• Horticultural Science & Technology
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• 제34권1호
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• pp.154-162
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• 2016

The aim of this study was to develop a transgenic petunia with enhanced resistance to sulfur dioxide ($SO_2$) gas by stacking two genes, SOD2 and NDPK2, which are both known to confer resistance to abiotic stresses. The first-generation hybrids ($TF_1$) were obtained through reciprocal crosses between an SOD2-transgenic line SOD2-2-1-1-35($T_4$)[S($T_4$)] and an NDPK2-transgenic line NDPK2-7-1($T_2$)[N7-1($T_2$)]. Approximately 32.1-73.0% of the first-generation hybrids ($TF_1$) carried both SOD2 and NDPK2 genes. These hybrids showed 2.6 and 5.1 times less damage than hybrids carrying only SOD2 or NDPK2 genes, respectively, when they were treated with $SO_2$ gas at 30 ppm. This confirmed that the heterozygous hybrids were more resistant to $SO_2$ than the hybrids carrying either one of the resistance genes. Second-generation hybrids ($TF_2$) were obtained by selfing the $TF_1$ individuals. We confirmed the expression of the stacked genes in the $TF_2$ hybrids by phenotypic observation of their response to $SO_2$ gas at 30 ppm as well as using RT-qPCR and photosynthetic efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제40권2호
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• pp.260-267
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• 1995

In temperate zone planting rice at different date subjects the Crop to different climatic condition. The present study aimed at comparison of the change in source-sink relationship of the Japonica(J) and that of IndicaxJaponica(I$\times$J) type rice cultivars caused by shift of heading date. Two J- and two I$\times$J-type cultivars were made to head on August 16, August 26, and September 5. Sink capacity was changed by shift of heading date in different mode between the types of cultivars. In both types major determinant of sink capacity was number of effective tillers, and the number of spikelets per panicle was the minor. In J-type earlier planting/heading was beneficial to increased panicle numbers and this was due mainly to a larger diurnal difference in temperature. I$\times$J-type cultivars favored a higher daily mean temperature to increase the sink capacity. The ability of source at heading, in terms of leaf area per panicle, chlorophyll content per spiklet, photosynthetic ability of leaves per unit area at 25$\^{\circ}C$, carbohydrate and N contents of leaves, was not so different among different heading dates in both types. However, the source activity was governed principally by temperature during grain filling. The J-type cultivars headed on Sept. 5 and I$\times$J-type cultivars headed later than August 16 could not have had sufficient source activity in grain filling due to lower temperature.

• Journal of Wetlands Research
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• 제26권1호
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• pp.62-71
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• 2024

To assess the ecological changes of Korean fir (Abies koreana E. H. Wilson) under climate change conditions, growth and physiological responses were analyzed over a 5-year period in a control group (outdoors) and in a treatment group where the temperature and CO2 levels were elevated to closely resemble RCP 4.5 conditions. The results showed an increasing trend in annual branch length of A.koreana in the climate change treatment group over time. While climate change conditions did not significantly impact the morphological differences of A.koreana leaves, they did influence the biomass of the leaves, suggesting that as climate change progresses, the productivity of A.koreana leaves may decline. On the other hand, the chlorophyll content in A.koreana under climate change conditions was higher in the climate change treatment group, whereas the photosynthesis rate, transpiration rate, water use efficiency and stomatal conductance was higher in the control group. This suggests that an environment with elevated temperature and CO2 could influence an increase in stomatal density, but having a negative impact on photosynthetic reactions. Further research on stomatal density under each environmental treatment will be required to confirm this hypothesis. Additionally, as this study only observed changes in leaf biomass, further empirical research should be considered to understand the changes in biomass of A.koreana under climate change conditions. In conclusion, the environmental adaptability of A.koreana is expected to weaken in the long term under elevated temperatures and CO2.

