• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.114-123
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• 1981

Diurnal acid fluctuations, stomatal resistance, and morphology and anatomy were investigated in leaves and stems P. oleracea L. growing under the natural environmental condition. A CAM-like pattern of acid fluctuation was exhibited not in leaves of the young purslane but in its stems. Defoliated stems showed a decreased in diurnal changes of total acidity as compared with normal stems. Excised stems stored in continuous darkness exhibited diurnal acid rhythms, and they showed light deacidifications for three days. Kranz-type arrangement was observed in leaves, but not in stems. Micrography of cross sections of stems showed cells with relatively large vaculoles and a few chloroplasts. The number of stomata was 3,275cm-2 in leaves, while the stomata could not be observed in stems. Stomatal resistance was high at night and low in daytime in leaves of the young purslane, and the range of its value was 5~40 sec.$\textrm{cm}^{-1}$. But stomatal resistance in leaves of the water-stressed plant was comparratively high in day time, and its value was 30 sec.$\textrm{cm}^{-1}$. The result of these studies showed the possibility that the stem of P.oleracea L. possesses CAM under certain stressed conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.317-323
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• 1993

In order to clarify the contents of active principles in floral inhibition cultured Angelica gigas roots, the amounts of crude extract and the contents of decursin and decursinol angelate in the yearly roots were analyzed and compared with respect to the root age, root part and growth stage. The woody cell, weight and width of pith and cortex were also investigated at different growth stage to observe the developmental characteristics of lignification in the roots as bolting and flowering in normal cultured Angelica gigas. The amount of crude extracts did not differ with plant ages, whereas the contents of decursin and decursinol angelate were differed and the highest in 3 year old roots. The contents of decursin in 1, 2 and 3 year old roots were 3.71, 4.76 and 8.20% and those of decursinol angel ate were 2.84, 3.40 and 5.01%, respectively. The amount of crude extracts, and the contents of decursin and decursinol angelate were the highest in fine roots, followed by the lateral roots and the lowest in the primary roots. On the other hand, the amount of the constituents in the cortex were much higher than those in the pith of the root. The amounts of crude extract, and the contents of decursin and decursinol angelate showed the highest value at the vagetative stage and decreased with development to bolting and blooming stage. Woody cells were accumulated in the pith of the root as advancing growth stage, so that the weight and radius of the pith increased, whereas the relative weight and width of the cortex decreased slightly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.33-41
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• 1997

This study was carried out to establish simple and easy methods to judge the survival, senescence and death of the protoplasts in culture system by identifying the marker substance related to metabolic status of the cells. When rice and tobacco protoplasts were cultured in MS and KM-8P media containing 2,4-D or coconut milk ABA decreased especially in the media containing coconut milk, but GA$_3$, IAA and zeatin increased as the cultures progressed. The decrease of ABA and increase of zeatin was especially remarkable. When the supraoptimal amount of osmoticum (mannitol) was added to the culture media ABA decreased after a momentary increase, but other growth hormones slowly increased as the concentration of the osmoticum increased. Contents of individual hormones were contrasted when protoplasts rice and tobacco were cultured on the same medium containing 10mM super mine or NaCl. Tobacco protoplasts were more sensitive to NaCl stress and stopped protoplast division at the late stage of culture. Protoplast viability decreased greatly in 48 hours when the protoplast were at 32$^{\circ}C$ on a medium lacking several components. ABA content increased up to 10 days from incubation in negative proportion to the protoplast viability. On the other hand contents of other growth hormones, especially zeatin, decreased. The present results clearly showed that the contents of individual growth hormones in the plant protoplasts in culture varied sensitively in response to environmental factors that they are faced with. This indicates that the physiological states of the protoplast, such as survival, senescence or death can be simply judged based on the quantitative analysis of those hormones by ELISA.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.274-281
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• 2006

A fibrinolytic enzyme gene was isolated from Bacillus subtilis BB-1 by PCR method. Primers for PCR cloning were designed according to pre-identified gene for fibrinolytic enzymes from B. subtilis. The primer sequences were 5'-CGG ATC CGT GAG AGG CAA AAA GGT G-3' and 5'-TGA ATT CTT AAT GTG CTG CTG CTT GTC C-3' as concensus sequences of the fibrinolytic genes of Bacillus species. The PCR product was 1,145 bp and the sequence homology was 99% with nattokinase gene isolated from Japanese natto. The cloned fibrinolytic gene was reconstructed in Bacillus-E. coli shuttle vector, pEB for bulk-production. The fibrinolytic enzyme was purified by FPLC from the cloned B. subtilis 168. The optimum pH and temperature of the enzyme were 7.0 and $35^{\circ}C$, respectively. The fibrinolytic enzyme did not show any activity toward to skim milk, gelatin, casein and blood agar plate. The enzyme specific polyclonal antibody was prepared in rabbit for further assays such as detection of the gene expression in plant cells. This means that the enzyme may be used for health-care such as thrombosis without any hamful effects in the blood vessel.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1323-1334
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• 2010

