• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.1-15
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• 2005

Salinity is one of the major limiting factors for agricultural productivity. In plants, accumulation of osmolytes plays a pivotal role in abiotic stress tolerance. Likewise, exclusion or compartmentation of $Na^+$ ions into vacuoles provides an efficient mechanism to avert deleterious effects of $Na^+$ in the cytosol. Both vacuolar and plasma membrane sodium transporters and $H^+-ATPases$ can provide the necessary ion homeostasis. A variety of crop plants were engineered with respect to the synthesis of osmoprotectants and ion-compartmentation, but there are other cellular pathways involved in the salinity responses that are still not completely explored. Genomics approaches are increasingly used to identify genes and pathway changes involved in salt-tolerance. The new knowledge may be used via guided genetic engineering of multiple genes to create crop plants with significantly increased productivity in saline soils. This review surveys how plants deal with high salt conditions and how salt tolerance can be improved by transgenic approaches.

• Childhood Kidney Diseases
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• v.15 no.2
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• pp.172-178
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• 2011

Nephrogenic diabetes insipidus is a rare genetic renal disease characterized by insensitivity of the kidney to the anti-diuretic effect of vasopressin in spite of elevated serum antidiuretic hormone (ADH). Failure of the kidney to respond to ADH results in impaired osmoregulation and water reabsorption of the kidney, therefore, nephrogenic diabetes insipidus presents with a large amount of hypotonic polyuria, polydipsia, and dehydration. We report our experience of two familial cases of nephrogenic diabetes insipidus in brothers both having c.910+1delG in intron 2 of the AVPR2 gene with the brief review of related literatures.

• Journal of Aquaculture
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• v.20 no.4
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• pp.205-211
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• 2007

Stress-inducible proteins may function in part as molecular chaperones, protecting cells from damage due to various stresses and helping to maintain homeostasis. We examined the mRNA expression patterns of a 68-kDa heat shock protein (HSP68) and 78-kDa glucose-regulated protein (GRP78) in relation to physiological changes in Pacific oyster Crassostrea gigas under osmotic stress. Expression of HSP68 and GRP78 mRNA in the gill significantly increased until 48 h in a hypersaline environment (HRE) and 72 h in a hyposaline environment (HOE), and then decreased. Osmolality and the concentrations of $Na^+$, $Cl^-$, and $Ca^{2+}$ in the hemolymph of HRE oysters significantly increased until 72 h (the highest value) and then gradually decreased; in HOE oysters, these values significantly decreased until 72 h (the lowest value), and then increased. These results suggest that osmolality and $Na^+$, $Cl^-$, and $Ca^{2+}$ concentrations were stabilized by HSP68 and GRP78, and indicate that these two stress-induced proteins play an important role in regulating the metabolism and protecting the cells of the Pacific oysters exposed to salinity changes.

• Ocean and Polar Research
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• v.38 no.2
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• pp.103-113
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• 2016

This study aimed to examine the role of two aquaporin isoforms (AQP3 and AQP8) in response to the hyperosmotic challenge of transitioning from freshwater (FW) to seawater (SW) during parr and smoltification (smolt) using the rainbow trout, Oncorhynchus mykiss. We examined the changes in the expression of AQPs mRNAs in the gills and intestine of the parr and smolt stages of rainbow trout transferred from FW to SW using quantitative real-time PCR in an osmotically changing environment [FW, SW, and recombinant AQP3 (rAQP3) injection at two dosage rates]. Correspondingly, AQPs were greater during smoltification than during parr stages in the rainbow trout. Plasma osmolality and gill $Na^+/K^+$-ATPase activity increased when the fish were exposed to SW, but these parameters decreased when the fish were exposed to SW following treatment with rAQP3 during the transition to seawater. Our results suggest that AQPs play an important role in water absorbing mechanisms associated with multiple AQP isoforms in a hyperosmotic environment.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.118-124
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• 1997

In the previous study(6), we constructed the CheY-OmpR hybrid, Chp, which affects the expressions of ompF and om pC genes. Here we further characterize these effects and present the regulatory mechanism based on in vivo and in vitro data. Although Chp retained the sequence-specific DNA-binding ability, it was not possible to enhance transcriptional activity, suggesting that it may act as a competitive inhibitor to OmpR. The DNA-binding affinity of Chp was not modulated by phosphorylation of its Che Y portion. Chp was able to increase ompR transcription. FurthemlOre, it was found that the wild-type OmpR also exerts the same effect, which is also eOlltrolled by changes in medium osmolarity and in EnvZ activity.

