• 한국작물학회지
• /
• 제37권3호
• /
• pp.288-298
• /
• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

• 대한의생명과학회지
• /
• 제11권4호
• /
• pp.539-543
• /
• 2005

Elevated level of serum cholesterol in humans is a risk factor correlated with the development of coronary heart disease. We have screened lactic acid bacteria from pig and human feces for the development of probiotics which have an anti-cholesterol effect. We have used special media to isolate only lactic acid bacteria and they were subjected to the experiments such as oxgal test, carbohydrate fermentation test. Results from the acid tolerance test and growth test in the presence of oxgal demonstrated that some strains would likely survive in thuman stomach, where acidity is high, and in small intestine, where bile fluid is present. In conclusion, we were able to screen lactic acid bacteria which were tolerant against bile acid and supposed to be prominent to lower the cholesterol level in human serum.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
• /
• pp.75-78
• /
• 1999

To obtain direct evidence for thed involvement of C-AB13, a carrot (Daucus carota L.) homolog of VPI/Ab13, seed-specific transcription factor, in the acquisition of desiccation tolerance carrot non-embryogenic cells (NC) in which the C-AB13 gene was expressed ectopically was prepared. Non-transgenic NC, in which expression of C-AB13 was not detected, did not exhibit desiccation tolerance even after treatment with abscisic acid (ABA). In transgenic NC that expressed C-AB13, embryo-specific ABA-inducible genes (ECP genes) were expressed upon ABA-treatment. Furthermore, the transgenic NC became desiccation-tolerant upon ABA-treatment, but not tolerate desiccation without ABA-treatment. These results provide direct evidence for the involvement of C-AB13 in the ABA-induced acquisition of desiccation tolerance.

• 한국축산식품학회:학술대회논문집
• /
• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
• /
• pp.349-352
• /
• 2004

Twelve strains of Lactobacillus acidophilus isolated from feces of human or animal sources were tested for probiotic properties such as cholesterol assimilation, bile and acid tolerances, and CLA production. Although the cultures showed some variation with respect to each test, the 12 strains could be classified into 3 groups based on their ability to assimilate cholesterol. The cholesterol assimilation showed positive correlation with bile tolerance and negative correlation with acid tolerance. The cholesterol assimilation of L. acidophilus strains may not be related to the deconjugation activity, but may in fact be attributed to its bile tolerance. CLA production by lactic acid bacteria (LAB) exhibited a wide variation that ranged from 2.69 to 7.64 mg/g fat. CLA production of Bifidobacterium longum ATCC 15707 was the highest among the LAB tested, but there was no evidence for differences in CLA production between genus and species.

• Animal Bioscience
• /
• 제34권7호
• /
• pp.1210-1220
• /
• 2021

Objective: Unlike mammals, goose fatty liver shows a strong tolerance to fatty acids without obvious injury. Stearyl-coenzyme A desaturase 1 (SCD1) serves crucial role in desaturation of saturated fatty acids (SAFs), but its role in the SAFs tolerance of goose hepatocytes has not been reported. This study was conducted to explore the role of SCD1 in regulating palmitic acid (PA) tolerance of goose primary hepatocytes. Methods: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide was examined to reflect the effect of PA on hepatocytes viability, and quantitative polymerase chain reaction was used to detect the mRNA levels of several genes related to endoplasmic reticulum (ER) stress, inflammation, and apoptosis, and the role of SCD1 in PA tolerance of goose hepatocytes was explored using RNA interfere. Results: Our results indicated that goose hepatocytes exhibited a higher tolerant capacity to PA than human hepatic cell line (LO2 cells). In goose primary hepatocytes, the mRNA levels of fatty acid desaturation-related genes (SCD1 and fatty acid desaturase 2) and fatty acid elongate enzyme-related gene (elongase of very long chain fatty acids 6) were significantly upregulated with 0.6 mM PA treatment. However, in LO2 cells, expression of ER stress-related genes (x box-binding protein, binding immunoglobulin protein, and activating transcription factor 6), inflammatory response-related genes (interleukin-6 [IL-6], interleukin-1β [IL-1β], and interferon-γ) and apoptosis-related genes (bcl-2-associated X protein, b-cell lymphoma 2, Caspase-3, and Caspase-9) was significantly enhanced with 0.6 mM PA treatment. Additionally, small interfering RNA (siRNA) mediated downregulation of SCD1 significantly reduced the PA tolerance of goose primary hepatocytes under the treatment of 0.6 mM PA; meanwhile, the mRNA levels of inflammatory-related genes (IL-6 and IL-1β) and several key genes involved in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), forkhead box O1 (FoxO1), mammalian target of rapamycin and AMPK pathways (AKT1, AKT2, FoxO1, and sirtuin 1), as well as the protein expression of cytochrome C and the apoptosis rate were upregulated. Conclusion: In conclusion, our data suggested that SCD1 was involved in enhancing the PA tolerance of goose primary hepatocytes by regulating inflammation- and apoptosis-related genes expression.

