• Journal of Environmental Science International
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• v.29 no.6
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• pp.579-603
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• 2020

In order to provide fundamental information about the floristic composition of the area along with an assessment of the environmental impact, a floristic study of the vascular plants in the Tamjin River estuary in Gangjin-gun was conducted for a total of nine days, in the period from June 2014 to September 2014. We found that the vascular plants in this region comprised 424 taxa belong to 102 families, 281 genera, 390 species, 5 subspecies, 26 varieties, and 3 forma. Five taxa of Korean endemic plants including Weigela subsessilis (Nakai) L.H.Bailey, Lespedeza maximowiczii var. tricolor (Nakai) Nakai, and Clematis trichotoma Nakai were collected. Two least concern (LC) taxa of rare plants (as designated by the Korea Forest Service) were collected: Hydrocharis dubia (Blume) Backer and Platycladus orientalis (L.) Franco. Ten the floristic regional indicator taxa from the third to the fifth grade were identified: two taxa belonged to grade IV, and eight taxa belonged to grade III. Twenty-four taxa of salt-tolerant plants, including Artemisia fukudo Makino, Carex rugulosa Kuk., and Suaeda glauca (Bunge) Bunge, as well as 44 taxa of aquatic plants, including Najas marina L., Nuphar oguraensis Miki, and Nymphoides indica (L.) Kuntze, were investigated in this region. Fifty-nine taxa of naturalized plants were recorded, among which the following six taxa were plants that caused ecosystem disturbance: Ambrosia artemisiifolia L., Humulus scandens (Lour.) Merr., Lactuca scariola L., Rumex acetosella L., Solidago altissima L., and Symphyotrichum pilosum (Willd.) G.L.Nesom.

• Current Research on Agriculture and Life Sciences
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• v.21
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• pp.1-9
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• 2003

Plants are often subjected to periods of soil and atmospheric water deficit during their life cycle. To find critical levels for identification of tolerant rice variety to salt- and drought-stresses, we investigated the water deficiency in the leaf of a Dongjinbyeo (DJ) cultivar, identified as intolerant variety, subjected to NaCl- and Polyethylene glycol 6000 (PEG)- treatments. The relative water content and water potential in leaf of DJ plant sharply declined along the high concentration and time after treatment in NaCl- and PEG-treated rice plants. To elucidate the method of simple screening of tolerant variety to salt- and drought-stresses, we examined the relationship between relative water content and water potential of leaves in NaCl- and PEG-treated rice plants. The relationship between relative water content and water potential in leaf of DJ plant showed the highest correlation in 80 mM NaCl-treatment, and showed high correlation only 8% PEG treatment. These results indicate that the critical level of salt stress for screening of tolerant rice was 80 mM NaCl at 48 h after NaCl treatment, and the critical concentration of drought stress for screening of tolerant rice was 8% PEG at 96 h after PEG treatment.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.1-8
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• 2011

Recently the increasing of vinyl and green houses and development of reclaimed land including Saemangeum induced the need for breeding salt-tolerant crops which can survive and grow in high salinity soil. So we try to develop salt-tolerant transgenic chrysanthemum (Dendranthema grandiflorum.) lines by using anti-porter gene TANHX and HVNHX. Through marker selection and plant regeneration step, we could get 284 putative transgenic chrysanthemum lines. On selected putative transgenic plants, 40 candidates were used for genetic analysis and 30 lines could be made up of target size band on PCR, so about 75% of marker selected lines were decided as real transgenic lines. Selected 284 transgenic lines were also used for salt-tolerance test as a range of NaCl 0.2 ~ 1.2% (300 mM). As a result of salt-tolerance test, 15 selected transgenic lines could live and grow on the continuous supply of 0.8% (200 mM) NaCl solution and another 7 lines were could survive under 1.2% (300 mM) NaCl solution. This salt-tolerant transgenic lines under salt stress also lead a cell alternation especially a guard cell. A stressed guard cell be swelled and grow larger in proportion to NaCl concentration. TTC test for cell viability on transgenic chrysanthemum lines pointed out that more strong salt-tolerant lines can be live more than another under same salt stress. The numerical value of strong salt-tolerant 7 transgenic lines were 0.206 ~ 0.331 under 1.2% NaCl stress, and then it's value is more larger than middle salinity lines' 0.114 ~ 0.193 and non-transgenic's 0.046. And the proline contents as indicated stress compound also pointed out that HVNHX introduced salt-tolerant transgenic lines were less stressed than other under same salt stress. The contents of strong salt-tolerant transgenic lines were 2.255 ~ 2.638 mg/kg and it is much higher than that of middle salinity lines' 1.496 ~ 2.125.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.1
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• pp.42-49
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• 2023

The plant-specific NAC transcription factors control various biological processes, including plant development and stress responses. We have isolated an ANAC032 gene, one of the NAC transcription factor family, which was highly activated by multi-abiotic stresses, including high salt and drought in Arabidopsis. Here, we generated transgenic plants constitutively expressing ANAC032 and its knockout to identify the functional roles of ANAC032 in Arabidopsis under abiotic stress responses. The ANAC032-overexpressing plants showed enhanced tolerance to salinity and drought stresses. The anac032 knockout mutants were observed no significant changes under the high salt and drought conditions. We also monitored the expression of high salt and drought stress-responsive genes in the ANAC032 transgenic plants and anac032 mutant. The ANAC032 overexpression upregulated the expression of stress-responsive genes, RD29A and ERD10, under the stresses. Thus, our data identify that transcription factor ANAC032 plays as an enhancer for salinity and drought tolerance through the upregulation of stress-responsive genes and provides useful genetic traits for generating multi-abiotic stress-tolerant forage crops.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.214-221
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• 2020

Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.93-100
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• 1998

This study was to investigate the dry weight, the amount of Na+ and K+ water potential and leaf photosynthesis rate in plants for determining the salt tolerance mechanism in rice cultivars on soil and solution culture with NaCl. The results obtained in this study are summarized as follows ; In general, rice cultivars, cv. Tetep and Jinbu, having high salt tolerance in ID(identified on dry matter production level) showed the higher salt tolerance in RGR (relative growth rate), compared with rice cultivars(cv. Nonglim 41ho, Dunraebyeo and Sobackbyeo) having low salt tolerance. The contents of Na in rice differed depending on culivars and plant parts. Tetep contained 2.9times higher amounts of Na+ than leaf blade and root part. High salt tolerance cultivar Obongbyeo showed a larger decrease in osmotic potential than low salt tolerance cultivar Dunraebyeo suggesting that osmotic adjustment was developed under salt stress conditions in a salt tolerant cultivar . In order to know the IY(identified on grain yeild level using rice cultivars having different salt tolerance the capacity of photosyntheiss was investigated. The capapcity of photosynthesis in cv. Tetep and Obongbyeo having high salt tolerance was much higher that in cv.Dunraebyeo and Nonglim 41 having low salt tolerance.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.156-156
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• 2023

Salinity is a major abiotic stress that limits rice productivity in many regions of the world. In order to develop salt stress tolerant rice plants, genetic engineering is a promising approach. We characterized the molecular function of rice C3H2C3 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under salinity conditions, OsRFPH2-3-overexpressing plants exhibited higher chlorophyll, proline, SOD, POD, CAT, and soluble sugar contents and lower H₂O₂ accumulation than wild-type plants, supporting transgenic plants with enhanced salinity tolerance phenotypes. OsRFPH2-3-overexpressing plants exhibited low Na+ accumulation and Na+/K+ ratios in their roots. Theses results suggest that overexpression of OsRFPH2-3 can make plant insensitivity about salinity conditions.

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

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.355-367
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• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.