• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.66-80
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• 1989

Salt injury in rice is caused mainly by the salinity in soil and in the irrigated water, and occasionaly by salinity delivered through typhoon from the sea. The salt concentration of rice plants increased with higher salinity in the soil of the rice growing. The climatic conditions, high temperature and solar radiation and dry conditions promote the salt absorption of rice plant in saline soil. The higher salt accumulation in the rice plant generally reduces the root activity and inhibits the absorption of minerals of rice plant, resulting the reduction of photosynthesis. The salt damages of rice plant, however, are different from different growth stage of rice plants as follows: 1. Germination of rice seed was slightly delayed up to 1.0％ of salt concentration and remarkably at 1. 5％, but none of rice seeds were germinated at 2.5％. This may be due to the delayed water uptake of rice seeds and the inhibition of enzyme activity, 2. It was enable to establish rice seedlings at seed bed by 0.2％ of salt concentration with some reduction of leaf elongation. The increasing of 0.3％ salt concentration caused to the seedling death with varietal differences, but most of seedlings were death at 0.4％ with no varietal differences. 3. Seedlings grown at the nursery over 0.1％ salt, gradually reduced in rooting activity after transplanting according to increasing the salt concentration from 0.1％ up to 0.3％ of paddy field. However, the seedlings grown in normal seed bed showed no difference in rooting between varieties up to 0.1％ but significantly different at 0.3％ between varieties, but greatly reduced at 0.5％ and died at last in paddy after transplanting. 4. At panicle initiation stage, rice plant delayed in heading by salt damage, at meiotic stage reduced in grains and its filling rate due to inhibition of glume and pollen developing, and salt damage at heading stage and till 3 weeks after heading caused to reduction of fertilization and ripening rate. In viewpoint of agricultural policy the overcoming strategy for salt injury is to secure sufficient water source. Irrigation and drainage systems as well as underground drainage is necessary to desalinize more effectively. This must be the most effective and positive way except cost. By cultural practice, growing the salt tolerant variety with high population could increase yield. The intermittent irrigation and fresh water flooding especially at transplanting and from panicle initiation to heading stage, the most sensitive to salt injury, is important to reduce the salt content in saline soil. During the off-cropping season, plough and rotavation with flooding followed by drainage, or submersion and drainage with groove could improve the desalinization. Increase of nitrogen fertilizer with more split application, and soil improvement by lime, organic matter and forign soil addition, could increase the rice yield. Shift of trans-planting is one of the way to escape from the salt injury.

• Molecules and Cells
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• v.41 no.5
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.125-131
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• 2017

Nine strains of high concentrations of salt-tolerant bacteria were isolated from the rhizosphere and rhizoplane of the halophyte plant Suaeda japonica grown in Gochang Buan tidal flat. The isolated bacteria were classified as genera Vibrio (strains JRS-1, -2, -3, -4, and -5, and JRL-1 and -4) and Bacillus (strains JRL-2 and -3) based on the 16S rRNA gene sequence similarity. The optical growth condition for salt concentration was examined on the selected, representative strains. Strain JRS-1 with the closest relative of Vibrio neocaledonicus showed the highest growth rate at the total salt concentration of 6% among the incubation conditions of 3-8% salt concentrations. Strain JRL-2 with the closest relative of Bacillus thuringiensis showed the tendency that growth rate increased with increasing salt concentrations and the maximum growth rate at 7% of the total salt concentration. The isolated bacteria showed salt-resistances to higher salt concentrations than their habitat soils with 3%. In addition, we identified evidences of potentially plant interaction-relevant enzymatic activities, from utilization of some substrates rich in plants, such as triglyceride, ${\rho}$-nitrophenyl-${\alpha}$,$\text\tiny{D}$-glucoside, and ${\rho}$-nitrophenyl-${\beta}$,$\text\tiny{D}$-glucoside.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.24-47
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• 1998

