광자매개에 의한 X-선 다단증폭 검출기의 제작 및 특성조사

정춘균,남욱원,김동진,강희동 경북대학교 센서기술연구소 1990 센서技術學術大會論文集 Vol.1 No.1

일반적으로 기체를 이용한 방사선 위치 검출기에 있어서 나타나는, 공간전하효과에 따른 한계 계수율(<□10^(4) cps )을 높이고 X-선에 대한 에너지 및 위치분해능을 향상시키기 위해 광자매개에 의한 전자증폭원리를 응용하여 이중증폭의 위치검출기를 제작하였으며 Cu Ka(8.04keV)에 대한 위치검출특성 및 에너지분해능을 조사하였다. 제작한 검출기는 기체유입형으로서 다중선위치검출기(MWPC)에 평행 전장의 전치증폭단을 직결시켜 다단 증폭위치검출기(MSAC)를 구성하였으며 검출 기체는 Ar(98%)과 아세톤(2%)를 각각 carrier 및 penning 가스로서 혼합 사용하였다. Cu Ka에 대한 에너지 분해능은 반치폭 12% 정도였으며, 위치분해능은 0.2mm slit에 대하여 반치폭 0.47mm를 얻었다. To overcome the count-rate limitation(□ 10^(4)cps) due to the space charge effect of positive ions in gas-type position sensitive detector, we have made position sensitive detector and investigated charge-multiplication mechanism, mainly photo-mediated electron avalanche that provides remarkable energy and position resolution for soft X-ray. The detector, it consists of a preamplification stage operating as a parallel plate avalanche chamber directly coupled to a multi-wire. proportional chamber, is gas-flow type multi-step avalanche chamber. The detection gas is the mixture of Ar(98%) and acetone(2%) as the carrier and the Penning gas respectively. For the Cu Ka, energy resolution 12%(fwhm) and spatial resolution 0.47mm(fwhm) for slit 0.2mm in diameter were obtained.

Quadruple 9-mer-Based Protein Binding Microarray Analysis Confirms AACnG as the Consensus Nucleotide Sequence Sufficient for the Specific Binding of AtMYB44

정춘균,김연기,오남이,심재성,서준성,최양도,남백희,정종주 한국분자세포생물학회 2012 Molecules and cells Vol.34 No.6

AtMYB44 is a member of the R2R3 MYB subgroup 22 transcription factors and regulates diverse cellular re-sponses in Arabidopsis thaliana. We performed quadruple 9-mer-based protein binding microarray (PBM) analysis, which revealed that full-size AtMYB44 recognized and bound to the consensus sequence AACnG, where n represents A, G, C or T. The consensus sequence was confirmed by electrophoretic mobility shift assay (EMSA) with a truncated AtMYB44 protein containing the N-terminal side R2R3 domain. This result indicates that the R2R3 domain alone is sufficient to exhibit AtMYB44 binding specificity. The sequence AACnG is the type I binding site for MYB transcription factors, including all members of the subgroup 22. EMSA showed that the R2R3 domain protein binds in vitro to promoters of randomly selected Arabidopsis genes that contain the consensus binding sequence. This implies that AtMYB44 binds to any promoter region that contains the consensus sequence, without determining their functional activity or specificity. The C-terminal side tran-scriptional activation domain of AtMYB44 contains an asparagine-rich fragment, NINNTTSSRHNHNN (aa 215-228), which, among the members of subgroup 22, is unique to AtMYB44. A transcriptional activation assay in yeast showed that this fragment is included in a region (aa 200-240) critical for the ability of AtMYB44 to function as a transcriptional activator. We hypothesize that the C-terminal side of the protein, but not the N-terminal side of the R2R3 domain, contributes to the functional activity and specificity of AtMYB44 through interactions with other regulators generated by each of a variety of stimuli.

