• The Korean Journal of Ecology
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• v.15 no.1
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• pp.47-58
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• 1992

This study is to investigate the change of the seasonal patterns of relative water relations parameters by the pressure-volume curves in pinus koraiensis needles. The osmotic potentials at full water saturated(Ψ0, sat) and at incipient plasmolysis(Ψ0, tlp) increased in growing season, while decreased in non-growing season. The maximum bulk modulus of elasticity(Emax), relative water content(RWCTLP), and relativefree water content(FWCtlp) at incipient plasmolysis in non-growing season were higher than these of growing season. The maximum pressure potential(Ψp, max) varied from 1.16 to 2.18MPa, torgor index(TI) varied from 3.1 to 4.7. The osmole number(Ns/dw) and symplastic water (Vo/DW) were variable seasonally. The maximum water content(Vt/DW) and apoplastic water(AW) were relatively high in early growing stage, and then decreased to needle aging. The pressure potential(Ψp) and water potential(Ψ) in winter needles were rapidly decreased with decreasing of relative water content. The matric potential occupied over 10 percent of water potential with less than-2.0 MPa.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.943-946
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• 2017

Although the genus Leuconostoc, generally found in various fermented foods, has often been suggested to be a novel probiotic for food fermentation and health promotion, the strains in this genus showed low acid tolerance and low osmotic stress resistance activities, which are required for survival during food fermentation events. Recently, a novel species of Weissella, W. jogaejeotgali $FOL01^T$ (= KCCM 43128 = JCM 30580), was isolated from Korean fermented clams. To determine the genomic features of this new species, its genome was completely sequenced and analyzed. The genome consists of a circular chromosome of 2,114,163 bp of DNA with a G+C content of 38.8%, and the plasmid pFOL01 consists of 35,382 bp of DNA with a G+C content of 39.1%. The genome analysis showed its potential for use in food fermentation and osmotic stress resistance abilities for processing in food industries. In addition, this strain was predicted to have acid tolerance and adhesion to the mucosal layer for survival and colonization in the gut. Subsequent experiments substantiated these abilities, suggesting that W. jogaejeotgali may have probiotic potential and a high survival rate during food fermentation. Therefore, it may be suitable as a novel probiotic strain for various applications in food industries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.516-526
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• 2003

Thirty-six barley varieties including Korean modern and local varieties were tested for drought-tolerance in the field of plastic rain shelter, Drought treatment was initiated at initial tillering stage (March 27, 2002) by withholding irrigation and lasted until harvest. Soil water potential maintained at around -0.05㎫ in the control plot and varied from -0.05㎫ (at the initial stage of drought treatment) to -0.29㎫ in the drought treatment plot. At forty days after drought treatment, relative water content (RWC), osmotic potential (OP), osmotic adjustment (OA), and $^{13}\textrm{C}$ discrimination ($\Delta$) were measured and then plants were sampled for leaf area index (LAI) and dry weight (DW). Barley was harvested at maturity for determining DW, grain yield, 1000 grains weight and number of spikelet. The tested varieties revealed wide spectrum of drought tolerance. Dongbori-1, Chalbori, Changyeongjaerae, Samdobori and Weolseong 87-31 showed strong drought-tolerance while Songhagbori and Suwonmaeg360 showed weak drought-tolerance. The drought injury indexes (drought/control ratio) of DW and yield revealed significant positive correlation with leaf RWC in drought treatment plot and $\Delta$ in the control plot, but obvious negative correlation with leaf OP and OA under drought condition. In addition, all the drought indexes of OP, $\Delta$ and RWC showed obvious positive correlation with the drought injury indexes of DW, 1000 grain weight and yield. Thus, OP and RWC under drought condition and $\Delta$ under well-watered condition would be used as the evaluation criteria for drought- tolerance of barley genotypes. However, further investigation is needed for the relationship between $\Delta$ and drought-tolerance as the other reports were not consistent with our result.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.205-210
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• 1991