This study examined ecophysiological characteristics, cultivation methods and planting uses of tree and shrub species native to Kangwon province and valuable as landscape plants. The results were as followos : 1. 73 species selected as shrubs were ; Rhododendron brachycarpum, Rhododendron micranthum, Abelia mosanensis, Abeliophyllum distichum, Acanthopanax sessiliflorus, Acanthopanax senticosus, Alangium platanifolium var. macrophyllum etc. 2. 38 species selected as trees were ; Cornus controversa, Sorbus commixta, Malus baccata, Prunus padus, Acer triflorum, Acer tegmentosum, Styrax japonica, Styrax obassia, Sorbus alnifolia etc. 3. Shade-tolerant species were ; Abies koreana, Rhododendron brachycarpum, Rhododendron micranthum, Prunus padus, Sorbus commixta, Acer triflorum, Rhus japonica, Cornus kousa, Kalopanax pictus, Chionanthus retusa, Sorbus alnifolia, Magnolia sieboldii, Sorbaria sorbifolia var. stellipila, Berberis koreana, Lindera obtusiloba, Rhododendron schlippenbachii and Euonymus alatus. 4. Species growing well even in less fertile soils were ; Pinus thunbergii, Quercus dentata, Koelreuteria paniculata, Rhus japonica, Quercus acutissima, Albizzia julibrissin, Sorbus alnifolia, Staphylea bumalda, Philadelphus schrenckii, Clerodendron trichotomum, Deutzia coreana, Weigela florida, Zanthoxylum schinifolium and Lindera obtusiloba. 5. Salt-tolerant species were ; Pinus thunbergii, Quercus aliena, Prunus padus, Styrax japonica, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Albizzia julibrissin, Tilia amurensis, Forsythia koreana, Lonicera maackii, Symplocos chinensis for. pilosa, Clerodendron trichotomum, Sambucus williamsii var. coreana, Abelia mosanensis, Deutzia coreana, Viburnum carlesii, Rhus japonica, Rhododendron yedoense var. poukhanense, Zanthoxylum schinifolium, Callicarpa dichotoma, Rhododendron schlippenbachii and Euonymus alatus. 6. Pollutant-tolerant species were ; Styrax japonica, Prunus padus, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Gleditsia japonica var. koraiensis, Styrax obassia, Forsythia koreana, Kpiraea salicifolia, Clerodendron trichotomum, Viburnum sargentii, Viburnum carlesii, Weigela florida and Rhododendron yedoense var. poukhanense.

• Journal of People, Plants, and Environment
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• v.23 no.4
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• pp.445-453
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• 2020

Background and objective: Calcium chloride (CaCl₂) and sodium chloride (NaCl) are commonly used as a deicing agent in South Korea and penetrate the soil on the roadside, causing damage to plants. This study was conducted to investigate the salinity reduction effect of Pennisetum alopecuroides and the chemical characteristics of soil leachate. Methods: The plants were treated with five different concentrations of CaCl₂ (0, 1, 2, 5, and 10g·L^-1) and were grouped into the Cont., C1, C2, C5, and C10 groups. CaCl₂ of 200 m·L^-1 was sprayed to each plant once every two weeks. The growth of P. alopecuroides (plant height, leaf length, leaf width and the number of leaves) was measured. The level of EC and pH, and exchangeable cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) in the leachate of soil was monitored. Results: The pH of soil leachate decreased as the CaCl₂ concentration increased, and the EC increased significantly. The content of K⁺ did not change significantly until the concentration of CaCl₂ reached 5 g·L^-1, but the content of Ca²⁺, Na⁺, and Mg²⁺ significantly increased. The plant height, leaf length, and leaf width of P. alopecuroides showed the highest value in CaCl₂ 1 g·L^-1 followed by CaCl₂ 2 g·L^-1 and the control group. Root fresh weight was the highest in CaCl₂ 2 g·L^-1. On the other hand, there was no change in the shoot fresh weight, dry weight and root dry weight, and P. alopecuroides growth inhibition at the concentration of 5 g·L^-1 or higher in the plant height and leaf length. Conclusion: P. alopecuroides is relatively highly salt-tolerant and can improve the salt damaged soil by lowering the content of the salt-based exchangeable K⁺ ions.

• BMB Reports
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• v.41 no.5
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• pp.382-387
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• 2008

It is known that the stable protein 1 (SP1) detected in aspen plants remains soluble upon boiling and that sp1 expression in transgenic aspen is resistant to salt stress. Presently, we analyzed the effect of expression of SP1 in Arabidopsis thaliana plants and their response to high temperature stress. After $45^{\circ}C$ for 16 h, relative to wild type plants, sp1 transgenic plants exhibited stronger growth and were better in several physiological properties including chlorophyII, chlorophyII fluorescence, water content, proline content, and malondialdehyde content. These preliminarily results suggest that the over-expression of SP1 may notably enhance heat-tolerant level of transgenic A. thaliana plants.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.353-365
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• 2011

The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the $H_2O_2$ and lipid peroxidation levels. Exogenous NO pretreatment of the seedlings had little influence on the nonenzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.

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

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.4
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• pp.242-249
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• 2021

Forage crop management is severely challenged by global warming-induced climate changes representing diverse a/biotic stresses. Thus, screening of valuable genetic resources would be applied to develop stress-tolerant forage crops. We isolated two NAC (NAM, ATAF1, ATAF2, CUC2) transcription factors (ANAC032 and ANAC083) transcriptionally activated by multi-abiotic stresses (salt, drought, and cold stresses) from Arabidopsis by microarray analysis. The NAC family is one of the most prominent transcription factor families in plants and functions in various biological processes. The enhanced expressions of two ANACs by multi-abiotic stresses were validated by quantitative RT-PCR analysis. We also confirmed that both ANACs were localized in the nucleus, suggesting that ANAC032 and ANAC083 act as transcription factors to regulate the expression of downstream target genes. Promoter activities of ANAC032 and ANAC083 through histochemical GUS staining again suggested that various abiotic stresses strongly drive both ANACs expressions. Our data suggest that ANAC032 and ANAC083 would be valuable genetic candidates for breeding multi-abiotic stress-tolerant forage crops via the genetic modification of a single gene.