S. demissum의 cpDNA와 가지과에 속하는 10개 종의 cpDNA 코딩서열을 이용하여 분석한 계통수에서는 S. demissum이 S. hougasii 및 S. stoloniferum과 거의 동일한 유전체 구성을 보였으며, 다음으로 S. berthaultii 및 S. tuberosum과 유연관계가 가까운 것으로 확인되었다. S. demissum과 다른 7종의 Solanum과의 전체 cpDNA 다중 정렬을 통해 S. demissum 특이적인 두 개의 InDel 영역을 구명하였으며 이를 기반으로 최종적으로 PCR을 기반으로 한 두 개의 S. demissum 특이적 마커를 개발하였다. 본 연구의 결과는 Solanum 종들을 대상으로 한 조금 더 세부적인 진화적 그리고 육종적 측면에서의 연구에 기여를 할 수 있을 것이다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.110.1-110
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• 2003

Control effect of grafting with rootstocks on Phythophthora blight of pepper was evaluated. The 40∼45 day old seedlings of five pepper cultivars, Wangdaeback, Jinmi, Boosa, Samsungcho and Pochunngchun, as a scion were grafted with ten species of root stocks. There wasn't graft incompatibility in all scion-root stock combinations. After 21 days from inoculation with Phytopkhora capsici, incidence of Phythophthora blight of plant grafted with Kataguruma, R-Safe, R-16, YCM 334 and SCM 334 of rootstocks tested was decreased by 64.6∼100％ compared to non-grafted plant whose disease severity was 3.7. However, plant grafted with Umsung native and Yeongdong native pepper was more sensitive to Phythophthora blight than non-grafed plant. Control effect by grafting was inversely proportional to virulence of inoculum and not significantly different among scion cultivars used. And resistant reaction of scion against Phytophthora blight was not affect that of scion-root stock plant in this study.

• The Plant Pathology Journal
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• 제16권4호
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• pp.189-199
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• 2000

To search for the antifungal substances, various actino-mycete isolates were obtained from various soils of Korea using plate dilution method on the humic acid vitamin agar plates. In the screening procedures using a dual culture method, 32 actionomycete isolates were selected, which showed the inhibitory activity against mycelial growth of plant pathogenic fungi Altirnaria mali, Colletotrichum gloeosporides, Fusarium oxysporum f.sp. cucumerinum, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. Bioassay of the crude extracts from culture filtrates and mycelial mets revealed that 12 antagonistic actionomycetes produced highly active antifungal substances. Actinomycete strain S5-55 which showed the substantial antifungal activity against the tested fungi was selected for production of the antifungal substances. Based on the cytochemical and morphological characteristics, strain S5-55 was identified as a Streptomyces species. The results of the numerical identification using the TAXON program confirmed that Streptomyces strain S5-55 was identical with Streptomyces humidus including in TAXON major cluster 19. The production of antifungal substance was most favorable when S. humidus strain S5-55 was cultivated for 10 dats on soluble starch broth supplemented with $K_2$HPO$_4$. The antifungal substances active against the plant pathogenic fungi P. capsici and M. grisea were partially purified using $\textrm{C}_{18}$ reversed-phase column chromatography.