Time-evolving genetic networks reveal a NAC troika that negatively regulates leaf senescence in <i>Arabidopsis</i>

Kim, Hyo Jung,Park, Ji-Hwan,Kim, Jingil,Kim, Jung Ju,Hong, Sunghyun,Kim, Jeongsik,Kim, Jin Hee,Woo, Hye Ryun,Hyeon, Changbong,Lim, Pyung Ok,Nam, Hong Gil,Hwang, Daehee National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.21

<▼1><P><B>Significance</B></P><P>Leaf senescence is regulated in a complex manner, involving time-dependent interactions with developmental and environmental signals. Genetic screens have identified key regulators of senescence, particularly late-stage senescence regulators. Recently, time-course gene-expression and network analyses, mostly analyses of static networks, have predicted many senescence regulators. However, senescence is defined by time-evolving networks, involving the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks of NAM/ATAF/CUC (NAC) transcription factors, central regulators of leaf senescence in <I>Arabidopsis</I>, via time-course gene-expression analysis of NACs in their mutants. These time-evolving networks revealed a unique regulatory module of NACs that controls the timely induction of senescence-promoting processes at a presenescent stage of leaf aging.</P></▼1><▼2><P>Senescence is controlled by time-evolving networks that describe the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks for NAM/ATAF/CUC (NAC) transcription factors in <I>Arabidopsis</I> during leaf aging. The most evident characteristic of these time-dependent networks was a shift from positive to negative regulation among NACs at a presenescent stage. ANAC017, ANAC082, and ANAC090, referred to as a “NAC troika,” govern the positive-to-negative regulatory shift. Knockout of the NAC troika accelerated senescence and the induction of other <I>NAC</I>s, whereas overexpression of the NAC troika had the opposite effects. Transcriptome and molecular analyses revealed shared suppression of senescence-promoting processes by the NAC troika, including salicylic acid (SA) and reactive oxygen species (ROS) responses, but with predominant regulation of SA and ROS responses by ANAC090 and ANAC017, respectively. Our time-evolving networks provide a unique regulatory module of presenescent repressors that direct the timely induction of senescence-promoting processes at the presenescent stage of leaf aging.</P></▼2>

청각, Codium fragile (Suringar) Hariot의 胞囊의 形態 및 成熟時期에 關하여

金南吉,元容仁,孫徹鉉 國立統營水産專門大學 附設 水産科學硏究所 1990 수산과학연구소보고 Vol.2 No.-

본 연구는 1984년 4월부터 1985년 3얼까지 채집된 충무 연안산 청각을 대상으로 포낭의 형태 및 성숙 시기를 구명하기 위하여 수행되었다. 조사지역의 수온은 7.5~25.4℃였으며, 염분은 32.9~34.5‰로 나타났다. 배우자낭은 조사한 조체들은 모두 성숙 또는 미성숙한 배우자낭을 가지는 신장된 형태의 포안이 많았다. 대부분의 조체가 자웅이체 이었으며, 일부가 자웅동체로 암배우체 보다는 숫배우체의 출현율이 높았다, 동계에 채집된 조체들 중 일부는 절두형 또는 신장된 형태의 포낭을 가진 것이 많았으며, 하난의 포낭에 암, 수의 배우자낭을 함께 가진 조체가 출현하였고 하나의 포낭에서 파생된 또 다른 포낭을 볼 수 있었다. The present work was carried out to investigate the maturing period and the morphology of utricle Codium fragile collected from April 1984 to March 1985 in the coast of Chumgmu southern of Korea. Ranges of water temperature and salinity during the survey period were 7.5∼27.0℃ and 32.9∼34.5%, respectively. The gametangia were produced throughout the year. Mature gametangia were present on plants collected from June to November, whereas most of plants collected from January to May occured as the elongated utricles with both mature and immature gametangia. As for the sexuality, most of plants were dioecious and some monoecious, and there were more male gametophytes rather than female gametophytes. Some plants collected during winter months of December to February were observed as thalli with both brunted and elongated utricles, and male and female gametangia occured together on a single utricle.

