• Proceedings of the Korean Society of Crop Science Conference
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• 1989.05a
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• pp.32-33
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• 1989

• BMB Reports
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• v.44 no.1
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• pp.52-57
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• 2011

Termites play an important role in the degradation of dead plant materials and have acquired endogenous and symbiotic cellulose digestion capabilities. The feruloyl esterase enzyme (FAE) gene amplified from the metagenomic DNA of Coptotermes formosanus gut was cloned in the TA cloning vector and subcloned into a pET32a expression vector. The Ft3-7 gene has 84% sequence identity with Clostridium saccharolyticum and shows amino acid sequence identity with predicted xylanase/chitin deacetylase and endo-1,4-beta-xylanase. The sequence analysis reveals that probably Ft3-7 could be a new gene and that its molecular mass was 18.5 kDa. The activity of the recombinant enzyme (Ft3-7) produced in Escherichia coli (E.coli) was 21.4 U with substrate ethyl ferulate and its specific activity was 24.6 U/mg protein. The optimum pH and temperature for enzyme activity were 7.0 and $37^{\circ}C$, respectively. The substrate utilization preferences and sequence similarity of the Ft3-7 place it in the type-D sub-class of FAE.

• Applied Biological Chemistry
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• v.18 no.2
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• pp.56-60
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• 1975

A rapid method for the measurement of the absolute activity of carbon-14 in cotyledons and root of etiolated pea seedlings has been developed. Fresh tissue was frozen in liquid air, ground and suspended in gel phosphor and subjected to measurement for its radioactivity by liquid scintillation counter. Apparent activity of the suspended tissue sample calculated by counting efficiency value obtained by internal standardisation, was found to be related to absolute activity of the tissue, determined by flask combustion technique, by a constant factor. Once this factor is determined experimentally, analysis of C-14 lebelled tissue involves only fairly simple suspension counting by liquid scintillation counter. Present method appears to be applicable to other tissues tagged with C-14.

• CELLMED
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• v.6 no.3
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• pp.21.1-21.15
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• 2016

In Kenya, traditional knowledge on herbal medicine has remained a mainstream source of maintaining wellbeing for generations in many communities. However, the knowledge has been eroded in the course of time due to sociocultural dynamics virtually advanced by Christianity and formal education especially in the Kikuyu community. The study documented current ethnobotanical knowledge and threat to the traditional knowledge on medicinal plants among the Kikuyu community. A survey was carried out in Mathira, Tetu, Kieni, Othaya, Mukurweini, and Nyeri Town constituencies. Thirty practicing herbalists were purposively sampled; 5 per constituency. Data was obtained through semi - structured questionnaires and analyzed both qualitatively and quantitatively. A total of 80 ailments treated using 111 medicinal plant species distributed within 98 genera and 56 families were documented. Prevalent communicable diseases treated using herbal medicine included; gonorrhea (17.5%), malaria (15%), respiratory infections (12%), colds (10%) and amoebiasis (10%). Non-communicable diseases were; joint pains (11.1%), ulcers/hyperacidity (8.7%), high blood pressure (8.7%), intestinal worms (11.1%) and arthritis/gout (10%). Frequently harvested plant materials were; roots, barks and leaves. The study concluded that, traditional medicine practitioners in Nyeri County possessed wide knowledge of herbal medicine but this knowledge was on the verge of disappearing as it was largely a preserve of the aged generation. The study recommended massive campaign about the benefits of using herbal medicine in the study area. Further pharmacological studies are recommended on the mentioned plant species aimed at establishing their efficacy and safety as well as standardization as potential drugs.

• BMB Reports
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• v.34 no.3
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• pp.194-200
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• 2001

Secreted arginase from Evernia prunastri thallus has been purified 616-fold from the incubation medium. Purified arginase was resolved as only one peak in a capillary electrophoresis with a pI value of 5.35. The protein contained high amounts of acidic amino acids, such as Asx and Glx, and a relatively high quantity of Ser and Gly. The molecular mass of native, purified arginase was estimated as about 26 kDa by SE-HPLC. Substrate saturated kinetic showed a typical Michaelis-Menten relationship with a K_m value of 3.3 mM L-arginine. Atranorin behaved as a mixed activator of the enzyme (apparent $K_m$ = 0.96 mM); whereas evernic and usnic acid were revealed as non competitive inhibitors (apparent $K_m$ values were 3.16 mM and 3.05 mM, respectively). Kinetics of atranorin binding indicated that saturation was reached from 0.18 ${\mu}mol$ of the total atranorin and the occurrence of multiple sites for the ligand. This agrees with a possible aggregation of several enzyme subunits during the interaction process. A value of binding sites of about 12 was obtained. The binding of evernic acid was saturated from 23 nmol of total phenol. The number of binding sites was about 5. The loss of the binding ability of evernic acid could be interpreted as a single negative cooperatively. Usnic acid behaves in a similar way to evernic acid, although the binding saturation occurs at $0.14\;{\mu}moles$ of the ligand. This binding appears to be unspecific, and has 28 usnic acid binding sites to the protein.