The freezing resistance of Eleocharis kuroguqai was evaluated in artifical and natural freezing conditions in relation to tuber size, depth of tuber burial and soil moisture conditions. Osmotic potential of immature and mature tuber of E. kuroguqai before hardening was -12.1 and -23.5 bar, respectively, but decreased to -61. 0 and -67.1 bar after 120-day hardening period. Percent survival of E. kuroguqai tubers during the winter period was 13% and 67% in dry and moist moisture conditions at burial of 5cm depth, but all tubers were survived in the three moisture conditions employed when buried at 25cm depth. Greater decrease of osmotic potential was observed in tubers buried at 5cm depth than tubers buried at 25cm depth, resulting in greater freezing resistance in the former. Large tuber was more susceptable to freezing temperatures than small tuber.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.95-103
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• 2018

Recently, many types of constructional steels have been often exposed to under severe corrosive environments due to acid rain with increasing environmental contamination. In order to inhibit their corrosion in severe corrosive environments, a painting method has been widely applied to numerous constructional steels of land as well as marine. Therefore, development of paint having a good quality of corrosion resistance is considered to be very important. In this study, four types of anti-corrosive paints (AP: Phenol epoxy, AC: Ceramic epoxy, AT: Coal tar epoxy, AH: High solid epoxy) were coated to the specimens, and then, were immerged in various salt solutions (0.1, 0.3, 3, 6, 9 and 15% NaCl solutions) for 11 days. And, the corrosion resistance of these samples by effect of osmotic pressure with salt concentration was investigated with electrochemical methods such as measurement of corrosion potential, impedance and corrosion current density. The corrosion current densities of all samples (AC, AT and AH) submerged in 3% NaCl solution exhibited the smallest values compared to other salt solutions. However, in the case of lower values of salt solutions than 3% NaCl solution, the corrosion current density increased again because it makes easier for water, dissolved oxygen and chloride ion etc. to invade toward inner side of coating film due to increasing of the osmotic pressure than 3% NaCl solution, but in the case of higher values of salt solutions than 3% NaCl solution, the coating film is easily deteriorated due to high concentration of chloride ion rather than the osmotic pressure, which resulted in increasing the corrosion current density. In particular, the AC sample indicated the best corrosion resistance in 6% NaCl solution compared to other samples. Consequently, it is considered that the corrosion mechanism of the coated steel plate is completely different from bare steel plate, and the corrosion resistance of coating film by osmotic pressure and chloride ion depend on various types of epoxy of paint in NaCl solution.

• The Korean Journal of Ecology
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• v.21 no.4
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• pp.321-328
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• 1998

To describe the major environmental factors operating in coastal wetland and to characterize the distribution of the plant species over the wetland in relation to the major environmental gradients, 12 soil physical and chemical properties were determined. The gradient of water and osmotic potential of soil, electrical conductivity, sodium and chloride content and soil texture alsong the three habitat types of salt marshes, salt swamp and sand dune were occurred. The 24 coastal plant communities from principal component analysis (PCA) on the 12 variables were at designated as a gradient for soil texture and water potential related with salinity by Axis I and as a gradient for soil moisture and total nitrogen gradient by Axis II On Axis I were divided into 3 groups (1) 9 salt marsh communities including Salicornia herbacea communities (2) 5 salt swamp communities including Scirpus fluviatilis communities and (3) 10 sand dune communities including Jmperata cylindrica communities on Axis II were divided into 2 groups (1) salt marsh and sand dune communities, and (2) 3 salt swamp communities. The results could account for the zonation of plant communities on coastal wetland observed alsong envionmental gradients.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.231-235
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• 2005

Comparative water relations of Quercus acuta and Castanopsis cuspidata var, sieboldii were analyzed to assess their resistance to drought and low temperature stresses from early November to early December, As air temperature decreased both species showed an increased content of osmotically active solute concentration per unit of dry weight (NS/DW), leading to lower osmotic potential of both species at both full turgid state $(OP_{sat})$ and turgor loss point $(OP_{tlp})$ in December than November. No major difference in the ability to adjust osmotically was noticed between the two. This finding suggests that both species must respond adaptively under water and low temperature stresses to maintain turgor pressure in winter season. In addition to osmotic adjustment, a low bulk modulus of elasticity $(E_{max})$ shown in Castanopsis cuspidata var. sieboldii must also play an important role in turgor maintenance during winter season being apt to happen water and low temperature stresses in plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.150-150
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• 2017