지보공법에 따른 토사터널의 거동에 관한 수치해석

김진태,박병수,정길수,유남재 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.A

Numerical analysis were performed to investigate the stability and internal movement of tunnel located beneath the base of abutment of bridge according to the method of supporting tunnel. Two supporting methods of the multi-staged grouting method with steel pipes and the large diameter of pipe supporting method were used in the centrifuge model tests. The slip form of model lining, specially built to simulate the process of tunnel excavating under the condition of accelerated g-level, was used in the centrifuge model tests. Four centrifuge model tests were performed, changing the supporting methods of the multi-staged grouting method with steel pipes and the large diameter of pipe supporting method and the location of model abutment base of bridge. For internal displacement of tunnel, movements of the crown. The left and the right sides of spring line were measured during the proceeds of excavating tunnel in centrifuge model tests. Test results were compared with numerically estimated values of internal displacement of tunnel by using the commercially available FEM software of PENTAGON-3D. It was found that they were in good agreements and the large diameter of pipe supporting method was more stable than the multi-staged grouting method with steel pipes with respect to the internal movement of tunnel.

흡입관에 부착된 디퓨저 효과에 대한 연구

김도태,이행남,박길문,이덕구,설재림 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

The diffuser is used to get low pressure, and it has been applied to a lot of industry field like the heat engine, the fluid instrument power plant, the food industry, environment industry etc... because there are not any problem even it is mixed with kinds of liquid, gas, and solid. The flow characteristics in diffuser are investigated by prv and CFD. The experiment using PIV measurement for mixing pipe's flow characteristics acquired velocity distribution, .Condition : when mixing pipe's diameter ratio is 1:2.3, and the flux is Q₁ = 1.136 l/s, Q₂ = 1.706 l/s, Q₃ = 2.276 l/s . Based on the PIV and the CFD results, the flow characteristics in ejector are discussed, and it shows the validity of this study.

충무 연안의 해조상

김남길 國立統營水産專門大學 附設 水産科學硏究所 1992 수산과학연구소보고 Vol.3 No.-

본 연구는 충무 연안의 환경변화가 이지역의 생물상에 미칠 영향을 예찰하고 평가할 환경생물학적 기초자료를 얻고자 1990년 11월부터 1991년 10월까지 충무연안의 12개 정점에서 채집, 조사한 해조류를 대상으로 해조상을 파악코저 하였으며 그 결과는 다음과 같다. 출현한 해조류는 총 72종으로 녹조류 9종, 갈조류 19종, 홍조류 41종, 남조류 2종과 해산현화식물 1종 이었다. 북신만내 해역에 비하여 충무수로 해역의 출현종 수가 많았으며 대체로 내만성 해조군락의 특성이 강하게 나타났다. R/P 값은 남해안의 다른 지역에 비하여 낮게 나타났으며, 충무수로 해역에서의 우점종은 납짝파래, 구멍갈파래, 청각, 불레기말, 미역, 괭생이모자반, 구슬모자반, 잎꼬시래기로 나타났고, 북신만내 해역에서는 흔들말, 납짝파래, 구멍갈파래, 청각, 괭생이모자반, 미야베모자반, 모로우붉은실로 나타났으며 전 조사정점에서 뚜렷한 층상구조를 볼 수 없었다. The intertidal and subtidal benthic marine algae were investigated at Ch'ungmu area in the southern coast of Korea, from November 1990 to October 1991. As a result, a total of 72 species, including 41 red, 19 brown, 9 green, 2 blue-green algae and 1 spermatophyta, were identified. The number of algal species were rich in Ch'ungmu channel and poor in Pukshin bay. These species belong to typical inshore type. The R/P value is lower than that of other regions in the southern coast of Korea. The dominant species investigated from this area were Enteromorpha compressa, Uiva pertusa, Codium fragile, Colpomenia sinnosa, Undaria pinnatifida, Sargassum horneri, Sargassum pilulierum and Gracilaria textorii in Ch'ungmu channel and Oscillatoria sp. Enteromorpha compressa, Ulva pertusa, Codium fragile, Sargassum horneri, Sargassum miyabei and Polysiphonia morrowii in Pukshin bay. The vertical zonation of algal vegetation in this area was not characterize.

