• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1457-1466
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• 2018

In the present study, the stabilizing effect of four different biological osmolytes on Bacillus licheniformis ${\gamma}$-glutamyl transpeptidase (BlGGT) was investigated. BlGGT appeared to be stable under temperatures below $40^{\circ}C$, but the enzyme retained less than 10% of its activity at $60^{\circ}C$. The tested osmolytes exhibited different degrees of effectiveness against temperature inactivation of BlGGT, and sucrose was found to be the most effective among these. The use of circular dichroism spectroscopy for studying the secondary structure of BlGGT revealed that the temperature-induced conformational change of the protein molecule could be prevented by the osmolytes. Consistently, the molecular structure of the enzyme was essentially conserved by the osmolytes at elevated temperatures as monitored by fluorescence spectroscopy. Sucrose was further observed to counteract guanidine hydrochloride (GdnHCl)-and urea-induced denaturation of BlGGT. Taken together, we observed evidently that some well-known biological osmolytes, especially sucrose, make a dominant contribution to the structural stabilization of BlGTT.

• Applied Biological Chemistry
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• 제38권3호
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• pp.218-223
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• 1995

고염분으로 삼투압 스트레스를 받은 Yersinia enterocolitica ATCC 9610 세포내에 축적되는 osmolyte를 $^{13}C$ NMR을 통해 조사하였다. 자연계에 흔히 존재하는 가장 강력한 osmolyte로 알려진 glycine betaine의 삼투압 스트레스를 받은 Y. enterocolitica ATCC 9610 세포내 농도 (801.9 nmol/mg protein)는 삼투압 스트레스를 받지 않은 세포 (19.2 nmol/mg protein) 보다 41.8배 많이 검출되어 Y. enterocolitica ATCC 9610의 가장 주요한 osmolyte로 작용하였다. Proline도 284.8 nmol/mg protein의 농도로 검출되어 Y. enterocolitica ATCC 9610의 osmolyte로 작용하였다. Glycine betaine을 비롯한 각종 osmolyte가 삼투압 스트레스를 받은 Y. enterocolitica 세포성장에 미치는 역할을 검증하기 위해 Y. enterocolitica의 성장속도에 미치는 이들의 영향을 조사하였다. 2.5%의 NaCl이 첨가된 MMA 배지에 glycine betaine과 proline을 각각 첨가했을때, 1mM glycine betaine의 경우 osmolyte를 첨가하지 않은 대조구에 비해 성장속도가 3.6배 증가하였으며 5mM proline의 경우는 1.3배 증가하였다. Dimethylglycine도 2.5%의 NaCl을 첨가한 MMA 배지에 5mM의 농도로 첨가하였을때 대조구에 비해 성장속도가 3.1배 증가하였는데, monomethylglycine은 삼투압 스트레스를 받은 Y. enterocolitica의 성장에 어떤 영향도 미치지 못하였다. Carnitine은 2.5%의 NaCl이 첨가된 MMA 배지에 5mM의 농도로 첨가되었을때 대조구에 비해 2.4배 성장속도가 증가하였으며 choline은 성장에 어떤 영향도 미치지 못하였다. 이상의 결과로 glycine betaine은 Y. enterocolitica ATCC 9610의 가장 주요한 osmolyte로 작용하며, proline, dimethyglyine 그리고 carnitine도 Y. enterocolitica ATCC 9610의 osmolyte로 작용하여 삼투압 스트레스를 받은 Y. enterocolitica ATCC 9610의 성장속도를 증가시켰다.

• ALGAE
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• 제36권2호
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• pp.123-135
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• 2021

The taxonomy of green microalgae relies traditionally on morphological traits but has been rapidly changing since the advent of molecular methods. Stichococcus Nägeli is a cosmopolitan terrestrial algal genus of the class Trebouxiophyceae that has recently been split into seven lineages, which, along with Pseudostichococcus, comprise the Stichococcuslike group; there is a need to further characterize these genera, since they are morphologically enigmatic. Here we used organic osmolytes as chemotaxonomic marker to verify the phylogenetic position of Stichococcus-like strains and were also able to exclude a strain hitherto identified as Gloeotila contorta from this group. Stichococcus-like organisms, including those recently revised, were characterized by the production of the polyol sorbitol and the disaccharide sucrose in high amounts, as is typical of Prasiola-clade algae. The results demonstrate that organic osmolyte chemotaxonomy can support green algal taxonomic designations as fundamental research.