• Korean Journal of Soil Science and Fertilizer
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• 제46권6호
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• pp.659-664
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• 2013

The aim of this study is to determine the drought stress index through photochemical analysis in red pepper (Capsiumannuum L.). The photochemical interpretation was performed in the basis of the relation between Kautsky effect and Photosystem II (PSII) following the measurement of chlorophyll, pheophytin contents, and $CO_2$ assimilation in drought stressed 5-week-old red pepper plants. The $CO_2$ assimilation rate was severely lowered with almost 77% reduction of chlorophyll and pheophytin contents at four days after non-irrigation. It was clearly observed that the chlorophyll fluorescence intensity rose from a minimum level (the O level), in less than one second, to a maximum level (the P-level) via two intermediate steps labeled J and I (OJIP process). Drought factor index (DFI) was also calculated using measured OJIP parameters. The DFI was -0.22, meaning not only the initial inhibition of PSII but also sequential inhibition of PSI. In real, most of all photochemical parameters such as quantum yield of the electron transport flux from Quinone A ($Q_A$) to Quinone B ($Q_B$), quantum yield of the electron transport flux until the PSI electron acceptors, quantum yield of the electron transport flux until the PSI electron acceptors, average absorbed photon flux per PSII reaction center, and electron transport flux until PSI acceptors per cross section were profoundly reduced except number of QA reducing reaction centers (RCs) per PSII antenna chlorophyll (RC/ABS). It was illuminated that at least 6 parameters related with quantum yield/efficiency and specific energy fluxes (per active PSII RC) could be applied to be used as the drought stress index. Furthermore, in the combination of parameters, driving forces (DF) for photochemical activity could be deduced from the performance index (PI) for energy conservation from photons absorbed by PSII antenna until the reduction of PSI acceptors. In conclusion, photochemical responses and their related parameters can be used as physiological DFI.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제30권2호
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• pp.126-130
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• 1985

Photoinhibition studies were conducted with ginseng (Panax ginseng) grown under shade and tobacco (N. tobaccum cv. Bulgaria) grown under full sunlight. The plants were exposed to light intensity of 580, 1280, 1770, 2580 ${\mu}$E/㎡/sec in normal air for 3.6 9 hours. Light saturation of ginseng was observed at 550 ${\mu}$E/㎡/sec and that of tobacco was at 1600 ${\mu}$E/㎡/sec. Tobacco exposed to high light intensity and long duration of light irradiation didn't show entire reduction in photosynthetic capacity. But in ginseng, 20.3% of photosynthesis was reduced in light intensity of 2,580 ${\mu}$E/㎡/sec during 9 hours. Light response in photosynthesis differed considerably between tobacco and ginseng, and ginseng exposed to high light intensity showed remarkable reduction in photosynthesis. The extent of photoinhibition of ginseng was dependent on the length of exposure to the high light intensity. Stomatal resistance of ginseng seemed not to be changed by photoinhibition but mesophyll resistance was increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제41권6호
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• pp.665-671
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• 1996

The salt stress at seedling stage of barley was examined in different concentrations of NaCl containing 1/2 Hoagland solution. Among the physiological factors electric conductivity and sodium content of cell sap outflow solution were increased according to the in-crease of NaCl concentration in 1/2 Hoagland solution but the total protein content of root cell sap outflow solution was decreased. Changing pattern of amino acids content in plant was divided into 3 groups which were increased, decreased or unchanged by NaCl concentration in solution. In normal condition, sugar content in plant was higher than potassium or sodium but if NaCl was added more than 25mM in 1/2 Hoagland solution, sodium was the highest. Potassium content in shoot was decreased as 67% of control at 100mM of NaCl containing solution and in root it was decreased as 8%. Sum of the potassium and sodium content in shoot was seriously increased in accordant with NaCl concentration in culture solution, but in root it was gradually decreased. Chlorophyll content per g fresh weight and photosynthetic ability per $\textrm{cm}^2$ in first leaf were not affected by NaCl concentration of 1/2 Hoagland solution but root activity was slightly decreased compared to control.

• Journal of Bio-Environment Control
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• 제13권4호
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• pp.209-216
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• 2004

This study was aimed to assess the effects of microclimate factors on lettuce chlorophyll fluorescent responses and to develop an environment control system for plant growth by adopting a simple genetic algorithm. The photosynthetic responses measurements were repeated by changing one factor among six climatic factors at a time. The maximum Fv'/Fm' resulted when the ambient temperature was $21^{\circ}C,\;CO_2$ concentration range of 1,200 to 1,400 ppm, relative humidity of $68\%$, air current speed of $1.4m{\cdot}s^{-1}$, and the temperature of nutrient solution of $20^{\circ}C$. In PPF greater than $140{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, Fv'/Fm' values were decreased. To estimate the effects of combined microclimate factors on plant growth, a photosynthesis efficiency model was developed using principle component analysis for six microclimate factors. Predicted Fv'/Fm' values showed a good agreement to measured ones with an average error of $2.5\%$. In this study, a simple genetic algorithm was applied to the photosynthesis efficiency model for optimal environmental condition for lettuce growth. Air emperature of $22^{\circ}C$, root zone temperature of $19^{\circ}C,\;CO_2$ concentration of 1,400 ppm, air current speed of $1.0m{\cdot}s^{-1}$, PPF of $430{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and relative humidity of $65\%$ were obtained. It is feasible to control plant environment optimally in response to microclimate changes by using photosynthesis efficiency model combined with genetic algorithm.