손상받은고양이 줄무늬체에서 축삭반응에 관한 미세구조적 연구

양남길,조영열,안의태,고정식,박경호,김진국 대한해부학회 1994 Anatomy & Cell Biology Vol.27 No.3

중금속물질이 생쥐 신장사구체에 미치는 영향에 대한 미세구조 연구

김주원,고정식,양남길,안의태,박경호 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.2

본 실험은 중금속물질이 섭취되었을 때 신장사구체의 미세구조적 변화를 알아보기 위하여 시행하였다. 실험동물로는 체중 25gm내외의 성숙한 마우스(IRC)를 사용하였는데 실험군은 염화제이수은(HgCl₂)을 2mg/kg, 5mg/kg, 10mg/kg씩, 중크롬산칼륨(K₂Cr₂O7)을 5mg/kg, 10mg/kg, 20mg/kg씩 피하주사하여 사용하였다. 각 실험군은 주사 후 6시간, 3일, 2주일에 희생시킨 후 신장조직을 떼어내어 2.5% glutaraldehyde- 1.5% paraformaldehyde혼합액(0.1M Millonig's phosphate buffer, pH 7.3)에 다시 고정한 다음, 1% osmium tetroxide(0.1M Millonig's phosphate buffer, pH 7.3)에 다시 고정하였다. 고정된 조직은 ethyl acohol과 acetone으로 탈수하여 araldite 혼합액에 포매하였으며 포매된 조직은 LKB-V Ultramicrotome으로 얇은 절편을 만들어 uranyl acetate와 lead citrate액으로 염색한 후 JEM 100CX-Ⅱ전자 현미경으로 관찰하여 다음과 같은 결론을 얻었다. 1. 사구체기저막의 경우, 염화제이수은 투여군은 5mg/kg, 10mg/kg투여군에서, 중크롬산칼륨 투여군은 10mg/kg, 20mg/kg투여군에서 실험초기(6시간과 3일)에 사구체기저막의 전자밀도가 다소 불규칙하고 혹 모양의 물질이 기저막에 침착되었으나 2주일군에서 거의 정상군의 것에 비하여 별다른 변화를 볼 수 없었다. 2. 내피세포의 경우, 염화제이수은 투여군은 2mg/kg, 5mg/kg, 10mg/kg, 투여군에서, 중크롬산칼륨투여군은 10mg/kg, 20mg/kg투여군에서 실험초기( 6시간군과 3일 )에 내피세포 내에 공포와 myelin구조가 자주 관찰되었다. 3. 문어발세포의 경우, 염화제이수은 투여군은 2mg/kg, 5mg/kg, 10mg/kg 투여군에서, 중크롬산칼륨투여군은 10mg/kg, 20mg/kg 투여군에서 실험초기( 6시간군과 3일) 에 팽창된 과립형질내세망의 수조와 납작한 Golgi복합체 수조가 관찰되었다. 4. 혈관사이세포의 경우, 염화제수은 투여군은 2mg/kg, 5mg/kg, 10mg/kg 투여군에서, 중크롬산칼륨 투여군은 10mg/kg, 20mg/kg투여군에서 실험초기( 6시간군과 3일)에 기질내에 전자밀도가 높은 침착물이 관찰되었으며 혈관사이세포의 세포돌기가 내피세포 쪽으로 돌출되어 내피세포의 세포질판에 의해 둘러싸여 있는 모습이 자주 관찰되었다. 이상의 결과를 종합해보면 마우스가 일정량의 염화제이수은 또는 중크롬산칼륨을 한번 섭취하면 급성사구체신염의 형태학적 특징을 보이나 2주일정도가 지나면 사구체의 경우에는 거의 정상상태로 회복하며, 염화제이수은이 중크롬산칼륨에 비하여 사구체에 더 많은 손상을 준다고 생각된다. This experiment was performed to study the Ultrastructural changes of the renal glomerulus, induced by heavy metallic agents. Healthy adult mice weighing 25gm each were divided into normal an dexperimental grouops. Mercuric chloride(2mg/kg, 5mg/kg, 10mg/kg) or potassium bichromate(5mg/kg, 10mg/kg, 2-mg/kg) were injected subcutaneously to the animals. Animals were sacrificed at 6 hours, 3 days and 2 weeks following the injections. Pieces of tissues were taken from renal corticies, prefixed with 