• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.10a
• /
• pp.123-123
• /
• 2018

• Journal of Bio-Environment Control
• /
• v.29 no.4
• /
• pp.354-364
• /
• 2020

This study was conducted to examine the potential of inducing salinity stress on cylindrical paper pot tomato seedlings to inhibit overgrowth. Potassium fertilizers, sulfate of potash (K₂SO₄), muriate of potash (KCl), and monopotassium phosphate (KH₂PO₄), were prepared as two solutions of (5 and 10) dS·m^-1 salinity level, respectively, to investigate the influence on tomato (Lycopersicon esculentum Mill.) seedling growth. We also investigated the adaptability and survivability of treated tomato seedlings with high-salinity potassium (10 dS·m^-1 KCl) to harsh environmental conditions (water deficit, low temperature, and storage conditions). Repeated addition of high-salinity level KCl, K₂SO₄, or KH₂PO₄ markedly decreased the dry matter of shoot and root, leaf area, and net assimilate rates (NAR) but increased the stem diameter of seedlings. Among the three sources, the relative growth rate of plant height (RGR_H) was most sensitive to KCl addition; increasing salinity levels of KCl solution decreased the RGR_H of seedlings. The compactness, which directly reflects the stocky growth index, increased in KCl or KH₂PO₄ treatments. After a week's water deficit, severely wilted seedlings were observed in control seedlings (untreated with KCl), but no wilted seedlings were observed in the KCl treated seedlings, and the relative water content (RWC) of the untreated seedlings significantly decreased by 23 %, while that of the pretreated seedlings only decreased by 8 %. The increase in ion leakage of KCl treated seedlings at low temperatures was less than that of untreated seedlings. Furthermore, there was far lower damage proportion on pretreated seedlings at (9, 12, and 15)℃ storage temperatures after 20 days, compared with on unpretreated seedlings. Our results suggest that high-salinity potassium fertilizer, especially KCl, is effective in preventing tomato seedling overgrowth, while it also improves tolerance.

• Korean Journal of Breeding Science
• /
• v.51 no.4
• /
• pp.318-325
• /
• 2019

Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The objective of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M₂ mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.

• Current Research on Agriculture and Life Sciences
• /
• v.21
• /
• pp.1-9
• /
• 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 the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.95-103
• /
• 2019

Periodontal inflammation, a major kind of periodontal diseases, is characterized to bleed, pain, and teeth loss, and it is resulted from oxidative stress. Membrane-free stem cell extract could avoid the immunogencity rejection by removal of cell membrane. In the present study, we investigated the protective effect of membrane-free stem cell extract from oxidative stress-induced periodontal inflammation in human periodontal ligament fibroblasts (HPLF). In the cell viability measurement, membrane-free stem cell extract showed significant increase of cell viability, compared with the $H_2O_2$-treated control group. To further investigation of molecular mechanisms, we measured inflammation and apoptosis related protein expressions. Membrane-free stem cell extract attenuated inflammation-related protein expressions such as nuclear factor kappa light chain enhancer of activated B cells, inducible nitric oxide synthase, and interleukin-6. In addition, the treatment of membrane-free stem cell extract decreased apoptotic protein expressions such as cleaved caspase-9, -3, poly (ADP-ribose) polymerase, and B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 ratio in the $H_2O_2$-treated HPLF cells. In conclusion, membrane-free stem cell extract exhibited anti-oxidative stress effects by regulation of inflammation and apoptosis in HPLF, suggesting that it could be used as the treatment agents for periodontal inflammatory disease.

• Horticultural Science & Technology
• /
• v.31 no.6
• /
• pp.748-755
• /
• 2013

This study was conducted to find a salt tolerance gene in Brassica rapa. In order to meet this objective, we analyzed data from a KBGP-24K oligo chip [BrEMD (Brassica rapa EST and microarray database)] of the B. rapa ssp. pekinensis 'Chiifu' under salt stress (250 mM NaCl). From the B. rapa KBGP-24K microarray chip analysis, 202 salt-responsive unigenes were primarily selected under salt stress. Of these, a gene with unknown function but known full-length sequence was chosen to closely investigate the gene function. The selected gene was named BrSSR (B. rapa salt stress resistance). BrSSR contains a 285 bp open reading frame encoding a putative 94-amino acid protein, and a DUF581 domain. The pSL94 vector was designed to over-express BrSSR, and was used to transform tobacco plants for salt tolerance analysis. T1 transgenic tobacco plants that over-expressed BrSSR were selected by PCR and DNA blot analyses. Quantitative real-time RT PCR revealed that the expression of BrSSR in transgenic tobacco plants increased by approximately 3.8-fold. Similar results were obtained by RNA blot analysis. Phenotypic characteristics analysis showed that transgenic tobacco plants with over-expressed BrSSR were more salt-tolerant than the wild type control under 250 mM NaCl for 5 days. Based on these results, we hypothesized that the over-expression of BrSSR may be closely related to the enhancement of salt tolerance.

