• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.257-264
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• 2004

Selection of stress-tolerant ginseng lines in fields is very difficult because it is almost impossible to control properly the environmental conditions of soil. On the contrary, it can be studied with ease to search for stress-tolerant ginseng lines through in vitro culture because of easy manipulation of stress conditions. This study was conducted for the selection of ginseng pure lines tolerant to salt stress. Murashige ＆amp; Skoog(MS) media with 2.5 folds of KNO$_3$, NH$_4$NO$_3$, MgSO$_4$.7$H_2O$, KH$_2$PO$_4$, and CaC1$_2$.2$H_2O$ was established for the selection of ginseng pure lines tolerant to salt stress in vitro. Among 88 ginseng pure lines bred by Korea Ginseng and Tobacco Research Institute, Punggi Hwangsuk, 78093, 82886, 78135, 86024 and KG104 lines was tolerant to salt stress. For the stable production of quality Korean ginseng, genetic tolerance to salt stress is one of important factors since relatively high salt concentrations in the ginseng nursery soil environment of Korea. Ginseng inbred pure lines were tested for their tolerance to salt stress through in vitro culture technique.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.175-175
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• 2017

To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the acquired salt tolerance of adapted cells was memorized. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. Consistently, salt adapted cells contained more lignin in their cell walls compared to control cells. The results provide new insight into mechanisms of plant adaptation to saline stress as well as stress memory in metabolic level.

• 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.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.69-77
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• 2008

Jatropha curcas L. is an oil bearing species with many uses and considerable economic potential as a biofuel crop. Salt stress effect on growth, ion accumulation, contents of protein, proline and antioxidant enzymes activity was determined in callus and seedling to understand the salt tolerance of the species. Exposure of callus and seedling to salt stress reduced growth in a concentration dependent manner. Under salt stress Na content increased significantly in both callus and seedling whereas, differential accumulation in the contents of K, Ca, and Mg was observed in callus and seedling. Soluble protein content differed significantly in callus as compared to seedling, however proline accumulation remained more or less constant with treatments. The proline concentration was ~2 to 3 times more in callus than in seedling. Salt stress induced qualitative and quantitative differences in superoxide dismutase (SOD; E.C. 1.15.1.1) and peroxidase (POX; E.C. 1.11.1.7) in callus and seedling. Salt induced changes of the recorded parameters were discussed in relation to salinity tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.314-321
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• 2018

Durum (Triticum turgidum L. ssp. durum) is a major crop species cultivated for human consumption worldwide. In Tunisia, salt stress is one of the main problems that limit crop production. 'Mahmoudi' was selected as the most salt-sensitive out of 11 Tunisian durum cultivars. Using the salt-tolerant cultivar 'Om Rabia', resistant and susceptible cultivars were evaluated to compare genetic responses under salt stress. At the fully expanded third leaf stage, salt stress was applied by submerging the pots in 500 mM NaCl for 5 min every day for saline water irrigation in the greenhouse. The treatment was applied for 1 week and salt stress tolerance was determined by changes of growth parameters to the control condition. The salt tolerance trait index and salt tolerance index were calculated and used as selection criteria. The expression levels of TdHKT1;4, TdHKT1;5, and TdSOS1 were examined using qPCR. For further evaluation of physiological responses, salt stress (150 mM NaCl) was additionally applied for 48 h at the fully expanded third-leaf stage. Increased expression of the genes responsible for salt tolerance and proline content in tolerant durum can be used to broaden genetic diversity and provide genetic resources for the durum breeding program.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.398-407
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• 2021

