• Journal of Plant Biotechnology
• /
• v.31 no.4
• /
• pp.273-278
• /
• 2004

Complementary DNA encoding chloroplast outer envelope membrane protein (OEP) from the halophyte Salicornia herbacea has been cloned and sequenced. The full length cDNA is 596 bp and encodes a polypeptide of 91 amino acid residues with a molecular mass of 8.9 kDa. The expression level of ShOEP increased by salt, drought and ABA treatments. ShOEP expression was largely induced in roots and shoots by high salts. The biological function of ShOEP was examined by yeast complementation. ShOEP can suppress Na$^{+}$ sensitivity of yeast mutant (cnb$\Delta$) in the presence of salt. These results suggest that ShOEP is a salt inducible gene and may have functions in the regulation of plant salt stress.ant salt stress.

• Molecules and Cells
• /
• v.37 no.2
• /
• pp.109-117
• /
• 2014

Microbiota in the niches of the rhizosphere zones can affect plant growth and responses to environmental stress conditions via mutualistic interactions with host plants. Specifically, some beneficial bacteria, collectively referred to as Plant Growth Promoting Rhizobacteria (PGPRs), increase plant biomass and innate immunity potential. Here, we report that Enterobacter sp. EJ01, a bacterium isolated from sea china pink (Dianthus japonicus thunb) in reclaimed land of Gyehwa-do in Korea, improved the vegetative growth and alleviated salt stress in tomato and Arabidopsis. EJ01 was capable of producing 1-aminocy-clopropane-1-carboxylate (ACC) deaminase and also exhibited indole-3-acetic acid (IAA) production. The isolate EJ01 conferred increases in fresh weight, dry weight, and plant height of tomato and Arabidopsis under both normal and high salinity conditions. At the molecular level, short-term treatment with EJ01 increased the expression of salt stress responsive genes such as DREB2b, RD29A, RD29B, and RAB18 in Arabidopsis. The expression of proline biosynthetic genes (i.e. P5CS1 and P5CS2) and of genes related to priming processes (i.e. MPK3 and MPK6) were also up-regulated. In addition, reactive oxygen species scavenging activities were enhanced in tomatoes treated with EJ01 in stressed conditions. GFP-tagged EJ01 displayed colonization in the rhizosphere and endosphere in the roots of Arabidopsis. In conclusion, the newly isolated Enterobacter sp. EJ01 is a likely PGPR and alleviates salt stress in host plants through multiple mechanisms, including the rapid up-regulation of conserved plant salt stress responsive signaling pathways.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.189-189
• /
• 2017

Salinity is one of the major abiotic stresses that severely affect crop production throughout the world; especially rice plant which is generally categorized as a typical glycophyte as it cannot grow in the presence of salinity. Phenotypic resistance of salinity is expressed as the ability to survive and grow in a salinity condition. Salinity resistance has, at least implicitly, been treated as a single trait. Physiological studies of rice suggest that a range of characteristics (such as low shoot sodium concentration, compartmentation of salt in older rather than younger leaves, high potassium concentration, high $K^+/Na^+$ ratio, high biomass and plant vigour) would increase the ability of the plant to cope with salinity. Criteria for evaluating and screening salinity tolerance in crop plants vary depending on the level and duration of salt stress and the plant developmental stage. Plant growth responses to salinity vary with plant life cycle; critical stages sensitive to salinity are germination, seedling establishment and flowering. We have established a standard protocol to evaluate large rice germplasms for overall performance based on specific physiological traits for salt tolerance at seedling stage. This protocol will help in identifying germplasms which can perform better in the presence of different salinity treatments based on single trait and also combination of different physiological traits. The salt tolerant germplasm can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.2 no.3
• /
• pp.211-217
• /
• 2004

A Li recovery technology has been developed and related experimental verification efforts were carried out to improve the economical viability and environmental friendliness of the 'Advanced Spent Fuel Conditioning Process' being developed at KAERI. This technology is characterized by the combination of 1) the electrolysis of $Li_2O$ in a molten salt by using a porous non-conducting magnesia container at the cathode, 2) the separation of the Li in the container from the molten salt by elevating the container above the level of a molten salt, 3) the transport of the Li in the container by using a vacuum siphon to a separated reservoir. Li was semi-continuously recovered from a LiCl-$Li_2O$ molten salt with a more than 95% yield by using the developed technology.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.22 no.1
• /
• pp.162-170
• /
• 2008