• Molecules and Cells
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• 제41권11호
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• pp.979-992
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• 2018

Potato (Solanum tuberosum L.) is the third most important food crop, and breeding drought-tolerant varieties is vital research goal. However, detailed molecular mechanisms in response to drought stress in potatoes are not well known. In this study, we developed EMS-mutagenized potatoes that showed significant tolerance to drought stress compared to the wild-type (WT) 'Desiree' cultivar. In addition, changes to transcripts as a result of drought stress in WT and drought-tolerant (DR) plants were investigated by de novo assembly using the Illumina platform. One-week-old WT and DR plants were treated with -1.8 Mpa polyethylene glycol-8000, and total RNA was prepared from plants harvested at 0, 6, 12, 24, and 48 h for subsequent RNA sequencing. In total, 61,100 transcripts and 5,118 differentially expressed genes (DEGs) displaying up- or down-regulation were identified in pairwise comparisons of WT and DR plants following drought conditions. Transcriptome profiling showed the number of DEGs with up-regulation and down-regulation at 909, 977, 1181, 1225 and 826 between WT and DR plants at 0, 6, 12, 24, and 48 h, respectively. Results of KEGG enrichment showed that the drought tolerance mechanism of the DR plant can mainly be explained by two aspects, the 'photosynthetic-antenna protein' and 'protein processing of the endoplasmic reticulum'. We also divided eight expression patterns in four pairwise comparisons of DR plants (DR0 vs DR6, DR12, DR24, DR48) under PEG treatment. Our comprehensive transcriptome data will further enhance our understanding of the mechanisms regulating drought tolerance in tetraploid potato cultivars.

• Korean Journal of Agricultural Science
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• 제40권4호
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• pp.325-331
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• 2013

This experiment has been carried out to determine optimal culture conditions for the production of cut flowers and tubers of Calla (Zantedeschia 'Golden Affair' and 'Black Magic') in highlands. Treatments consisted of various levels of root zone environments, Results are as follows: Calla 'Golden Affair' were grown with different mulching materials such as Non-mulching, Black film, reflective film, Rice hull. Mulching materials resulted in no difference in the number of cut flowers but flower length was highest in reflective film. Calla 'Black Magic' were treated with various soil water content, soil type and watering time. Number of cut flowers and flower quality were greatest when the plants were watered at -80 kPa soil water content. No symptoms of soft rot (Erwinia carotovora) was observed at this soil water content. The occurrence of soft rot was observed with similar percentage according to soil type and the soil water content. When Calla 'Black Magic' were watered at the time of soil surface drying, growth was greater compared to others. Air temperature and PPF affected plant growth and photosynthesis. Photosynthetic rate was greatest at $25^{\circ}C$ and PPF $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, while lowest at $28^{\circ}C$ and PPF $800{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Soft rot did not occur without regard to dipping treatment (0, 5, 10, 24, 48 hours) when the day and night temperature were maintained at $25^{\circ}C$ and $20^{\circ}C$, respectively.

• Korean Journal of Environment and Ecology
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• 제30권4호
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• pp.651-657
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• 2016

It is important to know know deleterious impact of deicing salt on plants for guidelines of planting along roads. The aim of this study was to determine the effect of calcium chloride ($CaCl_2$) on the growth and physiological characteristics of Liriope platyphylla and Pachysandra terminalis. The plants were grown from November of 2015 to March of 2016 in pots containing growing media with $CaCl_2$ at 0% (Control), 0.5%, 1.0%, 3.0%, and 5.0% (based on the weight). While plant growth and photosynthetic activity were significantly decreased in both plant species grown on the media with $CaCl_2$, the degree of sensitivity to $CaCl_2$ differed. The plant growth of Liriope platyphylla was considerably injured under higher than 3.0% of $CaCl_2$, whereas Pachysandra terminalis was all dead under higher than 1.0% of $CaCl_2$. This results indicate that Liriope platyphylla has higher degree of tolerance to the deicing salt than Pachysandra terminalis.