• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.152-152
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• 2017

Plants exposed to environmental stress for long durations often can adapt to stress conditions with improved tolerance. Moreover this acquired tolerance to stress can be retained even after reverting to destressed growth conditions, which is known to stress memory. In these adaptation and stress memory processes, epigenetic regulation, such as DNA methylation and histone modifications play a key role. Here, we showed that regenerated rice plants from embryogenic callus exposed to gradually increasing NaCl concentrations (up to 120 mM NaCl) acquired salt tolerance and their enhanced tolerance are inherited to subsequent generations. The rice plants (R0) regenerated from rice callus under saline conditions were transplanted into normal paddy field and R1 seeds were harvested. These R1 seeds displayed higher germination rate on MS medium containing 100mM NaCl than wild-type. The callus derived from R1 seeds showed better growth than control callus on high salinity medium. And the salt-adapted R1 plants exhibited higher chlorophyll contents and also higher $K^+/Na^+$ ratio than wild-type rice under saline conditions. The results indicated that rice plants successfully adapted to saline growth conditions during regeneration on high salt medium and moreover this acquired tolerance to salt stress was inherited subsequent generation.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.10a
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• pp.15-20
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• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.22-27
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• 2005

To find out the optimum mixture ratio of ammonium and nitrate on rice plant, 4 rice varieties were examined during 14days after transplanting in hydroponics with the different ratio of ammonium to nitrate(100 : 0, 75: 25,50: 50, 25: 75 and 0: 100). The highest N uptake from solution and the maximum plant dry weight were $60\~70\%$ ammonium and $30\~40\%$ nitrate mixture treatment both in Japonica and Tongil type rice plants. And with the same varieties N-uptake and N use-efficiency were compared between 10.0 mM and 1.0 mM nitrogen using $70\%$ ammonium and $30\%$ nitrate for 24 days after transplanting. Rice plants absorbed more nitrogen$(131\~145\%)$ in 10.0mM than 1.0mM treatment but accumulated N in rice plants were almost the same in both treatment. Among the tested rice cultivars, dry matter production and total accumulative nitrogen in rice plants were much high in Tongil type than japonica type rice cultivars. N-recovery ratios of rice plants from uptake N were $90.8-99.0\%$ in low concentration N solution(1.0 mM), but $69.4-81.7\%$ were observed in high concentration N solution(10.0 mM). It means that suppling low concentration N steadily will be better to prevent loss of N without reducing of growth in rice plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.356-361
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• 2006

The present study was conducted to determine plant growth and physiological responses of corn, barnyardgrass, and soybean to ALA (5-aminolevulinic acid). ALA effect on early seedling growth of test plants was greatly concentration dependant, suggesting that it inhibits at higher concentrations. No significant difference in herbicidal activity of two types of ALA on plant height and weight of test plants was observed. Barnyardgrass was the most sensitive to ALA and followed by corn and soybean, indicating that both crop plants were less affected by ALA concentration as well as different growth stages than barnyardgrass. Greatly reduced chlorophyll contents from leaves of three plant species were observed with increasing of ALA concentration. Compared with untreated controls, higher amounts of three tetrapyrroles were detected from three crop plants, indicating more accumulation in ALA-treated plants. The differential selectivity among plant species would be explained with the differences in tetrapyrrole accumulating capabilities, the susceptibility of various greening groups of plant species to the accumulation of various tetrapyrroles, and their metabolism in various plant tissues. The results indicate that negative biological potential of ALA exhibited differently on plant species, and that the photodynamic herbicidal activity against susceptible plants highly correlated with the extent of tetrapyrrole accumulation by the species.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.5
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• pp.15-41
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• 2017

The purpose of this study is to present the basic data for conservation of forest ecosystem by surveying and analysing the flora distributed in Nakdong-Jeongmaek Mountains, Korea. The numbers of flora were 901 taxa including 116 families, 433 genera, 790 species, 4 subspecies, 90 varieties, 15 forms and 2 hybrids. The threatened species was Pedicularis ishidoyana. The rare plants were 33 taxa including Pseudostellaria sylvatica, Cimicifuga heracleifolia var. bifida, Isopyrum mandshuricum, Paeonia japonica, Syringa patula var. kamibayshii, Lilium distichum, Iris odaesanensis and so forth. The Korean endemic plants were 35 taxa including Salix koriyanagi, Thalictrum actaefolium var. brevistylum, Corydalis maculata, Lespedeza maritima, Cirsium setidens, Carex okamotoi and so forth. The specific plants by floristic region were 155 taxa including 55 taxa of grade I, 41 taxa of grade II, 36 taxa of grade III, 18 taxa of grade IV and 5 taxa of grade V. The naturalized plants were 62 taxa including Rumex obtusifolius, Amaranthus lividus, Medicago sativa, Geranium carolinianum, Malva sylvestris var. mauritiana, Foeniculum vulgare, Sonchus oleraceus, Tradescantia reflexa and so forth. The invasive alien plants were 5 taxa including Rumex acetocella, Solanum carolinense, Ambrosia artemisiifolia, Aster pilosus and Lactuca scariola.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.171-174
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• 2007