Kamisungihwalhyul-tang(KSHT) has been used for many years as a therapeutic agent for cerebrovascular disease and hypertension in Oriental Medicine. But the effect of KSHT on hypertension and reactive oxygen is not well-known. This study was examined to investigate the effect of KSHT on hypertension and reactive oxygen. After administering KSHT extract to Sprague- Dawley Rat forinjected subcutaneous with deoxycorticosterone acetate(DOCA) 8 weeks, changes in blood pressure, pulse rate, 2,2-diphenyl-1-picrylhydrazyl, reactive oxygen species, angiotensin converting enzyme, aldosterone, catecholamine levels, electrolyte, uric acid, BUN, creatinine in plasma were examined, and immunohistochemical changes and scanning electron microscopic changes were observed. 2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging activity was increased, reactive oxygen species(ROS) was decreased in a KSHT concentration-dependent. Angiotensin converting enzyme(ACE) inhibitory activity was increased in a concentration-dependent by KSHT. KSHT significantly decreased the blood pressure and heart rate in DOCA-salt hypertensive rat. KSHT significantly decreased the levels of aldosterone in DOCA-salt hypertensive rat. KSHT significantly decreased the level of dopamine, norepinephrine, epinephrine in DOCA-salt hypertensive rat. $Na^+$, $K^+$ and Cl- were decreased significantly, $Ca^{2+}$ was increased significantly by KSHT. KSHT significantly decreased uric acid, BUN, creatinine.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.30 no.4
• /
• pp.85-93
• /
• 1988

This laboratory study was carried out in order to produce fundamental data for analyzing salt movement and desalinization effects, using samples of silt loam soil collected in Gyehwado and Daeho reclaimed tidelans, and samples of silty clay loam soil collected in Kimie tideland. Desalinization experiments with gypsum treatment were performed to analyze changes of the hydraulicc conductivity with changes of the soil property and the salt concentration during the desalinization of reclaimed tideland soils by leaching through the subsufface drainage, and correlations between factors infl uencing the reclamation of salt affected soils were analyzed by the statistical method. The results were summarized as follows: 1. The reclaimed tideland soils used in this study were saline-sodic soils with the high exchangeable sodium percentage and the high electrical conductivity. 2. Changes of the hydraulic conductivity with the amount of leaching water and the leaching time elapsed were affected by the amount of gypsum except exchangeable sodium and clay contents. The regression equation between the depth of water leached per unit depth of soil (Dw / Ds : X) or the square root of the leaching time elapsed (T $^1$ $^2$ : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a . bx. 3. The more exchangeable sodium and clay contents regardless of the amount of gypsum, the more the leaching time was required until a given volume of water was leached through the soil profile. The regression analysis showed that the relationship between the depth of water leached per unit depth of soil(Dw /Ds:X) and the square root of the leaching time elapsed(T$^1$$^2$ :Y) could be described by Y=a . Xb. 4. The hydraulic conductivity was influenced to a major degree by the salt concentration provided that the electrical conductivity was below 10 mmhos / cm during the desalinization of reclaimed tideland soils. The regression equation between the relative electrical conductivity ( ECr : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a + b . X-$^1$. 5. In conclusion, the hydraulic conductivity, leaching requirements and the leaching time elapsed can be estimated when the salt concentration decreases to a certain level during the desalinization of reclaimed tidelands, and the results may be applied to the analysis of salt movement and desalinization effects.

• Asian Journal of Turfgrass Science
• /
• v.2 no.1
• /
• pp.5-30
• /
• 1988

The object of this experiments was to know the salt tolerance of Fults and other lawn grasses. Fults, Olympic (Tall fescue, Festuca arundinacea Schred), Ceeping red fescue, Kentucky bluegrass and Zoysia grass (Z. japonica S.) were grown in hydroponics with vermiculite at various concentrations of NaCl. Hoagland's solution was used as the basic solution (control), and the concentrations of Cl to it were 1000, 2000, 3000, 4000 and l5OOOppm, respectively. Each was cultivated under the circumstances during 2 months. The results obtained are summarized as follows: 1.The growth of Fults, Olympic, Creeping red fescue and others were better at Cl lOOOppm than control. In the 5OOOppm application, Fescues become worse and 23.9% of them were withered. In concentration of Cl above 9OOOppm, it was impossible to live. 2.In the l0000~l1000ppm application, Olympic and Kentucky bluegrass were become worse and most of them died. 3.Fults were almost possible to live in the below of 9OOOppm, but they began to die in the above of 10000 ppm. 4.With the increasing concentration of Cl, plants were dwarfed and the number of stems, leaves and roots were reduced, but it was especially observed that the number of stolons of Creeping red fescue were increased at 1000~4000ppm. 5.Fults grass was the most salt tolerant turfgrass, but was impossible to live at salt level of about 36 millimhos (Exchange NaCI conductivity-ppm). Among the grasses, according to salt tolerance, they were arranged as follows. Fults > Zoysia japonica S. > Ky belugrass > Olympic grass > Creeping red fescue 6.The number of leaves, stems, tillers, and dry weight of Olympic grass, Fults and others were increased more at Cl 1OOOppm application than control, but in the above 4OOOppm application, those of plants were decreased. 7.The productivity of all grasses under the experiments was increased at 3.l75millimhos (Exchange NaCi conductivity ppm) in the concentration of Cl. The each dry-weight of Olympic, Creeping red fescue, Kentucky bluegrass and Zoysia grass was decreased at 8.85millimhos, and the weight of Fults grass was also decreased remarkably at 12.20millimhos. 8.As the result of this experiments, most plants grow normally at low concentration of NaCI-l000ppm. That seems to stimulate more the grasses to grow than non-salt.

