• Title/Summary/Keyword: Plant Cells

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Anti-oxidative and Anti-inflammatory Activities of Decaisnea insignis Ethanol Extract (Decaisnea insignis 에탄올 추출물의 항산화 및 항염증 활성)

  • Jin, Kyong-Suk;Lee, Ji Young;Kwon, Hyun Ju;Kim, Byung Woo
    • Journal of Life Science
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    • v.24 no.9
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    • pp.973-980
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    • 2014
  • This study was conducted to explore new nutraceutical resources from the plant kingdom possessing biological activities. To fulfill this purpose, the anti-oxidative and anti-inflammatory activities of Decaisnea insignis ethanol extract (DIEE) were evaluated. First, DIEE possessed potent scavenging activity against 1,1-diphenyl-2-picryl hydrazyl (DPPH), similar to ascorbic acid used as a positive control. Moreover, DIEE inhibited lipopolysaccharide (LPS)- and hydrogen peroxide ($H_2O_2$)-induced reactive oxygen species (ROS) in RAW 264.7 cells. Furthermore, DIEE induced the expression of an anti-oxidative enzyme, heme oxygenase 1 (HO-1), and its upstream transcription factor, nuclear factor-E2-related factor 2 (Nrf2), in a dose-dependent manner. The modulation of the HO-1 and Nrf2 expressions might be regulated by mitogen-activated protein kinases (MAPKs) and their upstream signaling pathways. On the other hand, DIEE suppressed LPS-induced nitric oxide (NO) formation without cytotoxicity. The inhibition of the NO formation was the result of the downregulation of inducible NO synthase (iNOS) by DIEE. The suppression of NO and iNOS by DIEE might be modulated by their upstream transcription factors, nuclear factor ${\kappa}B$ ($NF-{\kappa}B$), and activator protein 1 (AP-1) pathways. Taken together, these results provide important new insights that D. insignis possesses anti-oxidative and anti-inflammatory activities. Therefore, it might be utilized as a promising material in the field of nutraceuticals.

Characterization of a Novel DWD Protein that Participates in Heat Stress Response in Arabidopsis

  • Kim, Soon-Hee;Lee, Joon-Hyun;Seo, Kyoung-In;Ryu, Boyeong;Sung, Yongju;Chung, Taijoon;Deng, Xing Wang;Lee, Jae-Hoon
    • Molecules and Cells
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    • v.37 no.11
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    • pp.833-840
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    • 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.

Confirmation of Drought Tolerance of Ectopically Expressed AtABF3 Gene in Soybean

  • Kim, Hye Jeong;Cho, Hyun Suk;Pak, Jung Hun;Kwon, Tackmin;Lee, Jai-Heon;Kim, Doh-Hoon;Lee, Dong Hee;Kim, Chang-Gi;Chung, Young-Soo
    • Molecules and Cells
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    • v.41 no.5
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    • pp.413-422
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    • 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.

Characterization of the Immunologically Active Components of Glycyrrhiza uralensis Prepared as Herbal Kimchi

  • Hwang, Jong-Hyun;Lee, Kyong-Haeng;Yu, Kwang-Won
    • Preventive Nutrition and Food Science
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    • v.8 no.1
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    • pp.29-35
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    • 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).

Effect of Haedokjeongki-tang in Rat Liver after Monocrotaline Exposure (Monocrotaline으로 유발된 흰쥐의 간독성에 대한 해독정기탕의 효과)

  • Park, Hyun-Jeong;Kim, Jeong-Sang
    • Applied Microscopy
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    • v.37 no.1
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    • pp.1-10
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    • 2007
  • Monocrotaline (MCT) is a pyrrolizidine alkaloid (PA) plant toxin that produces hapatotoxicity in humans and animals. To felt the hypothesis, we investigated the possible protective effects of Haedokjeongki-tang as an antioxidant against MCT-induced liver injury in rats. Cells with apoptotic morphology have been observed in the livers of animals exposed to Ph and Haedokjeongki-tang. Whether apoptosis occurs in the livers of MCT-treated animals and whether it is required for full manifestation of pathological changes is not known, To determine this, rats were treated with 100 mg MCT/kg, and apoptosis was detected by transmission electron microscopy and TUNEL assay. MCT produced apoptosis in the liver by 6 h after treatment and increased by 24 h. Administration of Haedokjeongki-tang did affect liver structure and inhibit apopotosis in MCT-induced liver injury. Upon light and electron microscopic examination, we observed that Haedokjeongki-tang improved the morphological and histopathological changes of the liver caused by MCT-induced injury. MCT caused a time-dependent release of GOT and GPT, a marker of liver injury. Furthermore, we observed with respect to antioxidants status, catalase and superoxide dismutase activity tended to be higher in the MCT-treated rats than in the Haedokjeongki-tang administered rats. Our finding showed that Haedokjeongki-tang administration partially reduced liver injury after MCT exposure.

