• Plant Biotechnology Reports
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• 제4권2호
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• pp.165-172
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• 2010

Genes that are expressed early in specific response to high salinity conditions were isolated from rapeseed plant (Brassica napus L.) using an mRNA differential display method. Five PCR fragments (DD1.5) were isolated that were induced by, but showed different response kinetics to, 200 mM NaCl. Nucleotide sequence analysis and homology search revealed that the deduced amino sequences of three of the five cDNA fragments showed considerable similarity to those of ${\beta}$-mannosidase (DD1), tomato Pti-6 proteins (DD5), and the tobacco harpin-induced protein hin1 (DD4), respectively. In contrast, the remaining clones, DD3 and DD2, did not correspond to any substantial existing annotation. Using the DD3 fragment as a probe, we isolated a full-length cDNA clone from the cDNA library, which we termed BnSWD1 (Brassica napus salt responsive WD40 1). The predicted amino-acid sequence of BnSWD1 contains eight WD40 repeats and is conserved in all eukaryotes. Notably, the BnSWD1 gene is expressed at high levels under salt-stress conditions. Furthermore, we found that BnSWD1 was upregulated after treatment with abscisic acid, salicylic acid, and methyl jasmonate. Our study suggests that BnSWD1, which is a novel WD40 repeat-containing protein, has a function in salt-stress responses in plants, possibly via abscisic acid-dependent and/or -independent signaling pathways.

• Journal of Plant Biotechnology
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• 제41권1호
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• pp.26-32
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• 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.

• Ocean and Polar Research
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• 제26권3호
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• pp.433-438
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• 2004

Stress response to the seawater acclimation in coho salmon (Oncorhynchus kisutch) smolt was investigated. Salt concentration of rearing water was gradually increased for 3 days from freshwater to seawater (30 ppt salt level). The changes of serum concentrations of cortisol as a primary stress indicator, and as secondary indicators, glucose (GLC), lactate (LAC), triglyce.ide (TG), cholesterol (CHOL), sodium ion $(Na^+)$, chloride ion $(Cl^-)$ and enzyme activities (alanine aminotransferase, ALT: aspartate aminotrasferase, AST; lactate dehydrogenase, LDH) were quantified during the acclimation experiment. Among them, cortisol, LAC, TG, CHOL, ALT, AST concentrations showed rapid increase at the first exposure to the 10ppt salt level (day 1), and began to decrease to the constant values after day 2 of adaptation at 20ppt salt level. However, LDH concentration tended to decrease during the whole experimental period. $Na^+\;and\;Cl^-$ showed slight decrease at day 1, and increased to a little bit higher values after day 2 rather than those in freshwater. All the fishes started on taking a food after day 4 of seawater adaptation. From these results, to reduce osmotic shock inducible stress to fish in seawater acclimation, gradual increase of salt levels is recommended.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.246-246
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• 2017

Salinity inhibits plant growth and restricts the efficiency of arbuscular mycorrhizal fungi. The selective uptake of nutrients from the soil and their effective transport to host roots make it essential for plant growth and development under salt stress. AMF spore associated bacteria shown to improve mycorrhizal efficiency under stress. Thus, this study aimed to understand the co-inoculation efficiency of AMF and SAB on maize growth and ion homeostasis under salt stress. Two AMF strains and one SAB were inoculated with maize either alone or in combination with one another. The results of our study showed that AMF and SAB co-inoculation significantly improved dry weight and nutrient uptake of maize under salt stress. Co-inoculation significantly reduced proline accumulation in shoots and Na+ accumulation in roots. Co-inoculation treatment also exhibited the high K+/Na+ ratios in roots at 25 mM NaCl. Mycorrhizal colonization showed positive influence for regulation of ZmAKT2, ZmSOS1 and ZmSKOR gene expressions, contributing to K+ and Na+ ion homeostasis. CLSM view showed that SAB were able move and localize into inter and intra cellular spaces of maize roots. In addition, CLSM view of AMF spores showed that gfp-tagged SAB also associated on the spore outer hyaline layer.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.483-493
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• 2010

Knock-out of a gene by insertional mutagenesis is a direct way to address its function through the mutant phenotype. Among ca. 15,000 gene-trapped Ds insertion lines of rice, we identified one line from selected sensitive lines in highly salt stress. We conducted gene tagging by TAIL-PCR, and DNA gel blot analysis from salt sensitive mutant. A gene encoding an oligopeptide transporter (OPT family) homologue was disrupted by the insertion of a Ds transposon into the OsOPT10 gene that was located shot arm of chromosome 8. The OsOPT10 gene (NP_001062118.) has 6 exons and encodes a protein (752 aa) containing the OPT family domain. RT-PCR analysis showed that the expression of OsOPT10 gene was rapidly and strongly induced by stresses such as high-salinity (250 mM), osmotic, drought, $100\;{\mu}M$ ABA. The subcellular localization assay indicated that OsOPT10 was localized specifically in the plasma membrane. Overexpression of OsOPT10 in Arabidopsis thaliana and rice conferred tolerance of transgenic plants to salt stress. Further we found expression levels of some stress related genes were inhibited in OsOPT10 transgenic plants. These results suggested that OsOPT10 might play crucial but differential roles in plant responses to various abiotic stresses.