• The Korean Journal of Physiology and Pharmacology
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• 제11권3호
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• pp.135-138
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• 2007

Hypertonicity imposes a great deal of stress to cells since it causes rise in cellular ionic strength, which can be reduced by the accumulation of compatible osmolytes. TonEBP plays a central role in the cellular accumulation of compatible osmolytes via transcriptional stimulation of membrane transporters and aldose reductase. Alternatively spliced forms of TonEBP mRNA have previously been reported and two of them showed different transcriptional activity. In the present study, isoform-specific antibodies were produced to confirm the translation of the spliced mRNA to protein. TonEBP was immunoprecipitated by using anti-TonEBP antibody and then immunoblotted using anti-TonEBP or isoform specific antibodies to find out the expression profile of TonEBP isoforms in basal or stimulated condition. From these results, we conclude that all TonEBP isoforms are expressed in mammalian cells and their expression patterns are not same in every cells.

• Journal of Plant Biotechnology
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• 제7권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제27권9호
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• pp.1681-1691
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• 2017

This study investigated the effect of proline addition on the salt tolerance of Tetragenococcus halophilus. Salt stress led to the accumulation of intracellular proline in T. halophilus. When 0.5 g/l proline was added to hyperhaline medium, the biomass increased 34.6% (12% NaCl) and 27.7% (18% NaCl) compared with the control (without proline addition), respectively. A metabolomic approach was employed to reveal the cellular metabolic responses and protective mechanisms of proline upon salt stress. The results showed that both the cellular membrane fatty acid composition and metabolite profiling responded by increasing unsaturated and cyclopropane fatty acid proportions, as well as accumulating some specific intracellular metabolites (environmental stress protector). Higher contents of intermediates involved in glycolysis, the tricarboxylic acid cycle, and the pentose phosphate pathway were observed in the cells supplemented with proline. In addition, addition of proline resulted in increased concentrations of many organic osmolytes, including glutamate, alanine, citrulline, N-acetyl-tryptophan, and mannitol, which may be beneficial for osmotic homeostasis. Taken together, results in this study suggested that proline plays a protective role in improving the salt tolerance of T. halophilus by regulating the related metabolic pathways.

• ALGAE
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• 제26권1호
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• pp.21-32
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• 2011

Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

• 생물환경조절학회지
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• 제16권4호
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• pp.303-308
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• 2007

저온 스트레스에 대한 호박의 생육과 식물체 내 삼투조절 물질의 반응을 분석한 결과, 삼투조절물질의 축적은 저온에 대한 내성 증가에 큰 영향을 미쳤다. 가용성 당은 저온에 강한 품종보다는 저온에 약한 품종에서 축적량이 많았다. 저온 처리 시 proline은 대조구에 비해 저온에 강한 품종과 약한 품종에서 모두 증가하는 경향을 보였다. 그러나 저온에 대한 내성에 따라 축적량에는 차이가 뚜렷하였는데, 저온 처리 후 20일째의 proline축적량은 대조구에 비해 저온에 약한 품종에서는 22배 증가하였고, 저온에 강한 품종에서 는 26.6배 증가하였다. 또한 저온에 약한 품종에서는 glycine betaine이 축적되지 않았지만, 강한 품종에서는 대조구에 비해 1.9배의 증가를 보였다. Glycine betaine을 엽면 처리하면 두 품종 모두 저온에 대한 내성이 증가하였는데, 이는 체내에 glycine betaine의 축적과 밀접한 관계가 있었다.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.71-77
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• 2011

Drought and salinity are the most important abiotic stresses that affect the normal growth and development of plants. Glycine betaine is one of the most important osmolytes present in higher plants that enable them to cope with environmental stresses through osmotic adjustment. In this study, a betaine aldehyde dehydrogenase (BADH) gene from spinach under the control of the stress-induced promoter rd29A from Arabidopsis thaliana was introduced into potato cultivar Gannongshu 2 by the Agrobacterium tumefaciens system. Putative transgenic plants were confirmed by Southern blot analysis. Northern hybridization analysis demonstrated that expression of BADH gene was induced by drought and NaCl stress in the transgenic potato plants. The BADH activity in the transgenic potato plants was between 10.8 and 11.7 U. There was a negative relationship (y = -2.2083x + 43.329, r = 0.9495) between BADH activity and the relative electrical conductivity of the transgenic potato plant leaves. Plant height increased by 0.4-0.9 cm and fresh weight per plant increased by 17-29% for the transgenic potato plants under NaCl and polyethylene glycol stresses compared with the control potato plants. These results indicated that the ability of transgenic plants to tolerate drought and salt was increased when their BADH activity was increased.

• 한국작물학회지
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• 제52권4호
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• pp.458-468
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• 2007

To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.