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Rpi-blb2 Gene-Mediated Late Blight Resistance in Plants

  • Oh, Sang-Keun
    • 한국균학회소식:학술대회논문집
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    • 2015.11a
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    • pp.26-26
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    • 2015
  • Phytophthora infestans is the causal agent of potato and tomato late blight, one of the most devastating plant diseases. P. infestans secretes effector proteins that are both modulators and targets of host plant immunity. Among these are the so-called RXLR effectors that function inside plant cells and are characterized by a conserved motif following the N-terminal signal peptide. In contrast, the effector activity is encoded by the C terminal region that follows the RXLR domain. Recently, I performed in planta functional profiling of different RXLR effector alleles. These genes were amplified from a variety of P. infestans isolates and cloned into a Potato virus X (PVX) vector for transient in planta expression. I assayed for R-gene specific induction of hypersensitive cell death. The findings included the discovery of new effector with avirulence activity towards the Solanum bulbocastanum Rpi-blb2 resistance gene. The Rpi-blb2 encodes a protein with a putative CC-NBS-LRR (a coiled-coil-nucleotide binding site and leucine-rich repeat) motif that confers Phytophthora late blight disease resistance. We examined the components required for Rpi-blb2-mediated resistance to P. infestans in Nicotiana benthamiana. Virus-induced gene silencing was used to repress candidate genes in N. benthamiana and to assay against P. infestans infections. NbSGT1 was required for disease resistance to P. infestans and hypersensitive responses (HRs) triggered by co-expression of AVRblb2 and Rpi-blb2 in N. benthamiana. RAR1 and HSP90 did not affect disease resistance or HRs in Rpi-blb2-transgenic plants. To elucidate the role of salicylic acid (SA) in Rpi-blb2-mediated resistance, we analyzed the response of NahG-transgenic plants following P. infestans infection. The increased susceptibility of Rpi-blb2-transgenic plants in the NahG background correlated with reduced SA and SA glucoside levels. Furthermore, Rpi-blb2-mediated HR cell death was associated with $H_2O_2$, but not SA, accumulation. SA affects basal defense and Rpi-blb2-mediated resistance against P. infestans. These findings provide evidence about the roles of SGT1 and SA signaling in Rpi-blb2-mediated resistance against P. infestans.

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Augmentation of Field Measurements Using a Rigid Scatterer in the BEM-based NAH (역경계요소법에 기초한 음향홀로그래피에서 강체산란체를 이용한 음장 측정 개수 증가)

  • Kim Sung-Il;Jeong Ji-Hoon;Ih Jeong-Guon
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.305-308
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    • 2004
  • 경계요소법을 이용한 음향홀로그래피 구현에 요구되는 많은 측정 노력을 줄이기 위하여 강체 산란체를 이용한 홀로그래피의 기본이론을 제시하였다. 강체산란체를 음장에 위치시켰을 때의 기본이론을 제시하고, 피스톤의 자유공간방사경우에 산란체의 거리의 변화에 따른 음향진동전달함수의 특이성 변화를 관찰하였다.

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Pericoronal radiolucency associated with incomplete crown

  • Nah, Kyung-Soo
    • Imaging Science in Dentistry
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    • v.43 no.4
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    • pp.295-301
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    • 2013
  • The author experienced 8 cases of pericoronal radiolucency involving an incomplete tooth crown that had not developed to form the cemento-enamel junction, and the underdeveloped crown sometimes appeared to be floating within the radiolucency radiographically. The first impression was that these cystic lesions had odontogenic keratocysts, but half of them turned out to be dentigerous cysts histopathologically. There has been no report concerning odontogenic cysts involving an incompletely developed crown. The purpose of this paper is to report that dentigerous cysts may develop before the completion of the cemento-enamel junction of a developing crown.

Security Considerations for P2P-based Media Streaming (P2P 기반의 미디어 스트리밍 보안 고려사항)

  • Hyeokchan Kwon;Sangchoon Kim;Jaehoon Nah
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.11a
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    • pp.1441-1443
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    • 2008
  • 최근 들어 미디어 스트리밍 서비스 제공 시 서버의 부하 및 비용을 줄이기 위해 P2P 기반의 오버레이 네트워크를 이용하여 미디어 스트리밍 콘텐츠를 분배하는 방안이 등장하고 있다. 하지만 이 방안은 그 효율성만큼이나 보안 취약성도 많이 존재하는 방안이다. 본 논문에서는 P2P 기반의 미디어 스트리밍 서비스에 대한 보안 위협과 이에 대응하기 위한 보안 고려사항을 분석하였다.

A Two-Strain Mixture of Rhizobacteria Elicits Induction of Systemic Resistance Against Pseudomonas syringae and Cucumber Mosaic Virus Coupled to Promotion of Plant Growth on Arabidopsis thaliana

  • Ryu Choong-Min;Murphy John F.;Reddy M.S.;Kloepper Joseph W.
    • Journal of Microbiology and Biotechnology
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    • v.17 no.2
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    • pp.280-286
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    • 2007
  • We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (Bio Yield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.

Ginsenosides That Show Antinociception in Writhing and Formalin Tests

  • Shin, Young-Hee;Jeong, Ok-Mi;Nah, Jin-Ju;Yoon, So-Rah;Nam, Ki-Youl;Kim, Si-Kwan;Kim, Seok-Chang;Nah, Seung-Yeul
    • Journal of Ginseng Research
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    • v.22 no.1
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    • pp.43-50
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    • 1998
  • We demonstrated in previous study that protopanaxadiol and protopanxatriol saponins show antinociceptive activity in acetic acid induced writhing test and in the second phase (11-40 min) of formalin test but not tail-flick test. To identify further which ginsenoside has antinociceptive activity among various ginseng saponins, we have investigated antinociceptive effects of several ginsenosides using writhing and formalin test. Ginsenoside Rc, Rd, Re, and Rf induced antinociception in writhing test. These four ginsenosides also induced antinociception in the second phase of formalin (11-40 min) test but these ginsenosides showed a slight antinociception in the first phase (010 min) of formalin test except ginsenoside Rf. The antinociceptive effects induced by the ginsenosides were dose dependent and were not blocked by an opioid receptor antagonist, naloxone. The order of antinociceptive potency was Rd > Rc > Re > Rf in the formalin test. However, these ginsenosides did not show any significant analgesic effects in a tail-flick test. These results suggest that ginsenosides such as Rc, Rd, Re, and Rf inhibit tonic pain rather than acute pain induced by noxious heat. These results also indicate that the antinociceptive activity. Induced by ginsenosides may be one of the actions for pharmacological effects of Panax ginseng.

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A Failure of disturbed natural-slope ground caused by cutting slope (절토에 의한 상부자연지반의 붕괴 특성 연구)

  • Nah, Kwang-Hee;Chang, Buhm-Soo;Shin, Chang-Gun;Kim, Yong-Soo;Choi, Yong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.629-634
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    • 2004
  • When it was a localized torrential downpour last year, a natural-slope fell down above a cut-slope. They were caused that stress was opened by cutting slope, ground water level rose quickly and a ground mass strength fell etc. So volume of ground mass increase because of that reasons, finally the disturbed ground was collapse. Therefore I suggest that safety of a natural-slope is a consideration, when a cut-slope is made by cutting ground.

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