• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.244-244
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• 2017

Soil salinity due to accumulation of salts particularly sodium chloride affects agricultural lands and their vegetation. Generally, rice is a moderately sensitive plant with some cultivars with varying tolerance to salinity. Though there are physiological differences between salt-sensitive and salt-tolerant rice cultivars, both are still affected especially during high salinity and prolonged exposure. This also ultimately affects their indigenous bacterial endophytes particularly those that inhabit the rice seed endosphere. This study investigates the dynamic structure of seed bacterial endophytes of salt-sensitive and tolerant rice cultivars grown in different levels of soil salinity. Endophytic bacterial diversity was studied Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Results revealed a very interesting pattern of diversity and shifts in community structure of bacterial endophytes in the rice seeds. There is a general decrease in diversity for the salt-sensitive rice cultivar, IR29 as soil salinity increases. For the salt-tolerant cultivars, IC32 and IC37, diversity interestingly increased at moderate salinity then decreased at high soil salinity. The patterns of community structure is also strikingly different for the salt-sensitive and salt-tolerant rice cultivars. IR29 has a more even distribution of abundance, but under soil salinity, the community shifted where Curtobacterium, Pantoea, Flavobacterium and Microbacterium become the more dominant bacterial communities. For IC32 and IC37, the dominant bacterial groups under normal stress conditions were also the dominant bacterial groups during salt stress conditions. Their seed bacterial community is dominated by endophytes belonging to Microbacterium, Flavobacterium, Pantoea, Kosakonia and Enterobacter. Stenotrophomonas and Xanthomonas have not changed in terms of abundance under different salinity stress level in the salt-sensitive and salt-tolerant rice cultivars. This study showed that soil salinity greatly influenced the seed bacterial communities of rice seeds irrespective of their physiological tolerance to salinity.

• 농업과학연구
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• 제11권2호
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• pp.183-189
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• 1984

본(本) 실험(實驗)은 몇가지 사료작물종자(飼料作物種子)의 내염발아성(耐鹽發芽性)과 아울러 발아한계염분농도(發芽限界鹽分濃度) 및 내염성(耐鹽性) 사료작물(飼料作物)을 탐색(探索)코져 수행(수行)되었던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 발아율(發芽率)은 염농도(鹽濃度) 0.4% 까지는 대조구(對照區)에 비(比)해 약간(若干)의 감소(減少)를 보였으나 0.8%에서는 급격(急激)한 감소(減少)를 보였다. 2. 발아소요일수(發芽所要日數)는 염분농도(鹽分濃度)의 증가(增加)에 따라 완만(緩晩)한 증가(增加)를 나타냈다. 3. 유묘장(幼苗長) 및 근장(根長)은 0.4% 염농도하(鹽濃度下)에서는 대비구(對比區)에 비해 약간(若干) 감소(減少)되었으나 0.8%에서는 급격(急激)한 감소(減少)를 보였고 1.2%에서는 발아후(發芽後) 곧 생육(生育)이 정지(停止)되었다. 4. 식물체내(植物體內)의 NaCl함량(含量)은 내염성(耐鹽性)과 밀접(密接)한 관계(關係)를 나타냈던 바 염분농도(鹽分濃度)의 증가(增加)에 따라 식물체내(植物體內) NaCl함량(含量)도 높아졌으나 그 정도(程度)는 작물(作物)에 따라 달랐다. 5. 사료작물(飼料作物)의 발아한계염농도(發芽限界鹽濃度)는 0.4% 내지 0.8% 범권(範圈)이었으며 내염발아성(耐鹽發芽性)이 가장 강(强)한 작물(作物)은 perennial ryegrass였고 tall fescue, creeping red fescue, orchardgrass의 순(順)으로 나타났다.

• ALGAE
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• 제36권2호
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• pp.137-146
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• 2021

Intertidal macroalgae are regularly exposed to hypo- or hypersaline conditions which are stressful. However, red algae in New Zealand are generally poorly studied in terms of salinity tolerance. Consequently, two native (Bostrychia arbuscula W. H. Harvey [Ceramiales], Champia novae-zelandiae [J. D. Hooker & Harvey] Harvey [Rhodymeniales]) and one introduced red algal taxon (Schizymenia spp. J. Agardh [Nemastomatales]) were exposed for 5 days in a controlled salt stress experiment to investigate photosynthetic activity and osmotic acclimation. The photosynthetic activity of B. arbuscula was not affected by salinity, as reflected in an almost unchanged maximum quantum yield (F_v/F_m). In contrast, the F_v/F_m of C. novae-zelandiae and Schizymenia spp. strongly decreased under hypo- and hypersaline conditions. Treatment with different salinities led to an increase of the total organic osmolyte concentrations with rising salt stress in B. arbuscula and Schizymenia spp. In C. novae-zelandiae the highest organic osmolyte concentrations were recorded at S_A 38, followed by declining amounts with further hypersaline exposure. In B. arbuscula, sorbitol was the main organic osmolyte, while the other taxa contained floridoside. The data presented indicate that all three red algal species conspicuously differ in their salt tolerance. The upper intertidal B. arbuscula exhibited a wide salinity tolerance as reflected by unaffected photosynthetic parameters and strong sorbitol accumulation under increasing salinities, and hence can be characterized as euryhaline. In contrast, the introduced Schizymenia spp. and native C. novae-zelandiae, which preferentially occur in the mid-intertidal, showed a narrower salinity tolerance. The species-specific responses reflect their respective vertical positions in the intertidal zone.