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that NO serves as antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. $N^{\omega}$-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased $H_2O_2$ and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.260-267
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• 2000

Giant cell interstitial pneumonia. a synonym for hard metal pneumoconiosis, is a unique form of pulmonary fibrosis resulting from an exposure to hard metal dust. A case of biopsy-proved giant cell interstitial pneumonia in the absence of appropriate history of exposure to hard metal dust is reported. The patient presented with clinical features of chronic interstitial lung disease or idiopathic pulmonary fibrosis. He worked in a chemical laboratory at a fertilizer plant, where he had been exposed to various chemicals such as benzene and toluene. He denied having any other hobby in his house or job at work, which may have exposed him hard metal dust. High-resolution CT scan revealed multi-lobar distribution of ground glass opacity with peripheral and basal lung predominance. The retrieved fluid of bronchoalveolar lavage contained asbestos fiber and showed neutrotphil predominance. Surgical lung biopsy was performed for a definite diagnosis. Lung specimen showed alveolar infiltration of numerous multinucleated giant cells with mild interstitial fibrosis. Upon detailed examination of the lung tissue, one asbestos body was found. An analysis for mineral contents in lung tissue was performed. Compared with the control specimen, the amount of cobalt and several hard metal components in the lung tissue of this patient was ten times higher. We speculated that the inconsistency between occupational history and the findings of pathologic and mineralogical analyses could be explained by the difference in individual immunologic reactivity to hard metal dust despite the relatively small amount of unrecognized environmental exposure(ED: It's hard to understand what this phrase is trying to say).

• KSBB Journal
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• v.25 no.3
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• pp.289-296
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• 2010

Lectins are carbohydrate-binding and a cell-agglutinating proteins, and are concerted with a plants defence mechanism. In particular, chitin-binding lectins in locular fluid of cherry tomato fruit seemed to have a role in defending plants against fungi. The antifungal activity using lectin isolated from locular fluid of cherry tomato fruit was measured in the plant pathogen Cladosporium cucumerinum, Monosporascus cannonballus, Fusarium oxysporum, and Rhizoctonia solani. Amoung the four strains, a potent antifungal activity was detected in Cladosporium cucumerinum and Monosporascus cannonballus, not in Fusarium oxysporum, and Rhizoctonia solani. The molecular weight of this lectin isolated as double protein bands by SDS-PAGE was calculated to be 87 kDa and 47 kDa from the relative mobilities compared with those of reference molecular weight markers. The isolated lectin agglutinated human red blood cells (A, B, AB, O) treated with trypsin, and the most activity was found at B. The optimal temperature of isolated lectin was at $30^{\circ}C$. For the thermal stability, lectin was stable at $20-80^{\circ}C$. The optimal pH of this lectin was at 7.2, and showed complete loss below pH 9.0.

• Journal of Life Science
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• v.20 no.12
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• pp.1777-1783
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• 2010

Plants generate reactive oxygen species (ROS) as a by-product of normal aerobic metabolism or when exposed to a variety of stress conditions, which can cause widespread damage to biological macromolecules. To protect themselves from oxidative stress, plant cells are equipped with a wide range of antioxidant proteins. However, the detailed reaction mechanisms of these are still unknown. Peroxiredoxins (Prxs) are ubiquitous thiol-containing antioxidants that reduce hydrogen peroxide with an N-terminal cysteine. The active-site cysteine of peroxiredoxins is selectively oxidized to cysteine sulfinic acid during catalysis, which leads to inactivation of peroxidase activity. This oxidation was thought to be irreversible. Recently identified small protein sulphiredoxin (Srx1), which is conserved in higher eukaryotes, reduces cysteine.sulphinic acid in yeast peroxiredoxin. Srx1 is highly induced by $H_2O_2$-treatment and the deletion of its gene causes decreased yeast tolerance to $H_2O_2$, which suggest its involvement in the metabolism of oxidants. Moreover, Srx1 is required for heat shock and oxidative stress induced functional, as well as conformational switch of yeast cytosolic peroxiredoxins. This change enhances protein stability and peroxidase activity, indicating that Srx1 plays a crucial role in peroxiredoxin stability and its regulation mechanism. Thus, the understanding of the molecular basis of Srx1 and its regulation is critical for revealing the mechanism of peroxiredoxin action. We postulate here that Srx1 is involved in dealing with oxidative stress via controlling peroxiredoxin recycling in Arabidopsis. This review article thus will be describing the functions of Prxs and Srx in Arabidopsis thaliana. There will be a special focus on the possible role of Srx1 in interacting with and reducing hyperoxidized Cys-sulphenic acid of Prxs.

