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>

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.

머리부분에 과량의 방사선을 조사받은 흰쥐 위점막 벽세포의 미세구조 연구

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

본 실험은 머리부분이 많은 양의 방사선에 노출되었을 때 위점막 벽세포에 나타나는 미세구조적 변화를 관찰하기 위하여 시행하였다. 실험동물로는 체중 200-250g의 건강한 숫흰쥐를 사용하였으며, 이를 정상군과 실험군(방사선 조사군)으로 나누었다. 실험군은 3,000 rad조사군과 6,000 rad조사군으로 구분하였으며, 방사선 조사후 6시간, 2일 및 6일후에 희생시켰다. 실험군은 sodium thiopental로 마취시킨후 치료방사기(Mitsubishi Linear Accelerator ML-4MV)를 사용하여 머리부분에만 분당 200 rad씩 X-선을 조사하였다. 위조직은 통상적인 전자현미경을 시료작성법에 따라 2.5% glutaraldehyde- 1.5% paraformaldehyde혼합액(0.1M phosphate buffer, pH 7.3)에 1차 고정한 후, 1% osmium tetroxide(0.1M phosphate buffer, pH 7.3)에 2차 고정하였다. 고정된 조직은 탈수과정을 거쳐 araldite혼합액에 포매하였으며, LKB-V ultratome르로 60-70nm두께의 얇은 절편을 작성하였다. 각 절편은 uranyl acetate와 lead citrate로 염색한후, JEM 100CX-Ⅱ전자현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1. 방사선 조사후 6시간군의 경우, 위샘내강쪽으로 벽세포의 일부가 돌출되어 있는 것이 가끔 관찰되었으며, 미세사와 용해소체가 정상군의 것에 비하여 다소 증가되었으나 기타 세포질소기관의 미세구조적 변화는 관찰할 수 없었다. 2. 방사선 조사후 2일군이 경우, 미세사와 용해소체가 6시간군의 것에 비하여 더 많이 관찰되었다. 3. 방사선 조사후 6일군의 경우, 벽세포는 세포내세관과 미세융모가 미약하였으며 관소포구조의 막성구조가 파괴되고 세포질이 부분용해된 변성세포가 자주 관찰되었다. 이상의 결과로 보아 머리부분이 과도한 방사선에 노출되면 위점막의 벽세포는 초기에는 별다른 미세구조적 변화가 없으나 6일 정도가 지나면 분비기능에 관계된 미세구조들이 큰 손상을 받게 되므로 분비기능이 매우 약화된다고 생각된다. This experiment was performed to study the morphological responses of the gastric parietal cells of the head-irradiated rats. Male rats were divided into normal and experimental groups. The head region of the rat, under sodium thiopental anesthesia. was exposed to 3,000rads or 6,000rads of X-ray radiation in a single dose, respectively. The source was a Mitsubishi Linear Accelerator ML-4MV. The target to skin distance was 80cm, and the dose rate was 200rads/min. The rats of experimental groups were sacrificed on the 6 hours, 2 days and 6 days after X-ray irradiation. Pieces of the tissue taken from the body of the stomach were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde(0.1M Millonig's phosphate buffer, pH 7.3), and in 1% osmium tetroxide(0.1M Milloning's phosphate buffer, pH 7.3), and embedded in araldite mixture. The ultrathin sections stained with uranyl acetate and lead citrate were observed with JEM 100CX-II electron microscope. The results were as follow: 1. The morphological changes of the parietal cells were not pronounced, six hours after head irradiation. But the parietal cells protruding into the lumen of the gastric gland were infrequently observed and amounts of the microfilaments and lysosomes were slightly increased as compared with those of the control gorup. 2. Two days following irradiation, bundles of the microfilaments and the lysosome in the parietal cells were more frequently observed than those observed in the six hours group. 3. Dramatic decrease of intracellular canaliculi and microvilli of the parietal cells were observed on the 6th day, and destruction of tubulovesicular structures and partial cytolysis or necrosis were observed frequently. Above results suggest that high dose of head irradiation induces indirect hazardous effects on the gastric parietal cells of the rat, and the irradiated animals might suffered from weak acid secretion of the parietal cell, since the large number of the parietal cells are degenerated within a few days following irradiation.

Graph 位相에 關한 硏究

金南吉 조선대학교 기초과학연구소 1984 自然科學硏究 Vol.7 No.1

손상받은고양이 줄무늬체에서 축삭반응에 관한 미세구조적 연구

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

야생 등줄쥐 (Apodemus agrarius coreae) 간뇌의 Dopamine성 신경세포

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

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.

식물플라크톤의 세포외배출유기물을 고려한 소양호의 1차생산과 유기물 부하

남궁현,김범철,황길순,최광순,김철구 江原大學校 附設 環境硏究所 2001 環境硏究 Vol.18 No.-

The autochthonous and allochthonous organic carbon loading were measured in Lake Soyang, to estimate the amount of carbon loading into the lake and the contribution of their sources to the lake's carbon loading. Autochthonous carbon loading was estimated from phytoplankton primary production with the extracellular organic carbon(EOC). Allochthonous loding was determined by measuring dissolved organic carbon(DOC) and particulate organic carbon(POC) concentration in the main inflowing Soyang River. Both autochthonous and allochthonous organic carbon loading were high during the summer, from July to September, and accounted for 43.2% and 71.7% of the annual loading, respectively. Primary productivity was elevated up to 1,000 mgCm^(-2)d^(-1)during summer and lowest in winter. EOC production from phytoplankton was also large in summer, resulting in a high DOC concentration in the lake water. Primary production of phytoplankton and allochthonous organic matter loading from the watershed contributed to 53.6% and 46.4% of total loading, respectively. The EOC production accounted for 4.4~21.2% of POC primary production, implying that EOC production of phytolankton must be considered in estimation of primary production.

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.

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.