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>

쇄석의 진동다짐 특성에 관한 실험적 고찰

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

This Study is results of experimental works to investigate the characteristics of vibro-compaction of crushed stones having coarse grain sizes. For testing material, crushed stone, sieved within very narrow ranges of grain size distribution, was used. Cyclic loading apparatus was used to apply cyclic loading to the specimen prepared in the mold. Tests were performed by changing the ratio of the maximum to the minimum stress, frequency and the magnitude of the maximum and the minimum stresses. Settlement of specimen due to cyclic loading was measured to analyze the compaction efficiency and sieve analysis test after cyclic loading test was also carried out to find the crushing rate of the specimen. As results of cyclic loading test, normalized settlement in terms of specimen height tends to be converged around loading cycle number of 1500. The magnitude of normalized settlement is in the range of 3.11 ~ 8.57%. The crushing rate is in the range of 4.46 ~ 8.78%. Normalize settlement and the crushing rate tend to increase with decreasing the ratio of the maximum to the minimum stresses and they tend to increase with increasing the frequency and the magnitude of the maximum and the minimum stresses for the given ratio. In conclusions, compaction rate of crushed stone is controlled by the dynamic stress (difference between the maximum and the minimum stresses) and the crushing rate is dominated by applied energy to the specimen.

상사성을 고려한 배수재 설치 연약점토 지반의 원심모델링

유남재,홍영길,정길수,조한기 강원대학교 산업기술연구소 2007 産業技術硏究 Vol.27 No.A

This paper is results of experimental research on the effect of application of similarity related to permeability of soil on the consolidation behavior as centrifuge modeling of consolidation is performed with the centrifuge model facility. In this research, the permeability of soil was controlled by changing the viscosity of porewater as the mixed water with glycerin was used during the centrifuge model experiments. The effect of drainage path on consolidation was investigated by installing the vertical drains. A serise of centrifuge model tests with conditions of single vertical and radial horizontal drainage were carried out. Kaolinite and Jumunjin standard sand were used as soft clay and surcharges respectively during tests. For testing condition of single vertical drainage considering similarity of permeability, it was found that consolidation with mixed porewater with glycerin was delayed in comparisons with test results with water only. For conditions of horizontal drainage with vertical drains, a low permeability by changing the viscosity of pore water resulted in delayed degree of consolidation at an initial stage of consolidation. But, it predicted not much differences in settlement as long as the consolidation time was sufficiently long enough to finish consolidation. Consequently, it was found that similarity in permeability should be considered to be critical for the case of centrifuge model experiments related to consolidation with long drainage path.

고소성 해성점토지반의 압축지수에 대한 비교 연구

정길수,박병수,홍영길,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 paper, for the highly plastic marine soft clay distributed in west and southern coast of Korean peninsula of Kwangyang and Busan New Port areas, correlation between compression index and other indices representing geotechnical engineering properties such as liquid limit, void ratio and natural water content were analyzed. Appropriate empirical equations of being able to estimate the compressibility of clays in the specific areas were proposed and compared with other existing empirical ones. For analyses of the data and test results, data for marine clays were used from areas of the South Container Port of the Busan New Port, East Breakwater, Passenger Quay, Jungma Reclamation and Reclamation Containment in the 3rd stage in Kwangyang. In order to find the best regression model by using the commercially available software, MS EXCEL 2000, results obtained from the simple linear regression analysis, using the values of liquid limit, initial void ratio and natural water content as independent variables, were compared with the existing empirical equations. Multiple linear regression was also performed to find the best fit regression curves for compression index and other soil properties by combining those independent variables. On the other hands, another software of SPSS for non-linear regression was used to analyze the correlations between compression index and other soil properties.

강원도에 분포하는 화강토의 다짐특성 및 토질정수의 상관관계에 관한 연구

박병수,유남재,홍영길 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

This study is to provide the useful data for the design and construction of the geotechnicla engineering works by collecting and analyzing the soil properties of granite soil in the Kangwon Province. Data base was obtained from 92 field sites in the Kangwon province divided into 15 areas based on adminstration district Total numbers of data were 478. Correlations between soil constants, especially compaction properties, were obtained by performing statisical analysis. Analyzed results were as follows. 1.Most of granite soil consists of SM and GM based on United Soil Classification System. 2.Mean gravity of granitesoil is 2.65 3.High correlations between optimum moisture content and the maximum dry density, plasticity index and liquid limit are obtained. 4.Analyzed results between other soil constants show relatively low correlation. However, they show consistant trends matchable to geotechnical engineering senses.

점유후 평가(Post-Occupancy Evaluation:POE)를 통한 대학 공공시설의 건축계획연구 : 성균관대학교 자연과학캠퍼스의 학생회관과 도서관의 조사 POE

서기영,문홍길,권종남,김병기 成均館大學校 科學技術硏究所 1991 論文集 Vol.42 No.1

The purpose of this thesis is to study the theory of Post-Occupancy Evaluation(POE) and its application to existing buildings. POE is the process of evaluationg building in a systematic and rigorous manner after they have been built and occupied for some time. POE's focus on building occupants and their needs, and thus provide insights into the consequences of past design decisions and the resulting building performance. In this study, with recognizing the importance and usefulness of POE, two buildings were evaluated according to the process of POE that are the liberary and the student center at Natural Science Campus, Sung Kwun Kwan University. The resultant lessons learned from this POE will provide a line of achieving better building utilization for two buildings and be u sed to set up criteria useful to design similar buildings in the future.

심근부종으로 표현된 과호산구증에 동반된 호산구성 심근염 1예

심미승,안영미,조홍근,신길자,정남식,조상호 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.2

Two Dominant Photomorphogenic Mutations of Arabidopsis thaliana Identified as Suppressor Mutations of hy2

Hong Gil Nam 한국생화학분자생물학회 (구 한국생화학회) 1996 추계학술대회집 Vol.- No.-

Random Antisense Mutagenesis for functional genomics in Arabidopsis

Nam, Hong-Gil,Jun, Ji-Hyung Plant molecular biology and biotechnology research 1998 Proceedings the 2nd Korean-Germany joint symposium Vol.1998 No.-

Synthesis of an Artificial Gene for the Shorthorn sculpin Antifreeze Protein and Its Introduction into Tobacco Plants

Nam, Hong Gil,Park, Yu Shin,Kim, Dal Ung,Chang, Seok So,Park, Duch Hoon 경북대학교 유전공학연구소 1995 遺傳工學硏究所報 Vol.10 No.1

Antifreeze protein (AFP) is a family of small proteins found in the polar fishes and some insects. AFPs appear to prevent ice formation in the blood at subzero temperatures, thus reducing freezing injury. To exploit the possibility of introducing freezing tolerance into plants, we synthesized an artificial gene which codes for a 45 amino acid antifreezer protein and introduced it into tobacco cells. The synthetic gene was designed to code for a Shorthorn sculpin AFP by assembling from 4 oligonucleotides. The synthetic gene inserted into a plant expression vector pGA643 was used to transform tobacco cells by the Agrobacteriummediated leaf disk transformation method. Transgenic plants were generated by kanamycin selection and introduction of the synthetic gene into the plant genome was confirmed by NPT II assay and Southern hybridization. Furthermore transcripts of the synthetic gene were detected by Northern blot analysis and production of a new small polypeptide was observed in the extract of the transgenic plants as monitored by polyacrylamide gel electrophoresis.