• Korean Journal of Medicinal Crop Science
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• v.20 no.1
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• pp.36-41
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• 2012

This study was carried out to establish a proper cultivation site and diagnose the drought tolerance of Pleurospermum camtschaticum, Cirsium setidens and Parasenecio firmus leaves by using pressure-volume curves. The result of ${\Psi}_o^{sat}$ and ${\Psi}_o^{tlp}$ were lower in Pleurospermum camtschaticum leaves. On the other hand, it appeared that $E_{max}$ of Pleurospermum camtschaticum was approximately six times higher than that of Parasenecio firmus. The values of $RWC^{tlp}$ is all above 88% showing that the function of osmoregulation is somewhat better, and Vo/DW, Vt/DW, Ns/DW of Pleurospermum camtschaticum leaves were approximately 2~4 times Lower than other ones. Thus, responses to water relations of Pleurospermum camtschaticum, Cirsium setidens and Parasenecio firmus such as ${\Psi}_o^{sat}$, ${\Psi}_o^{tlp}$, $E_{max}$, ${\Psi}_{P,max}$, $RWC^{tlp}$ were shown that the Pleurospermum camtschaticum leave was higher drought tolerance than Cirsium setidens and Parasenecio firmus leaves.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.91-97
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• 2017

This study was carried out to establish a proper cultivation site and to diagnose the drought tolerance of Heracleum moellendorffii leaves by using pressure-volume curves. As a result of analysing data measured, the leaf of H. moellendorffii showed the osmotic pressure at full turgor (Ψ_o^sat) was -1.0MPa, and that at incipient plasmolysis (Ψ_o^tlp) -1.2MPa. Then, the value of maximum bulk modulus of elasticity Emax was 28MPa, showing the sightly strong drought tolerance of H. moellendorffii. Furthermore, the values of relative water contents RWC^tlp and RWC^* were above 88%, showing that the function of osmoregulation is somewhat better. Thus, responses to water relations such as Ψ_o^sat, Ψ_o^tlp, E_max, RWC^tlp and RWC^* of H. moellendorffii showed it's slightly high drought tolerance property.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.41-48
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• 2019

This study was carried out to establish a proper cultivation site and to diagnose the drought tolerance of Oplopanax elatus leaves by using pressure-volume curves. As a result of analysing data measured, the leaf of Oplopanax elatus showed the osmotic pressure at full turgor(Ψosat) was -0.77 MPa, and the osmotic pressure at incipient plasmolysis(Ψotlp) was -0.90 MPa. Then, the value of maximum bulk modulus of elasticity Emax was 3.7 MPa, showing that slightly lower drought tolerance of Oplopanax elatus. Furthermore, the values of relative water contents RWCtlp and RWC^* were above 80%, showing that the function of osmoregulation is somewhat better. Thus, responses to water relations such as Ψosat, Ψotlp, Emax, RWCtlp and RWC^* of Oplopanax elatus showed relatively lower drought-tolerance property indicating that those growth are appropriate in high moisture soil sites.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.25-28
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• 1980

The purpose of the this study was to compare the torlent tree to drought among the Pinus koraiensis, Abies holophylla, and Ginkgo biloba. The water relations parameters of leafy shoots were measured by the Pressure chamber technique from August 10 to September 4 in 1980. On the water relations parameters such as original osmotic pressure(${\pi}_0$), osmotic pressure(${\pi}_p$) and relative water content (RWC) at incipient plasmolysis, and Vp/Vo ratio of the volume of osmotic water (Vp) at incipient plasmolysis to total symplasmic water (Vo) basis, the Abies holophylla shoots showed ontogenetically a superior osmoregulation which are closely associated with drought resistance compared with Pinus koraiensis, and the Ginkgo biloba shoots showed the heighest among these three species.

• Journal of Life Science
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• v.10 no.5
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• pp.456-466
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• 2000

Aquaperin 4 (AQP4) is the mercurial water channel expressed abundantly in brain, especially the region related with cerebrospinal fluid reabsorption and osmoregulation. The primary structure of AQP4 water channel was elucidated but the molecular mechanism of AQP4 channel regulation is still unknown. To investigate the possible regulation of AQP4 water channel by phosphorylation via various protein kinases, osmotic water permeability of AQP4 expressed in Xenopus oocytes was measured by videomicroscopy technique. Forskolin (10 $\mu$M) did not affect osmotic water permeability of oocytes injected with AQP4 cRNA, excluding the regulation of AQP4 water cnannel by protein kinase A. Osmotic water permeability (P아래첨자) of AQP4-expressed oocytes was ingibited by the pretreatmeat of BAPTA/AM (up to 500$\mu$M), an intracellular Ca윗첨자 chelator, and calmidazolium (100$\mu$M), a specific Ca윗첨자/calmodulin antagonist, in a dose-dependent manner. The inhibition of osmotic water permeability (P아래첨자) by the calmidazolium treatment was completely reversed by the addition of calyculin A (0.1$\mu$M), a nonspecific phosphatase inhibitor. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, had biphasic effects on osmotic water permeability in AQP4 cRNA injected oocytes depending on its concentration; 21% increase by 100 nM PMA, 35% decrease by 1$\mu$M PMA. These effects were reversed with 2$\mu$M staurosporine, a nonspecific PKC inhibitor. These results suggest that phosphorylation of AQP4 water channel by Ca윗첨자/calmodulin kinase and protein kinase C might regulate the osmotic water permeability.