大邱地域 地殼 γ-線의 照射線量率 測定

이모성,김위수,강희동,최문규,장시호,정춘균 대한방사선 방어학회 1994 방사선방어학회지 Vol.19 No.2

본 연구는 대구지역의 지각 r-선에 의한 조사선량율을 측정하고 그에 따른 성분별 공간선량율 및 지역적 분포 등의 환경방사선 특성을 조사하였다. r-선 스펙트럼의 측정에는 4"ø ×4"Nal(Tl) 계측기와 휴대용 다중파고분석장치를 이용하여 이 지역내의 28개 지점에서 in-situ spectrometry를 수행하였으며, 측정된 스펙트럼으로부터 조사선량율을 환산하여 지각 r-선의 총선량율과 일반적으로 자연방사능의 주종이 되는 ?K, ?U계열 및 ?Th계열의 성분별 조사선량율을 구하였다. 조사결과 대구지역의 지각 r-선에 의한 평군조사선량율은 9.4 μR/h였으며 지점별 분포는 7.6∼11.0 μR/h범위로 다소 차이를 보였다. 측정시에 수반되는 기후나 우주선 등에 따른 일변화폭을 고려한다면 지점간의 차이는 주로 표토층의 자연방사성핵종인 ?K, ?U계열 및 ?Th계열의 핵종에 기인함을 알 수 있었으며, 성분별 선량율은 ?K2.9∼4.6 μR/h, ?U계열1.2∼3.1 μR/h, ?Th계열2.5∼5.0 μR/h의 분포를 나타냈다. This study concerns about the measurement and the investigation of environmental radiation characteristics which the components and the distribution of exposure rates by terrestrial r-rays in Taegu area. A 4"ø ×4"Nal(Tl) scintillation detector with a multichannel analyzer was used in the measurement of r-rays as a part of in-situ spectrometry at twenty eight different locations in this area. The conversion into the exposure rate from the measured r-rays spectrum has been carried out leading to a net exposure rate and component ones by ?K, ?U series and ?Th series products which are known by the major parts in the terrestrial r-rays generally. As a result, the average exposure rate by the terrestrial r-rays in Taegu area is 9.4 μR/h and the distribution of individual exposure rates shows more or less differences between these locations even after the consideration of diurnal and rearly variations which are always involved in these measurements. The component parts of exposure rates are distributed ?k2.92.9∼4.6 μR/h, ?U series1.2∼3.1 μR/h and ?Th series 2.5∼5.0 μR/h over the measured locations.

대구지역(大邱地域) 지각(地殼) ${\gamma}$-선(線)의 조사선량율(照射線量率) 측정(測定)

장시호,정춘균,강희동,이모성,최문규,김위수,Chang, Si-Ho,Jeong, Chun-Gyun,Kang, Hee-Dong,Lee, Mo-Sung,Choi, Mun-Kyu,Kim, Wi-Soo 대한방사선방어학회 1994 방사선방어학회지 Vol.19 No.2

This study concerns about the measurement and the investigation of environmental radiation characteristics which the components and the distribution of exposure rates by terrestrial y-rays in Taegu area. $4^{'}{\phi}{\times}4^{'}$ NaI(T1) scintillation detector with a multichannel analyzer was used in the measurement of y-rays as a part of in-situ spectrometry at twenty eight different locations in this area. The conversion into the exposure rate from the measured ${\gamma}-ray$ spectrum has been carried out leading to a net exposure rate and component ones by $^{40}K,\;^{238}U$ series and $^{232}Th$ series products which are known by the major parts in the terrestrial ${\gamma}-rays$ generally. As a result, the average exposure rate by the terrestrial ${\gamma}-rays$ in Taegu area is $9.4{\mu}R/h$ and the distribution of individual exposure rates shows more or less differences between these locations even after the consideration of diurnal and yearly variations which are always involved in these measurements. The component parts of exposure rates are distributed $^{40}K\;2.9{\sim}4.6{\mu}R/h,\;^{238}U$ series $1.2{\sim}3,\;1{\mu}R/h,\;^{232}Th$ series $2.5{\sim}5.0{\mu}R/h$ over the measured locations. 본 연구는 대구지역의 지각 ${\gamma}$-선에 의한 조사선량율을 측정하고 그에 따른 성분별 공간선량율 및 지역적 분포 등의 환경방사선 특성을 조사하였다. ${\gamma}$-선 스펙트럼의 측정에는 $4^{'}{\phi}{\times}4^{'}$ NaI(T1) 계측기와 휴대용 다중파고분석장치를 이용하여 이 지역내의 28개 지점에서 in-situ spectrometry를 수행하였으며, 측정된 스펙트럼으로부터 조사선량율을 환산하여 지각 ${\gamma}$-선의 총선량율과 일반적으로 자연방사능의 주종이 되는 $^{40}K,\;^{238}U$ 계열 및 $^{232}Th$계열의 성분별 조사 선량율을 구하였다. 조사결과 대구지역의 지각 ${\gamma}$-선에 의한 평균조사선량율은 $9.4{\mu}R/h$였으며 지점별 분포는 $7.6{\sim}11.0{\mu}R/h$ 범위로 다소 차이를 보였다. 측정시에 수반되는 기후나 우주선 등에 따른 일 변화폭을 고려한다면 지점간의 차이는 주로 표토층의 자연방사성핵종인 $^{40}K,\;^{238}U$계열 및 $^{232}Th$ 계열의 핵종에 기인함을 알 수 있었으며, 성분별 선량율은 $^{40}K\;2.9{\sim}4.6{\mu}R/h,\;^{238}U$ 계열 $1.2{\sim}3,\;1{\mu}R/h,\;^{232}Th$ 계열 $2.5{\sim}5.0{\mu}R/h$의 분포를 나타냈다.