• BMB Reports
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• v.41 no.2
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• pp.119-125
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• 2008

Our previous work confirmed that Sph2/LA1029 was a sphigomyelinase-like hemolyisn of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai. Characteristics of both hemolytic and cytotoxic activities of Sph2 were reported in this paper. Sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase C of Staphylococcus aureus upon sheep erythrocytes. The cytotoxic activity of Sph2 was shown in mammalian cells such as BALB/C mouse lymphocytes and macrophages, as well as human L-02 liver cells. Transmission electron microscopic observation showed that the Sph2 treated BALB/C mouse lymphocytes were swollen and ruptured with membrane breakage. They also demonstrated condensed chromatin as a high-density area. Cytoskeleton changes were observed via fluorescence confocal microscope in Sph2 treated BALB/C mouse lymphocytes and macrophages, where both cytokine IL-$1{\beta}$ and IL-6 were induced. In addition, typical apoptotic morphological features were observed in Sph2 treated L-02 cells via transmission electron microscope and the percentage of apoptotic cells did increase after the Sph2 treatment detected by flow cytometry. Therefore, Sph2 was likely an apoptosis-inducing factor of human L-02 liver cells.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.135-135
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• 2022

For abnormal weather disaster and building constructions, the shading stress could occur in crops more often. Those shading stress can effect on rice growth characters. Therefore, we investigated the shading effect on rice growth characters. Shading treatments were treated using shading screen as 35, 55, 75 and 100%. To check the shading effect on rooting after transplanting, shading stress treated after transplanting for 20 days as 35, 55 and 75%, And 35, 55, 75 and 100% of shading were treated 60 days after transplanting to check the growth characters. After transplanting, the shading stress effected on leaf and root growth. At 19 days after transplanting, leaf number reduced by shading stress. In 35, 55 and 75% shading stress, the leaf number reduced as 0.38, 0.45 and 0.9 respectively compared to control treatment. And root length was also reduced as 0.39, 0.6 and 1.93 cm respectively compared to control treatment. The plant height was slightly increased in 35 and 55% and reduced in 100%. Leaf growth speed per day was reduced as 0.0167 according to shading stress. And root growth speed also reduced as 0.0426 according to shading stress. The shading stress during vegetative stage effected on plant height and tiller number. In 35, 55 and 75% of shading stress, the plant height was slightly increased but it was reduced in 100%. Tiller number was significantly reduced by shading stress. According to 10% of shading stress, about 7% of the tiller number was reduced. However, leaf color did not change by the shading stress. The leaf area in 2^nd to 4nd leaf from new leaf reduced as 297 and 1044 in 75 and 100% of shading stress and increased as 70 and 99 in 35 and 55%. These leaf area change was affected by both the length and width of the leaf.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.438-444
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• 2023

Italian ryegrass (Lolium multiflorum Lam.; IRG) sowing season is delayed due to the autumn rainy season. Therefore, to address this problem, transplanting date and plant density were investigated. Transplant times investigated were October 20th, October 30th, and November 10th and planting densities were 50, 70, and 80 hills per 3.3 m². The plant height, leaf area index, and plant coverage rate were high in the following order: October 20th, October 30th, and November 10th. There was no significant difference among planting densities. In addition, the number of tillers and dry weight before and after wintering were high on October 20th. In terms of yield components, the number of tillers, dry weight, and seed yield per unit area were higher with the transplanting date of October 20th than with transplanting on November 10th. There was no difference in seed yield between the planting densities of 80 and 70 hills per 3.3 m². However, seed yield was low at 50 hills per 3.3 m². In conclusion, the transplanting time for stable seed production is late October, and optimal plant density is 70 and 80 hills per 3.3 m². A stable interplanting number before wintering will contribute to the seed yield.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.364-371
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• 2017

Limonium tetragonum is a halophyte grown naturally in the coastal region in South Korea. This study was conducted to investigate the effects of salt concentrations on seed germination, seedling growth, and antioxidant capacity of L. tetragonum. Seeds were collected from naturally grown plants of L. tetragonum and those at full maturity were used in this experiment. All experiments were performed at 0%, 0.5%, 1.0%, or 2.0% of salt concentrations. Seed germination rate was highest as 86% at $20^{\circ}C$ and followed as higher in order of $25^{\circ}C$, $30^{\circ}C$ and $15^{\circ}C$. The germination rate was about 80% at 0% or 0.5% of salt concentration, but it was very low at the salt concentrations higher than 1%. Growth of L. tetragonum seedlings showed no difference in Hoagland solution containing NaCl in the range of 0% to 1.0% and seedlings survived at 2.0% of NaCl concentration. As the salt concentration increased, the content of $Na^+$ in the shoot increased, but that of $K^+$, $Ca^{{+}{+}}$, or $Mg^{{+}{+}}$ decreased. The antioxidant activity and the content of total polyphenol and total flavonoid in the shoot were similar at 0% and 0.5% of NaCl and were highest at 2.0% of NaCl concentration. In conclusion, performance of seed germination and plant growth of L. tetragonum was highest at 0% and 0.5% of NaCl concentration, and showed no difference in antioxidant activity, total polyphenol contents, and total flavonoid contents at the same salt concentrations.

• Molecules and Cells
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• v.38 no.5
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• pp.390-395
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• 2015

Degradation of chlorophyll (Chl) by Chl catabolic enzymes (CCEs) causes the loss of green color that typically occurs during senescence of leaves. In addition to CCEs, STAYGREEN1 (SGR1) functions as a key regulator of Chl degradation. Although sgr1 mutants in many plant species exhibit a staygreen phenotype, the biochemical function of the SGR1 protein remains elusive. Many recent studies have examined the physiological and molecular roles of SGR1 and its homologs (SGR2 and SGR-LIKE) in Chl metabolism, finding that these proteins have different roles in different species. In this review, we summarize the recent studies on SGR and discuss the most likely functions of SGR homologs.