• Geomechanics and Engineering
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• 제9권4호
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• pp.499-511
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• 2015

The creep property of salt rock significantly influences the long-term stability of the salt rock underground storage. Triaxial creep tests were performed to investigate the creep behavior of salt rock. The test results indicate that the creep of salt rock has a nonlinear characteristic, which is related to stress level and creep time. The higher the stress level, the longer the creep time, the more obvious the nonlinear characteristic will be. The elastic modulus of salt rock decreases with the prolonged creep time, which shows that the creep damage is produced for the gradual expansion of internal cracks, defects, etc., causing degradation of mechanical properties; meanwhile, the creep rate of salt rock also decreases with the prolonged creep time in the primary creep stage, which indicates that the mechanical properties of salt rock are hardened and strengthened. That is to say, damage and hardening exist simultaneously during the creep of salt rock. Both the damage effect and the hardening effect are considered, an improved Maxwell creep model is proposed by connecting an elastic body softened over time with a viscosity body hardened over time in series, and the creep equation of which is deduced. Creep test data of salt rock are used to evaluate the reasonability and applicability of the improved Maxwell model. The fitting curves are in excellent agreement with the creep test data, and compared with the classical Burgers model, the improved Maxwell model is able to precisely predict the long-term creep deformation of salt rock, illustrating our model can perfectly describe the creep property of salt rock.

• Journal of Crop Science and Biotechnology
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• 제10권4호
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• pp.257-264
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• 2007

Rice is one of the world's staple crops and is a major source of carbohydrate. Rice is exported from several countries, providing a major source of income. There are many documents reporting that rice is a salt-sensitive crop in its developmental stages. The objective of this investigation is to evaluate the effective salt-tolerance defense mechanisms in aromatic rice varieties. Pathumthani 1(PT1), Jasmine(KDML105), and Homjan(HJ) aromatic rice varieties were chosen as plant materials. Rice seedlings photoautotrophically grown in-vitro were treated with 0, 85, 171, 256, 342, and 427 mM NaCl in the media. Data, including sodium ion$(Na^+)$ and potassium ion$(K^+)$ accumulation, osmolarity, chlorophyll pigment concentration, and the fresh and dry weights of seedlings were collected after salt-treatment for 5 days. $Na^+$ in salt-stressed seedlings gradually accumulated, while $K^+$ decreased, especially in the 342-427 mM NaCl salt treatments. The $Na^+$ accumulation in both salt-stressed root and leaf tissues was positively related to osmolarity, leading to chlorophyll degradation. In the case of the different rice varieties, the results showed that the HJ variety was identified as being salt-tolerant, maintaining root and shoot osmolarities as well as pigment stabilization when exposed to salt stress or $Na^+$ enrichment in the cells. On the other hand, PT1 and KDML105 varieties were classified as salt-sensitive, determined by chlorophyll degradation using Hierarchical cluster analysis. In conclusion, the HJ-salt tolerant variety should be further utilized as a parental line or genetic resource in breeding programs because of the osmoregulation defensive response to salt-stress.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.75-83
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• 2010

Glycine betaine has been reported as an osmoprotectant compound conferring tolerance to salinity and osmotic stresses in plants. We previously found that the expression of betaine aldehyde dehydrogenase 1 gene (OsBADH1), encoding a key enzyme for glycine betaine biosynthesis pathway, showed close correlation with salt tolerance of rice. In this study, the expression of the OsBADH1 gene in transgenic tobacco was investigated in response to salt stress using a transgenic approach. Transgenic tobacco plants expressing the OsBADH1 gene were generated under the control of a promoter from the maize ubiquitin gene. Three homozygous lines of $T_2$ progenies with single transgene insert were chosen for gene expression analysis. RT-PCR and western blot analysis results indicated that the OsBADH1 gene was effectively expressed in transgenic tobacco leading to the accumulation of glycine betaine. Transgenic lines demonstrated normal seed germination and morphology, and normal growth rates of seedlings under salt stress conditions. These results suggest that the OsBADH1 gene could be an excellent candidate for producing plants with osmotic stress tolerance.

• 한국수산과학회지
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• 제33권2호
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• pp.119-123
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• 2000

은연어가 운반과정 중에 어느 정도 스트레스를 받는지 조사하기 위하여 어류를 각각 담수와 염수 ($5{\%{\circ}}$)를 채운 수조차에 싫고 10 시간 운반하였다. 운반하기 전후에 혈청 중의 1차 스트레스 지표 물질인 코티졸을 비롯하여 2차 지표물질인 GLC, LAC, TG, CHOL, 전해질 ($Na^+, Cl^-$), 효소 (ALT, AST, LDH) 활성을 측정하여 두 운반구 간의 차이를 비교하였다. 그 결과, 운반작업은 은연어에게 상당한 스트레스를 주는 것으로 확인되었으나, 운반방법에 따라서는 스트레스 반응에 차이가 있었다. 즉, 담수운반구에 비해 염수운반구는 코티졸, GLC, LAC, TG, CHOL, AST 및 ALT가 유의적인 차이를 보이며 낮은 수준이었다. 이것으로 은연어의 운반시에는 담수보다 염수를 사용하는 것이 스트레스를 줄일 수 있다는 것을 알 수 있었다.

• Molecules and Cells
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• 제40권12호
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• pp.966-975
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• 2017

Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY $K^+$ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of $Na^+$ in roots up to the elongation zone and caused the reabsorption of $Na^+$ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to function in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.