Neuronal death is a common characteristic hallmark of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases, whereas oriental medicinal plants have to possess valuable therapeutic potentials to treat neurodegenerative diseases. In the present study, in an attempt to provide neuroprotective agents from natural plants, 80% methanol extracts of a wide range of medicinal plants, which are native to Jeju Island in Korea, were prepared and their protective effects on hydrogen peroxide-induced apoptotic cell death were examined. Among those tested, extracts from Smilax china and Saururus chinesis significantly decreased hydrogen peroxide-induced apoptotic cell death. The extracts attenuated hydrogen peroxide($H_2O_2$)-induced caspase-3 activation in a dose-dependent manner. Further, plant extracts restored $H_2O_2$-induced depletion of intracellular glutathione, a major endogenous antioxidant. The data suggest that Jeju native medicinal plants could potentially be used as therapeutic agents for treating or preventing neurodegenerative diseases in which oxidative stress is implicated.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.346-359
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• 2004

Flora was investigated in the Dongbok stream area of hwasun-gun, Jeonllanam-do from February in 2002 to August, were identified as 206 taxa; 75 families,158 genera,174 species,31 varieties and 1 form of plant. Hydrophytes of research site was investigated total, 29 taxa; 16 families, 23 genera, 26 species and 3 varieties. Emerged plants, submerged plant, floating leaved plants and floating plants among the hydrophytes was classified 22, 4, 2 and 1 taxa respectively. Naturalized plants of research site was investigated total, 19 taxa; 10 families, 17 genera, 17 species, 2 varieties. Based on the list of rare and endangered plants from the Forest Research Institute and the Ministry of Environment 1 species Sparganium stoloniferum were recorded in the studied area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.4
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• pp.37-45
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• 2008

The vascular plants of the studied area in Nonsan economical forest growing site appeared to be 341 taxa; 81 families, 218 genera, 290 species, 1 subspecies, 42 varieties and 9 forms. Based on the list of Korean endemic plants, 5 taxa existed; Cephalotaxus koreana, Thalictrum actaefolium, Asperula lasiantha, Populus tomentiglandulosa (Planted species), Paulownia coreana (Planted species). Specific plant species by floral region were total 13 taxa; Cirsium setidens in class III, Potentilla dickinsii in class II, Cephalotaxus koreana, Pinus koraiensis (Planted species), Hosta capitata, Juglans mandshurica, Alnus hirsuta, Quercus variabilis, Ulmus parvifolia, Dictamnus dasycarpus, Gwenia biloba var. parviflora, Vaccinium oldhami, Trigonotis icumae in class I. The naturalized plants in this site were 9 families, 19 genera, 20 species, 1 varieties, 21 taxa and naturalization rate was 6.1% of all 341 taxa vascular plants. The communities were classified into Quercus acutissima community, Pinus densiflora community, Quercus variabilis community, Platycarya strobilacea community, Quercus aliena community of natural forests and Pinus rigida community, Metasequoia glyptostroboides community, Larix leptolepis community of artificial forests.

• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.1
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• pp.121-134
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• 1994

This study was surveyed the vegetation on the 2∼3 walls at 22 districts in Seoul to get basic data for wall planting in urban environment. The results were as follows: 1. 45 families, 90 genera and 113 species were grown on the walls in Seoul and woody wall plants were 30 species(26.5%) and herbaceous plants were 83 species(73.5%). 2. Of 30 woody species, evergreen species were 7(23.3%) and deciduous species were 23(76.7%). 3. Of 83 herbaceous species, annuals were 43(51.8%), biennials 12(14.5%), and perennials 28(33.7%). 4. Climbing wall plants were 28 species(24.8%). 5. 35 species(31.0%) were planted artificially and 78 species(69.0%) were self-grown plants. 6. Of 138 planted walls, 46 walls were covered with Parthenocissus tricuspidata(33.3%), 11 walls Forsythia koreana(8.0%), 9 walls Pharbitis nil(6.5%), 9 walls Wisteria floribunda(6.5%), and 8 walls Rosa multiflora var. platyphlla(5.8%). 7. In the comparison of native and exotic plants on the walls in Seoul, native species were 84(74.3%) and exotic were 29(25.7%).

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.431-438
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• 2010

Anthers of sweet pepper $F_1$ cultivar 'Special' were cultured on Dumas De Vaulx (C medium), supplemented with $0.1mgL^{-1}$ 2, 4-D and $0.1mg{\cdot}L^{-1}$ kinetin with 3% sucrose, and 0.32% phytagel. The calluses obtained were further sub-cultured on Murashige and Skoog (MS) medium without growth regulators for regeneration. Regenerated plantlets were grown in plastic pots under plastic house and characterized their cytological and morphological characters in spring, 2008. Twenty percent plantlets were identified as haploid plants after chromosome and ploidy analysis. Haploid plants contained 12 chromosomes, high stomatal density with small stomatal length as compared to diploid plants. Stomatal length in haploids was 23.3% smaller than diploids. Haploid plants were characterized as small leaf and petiole size, poor vigor, thin stem and short plant height, short internodes and small flower buds, fruit size and fruit weight as compared to diploid plants and most of the haploid fruits were seedless. SP55, SP62, SP68, SP72 and SP77 are found high yielding double haploids with high total soluble content (8.6, 8.7, 9.2, 9.1 and $9.8^{\circ}Brix$, respectively) and desirable fruit shape, and recommended them to exploit as inbred lines for heterosis breeding.