• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.218-229
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• 1987

This study was carried out to investigate all the parts' weight growth under the different light intensity and root-cutting. As results : ${\cdot}$ Fresh and dry weight of leaf, shoot, root and seedling treated under 63% R.L.I showed the largest growth. ${\cdot}$ The largest growth in fresh and dry weight of shoot arid seedling appeared at 1/4 root cutting plot. ${\cdot}$ The value of T/R ratio was increased in low light intensity and high root-cutting. ${\cdot}$ The simple nonlinear relationship between light intensity, root-cutting and T/R ratio was recognized, respectively.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.1-10
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• 1987

This study was carried out to examine the influence of shading and root-cutting on the survival and growth of Pinus koraiensis seedlings. 1, The highest survival percentage of seedlings transplanted to transplanting bed appeared at the plot of 19% in shading. The 50% of the seedlings were survived if half of them were root-cutting. 2. Shoot elongation, root growth and diameter increment were the best at the plot of 100% in relative light intensity. However, those were the best at the plot with 1/4 root cutting. 3. The increase of needle fascicle number and the growth of needle surface area per seedling were the longest at the plot of 63% relative light intensity. Among root cutting treatments the 1/4 cutting plot showed the largest growth of needle areas.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.365-374
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• 2017

Objective: The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods: A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results: An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions: Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.353-358
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• 2012

This study was conducted to enhance the propagation of Acanthopanax divaricatus and Acanthopanax koreanum through different cutting practices. For propagation by cuttings, scions were taken on September 1. This already has hard skin and showed much higher values in terms of root length, root number, rooting ratio and root weight than those taken on June 30 and August 1. Regardless of cutting date, 50% shading resulted to the highest root length, root number, root ratio and root weight. Meanwhile, 95% shading significantly reduced these parameters compared with no shading. These results suggest that over-shading may inhibit root growth. Two growth regulators, IBA (concentration of 1,000, 2,000, 3,000 ppm) and Rootone-F (0.4%) were also tested of its effect to the cuttings. Rootone-F was found to be more effective than IBA. Cutting treated with Rootone-F had slightly higher root length and root number. A. koreanum which grows well in hot climatic condition showed better rooting ability than A. divaricatus.

• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.159-164
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• 2016

Plant growth regulator is an essential pesticide to date while the available active ingredient is not well understood unlike fungicide, insecticide and herbicide. This study was aimed to evaluate a new chemical class of plant growth regulator, and the total of 92 benzene derivatives were screened for their germination and early stage of the root growth regulation on Brassica campestris. Thirty benzaldehydes, nine acids, one amide, and one ester showed potent root growth inhibitory activity (>70 % inhibition) while only salicylaldehyde showed potent germination inhibition ($IC_{50}=81.2mg/L$) suggesting that benzaldehyde was a key module candidate for the growth inhibition. Benzaldehydes were further evaluated for root growth inhibition. 2,3-Dihydroxybenzaldehyde and salicylaldehyde showed $IC_{50}$ values of 8.0 and 83.9 mg/L, respectively. On the other hand, salicylaldehyde, and 2,4,5-trihydroxybenzaldehyde were found to have root growth promotion effects less than 10 mg/L. This result suggests that the benzaldehyde is a new class candidate for plant growth regulator.

• Journal of Ginseng Research
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• v.47 no.3
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• pp.469-478
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• 2023

Background: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. Methods: One-year-old P. ginseng seedlings treated with KNO₃ were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. Results: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. Conclusion: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.24-30
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• 1992

Extracts of Panax ginseng root significantly induced tolerance of Fusarium oxysporum to heavy metal, mecury, as the fungal mycelial growth was less inhibited by mercury chloride on potato dextrose medium(PDA) amended with ginseng root than on the PDA with no ginseng amendment. The most favorable concentration of ginseng root powder in detoxification of mercury chloride was 1%. The induced tolerance of F. oxysporum to mercury chloride appeared to be rather due to absorption of ginseng components, and was not related to stimulation of mycelial growth of the fungus per so by ginseng treatment. Ginseng components responsible for inducing tolerance of the fungus to mercury were involved in the water fraction of the ginseng root extract, although the water fraction had no effect on enhancement of the mycelial growth on the medium without mercury chloride. The hexane fraction of ginseng root extract, by which the mycelial growth was stimulated, was not related to the inducement of the tolerance to mercury chloride. However, more tolerance to mercury chloride was noted in PDA with both the water and hexane fractions combined than with either of the two fractions. Six-year-old ginseng roots were more effective in detoxification of mercury chloride than 4-year-old ginsng roots, and American ginseng (P quinquifolium) had no or little effect on inducing tolerance of the fungus to mercury chloride. This method may be used to screen other natural materials for test in the detoxification of mercury chloride.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.309-315
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• 2000