Silybin Synergizes with Wnt3a in Activation of the Wnt/${\beta}$-catenin Signaling Pathway through Stabilization of Intracellular ${\beta}$-Catenin Protein (Silybin에 의한 Wnt/${\beta}$-catenin 신호전달체계의 활성화)

  • Kim, Tae-Yeoun;Oh, Sang-Taek
    • Microbiology and Biotechnology Letters
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    • v.40 no.1
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    • pp.50-56
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    • 2012
  • The Wnt/${\beta}$-catenin signaling pathway regulates diverse developmental processes and adult tissue homeostasis. Inappropriate regulation of this pathway has been associated with human diseases, such as cancers, osteoporosis, and Alzheimer's disease. Using a cell-based chemical screening with natural compounds, we discovered silybin, a plant flavonoid isolated from the Silybum marianum, which activated the Wnt/${\beta}$-catenin signaling pathway in a synergy with Wnt3a-conditioned medium (Wnt3a-CM). In the presence of Wnt3a-CM, silybin up-regulated ${\beta}$-catenin response transcription (CRT) in HEK293-FL reporter cells and 3T3-L1 preadipocytes through stabilization of intracellular ${\beta}$-catenin protein. Silybin and Wnt3a-CM synergistically reduced expression of important adipocyte marker genes including peroxisome-proliferator-activated $receptor{\gamma}$ ($PPAR{\gamma}$) and CAATT enhancer-binding protein ${\alpha}$ (C/$EBP{\alpha}$) in 3T3-L1 preadipocytes, accompanied by the activation of Wnt/${\beta}$-catenin signaling pathway. Taken together, our findings indicate that silybin is a small-molecule synergist of the Wnt/${\beta}$-catenin signaling pathway and can be used as a controllable reagent for investigating biological processes that involve the Wnt/${\beta}$-catenin signaling pathway.

Effects of Some Plant Growth Regulators on Protein Biosynthesis of Carrot Cells (당근 세포의 단백질 생합성에 대한 몇가지 식물생장조절제의 영향)

  • Yoo, Ki-Jung;Park, Chang-Kyu;Song, Tae-Chul
    • Applied Biological Chemistry
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    • v.28 no.3
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    • pp.187-195
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    • 1985
  • Electrophoretic studies of protein extracts from carrot calluses suspension-cultured on the media containing kinetin, BA, IAA, NAA or $GA_3$ at the levels of $10^{-6},\;10^{-5},\;10^{-4}M$, respectively, were performed to identify polypeptides and proteins regulated by auxin, cytokinin or GA. Fifteen bands of polypeptide(s) were observed in the callus cultured in the control medium devoid of growth regulators, and their molecular weights were $18._4,\;20._2,\;20._0,\;34._9,\;35._7,\;37._4,\;40._3,\;42._2,\;44._1,\;44._4,\;49._3,\;55._0,\;56._6,\;58._1,\;and\;59._9\;KD$, respectively. The synthesis of polypeptide appeared to be promoted in two bands by kinetin, in six bands by BA, in one band by IAA, in two bands by NAA, and in four bands by $GA_3$, while inhibited in five bands by kinetin, in three bands by BA, in four bands by IAA, in three bands by NAA and in three bands by $GA_3$. The polypeptides of $40._3\;KD\;42._2\;KD$ seemed to be regulated by cytokinins, and those of $44._1\;KD,37._4\;KD,\;and\;56._6\;KD$ by auxins. The proteins of three bands with relative mobilities of 0.56, 0.84, and 0.92, respectively, increased in the calluses cultured on the media containing kinetin, IAA, $GA_3$, NAA or BA, compared to the control, but it was difficult to identify the proteins specific for each growth regulator.

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Herbicidal Selective Activity of Oxyfluorfen to the Selected Rice Cultivars and Major Paddy Weed Species (벼품종(品種) 및 주요(主要) 논잡초종(雜草種)에 대한 Oxyfluorfen의 선택활성(選擇活性) 연구(硏究))

  • Kim, Y.J.;Guh, J.O.;Pang, S.;Choi, K.J.
    • Korean Journal of Weed Science
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    • v.7 no.2
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    • pp.220-235
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    • 1987
  • The experiment was carried out to find the feasibility of using Oxyfluorfen in the paddy fields by investigating the difference of selective activity of Oxyfluorfen among rice cultivars and major paddy weed species. The dosage of Oxyfluorfen that show selective activity between rice cultivars and weed species ranged from 0.1 to 0.4kg ai/ha. The degree of growth inhibition was in order of whole-plant soaking application > root soaking application > stem bandage application, and in that case $10^{-5}$M Oxyfluorfen was treated after emergence. Especially the growth inhibition of rice cultivars and Cyperus serotinus was low, among others. Photosynthesis was severely inhibited at the Oxyfluorfen level above $10^{-4}$ M in all the tested weeds, but inhibition of respiration was not to be seen. Isolated single cells of two rice cultivars and Cyperus serotinus were tolerant to $10^{-5}$M Oxyfluorfen,but those of Echinochloa crus-galli and Sagittaria pygmaea were susceptible comparatively. The growth inhibition of suspension cultured rice cell induced by the increments of Oxyfluorfen concentration, and the degree of inhibition was higher in C.V. Mushakdanti than in C.V. Aichiasahi.

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Molecular Cloning and Expression of a Cu/Zn-Containing Superoxide Dismutase from Thellungiella halophila

  • Xu, Xiaojing;Zhou, Yijun;Wei, Shanjun;Ren, Dongtao;Yang, Min;Bu, Huahu;Kang, Mingming;Wang, Junli;Feng, Jinchao
    • Molecules and Cells
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    • v.27 no.4
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    • pp.423-428
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    • 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.

Effects of Light Quality and Intensity on the Carbon Dioxide Exchange Rate, Growth, and Morphogenesis of Grafted Pepper Transplants during Healing and Acclimatization

  • Jang, Yoonah;Mun, Boheum;Seo, Taecheol;Lee, Jungu;Oh, Sangseok;Chun, Changhoo
    • Horticultural Science & Technology
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    • v.31 no.1
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    • pp.14-23
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    • 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.