2.5% glutaraldehyde- 1.5% paraformaldehyde(0.1M Millonig's phosphate buffer, pH 7.3), and followed by post-fixation with 1% osmium tetroxide(0.1M Millonig's phosphate buffer, pH 7.3) Fixed blocks were dehydrated with alcohols and acetone, embedded in araldite mixture, cut with LKB V-ultratome. The ultrathin sections stained with uranyl acetate and lead citrate were observed with a JEM 100CX-II electron microscope. The results were as follow: 1. Glomerular basal laminae of the experimental groups showed some alterations, especially in the earlier stage-(6 hours and 3 days) of mercuric chloride-(5mg/kg. 10mg/kg) and potassium bichromate-(10mg/kg, 20mg/kg) treated groups. Irregularity of the electron density and accumulation of electron dense materials were observed. But morphological changes occurred in the basal laminae are generally recovered to normal appearance within 2 weeks. 2. In the glomerular endothelial cells of the mercuric chloride-(2mg/kg, 5mg/kg, 10mg/kg) and the potassium bichromate-(10mg/kg, 20mg/kg) treated groups. a large number of vacuoles and some myelin figures were observed frequently, especially in the earlier grous-(6 hours and 3 days). 3. In the podocytes of the mercuric chloirde-(2mg/kg, 5mg/kg, 10mg/kg) and potassium bichromate-(10mg/kg, 20mg/kg) treated groups. swollen cistern of rough endoplasmic reticulum and flattened cistern of the Golgi complexes were observed in the earlier groups-(6 hours and 3 days). 4. In the mesangial cell of the mercuric chloride-(5mg/kg, 10mg/kg) and potassium bichromate-(10mg/kg, 20mg/kg) treated groups. electron dense deposits were seen within the matrix and protruding cytoplasmic processes of the cells were surrounded by the cytoplasmic plates of the endothelial cells. From the above results. it was concluded that. the mercuric chloride or potassium bichromate induces acute glomerulonephritis on the mice, but ultrastructural changes occurred in the glomerulus after injection of the heavy metallic agents were recovered to normal appearance within 2 weeks. Mercuric chloride was more harmful on the renal glomerulus than potassium bichromte.