• Molecules and Cells
• /
• v.39 no.6
• /
• pp.447-459
• /
• 2016

Many studies have been conducted to understand plant stress responses to salinity because irrigation-dependent salt accumulation compromises crop productivity and also to understand the mechanism through which some plants thrive under saline conditions. As mechanistic understanding has increased during the last decades, discovery-oriented approaches have begun to identify genetic determinants of salt tolerance. In addition to osmolytes, osmoprotectants, radical detoxification, ion transport systems, and changes in hormone levels and hormone-guided communications, the Salt Overly Sensitive (SOS) pathway has emerged to be a major defense mechanism. However, the mechanism by which the components of the SOS pathway are integrated to ultimately orchestrate plant-wide tolerance to salinity stress remains unclear. A higher-level control mechanism has recently emerged as a result of recognizing the involvement of GIGANTEA (GI), a protein involved in maintaining the plant circadian clock and control switch in flowering. The loss of GI function confers high tolerance to salt stress via its interaction with the components of the SOS pathway. The mechanism underlying this observation indicates the association between GI and the SOS pathway and thus, given the key influence of the circadian clock and the pathway on photoperiodic flowering, the association between GI and SOS can regulate growth and stress tolerance. In this review, we will analyze the components of the SOS pathways, with emphasis on the integration of components recognized as hallmarks of a halophytic lifestyle.

• Journal of Plant Biotechnology
• /
• v.41 no.1
• /
• pp.26-32
• /
• 2014

Recent genome annotation revealed that Populus trichocarpa contains 81 glutathione S-transferase (GST) genes. GST genes play important and varying roles in plants, including conferring tolerance to various abiotic stresses. Little information is available on the relationship - if any - between drought/salt stresses and GSTs in woody plants. In this study, we screened the PatgGST genes in hybrid poplar (Populus alba ${\times}$ Populus tremula var. glandulosa) that were predicted to confer drought tolerance based on our expression analysis of all members of the poplar GST superfamily following exposure to salt (NaCl) and drought (PEG) stresses, respectively. Exposure to the salt stress resulted in the induction of eight PatgGST genes and down-regulation of one PatgGST gene, and the level of induction/repression was different in leaf and stem tissues. In contrast, 16 PatgGST genes were induced following exposure to the drought (PEG) stress, and two were down-regulated. Taken together, we identified seven PatgGSTs (PatgGSTU15, PatgGSTU18, PatgGSTU22, PatgGSTU27, PatgGSTU46, PatgGSTU51 and PatgGSTU52) as putative drought tolerance genes based on their induction by both salt and drought stresses.

• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.264-276
• /
• 2021

Background: Salt marshes provide a variety of ecosystem services; however, they are vulnerable to human activity, water level fluctuations, and climate change. Analyses of the relationships between plant communities and environmental conditions in salt marshes are expected to provide useful information for the prediction of changes during climate change. In this study, relationships between the current vegetation structure and environmental factors were evaluated in the tidal flat at the southern tip of Ganghwa, Korea, where salt marshes are well-developed. Results: The vegetation structure in Ganghwa salt marshes was divided into three groups by cluster analysis: group A, dominated by Phragmites communis; group B, dominated by Suaeda japonica; and group C, dominated by other taxa. As determined by PERMANOVA, the groups showed significant differences with respect to altitude, soil moisture, soil organic matter, salinity, sand, clay, and silt ratios. A canonical correspondence analysis based on the percent cover of each species in the quadrats showed that the proportion of sand increased as the altitude increased and S. japonica appeared in soil with a relatively high silt proportion, while P. communis was distributed in soil with low salinity. Conclusions: The distributions of three halophyte groups differed depending on the altitude, soil moisture, salinity, and soil organic matter, sand, silt, and clay contents. Pioneer species, such as S. japonica, appeared in soil with a relatively high silt content. The P. communis community survived under a wider range of soil textures than previously reported in the literature; the species was distributed in soils with relatively low salinity, with a range expansion toward the sea in areas with freshwater influx. The observed spatial distribution patterns may provide a basis for conservation under declining salt marshes.