Arabidopsis Histone Methyltransferase SET DOMAIN GROUP2 is Required for Regulation of Various Hormone Responsive Genes

김상희,이정근,양준이,정춘균,Nam-Hai Chua 한국식물학회 2013 Journal of Plant Biology Vol.56 No.1

Histone modifications are known to play importantroles in plant development through epigenetic regulation ofgene expression. How these modifications regulate downstreamtargets in response to various environmental cues anddevelopmental stimuli is still largely unknown. Here, weprovide evidence that Arabidopsis histone H3K4 methyltransferaseSET DOMAIN GROUP2 (SDG2) is required for fullactivation of hormone responsive genes upon hormonetreatment. The pleiotropic phenotypes of sdg2 were closelyrelated to those of auxin deficient mutants and RNA analysisrevealed that expression of early hormone responsive geneswas significantly reduced in sdg2-5. By ChIP analyses wefound that H3K4 tri-methylations on chromatin region ofhormone responsive genes such as SAUR27, KIN1 andGASA6 were enriched in WT upon hormone treatmentswhereas these enrichments were largely abolished in sdg2-5. After hormone treatment, chromatin regions of responsivegenes that accumulated H3K4me3 in WT overlapped withthose displaying decreased H3K4me3 levels in sdg2-5. Histone H3K4 di-methylation levels on tested genes wereincreased rather than decreased in sdg2-5, suggesting thatSDG2 mediates transition of H3K4me2 to H3K4me3. Takentogether, we conclude that the SDG2 activity is required toregulate the expression of hormone responsive genes viahistone H3K4 tri-methylation.

PLANT U‑BOX PROTEIN 10 negatively regulates abscisic acid response in Arabidopsis

서준성,Pingzhi Zhao,정춘균,Nam‑Hai Chua 한국응용생명화학회 2019 Applied Biological Chemistry (Appl Biol Chem) Vol.62 No.-

MYC2 is well known as a positive regulator for abscisic acid (ABA) signaling but whether PLANT U-BOX PROTEIN 10 (PUB10) is involved in ABA responses has not been reported. Here, we show that the E3 ubiquitin ligase PUB10 modulates ABA signaling in Arabidopsis. PUB10ox (35S:PUB10-myc) and myc2 loss-of-function mutants were hyposensitive to ABA during germination, whereas pub10 loss-of-function and MYC2ox (35S:MYC2-GFP) mutants were hypersensitive. In addition, pub10 mutants showed hypersensitivity to high salt and osmotic stress during germination; by contrast, PUB10ox line displayed the opposite phenotype. ABA-induced expression of KIN2 (Cold- and ABA-Inducible Protein), RD22 (Responsive to Dehydration 22), ANAC019 (NAC Domain-Containing Protein 19), and ANAC055 (NAC Domain- Containing Protein 55) was enhanced in both pub10 and MYC2ox plants. Taken together, pub10 plants phenocopied MYC2ox plants, whereas PUB10ox plants phenocopied myc2 in ABA response. Our results provide evidence that PUB10 negatively regulates ABA signaling in Arabidopsis.

Volatile methyl jasmonate is a transmissible form of jasmonate and its biosynthesis is involved in systemic jasmonate response in wounding

장규필,최양도,심재성,정춘균,송종태,이한용,정필중,김주곤 한국식물생명공학회 2014 Plant biotechnology reports Vol.8 No.6

