• Title/Summary/Keyword: Salinity stress

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NITROGEN EXCRETION IN THE BIVALVE MOLLUSCS (이매패의 질소배설 2. 굴)

  • CHIN Pyung;LEE Bok Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.12 no.4
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    • pp.293-296
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    • 1979
  • The effects of temperature and salinity on tile rates of ammonia and amino nitrogen excretion, and oxygen consumption were measured for Crassostrea gigas. There was variability with temperature and salinity changes in both the rates of nitrogen excretion and the proportionality between ,ammonia and amino acids in the excreta, and also in the rates of oxygen consumption. Rates of nitrogen excretion and oxygen consumption were markedly decreased with increase in salinity, especially at high salinity-high temperature, whereas at low salinity-high temperature condition they were significantly increased. These changes are considered as the responses of physiological tolerances to the high temperature stress and the results of the metabolic temperature compensation at the low salinity-high temperature condition. Most of nitrogenous excretory products was ammonia, and large amounts of amino-nitrogen was excreted, and especially the rate of amino-nitrogen excretion was dominant at $32.5\%_{\circ}-22^{\circ}C$. The amounts of amino-nitrogen excreted by animals were decreased in the medium of high salinity and increased in the medium of low salinity through the experimental temperature. The atomic ratios of oxygen consumed to ammonia-nitrogen excreted (O: N ratio) was low at the low temperature $(15^{\circ}C)$, and was high at $22^{\circ}$ and $29^{\circ}C$ in the medium of 32.5 and $37.5\%_{\circ}$ but low in the low salinity $27.5\%_{\circ}$.

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The 1996 Mass Mortality of Macrobenthic Animals in Cheju Island: A Possible Role of Physical Oceanographic Factor (1996년 제주도에 나타난 대형저서동물의 대량폐사: 물리해양학적 요인의 역할)

  • 서해립;조양기;서호영;김대환
    • Korean Journal of Environmental Biology
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    • v.17 no.2
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    • pp.175-182
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    • 1999
  • An unprecedented mass mortality of commercially important macrobenthic animals, including Haliotis discus discus, H. diversicolor, Batilus cornutus, Sticopus japonious and Hemicentrotus puzoherrimus, occurred off the west coast of Cheju Island in summer of 1996. Phytoplankton blooms were absent along the coast. The appearances of the surface low-salinity water (SLSW) off the coast of Cheju Island preceded the mass mortality, leading to speculation that the low-salinity stress may have a crucial role in the mass mortality. Since there was no heavy rain for the same period, the precipitation was not a possible explanation for the decrease of salinity. Physical oceanographic data taken by NFRDI (1997) clearly indicated that the SLSW was present in the area between China and Cheju Island in August 1996. This is most likely due to a freshwater supply resulting from the existence of large river runoff. Evidence of the current and the distance between the Yangtz River and Cheju Island also supports the hypothesis that source of the SLSW was the freshwater originated from the Yangtz River runoff.[macrobenthic animals, mass mortality, surface low-salinity water].

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The Laboratory Study on Estimation of Depositional Properties of Kaolinite Sediments on Saltwater Condition (염도 존재시 고령토 퇴적물의 퇴적특성 산정에 관한 실험적 연구)

  • Hwang, Kyu-Nam;Kim, Nam-Hun;Lee, Yong-Hao
    • Journal of Korea Water Resources Association
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    • v.41 no.9
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    • pp.863-872
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    • 2008
  • In this study, a series of deposition tests have been conducted on saltwater condition(salinity 32 %o) using an annular flume, in order to estimate depositional properties of kaolinite sediments and to analyze the effect of the initial concentration on them. Total 37 deposition tests have been carried out in three different initial concentrations (1000, 5000, 15000 ppm) with varying the bed shear stress. From these test results, minimum shear stress (or critical shear stress for deposition; ${\tau}_{bmin}$) and the deposition rate parameters (${\sigma}_1,\;({\tau}^*_b-1)_{50},\;{\sigma}_2,\;t_{50}$) for kaolinite sediments have been quantified, and the effects of the initial concentration and salinity on depositional properties of cohesive sediments have been analyzed qualitatively. As the results, ${\tau}_{bmin},\;{\sigma}_1\;and\;({\tau}^*_b-1)_{50}$ are found to be 0.147, 0.74 and $0.65N/m^2$ respectively. Through comparing with results from previous studies, the performance of this study and tests results are shown to be good enough to verify.

Characterization and Gene Co-expression Network Analysis of a Salt Tolerance-related Gene, BrSSR, in Brassica rapa (배추에서 염 저항성 관련 유전자, BrSSR의 기능 검정 및 발현 네트워크 분석)

  • Yu, Jae-Gyeong;Lee, Gi-Ho;Park, Ji-Hyun;Park, Young-Doo
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.845-852
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    • 2014
  • Among various abiotic stress factors, soil salinity decreases the photosynthetic rate, growth, and yield of plants. Recently, many genes have been reported to enhance salt tolerance. The objective of this study was to characterize the Brassica rapa Salt Stress Resistance (BrSSR) gene, of which the function was unclear, although the full-length sequence was known. To characterize the role of BrSSR, a B. rapa Chinese cabbage inbred line ('CT001') was transformed with pSL94 vector containing the full length BrSSR cDNA. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the expression of BrSSR in the transgenic line was 2.59-fold higher than that in the wild type. Analysis of phenotypic characteristics showed that plants overexpressing BrSSR were resistant to salinity stress and showed normal growth. Microarray analysis of BrSSR over-expressing plants confirmed that BrSSR was strongly associated with ERD15 (AT2G41430), a gene encoding a protein containing a PAM2 motif (AT4G14270), and GABA-T (AT3G22200), all of which have been associated with salt tolerance, in the co-expression network of genes related to salt stress. The results of this study indicate that BrSSR plays an important role in plant growth and tolerance to salinity.

Screening of saline tolerant plants and development of biological monitoring technique for saline stress. II. Responses of emergence and early growth of several crop species to saline stress. (내염성 식물의 탐색 및 생물학적 염해 모니터링 기술의 개발 II.염분 스트레스에 대한 작물의 출현과 초기 생장 반응)

  • Shim, Sang-In;Lee, Sang-Gak;Kang, Byeung-Hoa
    • Korean Journal of Environmental Agriculture
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    • v.17 no.2
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    • pp.122-126
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    • 1998
  • This experiment was conducted to verify the responses of major crop species to saline stress.To determine the saline tolerance of crop species, sevral crop species were cultivated under sand-culture system using Hoagland's nutrient solution whit 200mM NaCl. The crop species showing saline tolerance were cotton(Gossypium indicum), maize(Zea mays), barely(Hordeum vulgare), and wheat(Triticum aestivum) but perilla (Perilla frutescens) and leguminous crops, mung bean(Phaseolus radiatus), azuki bean(Phaseolus angularis) and soy bean(Glycin max) showed very por tolerance. One the typical symptom was the darkening of leaf color due to increase of chlorophyll concentration.Among of the plant families, Fabaceae was the most susceptible but crop species belonging to Poaceae were more proper for cultivating on reclaimed tidal land in the course of desalinazation. It was suggrsted that the crop species belonging to Fabaceae, a sensitive family to soil salinity, must be cultivated when the soil salinity decreased below 10ds/m. To know the critical salinity level for crop growth,salinity of saline soil collected from reclaimed tidal land was adjusted from 10.0ds/m tp41.7ds/m with tap water. It was suggested that the ECs of the soil in which the plant height of each crop spicies was reduced to 50% of control plant were 22.6 and 21.7 ds/m in rice, barley, corn, mung bean, and soy bean,respectively.

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