• 생명과학회지
• /
• 제24권9호
• /
• pp.973-980
• /
• 2014

본 연구에서는 식물에 존재하는 신규 기능성 소재 개발의 일환으로 Decaisnea insignis 에탄올 추출물(DIEE)의 항산화 및 항염증 생리활성을 분석하였다. 먼저 DIEE의 항산화능을 DPPH 라디칼 소거능을 통해 분석한 결과 양성 대조군으로 사용한 아스코르빈산과 유사한 정도의 높은 소거활성을 보여 DIEE가 매우 강한 항산화능을 보유함을 확인하였다. 또한 RAW 264.7 세포주에서 $H_2O_2$ 및 LPS에 의해 유도된 ROS에 대한 DIEE의 소거능을 분석한 결과, 농도의존적인 강한 ROS 소거능을 보였다. 뿐만 아니라 대표적인 항산화효소 중 하나로 항산화능 보유 천연물에 의해 발현이 유도되는 hemeoxygenase 1 (HO-1) 및 그 전사 인자인 nuclear factor-E2-related factor 2(Nrf2)의 단백질 발현이 DIEE의 처리에 의해 유의적으로 증가됨을 보였으며 이러한 HO-1 및 Nrf2의 발현 유도는 상위신호전달계인 MAPKs에 의해 조절될 가능성을 보였다. 한편 DIEE가 LPS에 의해 유도된 NO 생성에 미치는 영향을 분석한 결과 농도의존적인 NO 생성 저해능을 보였으며 이는 NO 생성 단백질인 iNOS의 발현 저해에서 기인함을 확인하였다. 이와 같은 DIEE의 NO 생성 억제 효과는 염증 상위신호전달계인 $NF-{\kappa}B$ 및 AP-1의 조절을 통해 일어날 가능성을 보였다. 이러한 결과를 통해 DIEE의 높은 항산화능과 항염증 활성을 처음으로 확인하였으며 향후 기능성 소재로서 유용하게 활용될 수 있을 것으로 판단된다.

• Molecules and Cells
• /
• 제37권11호
• /
• pp.833-840
• /
• 2014

Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.

• Molecules and Cells
• /
• 제41권5호
• /
• pp.413-422
• /
• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Preventive Nutrition and Food Science
• /
• 제8권1호
• /
• pp.29-35
• /
• 2003

A crude polysaccharide fraction (GU-3) from the roots of Glycyrrhiza uralensis (licorice root), a screened herbal plant used in the preparation of herbal kimchi, enhanced Peyer's patch mediated bone marrow cell proliferation and NK cell-mediated tumor cytotoxicity against Yac-1 cells. GU-3 was further purified by DEAE-Sepharose CL-6B yielding fractions designated as GU-3I, and 3IIa∼3IIe. GU-3IIa is mainly composed of arabinose, galactose and galacturonic acid, and showed the highest bone marrow cell proliferation activity. In addition, GU-3IIb had arabinose, galactose, rhamnose and galacturonic acid as the component sugars with a small quantity of protein; GU-3IIb also enhanced activity of NK cell-mediated tumor cytotoxicity. After these fractions were further fractionated via gel filtration on Sepharose CL-6B or Sephacryl S-300, two immunological active polysaccharides, GU-3IIa-2 and 3IIb-1 were purified from the respective fractions. GU-3IIa-2 mostly contained neutral sugars (75%) such as arabinose and galactose (molar ratio; 1.0 : 0.7) in addition to a considerable amount of galacturonic acid (20%), whereas GU-3IIb-1 was composed of arabinose, galactose, rhamnose and galacturonic acid (molar ratio; 0.3 : 0.5 : 0.1 : 1.0). Methylation analysis indicated that GU-3IIa-2 was composed mainly of terminal, 4- or 5-linked and 3,4- or 3,5-branched arabinose, 3-linked, 4-linked and 3,6-branched galactose, and terminal and 4-linked galacturonic acid whereas GU-3IIb-1 contained various glycosidic linkages such as terminal and 4- or 5-linked arabinose, 2,4-branched rhamnose, terminal and 4-linked galactose, and terminal and 4-galacturonic arid. Single radial gel diffusion indicated that only GU-3IIa-2 strongly reacted with β-D-glucosyl-Yariv antigen. These results suggest that bone marrow cell proliferating activity and enhancement of NK cell-mediated tumor cytotoxicity of GU-3 are caused by polysaccharides containing a pectic arabinogalactan (GU-3IIa-2) and pectic polysaccharide (GU-3IIb-1).