배양된 간세포 담세관 및 세포질소기관의 미세구조 연구 : Phalloidin과 Cytochalasin D의 영향 Effects of Phalloidin and Cytochalasin D

김진국,양남길,안의태,고정식,박경호,김주원 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.2

간세포 담세관의 주위세포질에는 미세사가 풍부하게 분포하는데, 이 실험에서는 배양 간세포의 미세사형성을 촉진 또는 억제시킨 후에 담세관 및 세포질소기관의 미세구조를 관찰하여 미세사의 형태학적 및 기능적 의의를 연구하였다. Sprague Dawley계 숫흰쥐의 간조직에 IV형 collagenaseㄹ를 처리하여 간세포를 분리한 후 배양하며 phalloidin(미세사 중합 촉진제)이나 cytochalasin D(미세사 중합 억제제)를 배지에 투여하고 전자현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1. 분리된 간세포 세포질에는 골지복합체와 소포 및 용해소체들이 세포의 일부분에 분포되어 생체의 간세포와 같이 세포질소기관 분포의 극성을 나타냈다. 2. Phalloidin와 cytochalasin D 투여군이 담세관은 확장되고 미세융모의 소실이 뚜렷하였다. Phalloidin투여군에서는 미세사가 증식되고 외형질층이 두터워져 담세관은 경직된 모습이었고, cytochalasin D투여군에서는 미세사가 감소되고 담세관의 확장은 더욱 심했다. 3. Phalloidin이나 cytochalasin D 투여군 모두에서 간세포 표면에는 세포질이 돌출되었다. Phalloidin투여군에서는 돌출부의 연결부분이 잘록하였고 외형질에 미세사가 증식되어 돌출부와 세포질을 분리시키고 있었다. 반면에 cytochalasin D투여군에서는 외형질층에서 미세사가 뚜렷한 감소되었고 각종 세포질소기관들이 포함된 채로 세포질 일부를 밀고나와 반구형의 돌출부를 이루었고 연결부는 넓었다. 4. 세포질에는 많은 소포와 공포들이 융합되어 세포의 주변부분이나 담세관주위에 세포내공간이 형성되었는데, 이 공간은 세포바깥이나 담세관과 교통되었다. 이상의 결과를 보면, 미세사가 증식 혹은 감소되면 배양간세포의 모습이 변화되며, 담즙의 이동에도 장애가 생겨 담즙정체를 일으킨다. 따라서 미세사는 간세포의 형태유지 및 담즙분비에 중요하게 관여하는 것으로 생각된다. The cytoplasmic microfilaments of hepatocytes are abundant beneath the plasma membrane, especially in the pericanalicular ectoplasm. In this study, the ultrastructural changes of bile canaliculus and cytoplasmic organelles induced by alteration of the microfilaments on the cultured rat hepatocytes were examined. Sprague-Dawley rats(male, about 200gm) were used. The isolated hepatocytes obtained by perfusion of 0.05% collagenase type IV through the portal vein, were cultred in the L-15 medium containing phalloidin(stabilizer of microfilaments) or cytochalasin D(destabilizer of microfilaments) for 10 min, 30 min, 1 hour, 2 hours, 4 hours, 10 hours and 20 hours, respecitvely. The hepatocytes on the cultured dish were fixed in 2.5% glutaradehyde -1.5% paraformaldehyde and 1% osmium tetroside. After alcohol dehydration, the cells were embedded in the araldite mixture. Ultrathin sections were contrasted with uranyl acetate and lead citrate, and observed with JEM100 CX-II electron microscope. The results were as follow: 1. Isolated hepatocytes maintained the typical architectionic relationships of secretory organelles, i.e., Golgi apparatus, vesicles, lysosomes, etc., in the vicinity of bile canalicular region. 2. In the phalloidin or cytochalasin D treated groups, bile canaliculi were dilated and devoid of microvilli. In phalloidin treated group, the pericanalicular ectoplasm containing the microfilaments microfilaments was thicker than that of cytochalasin D treated group. Whereas, the dilation of bile canaliculus was more marked in cytochalasin D group. 3. Both drugs, phalloidin or cytochalasin D, produced the alteration of cell shaper to form cytoplasmic protrusions at the cell surface. In the phalloidin treated group, protusions were pedunculated, and the microfilaments were accumulatd at the narrow neck region. In cytochalasin D treated group, in contrast, no microfilament barrier was seen at the broad base of protrusion which exhibit direct continuity with the internal cytoplasm. 4. Numerous vesicles and vacuoles were formed near the cell surface and perianalicular cytoplasm in the treated groups, and later in culture they fused each other to form large intracellular space. Eventurally. this space was connected to the extracellular space or bile canaliculus. This experiment demonstrated that excessive accumulation or depletion of microfilaments induced by phallyoidein or cytochalasin D altered the cell shape and disturbed the vesicular transport of bile components into bile canaliculi. The results suggest that dysfunction of microfilaments may play an imprtant role in the impairement of canalicular contraction and the integrity of microfilaments is necessary for the billiary secretin as well as for the maintainance of the cell shape of hepatocytes.

모래다짐말뚝 개량폭에 따른 보강효과에 관한 연구

김시운,정길수,박병수,유남재 江原大學校 産業技術硏究所 2005 産業技術硏究 Vol.25 No.A

In this research, centrifuge model experiments and numerical approach of finite element method to analyze experimental results were performed to investigate the behavior of improved ground with sand compaction piles. One of typical clay minerals, kaolinite powder, were prepared for soft ground in model tests. Jumunjin standard sand was used to sand compaction pile installed in the soft soil. In order to investigate the characteristics of mechanical behavior of sand compaction piles with low replacement ratios, centrifuge model experiments with the replacement ratio of 40%, changing the width of improved area with respect to testing results the width of surcharge loads, were carried out to obtain of bearing capacity, characteristics of load-settlement, vertical stresses acting on the sand pile and the soft soil failure mechanism in improved ground.

야생 등줄쥐 (Apodemus agrarius coreae) 간뇌의 Dopamine성 신경세포

정영길,이남섭,민성기,김무강 대한해부학회 1997 Anatomy & Cell Biology Vol.30 No.6