Volatile organic compounds (VOCs) easilydiffuse due to their high hydrophobicity. Because of thisphysical property, VOCs are able to act as crucial signallingmolecules mediating intercellular and interplantcommunication. Methyl jasmonate (MeJA) is a volatileester form of jasmonic acid (JA) that is involved in interplantcommunication in response to biotic and abioticstresses. Despite its function in interplant communication,the specific role of MeJA in the regulation of intercellularjasmonate responses have been poorly understood. In thisstudy, we demonstrated that MeJA is much more effectivethan JA in inducing jasmonate response, and the higherefficacy of MeJA relies on its volatile property. Tounderstand the function of MeJA in the regulation of thejasmonate response, we analysed function of JMT gene,Jasmonic acid Methyl Transferase using its knockoutmutant (jmt) and overexpressing plants (35S:JMT). Mutantplants that lack JMT expression exhibited reduced jasmonateresponse, while JMT-overexpressing plants exhibiteda higher jasmonate response to JA treatment compared towild-type plants. In this study, we also showed that JMT isspecifically expressed in the phloem, the main vascularsystem for the transport of phytohormones, and that JMTexpression affects systemic jasmonate response inwounding. These results suggest the volatile MeJA is atransmissible form of jasmonate and that its biosynthesis isinvolved in systemic jasmonate response in wounding.

스마트팜과 관행 농가에서 재배된 토마토의 물리적, 기능적 특성 비교

김의황,김다빈,신혜정,이지영,최우리,홍은미,김용노,정춘균 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

본 연구에서는 스마트팜 재배 작물의 품질 기준 확립 및 품질 향상을 도모를 위해 스마트팜 재배 토마토와 일반 재배 토마토의 물리적, 기능적 특성을 분석하였다. 이를 위해 스마트팜 재배 농가 (A, B, C), 일반 재배 농가 (D, E, F) 각 3 곳에서 2021년 5월 수확된 토마토를 비슷한 시기에 구입하여 실험에 사용하였다. 당도와 외형 분석 결과 유의미한 차이는 없었으나, Texture analysis (TA) 실험결과 스마트팜 재배 농가에서 각 10.37, 18.59, 20.18 N 값으로 더 높은 경도 값이 나타나는 것을 확인하였다. 토마토의 기능적 특성 분석 결과, 총 폴리페놀 함량은 두 농가 그룹에서 큰 차이를 보이지 않았으며, 총 플라보노이드 함량의 경우 스마트팜 재배 토마토가 각 55.3, 96.1, 108.8 ppm으로 일반 재배보다 유의적으로 높은 값을 나타내었다. DPPH, ABTS radical 소거 활성능 비교 결과, 전체적으로 스마트팜 재배 토마토가 더 높은 값을 나타내었다. Cell viability 실험 결과에서는 그룹 간에 유의미한 차이가 있진 않았으나, ROS concentration실험 결과에서 스마트팜 재배 B 농가가 41355.9의 값으로 세포의 활성산소종 농도를 낮추는 데에 가장 큰 효과를 보였고, 일반 재배 F 농가는 49520.7로 비교적 낮은 효과를 보였다. 이 연구를 통해 점차 증가하고 있는 스마트팜 작물의 품질 개선 및 기능성 작물 재배를 위한 기초 연구자료로 이용될 수 있을 것으로 보인다.

Heterologous expression of bacterial trehalose biosynthetic genes enhances trehalose accumulation in potato plants without adverse growth effects

심재성,서주석,서준성,김용환,구연종,최양도,정춘균 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.4

Trehalose is a non-reducing disaccharide found in various organisms, including bacteria, fungi, invertebrates, and plants. It plays essential roles in diverse biological processes such as stress resistance, metabolism, and development in plants. Despite the important role of trehalose, it is challenging to increase trehalose levels because of its negative effects on plant growth and development. In this study, we tested several combinations of different promoters and trehalose biosynthetic genes to efficiently accumulate trehalose in potato plants. Transgenic potato plants expressing TPSP (trehalose-6-phosphate synthase/ phosphatase) fusion gene under the control of Rd29A promoter increased trehalose content in response to high salt stress and did not show significant growth retardation. Although constitutive overexpression of plastid-targeted MTSH (maltooligosyltrehalose synthase/trehalohydrolase) fusion gene driven by CaMV 35S promoter remarkably accumulated trehalose, the transgenic potato plants showed a severely stunted phenotype. By contrast, stress-inducible expression of plastid-targeted MTSH under the control of Rd29A promoter led to trehalose accumulation without growth defects in response to high salt stress. Besides, tuber-specific expression of plastid-targeted MTSH driven by GBSS (granule-bound starch synthase) promoter specifically increased trehalose level in potato tubers without stunting growth. Consequently, we suggest that heterologous expression of TPSP and MTSH fusion genes driven by stress-inducible or tuber-specific promoters can be an effective strategy for accumulating trehalose in potato plants as well as minimizing its adverse effects on potato growth.