Using salt-tolerant bacteria to protect plants from salt stress is a promising microbiological treatment strategy for saline-alkali soil improvement. Here, we conducted research on the growth-promoting effect of Brevibacterium frigoritolerans on wheat under salt stress, which has rarely been addressed before. The synergistic effect of B. frigoritolerans combined with representative salt-tolerant bacteria Bacillus velezensis and Bacillus thuringiensis to promote the development of wheat under salt stress was also further studied. Our approach involved two steps: investigation of the plant growth-promoting traits of each strain at six salt stress levels (0, 2, 4, 6, 8, and 10%); examination of the effects of the strains (single or in combination) inoculated on wheat in different salt stress conditions (0, 50, 100, 200, 300, and 400 mM). The experiment of plant growth-promoting traits indicated that among three strains, B. frigoritolerans had the most potential for promoting wheat parameters. In single-strain inoculation, B. frigoritolerans showed the best performance of plant growth promotion. Moreover, a pot experiment proved that the plant growth-promoting potential of co-inoculation with three strains on wheat is better than single-strain inoculation under salt stress condition. Up to now, this is the first report suggesting that B. frigoritolerans has the potential to promote wheat growth under salt stress, especially combined with B. velezensis and B. thuringiensis.

• 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.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.379-391
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• 2024

Tocopherol, carotenoids, and chlorophyll are the primary components of the antioxidative response in microalgae. Conditions of stress, such salt stress, can trigger the processes responsible for the accumulation of tocopherol and carotene. It has been found that the most difficult part of culturing microalgae is keeping it affordable. This study investigated the effects of different salt types and concentrations on the amount of α-tocopherol, carotenoid derivatives, and flocculation efficiency of Euglena sp. Cultures of Euglena sp. was developed under salt stress conditions of NaCl 200 mM and KCl 200 mM. UV-VIS spectrophotometry was used to confirm the presence of α-tocopherol and carotenoid derivatives under thirteen days of salt stress testing. Increasing salinity has a significant effect on Euglena sp., causing spherical cell morphologies with aspect ratio 1.385 ± 0.031 for NaCl 200 mM and 1.414 ± 0.040 for KCl 200 mM. Increasing salinity also slowing down development with specific growth rate value of 0.171 ± 0.006 per day and 0.122 ± 0.029 per day for NaCl and KCl 200 mM, respectively. Nevertheless, the amount of α-tocopherol in Euglena sp. increases with a high salt concentration; algal cells flocculated more successfully when increasing the salt concentrations (NaCl 200 mM and KCl 200 mM) was added. Due to the inhibition of photosynthetic activity in salt-stressed cells, the control group exhibited higher levels of carotenoid derivatives (ranging from 0.5-1 ㎍/mL) and pheophytin a and b (0.0062 ± 0.001 ㎍/mL and 0.0064 ± 0.001 ㎍/mL) than the group treated with salt stress. In conclusion, salt stress was an effective way to raises the concentration of α-tocopherol and significantly reduce the expense of harvesting Euglena sp.

• Molecules and Cells
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• v.24 no.1
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• pp.45-59
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• 2007

We describe the gene expression profile of third leaves of rice (cv. Nipponbare) seedlings subjected to salt stress (130 mM NaCl). Transcripts of Mn-SOD, Cu/Zn-SOD, cytosolic and stromal APX, GR and CatB were up-regulated, whereas expression of thylakoid-bound APX and CatA were down-regulated. The levels of the compatible solute proline and of transcripts of its biosynthetic gene, ${\Delta}^1$-pyrroline-5-carboxylate synthetase (P5CS), were strongly increased by salt stress. Interestingly, a potential compatible solute, ${\gamma}$-aminobutyric acid (GABA), was also found to be strongly induced by salt stress along with marked up-regulation of transcripts of GABA-transaminase. A dye-swap rice DNA microarray analysis identified a large number of genes whose expression in third leaves was altered by salt stress. Among 149 genes whose expression was altered at all the times assayed (3, 4 and 6 days) during salt stress, there were 47 annotated novel genes and 76 unknown genes. These results provide new insight into the effect of salt stress on the expression of genes related to antioxidant enzymes, proline and GABA as well as of genes in several functional categories.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.