• Applied Microscopy
• /
• 제37권1호
• /
• pp.1-10
• /
• 2007

MCT 유발 간독성 흰쥐에 해독정기탕의 투여가 시간경과에 따른 간세포의 항산화효소 활성변화, 세포사멸 억제와 간의 조직병리학적 변화에 미치는 영향을 조사하였다. 대조군은 생리식염수를 투여하였으며, 실험군은 해독정기탕 0.9 mL을 6시간, 24시간 간격으로 경구투여 하였다. 간기능의 지표가 되는 GPT 효소 활성은 해독정기탕 투여한 6시간 군에서 대조군에 비해 감소하였다. 항산화 효소인 SOD, catalase 활성도의 변화에 있어서도 6시간 실험군에서 변화를 보여주었고 24시간 경과 후에는 대조군과 실험군의 통계적인 유의성은 없었다. 간의 조직병리학적 관찰 결과 대조군은 심한 출혈, 간세포의 팽창과 중심정맥 내피세포의 파괴 현상이 뚜렷이 나타났으며, 24시간 경과 후에는 핵질의 응축과 사립체의 팽대현상이 현저하였다. 반면 해독정기탕 투여후 6시간 실험군은 일부 세포괴사와 세포사멸 보호 및 회복효과를 관찰하였다. 이상의 연구 결과로 보아 해독정기탕은 투여시간에 따라 간 기능회복 및 해독, 간세포의 항산화 활성변화, 세포사멸의 보호효과 약물로서 작용함이 사료된다.

• 한국미생물·생명공학회지
• /
• 제40권1호
• /
• pp.50-56
• /
• 2012

Wnt/${\beta}$-catenin 신호전달체계는 세포의 분화와 증식, 기관의 발생과 조절을 담당하는 중요한 세포내 신호전달체계이다. 발생과정에서 Wnt/${\beta}$-catenin 신호전달체계의 작용이 지방세포로의 분화를 억제하고 조골세포와 신경세포로의 분화는 촉진한다는 많은 연구들이 보고되어 있으며, 현재 Wnt/${\beta}$-catenin 신호전달체계의 조절을 통한 여러 질병의 치료와 예방에 대한 관심이 대두되고 있다. 본 연구에서는 세포를 기반으로 한 초고속 저분자 스크리닝 시스템을 이용하여 Wnt의 상승제인 silybin을 발굴하였다. silybin은 Wnt가 존재 않을 경우에는 ${\beta}$-catenin 단백질의 수준에 영향을 미치지 않지만 Wnt가 존재할 경우, mRNA 발현양의 변화 없이 세포질내의 ${\beta}$-catenin 단백질의 수준을 증가시킨다. 또한 silybin에 의해 증가된 ${\beta}$-catenin으로 인해 지방세포분화에 중요한 전사인자라고 알려진 PPAR-${\gamma}$와 C/EBP-${\alpha}$의 발현을 억제한다. 따라서 이 연구에서는 silybin이 세포질내 ${\beta}$-catenin 단백질의 수준을 증가시킴으로써 Wnt/${\beta}$-catenin 신호전달체계를 활성한다는 사실을 제시하였다.

• Applied Biological Chemistry
• /
• 제28권3호
• /
• pp.187-195
• /
• 1985

당근에서 cytokinin, auxin 또는 GA에 의해 조절되는 polypeptide 및 단백질들을 동정하기 위하여, kinetin, BA, IAA, NAA 혹은 $GA_3$가 각각 $10^{-4},\;10^{-5},\;10^{-6}M$인 배지에서 suspension culture 한 당근 callus들의 추출물의 전기영동양상을 조사하였다. 생장조절제를 처리하지 않은 callus에서 15개 polypeptide band가 관찰되었는데, 이들의 분자량은 각각 $18._4,\;20._2,\;24._0,\;34._9,\;35._7,\;37._4,\;40._3,\;42._2,\;44._1,\;44._4,\;49._3,\;55._0,\;56._6,\;58._1$ 그리고 $59._9KD$였다. Kinetin, BA, IAA, NAA 그리고 $GA_3$에 의하여 합성이 촉진되는 것으로 보이는 polypeptide band는 각각 2개, 6개, 1개, 2개 그리고 4개였고, 합성이 억제되는 것으로 보이는 것은 각각 5개, 3개, 4개, 3개, 그리고 2개였다. 분자량 $40._3KD$ 및 $42._2KD$의 polypeptide들은 cytokinin류 생장조절제에 의하여 합성이 촉진되는 것으로 나타났고, $44._1KD$의 것은 auxin류에 의하여 합성이 촉진되며 $37._4,\;44._4,\;56._6KD$의 것은 auxin류에 의하여 합성이 억제되는 것으로 나다났다. Kinetin, BA, IAA, NAA 및 $GA_3$처리에서 상대 이동도가 0.56, 0.84, 0.92인 단백질 band들이 증가된 것이 관찰되었으나, 각 생장조절제들에 특유한 단백질은 동정할 수 없었다.

