• Plant Biotechnology Reports
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• v.5 no.4
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• pp.309-315
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• 2011

Rice grown in anaerobic waterlogged soil accumulates ammonium as a major source of nitrogen (N). We have compared the physiological symptoms of rice seedlings subjected to N-starvation stress with those receiving sufficient N, based on measurements of shoot/root length and weight and an analysis of protein expression patterns. N starvation marginally increased root growth but notably decreased shoot biomass. N uptake was reduced by >50% in the roots and shoots of N-starved seedlings. To better understand the mechanism of N starvation in rice, we performed a comparative proteome analysis of proteins isolated from rice leaves. Twenty-five differentially expressed proteins were analyzed by matrixassisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and electron spray ionization quadrupole TOF. Functional analysis of the N-starvation response proteins suggested their involvement in protein synthesis and fate, metabolism, and defense. These results indicate that these proteins may play important roles in regulating the plant's complex adaptation responses for N use during N starvation. The proteins may be useful for further characterization of protein function in plant N nutrition.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.960-966
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• 2021

A technical approach to design and carry out an experiment to determine the uptake of selected radionuclides in site-specific conditions in Kuwait was developed and successfully executed for developing a radioecological decision support system. The radionuclides from soil-to-plant transfer factors have been obtained for leafy and non-leafy vegetables, and root crops cultivated in Kuwait. Two types of vegetated soils were selected and spiked with high concentrations of three relatively short-lived selected radionuclides (⁸⁵Sr, ¹³⁴Cs, and ¹³³Ba). The highest strontium and barium transfer factors were found in the order: leafy vegetables > root crops > non-leafy vegetables. The approximate range of radiocesium transfer factor was found to be low in all plant groups and was comparable to those reported elsewhere in different soil types of temperate and tropical environments. A strong negative correlation between the obtained transfer factors and the distribution coefficient of the radionuclide in soil was found. It is recommended to adopt the newly derived parameters for the sensitive areas in Kuwait and other Gulf countries instead of using the generic parameters, whenever dose calculation codes are used. This will help to more accurately assess and predict the end results of the committed effective dose equivalent through ingestion pathway.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.209-214
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• 1994

A study was conducted to study yield response and nutrient uptakes with N, P, K application. Its growth and root yield of Aralia continentalis was increased along with the added amount of fertilizer, and optimum fertilization rates of N, P, K were 38, 21, 18kg/10a, respectively. On the path coefficient analysis between the growth characters and root yield, its values showed in the order of plant height, root width, number of budstocks, number of branch, stem width and number of root. Relative yield of non-fertilization against fertilization of N, P, K were low in the order of N, P and K, that is, responses of fertilization on root yield of Aralia continentalis were affected greatly in the order of N, K and P, but the fertilization efficiency was high in the order of K, P and N. Calcium content was the highest and phosphorus content was the lowest among the mineral nutrients contained in the leaf, but relationships between nitrogen content and root yield was showed positive correlation the difference distinctly between the chemicals and the organics.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.71-80
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• 2005

Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.255-263
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• 1995

Root uptakes of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ by rice were studied through a greenhouse experiment in which the upper 20 cm of the culture box was filled with an acidic loamy-sandy soil and a mixed solution of the radionuclides was applied to the surface water on the soil 2 days before, and 5 different times after, transplanting. Percent uptakes of the radionuclides to rice tops varied $3.4{\sim}13.7%,\;0.03{\sim}0.1%,\;0.6{\sim}1.5%,\;0.02{\sim}0.15%$, respectively, with application time. Among radionuclides, soil-to-plant transfer factors decreased, on the whole, in the order of $^{54}Mn>^{85}Sr>^{60}Co{\geq}^{137}Cs$, and among plant parts, in the order of straw > chaff > hulled seed. Transfer factors $(m^2/kg-dry)$ in hulled seed were, depending on application time, $1.2{\times}10^3{\sim}5.0{{\times}10^3\;for\;^{54}Mn,\;1.6{\times}10^5{\sim}2.6{\times}10^4\;for\;^{60}Co,\;1.1{\times}10^4{\sim}7.6{\times}10^4\;for\;^{85}Sr\;and\;5.2{\times}10^5{\sim}7.0{\times}10^4\;for\;^{137}Cs$. The highest factors of all the radionuclides in straw came from the application at 67 days after transplanting while those of $^{54}Mn,\;^{60}Co\;and\;^{85}Sr$ in hulled seed appeared at later applications. The data from this studv can be referred to in assessing the radiological impact of an accidental contamination during the rice growth.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.13-21
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• 2014

This study generated regression models to quantify storage and annual uptake of carbon from five native landscape tree species through a direct harvesting method, and established essential information to estimate carbon reduction effects from urban greenspaces. Tree species for the study included the Chionanthus retusus, Prunus armeniaca, Abies holophylla, Cornus officinalis, and Taxus cuspidata, which are usually planted in cities of middle Korea, but for which no information on carbon reduction is available. Ten tree individuals for each species were sampled reflecting various stem diameter sizes at a given interval. The study measured biomass for each part including the roots of sample trees to compute total carbon storage per tree. The annual carbon uptake per tree was quantified by analyzing the radial growth rates of stem samples at breast height or ground level. Regression models were developed using diameter at breast height (dbh) or ground level (dg) as an independent variable to easily estimate storage and annual uptake of carbon per tree for each species. All the regression models showed high fitness with $r^2$ values of 0.92~0.99. Storage and annual uptake of carbon from a tree with dbh of 10 cm were greatest with C. retusus (20.0 kg and 5.9 kg/yr, respectively), followed by P. armeniaca (17.5 kg and 4.5 kg/yr) and A. holophylla (13.2kg and 1.8 kg/yr) in order. A C. officinalis tree and T. cuspidata tree with dg of 10 cm stored 9.3 and 6.3 kg of carbon and annually sequestered 3.2 and 0.6 kg, respectively. The above-mentioned carbon storage equaled the amount of carbon emitted from gasoline consumption of about 23~35 L for C. retusus, P. armeniaca, and A. holophylla, and 11~16 L for C. officinalis and T. cuspidata. A tree with the diameter size of 10 cm annually offset carbon emissions from gasoline use of about 6~10 L for C. retusus, P. armeniaca, and C. officinalis, and 1~3 L for A. holophylla and T. cuspidata. The study breaks new ground to easily quantify biomass and carbon reduction for the tree species by overcoming difficulties in direct cutting and root digging of urban landscape trees.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.382-385
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• 2006