Panax ginseng is an important medicinal plant that has been used worldwide for geriatric, tonic, stomachic, and aphrodisiac treatments. Ginsenosides contained in the ginseng root are the main substances having active functions for human body. The price of ginseng is very expensive due to a complex process of cultivation, and the yield of ginseng is limited, which cannot meet the demand of the increasing market. Researchers have applied plant biotechnology to solve the problems but there are still things to be determined towards ginsenoside production by large-scale adventitious root culture. In this experiment, 5 to 20 liter bioreactors were employed to determine optimal conditions for adventitious root culture and ginsenoside production of Panax gineng. Callus was induced from the ginseng root on MS agar medium containing 1.0 mg. $L^{-1}$ 2,4-D and 0.1 mg. $L^{-1}$ kinetin. Then the callus was cultured on MS agar medium supplemented with 2.0 mg. $L^{-1}$ IBA, 0.1 mg. $L^{-1}$ kinetin, and 30 g. $L^{-1}$ to induce adventitious roots. The maximum root growth and ginsenoside production were obtained in 1/2 MS medium. 2.0 mg. $L^{-1}$ naphthalene acetic acid resulted in greater root growth than 2.0 mg $L^{-1}$ indole-3-butyric acid. Ginsenoside content increased with 2.0 mg. $L^{-1}$ benzyl adenin or kinetin. High concentrations of benzyl adenin (above 3.0 mg. $L^{-1}$ ) decreased the adventitious root growth and ginsenoside productivity. N $H_{4}$$^{+}$ inhibited the ginsenoside accumulation, while high concentrations of $K^{+}$, $Mg_{2}$$^{+}$, and $Ca_{2}$$^{+}$ increased it. N $H_{4}$$^{+}$ at 0.5 and 1.0 times of the normal amount in 3/4 SH medium resulted in the greatest biomass increase, but the highest ginsenoside productivity was obtained when N $O_{3}$$^{-}$ was used as the sole nitrogen source in the medium. Most microelements at high concentrations in the medium inhibited the root growth, but high concentrations of MnS $O_4$enhanced the root growth. Root dry weight increased with increasing sucrose concentrations up to 50 g. $L^{-1}$ , but decreased from 70 g $L^{-1}$ Ginsenoside productivity was maximized at the range of 20 to 30 g. $L^{-1}$ sucrose. In the experiment on bioreactor types, cone and balloon types were determined to be favorable for both adventitious root growth and ginsenoside production. Jasmonic acid was effective for increasing ginsenoside contents and Rb group ginsenosides mainly increased. These results could be employed in commercial scale bioreactor cultures of Panax ginseng.x ginseng.

• Journal of Life Science
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• v.20 no.2
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• pp.298-303
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• 2010

In this work, the effects of $Cs^+$ on root growth of 2-day-old maize seedlings were scrutinized. CsCl (5 mM - 30 mM) decreased the fresh weight of the primary root and of the shoot above the coleoptilar node. The elongation growth of the primary root was also inhibited by CsCl. The CsCl-inhibited growth was partially restored by 60 mM KCl. Lineweaver-Burk plot of the reaction in the presence and absence of 60 mM KCl displayed competitive interaction of CsCl (at higher than 10 mM). However, the Reversal of the inhibition by 60 mM KCl did not follow the competitive relationship with 5 mM CsCl, indicating the presence of differential mechanisms of $K^+$ influence depending on the concentration of CsCl. The differential effects of CsCl dependent on the concentrations were also observed in the CsCl-evoked radial expansion of the subapical region of the root. In spite of the decrease in length of the root, shrinkage of the root apical meristem was not observed. CsCl above 10 mM induced the expression of ZmKUP1, indicating functional deficiency of $K^+$ due to competition with Cs. However, the expression of ZmKUP1 by 5 mM CsCl was unclear. Conclusively, exogenously applied $Cs^+$ decreased root elongation and fresh weight and caused radial expansion of the subapical region of the primary root in 2-day-old maize seedlings by complex mechanisms including competitive and noncompetitive interactions with $K^+$. Because the shrinkage of the root apical meristem was not observed, it is concluded that the effects of CsCl on maize root growth was mainly related to cell expansion.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.43-48
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• 1970

In order to investigate the inter-relation with the growth of the barley root and GOT and GPT activities the growth of root and GOT, GPT activities were measured those which have been supplied various nitrogen compounds ($NO_3-N$, $NH_4-N$, Urea, and Amino acid). The results obtained are summarized as follows: 1. Growth of barley root supplied with $NH_4-N$ is generally increased in length and weight compared with that of the root fertilized by $NH_4-N$. 2. The above-mentioned root with $NH_4-N$ is not only decreased in its weight and length but also is apt to inhibited its growth, in compared with the root provided with $NO_3-N$. 3. The activities of GOT and GPT for the root fertilized by $NH_4-N$, the badly grown root is generally increased, while of the root supplied with $NO_3-N$ is decreased compared with that of the root fertilized by $NH_4-N$. 4. The activities of GOT and GPT for the root provided with amino acid known as the considerable growth inhibiting compound for rice is generally decreased, while that of the badly known-grown root is increased. 5. The activities of GOT and GPT in the supernatant fraction of the barley is for the most part, high and low in the mitocondrial fraction.