• Journal of Life Science
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• v.28 no.6
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• pp.738-744
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• 2018

Sasa quelpaertensis Nakai is a native Korean plant that grows only on Mt. Halla of Jeju Island. Its leaf is used for a popular bamboo tea due to its various health-promoting properties, and it has been increasingly used as food and cosmetic ingredients. To utilize the S. quelpaertensis leaf efficiently, the preparation method for phytochemical-rich extract (PRE) using the leaf's residue was previously reported, which was produced after hot water extraction. This study was undertaken to evaluate the anti-oxidant and anti-inflammatory potential of PRE and its solvent fractions. The ethyl acetate fraction of PRE (EPRE) showed higher DPPH, ABTS, and superoxide radical scavenging activities, and it effectively inhibited intracellular reactive oxygen species (ROS) and nitric oxide (NO) production in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells. EPRE also induced the expression of heme oxygenase-1 (HO-1) by increasing the level of nuclear factor E2-related factor 2 (Nrf2) in a nuclear fraction. The inhibiting effect of EPRE on LPS-induced NO production was partially reversed by the HO-1 inhibitor (zinc protoporphyrin, ZPP), suggesting that HO-1 is involved in suppressing NO production. Taken together, the results suggest that EPRE has potential as a promising anti- oxidant and anti-inflammatory agent.

• Molecules and Cells
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• v.25 no.1
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• pp.30-42
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• 2008

The disease-specific (dsp) region and the hypersensitive response and pathogenicity (hrp) genes, including the hrpW, $hrpN_{Ep}$, and hrpC operons have previously been sequenced in Erwinia pyrifoliae WT3 [Shrestha et al. (2005a)]. In this study, the remaining hrp genes, including the hrpC, hrpA, hrpS, hrpXY, hrpL and hrpJ operons, were determined. The hrp genes cluster (ca. 38 kb) was comprised of eight transcriptional units and contained nine hrc (hrp conserved) genes. The genetic organization of the hrp/hrc genes and their orientation for the transcriptions were also similar to and collinear with those of E. amylovora, showing ${\geq}80%$ homologies. However, ORFU1 and ORFU2 of unknown functions, present between the hrpA and hrpS operons of E. amylovora, were absent in E. pyrifoliae. To determine the HR active domains, several proteins were prepared from truncated fragments of the N-terminal and the C-terminal regions of $HrpN_{Ep}$ protein of E. pyrifoliae. The proteins prepared from the N-terminal region elicited HR, but not from those of the C-terminal region indicating that HR active domains are located in only N-terminal region of the $HrpN_{Ep}$ protein. Two synthetic oligopeptides produced HR on tobacco confirming presence of two HR active domains in the $HrpN_{Ep}$. The HR positive N-terminal fragment ($HN{\Delta}C187$) was further narrowed down by deleting C-terminal amino acids and internal amino acids to investigate whether amino acid insertion region have role in faster and stronger HR activity in $HrpN_{Ep}$ than $HrpN_{Ea}$. The $HrpN_{Ep}$ mutant proteins $HN{\Delta}C187$ (D1AIR), $HN{\Delta}C187$ (D2AIR) and $HN{\Delta}C187$ (DM41) retained similar HR activation to that of wild-type $HrpN_{Ep}$. However, the $HrpN_{Ep}$ mutant protein $HN{\Delta}C187$ (D3AIR) lacking third amino acid insertion region (102 to 113 aa) reduced HR when compared to that of wild-type $HrpN_{Ep}$. Reduction in HR elicitation could not be observed when single amino acids at different positions were substituted at third amino acids insertion region. But, substitution of amino acids at L103R, L106K and L110R showed reduction in HR activity on tobacco suggesting their importance in activation of HR faster in the $HrpN_{Ep}$ although it requires further detailed analysis.