Plants suffer from various abiotic stresses among them; soil salinity is one of major adverse factor in declining agricultural productivity. So, development of salt stress tolerance crops have potential role to increase crop production. The RING finger proteins are known to play crucial roles in abiotic stress environment to plants. In this study, we identified one Salt-responsive Really${\underline{I}nteresting}$ ${\underline{n}ew}$ ${\underline{g}ene}$ (RING) E3 ubiquitin ligase gene OsSIRF1 from rice root tissues during salt stress and studied its molecular function. Expression of OsSIRF1 was induced under various abiotic stress conditions, including salt, heat, drought, and ABA. Result of an in vitro ubiquitination assay clearly showed that OsSIRF1 Possess an E3 ligase activity. Moreover, OsSIRF1 was found to be localized to the nucleus within the cell. Heterogeneous overexpression of OsSIRF1 in Arabidopsis improved seed germination and increased root length under salt and Manitol stress conditions. Taking together, these results suggested that OsSIRF1 may be associated with plant responses to abiotic stressors and positively regulates salt and osmotic stress environment.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.1-11
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• 1998

The generally accepted idea for carbohydrate translocation in plants is an osmotic pressure flow hypothesis. According to the hypothesis, a high concentration of carbohydrate in the phloem of carbohydrate synthesis regions (source) causes a water influx into the phloem. The generated osmotic potential in the phloem is responsible for long distance carbohydrate transport through the positive hydrostatic pressure. In regions of carbohydrate utilization and storage (sink), translocated carbohydrates are continuously metabolized and compartmentalized, generating a concentration gradient between source and sinks. In this system, carbohydrates load into the phloem (phloem loading) and unload out of the phloem (phloem unloading). Phloem-mobile herbicides that are applied to plants are also translocated from the source to sinks. However, some experimental results reveal that the patterns of phloem translocation between carbohydrates and herbicides are different. The differences are due, in part, to the physico-chemical properties of herbicides and to the absence/presence of specific carrier(s) in the phloem.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.50-54
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• 2000

The elongation of mesocotyl and coleoptile plays important roles in the seedling emergence and stand establishment of dry direct-seeded rice. Experiments were carried out to elucidate the effects of seed-presoaking treatments of GA$_3$ and some inorganic salts on the mesocotyl, and coleoptile elongation of rice. Seed-soaked GA$_3$ promoted the elongation of mesocotyl, but little effect on the coleoptile elongation. The stimulation effects of GA$_3$ were found to be enhanced by addition of CaCl$_2$ However, the sole treatment of CaCl$_2$ showed no stimulating effect on the mesocotyl and coleoptile elongation. Mesocotyl elongation was most prominent in the combined treatments of 50ppm GA$_3$ with 100 mM CaCl$_2$. The synergistic effects of GA$_3$ and CaCl$_2$ on mesocotyl elongation varied with varietal groups. The stimulating effects of GA$_3$ were enhanced significantly by the addition of CaCl$_2$ in japonica varieties, Dongjinbyeo, Ilpumbyeo and Milyang 95, and tall indica variety, Labelle, but not in semidwarf Tongil type varieties, Tongilbyeo, Milyang 23, and Nampungbyeo, and semi-dwarf indica, Short Labelle. The promoting effects of GA$_3$ on the mesocotyl elongation were decreased in proportion to the lowered osmotic potential by PEG 6000 on the contrary to CaCl$_2$ This implies that the synergistic effects of CaCl$_2$ with GA$_3$ on mesocotyl elongation was not caused by osmotic potential lowered by CaCl$_2$ addition but by the salt itself. Salts such as Ca(NO$_3$)$_2$, MgCl$_2$ BaCl$_2$, NaCl, KCl and KNO$_3$ showed the synergistic effects with GA$_3$ on mesocotyl elongation as well. The degree of synergistic effects showed no differences among salts tested, implying that there is no specificity of ions constituting the salts.