To know the effect of water treatment sludge (WTS) as a rice seedling culture soil, rice seeds are sown, germinated and grown on the culture soils mixed with different ratios of WTS to sand (100:0, 50:50, 30:70, respectively), and their growth effects was compared to that of control, commercial culture soil. When WTS is used as a culture soil for rice, the length and weight of the top part of rice seedling somewhat decreased than those of control treatment while their root length and weight in all WTS treatments significantly increased. Although phosphorus and potassium uptake of rice seedling in WTS treatments was slightly decreased, WTS treatment showed to develop root growth which is necessary in the seedling stage of all plane. Such a stimulatory effect on root growth of rice seedling was significant in the mixture ratio of 50% WTS to 50% sand.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.423-429
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• 2015

This study was conducted to evaluate the effects of reduced nitrogen (N) and potassium (K) fertigation as additional fertilizer on tomato yield and nutrient contents in excessively nutrients-accumulated soil. Shoot and root dry weights (DW), dry matter rate for shoot, root and fruit and number of fruit in both AF50 and AF100 (50 and 100% levels of additional fertilizer) treatments were increased in comparison with those in AF0 (0% level of additional fertilizer) treatment. In case of nutrient uptake by tomato, nitrogen, phosphorous (P) and potassium contents in all tomato parts (leaf, stem, root and fruit) in AF50 and AF100 treatment were lower than those in AF0 treatment. On the contrary, soluble sugar and starch contents in all tomato parts in AF50 and AF100 were higher than those in AF0 treatment. There were differences between AF0 and AF50 or AF100 in tomato growth, yield, nutrient level and contents of soluble sugar and starch. In contrast, the level and initiation point of fertigation did not significantly affect the parameters. Based on our results, the application of properly reduced level of additional fertilizer is possible to maintain the productivity of tomato and alleviate the nutrient accumulation in plastic film house soils.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.71-95
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• 1995

Bacteria have been regarded as a one of major etiologic factors in root canal infections. In endodontic treatment the effective removal of pathogenic microorganisms in the root canal is the key to successful outcome. Bacterial cell wall components may play an important role in the development of pulpal and periapical disease. The purpose of this study was to evaluate the effect of sonic extracts of Streptococcus spp. on cultured L929 cells and to characterize cell wall protein profiles of Streptococcus spp. Streptococcus spp. were isolated from infected root canals and identified with Vitek Systems(Biomeriux, USA). Five streptococci, namely S. sanguis, S. mitis, S uberis, S. mutans (ATCC 10449) and S. faecalis (ATCC 19433) weere enriched in brain heart infusion broth. Cell pellets were sonicated and cell wall extracts were dialyzed and membrane filtered. Prepared cell wall proteins were applied to cultured L929 cell. The cell reaction were evaluated by monitoring DNA synthesis, cell numbers and the change of cell morphology. The total cell wall protein profiles of microorganisms were characterized by sodium dodecyl sulfate polyacrylamide-gel eledruphoresis(SDS-PAGE). DNA synthesis of L929 cells were reduced by the increasing concentration of sonic extracts. DNA synthesis was significantly suppressed in more than $50{\mu}g$/ml of sonic extract conentration in five streptococci. S. nutans (ATCC 10449) showed stronger suppression on DNA synthesis than remaining four streptococci, which had the similar effect on DNA synthesis. Analysis of DNA synthesis measured by [$^3H$]-thymidine uptake was more sensitvie method than cell counting. Sonic extracts affected the microscopic findings of L929 cells. The protein profiles indicated that all five strains shared two major proteins with molecular masses of 70.8 and 57.5 kD respectively. S. uberis and S. mutans shared common minor proteins of which molecular weights were 147.9 and 112.2 kD respectively. However some minor proteins were unique for S. mitis, S. uberis and S. faecalis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.204-209
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• 2004

The main purpose of this study was to select a B. schmidtii population which has high cadmium tolerance and remediation and to determine the difference of cadmium uptake patterns among populations. One-year-old B. schmidtii seedlings were treated with 0, 0.4, 0.8mM CdSO$_4$. 3/8H$_2$O for two months. Cadmium concentrations in different positions of stem and cadmium concentrations and contents of leaves, stems and roots were analyzed. Also soil cadmium concentrations were analyzed. B. schmidtii was highest in root and lowest in shoot tip, showing a gradual decrease from root to shoot tip. The shoot to root Cd concentration ratios were over 1.26. It is concluded that B. schmidtii has good potential for phytoextraction as a shoot accumulator, which can be used for remediation of cadmium-contaminated areas. But tolerance differs between populations. Therefore B. schmidtii should be used as a means of phytoremediation after selection for Cd tolerance is performed.