• 한국잡초학회지
• /
• 제7권2호
• /
• pp.220-235
• /
• 1987

본연구(本硏究)는 벼품종(品種) 및 주요(主要) 논 잡초종(雜草種)에 대(對)한 Oxyfluorfen의 선택활성차이(選擇活性差異)를 구명(究明)하여 수도(水稻) 포장(圃場)에서의 이용가능성(利用可能性)을 살펴 보고자 수행(遂行)되었으며 결과(結果)를 요약(要約)하연 다음과 같다. 1. Oxyf1uorfen의 발생전처리(發生前處理)에서 너도방동사니를 포함(包含)한 공시잡초종(供試雜草種)과 벼와의 선택활성차이(選擇活性差異)는 $ED_{50}$으로 보아 0.1~0.4 kg a. i./ha 수준(水準)에서 성립(成立)되었다. 2. $10^{-5}$ M Oxyfluorfen의 발생후처리(發生後處理)에서 생육(生育)의 억제(抑制)는 전체처리(全體處理)>뿌리처리(處理)>경부대상처리(莖部帶狀處理) 순(順)으로 심(甚)하였으며, 특(特)히 너도방동사니와 벼에서는 생육억제(生育抑制)가 경미(輕微)하였다. 3. 광합성(光合成)의 저해(沮害)는 공시초종(供試草種) 모두, $10^{-4}$ M Oxyfluorfen 농도(濃度)에 서부터 심(甚)하게 나타났으며 호흡저해(呼吸沮害)의 차이(差異)는 인정(認定)되지 않았다. 4. 유리단세포(遊離單細胞)에서 Oxyfluorfen 처리시(處理時) 벼 2 품종(品種)과 너도방동사니가 $10^{-5}$ M 농도수준(濃度水準)에서 내성(耐性)을 보인 반면 피와 올미는 상대적(相對的)으로 감수성(感受性)을 보였다. 5. 벼의 현탁배양(懸濁培養)에서 세포(細胞)의 생장(生長)은 Oxyfluorfen의 농도증가(濃度增加)에 따라 억제(抑制)되었으며 Aichiasahi 보다 Mushakdanti 에서 크게 억ㅈ(抑制)되었다.

• Molecules and Cells
• /
• 제27권4호
• /
• pp.423-428
• /
• 2009

Superoxide dismutases (SODs) constitute the first line of cellular defense against oxidative stress in plants. SODs generally occur in three different forms with Cu/Zn, Fe, or Mn as prosthetic metals. We cloned the full-length cDNA of the Thellungiella halophila Cu/Zn-SOD gene ThCSD using degenerate RT-PCR and rapid amplification of cDNA ends (RACE). Sequence analysis indicated that the ThCSD gene (GenBank accession number EF405867) had an open reading frame of 456 bp. The deduced 152-amino acid polypeptide had a predicted molecular weight of 15.1 kDa, an estimated pI of 5.4, and a putative Cu/Zn-binding site. Recombinant ThCSD protein was expressed in Escherichia coli and assayed for SOD enzymatic activity in a native polyacrylamide gel. The SOD activity of ThCSD was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide, confirming that ThCSD is a Cu/Zn-SOD. Northern blotting demonstrated that ThCSD is expressed in roots, stems, and leaves. ThCSD mRNA levels increased by about 30-fold when plants were treated with sodium chloride (NaCl), abscisic acid (ABA), and indole-acetic acid (IAA) and by about 50-fold when treated with UVB light. These results indicate that ThCSD is involved in physiological pathways activated by a variety of environmental conditions.

• 원예과학기술지
• /
• 제31권1호
• /
• pp.14-23
• /
• 2013

This study evaluated the influence of light quality and intensity during healing and acclimatization on the $CO_2$ exchange rate, growth, and morphogenesis of grafted pepper (Capsicum annuum L.) transplants, using a system for the continuous measurement of the $CO_2$ exchange rate. C. annuum L. 'Nokkwang' and 'Tantan' were used as scions and rootstocks, respectively. Before grafting, the transplants were grown for four weeks in a growth chamber with artificial light, where the temperature was set at $25/18^{\circ}C$ (light/dark period) and the light period was 14 hours $d^{-1}$. The grafted pepper transplants were then healed and acclimatized under different light quality conditions using fluorescent lamps (control) and red, blue, and red + blue light-emitting diodes (LEDs). All the transplants were irradiated for 12 hours per day, for six days, at a photosynthetic photon flux (PPF) of 50, 100, or 180 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The higher PPF levels increased the $CO_2$ exchange rate during the healing and acclimatization. A smaller increase in the $CO_2$ exchange rates was observed in the transplants under red LEDs. At a PPF of 180 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the $CO_2$ exchange rate of the transplants irradiated with red LEDs was lowest and it was 37% lower than those irradiated with fluorescent lamps. The $CO_2$ exchange rates of transplants irradiated with blue LEDs was the highest and 20% higher than those irradiated under fluorescent lamps. The graft take was not affected by the light quality. The grafted pepper transplants irradiated with red LEDs had a lower SPAD value, leaf dry weight, and dry matter content. The transplants irradiated with blue LEDs had longer shoot length and heavier stem fresh weight than those irradiated with the other treatments. Leaves irradiated with the red LED had the smallest leaf area and showed leaf epinasty. In addition, the palisade and spongy cells of the pepper leaves were dysplastic and exhibited hyperplasia. Grafted pepper transplants treated with red + blue LEDs showed similar growth and morphology to those transplants irradiated with fluorescent lamps. These results suggest that high-quality grafted pepper transplants can be obtained by healing and acclimatization under a combination of blue and red lights at a high PPF level.