• 한국작물학회지
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• 제67권1호
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• pp.41-52
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• 2022

1. 본 연구에서는 우리밀 품종인 금강밀과 염 저항성을 가지는 돌연변이 라인 2020-s1340을 재료로 200 mM 염 스트레스 처리에 따른 전사체 발현을 확인하였다. QuantSeq을 통해 23,634,438개의 reads가 생산되었고 7,331,269개의 reads가 mapping됐다. 2. 염 스트레스 상황에서 총 282개의 DEG가 확인이 되었고 이러한 DEGs는 UDP-glucosyltransferase, receptor kinase-like protein, Lectin receptor-like kinases, cytochrome P450등의 단백질들을 코딩하는 유전자들이다. 이러한 DEGs는 염 저항성과 관련된 후보 유전자들이 될 수 있다. 염 저항성과 관련하여 역할이 밝혀지지 않은 유전자들은 추후 연구를 통해 확인이 필요하다. 3. GO연구에서는 DEGs를 세가지 범주로 분류하였으며 대부분 식물체 내 세포 기초 경로와 관련된 GO term들이 주로 되었으며 각각 범주에 있어서 biological process, molecular process에서는 single-organism process (GO: 0044699), single-organism metabolic process (GO:0044710), oxidation-reduction process (GO:0055114), copper ion transport (GO:0006825), copper ion transmembrane transport (GO:0035434), alternative oxidase activity (GO:0009916) GO term들이 유의성이 높게 나타났다. 4. 이러한 QuantSeq의 분석결과는 밀에 관한 염에 의해 발현되는 전사 발현에 대한 이해를 향상시킬 수 있다. 또한 염 스트레스 반응의 복잡한 분자 메커니즘에 대한 좋은 통찰력을 제공하고 염분 스트레스에 대한 작물 내성의 유전적 개선을 위한 실질적인 토대를 마련할 수 있을 것이다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.222-224
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• 2011

The effects of seawater on growth of lettuce(Lactuca sativa L.), leaf perilla(Perilla frutescens var. japonica Hara), red pepper(Capsicum annuum L.) and cucumber(Cucumis sativus L.) seedlings were investigated in the glass greenhouse. These effects were studied on seedlings, and diluted seawater (1%, 5%, 10%, 20%, 50%, 100% v/v) was sprayed enough on leaves. The tested four vegetable crops have well grown up to 10% diluted seawater, but the tested vegetable crops were damaged from increasing salt levels. Of these, lettuce was provided salt-tolerant vegetable crop and red pepper was considered salt-sensitive vegetable crop. The salt tolerance of vegetable crops is different between crops and complicated because of additional detrimental effects caused by accumulated ions or specific ion toxicities in their leaves. These results show that agricultural use of seawater may be benefit crop cultivation in organic farming system as well as in conventional farming system.

• Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.349-357
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• 2015

To reutilize fisheries waste, we isolated a bacterial strain from a coastal area located in Busan. It was identified as Bacillus licheniformis TK3-Y. Using plate assay and 500-mL flask experiments, we found that the isolate simultaneously possessed cellulolytic, proteolytic, and lipolytic activities with salt tolerance. 10% (v/v) inoculums, were used to examine the biodegradation characteristics of the TK3-Y strain on carboxymethylcellulose, skim milk, and olive oil media. The optimum conditions for pH, temperature, agitation speed, and NaCl concentration on each 1% substrate were 6, $50^{\circ}C$, 180 rpm, and 17.5%, respectively. Under optimal conditions, the TK3-Y strain showed 1.07 U/mL cellulolytic, 1,426 U/mL proteolytic, and 6.45 U/mL lipolytic activities. Each enzyme was stable within a range of 17.5-35% NaCl. Therefore, the salt tolerance ability of strain TK3-Y was superior to other related strains. In degradation of a mixed medium containing all three substrates, both the cellulolytic and proteolytic activities were somewhat lower than those on each single substrate, while the lipolytic activity was somewhat higher. From the above results, the TK3-Y strain appears to be a good candidate for use in the efficient treatment of fisheries waste in which components are not collected separately.

• 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.

• 한국작물학회지
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• 제48권1호
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• pp.20-24
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• 2003

Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.62-70
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• 2020

Zygosaccharomyces rouxii is an important yeast that is required in the food fermentation process due to its high salt tolerance. In this study, the responses and resistance strategies of Z. rouxii against salt stress were investigated by performing physiological analysis at membrane level. The results showed that under salt stress, cell integrity was destroyed, and the cell wall was ruptured, which was accompanied by intracellular substance spillover. With an increase of salt concentrations, intracellular Na⁺ content increased slightly, whereas intracellular K⁺ content decreased significantly, which caused the increase of the intracellular Na⁺/K⁺ ratio. In addition, in response to salt stress, the activity of Na⁺/K⁺-ATPase increased from 0.54 to 2.14 μmol/mg protein, and the ergosterol content increased to 2.42-fold to maintain membrane stability. Analysis of cell membrane fluidity and fatty acid composition showed that cell membrane fluidity decreased and unsaturated fatty acid proportions increased, leading to a 101.21% rise in the unsaturated/saturated fatty acid ratio. The results presented in this study offer guidance in understanding the salt tolerance mechanism of Z. rouxii, and in developing new strategies to increase the industrial utilization of this species under salt stress.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.94-94
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• 2002