• Journal of muscle and joint health
• /
• v.9 no.1
• /
• pp.68-81
• /
• 2002

Arthritis patients living in a rural town are thought to have more problems in terms of life stress, social support, and depression than those living in an urban city. But there were few studies which investigated the status of arthritis patients living in a rural town. This study investigated how much life stress they got, which life events were perceived as stress, what kind of social support were most perceived, and how much they were depressed. Fifty six arthritis patients were surveyed using structured questionnaire. Life stress, social support, and depression were assessed using the following scales: Life changes scale, Duke's short scale to measure social support, and CES-D(Center for Epidemiologic Study- Depression), respectively. They were found to perceive life stress in home-work, health and work, in order. And they were found to perceive relatively good social support. But they sot most of social support from their family members especially their spouses and children. Lastly, it was found that they were moderately depressed. Based upon these results, it is suggested that integrative rehabilitation programs which provide professional support and reduce depression are necessary for arthritis patients living in rural towns.

• Journal of Life Science
• /
• v.11 no.5
• /
• pp.464-469
• /
• 2001

A gene, dnaK2, encoding a distinct member of the HSP70 family of molecular chaperones is isolated from the halotolerant cyanobactrium Aphanothece halophytica. The dnak2 gene encodes a molecular wight of 68 kDa polypeptide with predicted 616 amino acid residues. The DnaK2 protein has a structural characteristic of bacterial DnaK homologues and shows high similarity to other HSP70/Dank proteins. The danK2 transcripts are hardly detectable at 28$^{\circ}C$ and strongly induced upon heat stress. It is also found that dnaK2 transcript is increased by high-salinity stress even in the absence of heat stress. These results suggest that the DnaK2 protein plays an important role in protecting A. halophytica against damage caused by salt stress at well as heat stress.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2010.10a
• /
• pp.23-23
• /
• 2010

전북 서해안 새만금 지역에 조성되는 간척지 면적 28,300ha의 30%인 8,400ha 정도가 농업용지로 사용되는 계획이 확정됨에 따라 해당 용지를 효율적으로 사용 할 수 있는 다양한 활용 방안이 요구되고 있다. 대단위 농업지구가 들어설 예정지인 새만금 광활 간척지는 네덜란드와 유사하게 토양의 대부분이 미사질 양토로 이루어져있어 적용 가능한 화훼류를 적절히 선발하고 적합한 재배기술을 도입한다면 대규모 화훼제배 단지로서의 성장 가능성이 충분할 것으로 판단된다. 따라서 전북 농업기술원에서는 2004년부터 7년에 걸쳐 새만금 간척지의 농업적 활용도 제고와 경관농업 육성을 통한 관광자원화 가능성을 확인하기 위하여 72종의 원예작물 적응시험을 실시하였으며 22종의 자생식물과 튤립, 아이리스, 수선화, 히아신스, 참나리 등 5종의 구근 화훼류를 적합 화훼류로 선발하였다. '08~09년에는 내염성과 저온 및 풍해 저항성이 있는 아펠톤, 골든아펠톤, 네그리타, 프랑소와즈, 키스네리스 등을 간척지적용 가능 주요 튤립 품종으로 선발 하였는데 선발된 품종들을 대상으로 높은 염농도 하에서의 체내축적 무기성분을 조사한 결과, K와 Mg은 증가되는 경향이었으나 Ca은 감소되었으며, Cl이온은 현저하게 증가하였다. 또한 튤립체내의 산도 및 전기전도도와 항산화효소의 활성이 증가하였는데 스트레스 반응결과 유해산소가 체내에 축적되고, 이를 중화시키기 위하여 수소이온을 소모함으로써 체내의 산도는 상승된 것으로 추정되며 염분함량이 높을수록 삼투압에 의하여 뿌리에서 흡수는 양분이 적은 반면 잎 줄기의 증산작용은 동일하기 때문에 상대적으로 체내의 농도가 높아져 전기전도도가 상승된 것으로 판단된다. 식물 스트레스의 지표물질로 사용되고 있는 proline 함량도 토양내의 염도가 상승되면서 증가되었으며 엽록소 함량은 감소되는 경향을 보였다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.6
• /
• pp.492-499
• /
• 2009

Effect of drip irrigation on soil salinity control and growth of vegetable crops was studied in the three reclaimed lands of Korea in 2007. Drip irrigation was done one or two times per month for reduction of salt stress by using vinyl hose with tiny holes laid on ridge surface under black plastic film mulch during growing season of cabbage and chinese cabbage. It was observed that drip irrigation was generally effective to soil salinity control, but soil salinity variation of some place was not fully solved to lower down under level of free salt stress. It is also considered that high salinity of runoff water spilled out from cultivation ridge plays another key role for soil salinity management. Consequentially, this soil salinity variation might be one of factors brought low average yield and low commercial ratio of agricultural products. Relation between soil salinity and head growth of cabbage and chinese cabbage was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the heaviest head can be estimated was $6.1dS^{\circ}{\S}m^{-1}$ for cabbage and $5.7dS\;m^{-1}$ for chinese cabbage transplanted at optimum season.