• KSBB Journal
• /
• 제14권4호
• /
• pp.389-395
• /
• 1999

Bifidobcterium spp. can provide human being with several beneficial physiological. Therefor, there has been a considerable interest in products Bifidobcterium spp. dietary supplements or as starter cultures for probiotic products that may assint in the improvement of health on the human. But indusrial applications have been limited because Bifidobcterium spp. are sensitive to acidic pH due to organic acid produced by themselves and various conditions. The objective of this study was to establish new method for improvement of Bifidobcterium viability by entrapment im calcium alginate beads. We have a plan to select the most suitable polymer through the comparison with acid tolerance oxygen tolerance and theological properties of polymer. Increase of the viable number of Bifidobcterium induced increasing acid tolerance and oxygen tolernce trough the development of entrapment technique. The 4%, 3030mm diameter) sodium alginate beads led to the best survivability under acid condition. Especially, addition of 6% mannitol, 6% glycerol or 6% sorbitol to the sodium alginate helped a beneficial effect on viability against acid, bile salt, hydrogen peroxide and cold strage. The number of viability of entrapeede cells by retreatment was 96 fold higher than non-entrapeed cells after 5 hours of storage under pH 3 acidic condition. These experimental data clearly demonstrate that a whole cell immobilization by entrapment in calcium alginate beads is an important survival mechanism enable to withstand environmental stresses as the acidic condition, hydrogen peroxide toxicity and frozen state.

• 한국환경과학회지
• /
• 제11권11호
• /
• pp.1173-1181
• /
• 2002

The present study was undertaken to investigate the effect of low temperature and salicylic acid(SA) on the chilling tolerance of acclimated and nonacclimated cucumber(Cucurmis sativus L.) seedlings. The acclimation phenomenon was characterized in chilling-sensitive cucumber seedlings and found to have a significant effect on the survival and shoot dry weights. The injuries experienced by the acclimated seedlings in the third leaf stage were on average smaller by half than those experienced by the nonacclimated seedlings. Chilling also caused a large increase in the free proline levels, regardless of the acclimation status. Exogenous treatment with SA(0.5mM) resulted in improved growth and survival of the nonacclimated chilled seedlings, indicating that SA induced chilling tolerance and SA and acclimation had common effects. The application of cycloheximide in the presence of SA restored the acclimation-induced chilling tolerance. The elevated proline level observed in the cold-treated and SA-treated plants was more pronounced in the light than in the dark at a chilled temperature, indicating that endogenous proline may play a role in chilling tolerance by stabilizing the water status in response to chilling. From these results it is suggested that SA provided protection against low-temperature stress by increasing the proline accumulation, and pre-treatment with SA may induce antioxidant enzymes leading to increased chilling tolerance.

• Asian-Australasian Journal of Animal Sciences
• /
• 제11권4호
• /
• pp.434-440
• /
• 1998

Seven hybrid lines of Leucaena leucocephala $\times$ L. diversifolia and two control lines of L. leucocephala were compared for their adaptation to acid-soils and tolerance to damage by the psyllid, Heteropsyla cubana, at four locations over two years in Peninsular Malaysia. Primary data on leaf composition and in vitro digestibility (nutrition variables) and secondary data on plant height, stem girth and psyllid damage (agronomy variables) were the measures of performance. Cluster solutions of the nine lines were different within locations, between locations and between years for nutrition and agronomy variables. Controls and hybrids did not cluster separately. Principal component scores of the nine lines gave rank orders which were different by location and by year. No performance trend could be detected between hybrids and controls. The conclusion is that nutritional and agronomic characteristics in Leucaena are independent, soil composition and weather did not consistently affect performance, and evidence is inconclusive as to the benefits of interspecific crossing with L. diversifolia.

• 한국산림과학회지
• /
• 제11권1호
• /
• pp.1-24
• /
• 1970

본(本) 실험(實驗)은 우리나라 주요조림수종(主要造林樹種)인 해송, 소나무, 리기다소나무, 잣나무, 낙엽송, 전나무에 대하여 토양(土壤) pH에 따른 영양흡수동태(營養吸收動態)와 내산도(耐酸度)를 밝히기 위하여 인공적(人工的)으로 pH를 조절(調節)한 사경배지(砂耕培地)에서의 N, P, K, Ca 및 Fe의 흡수동태(吸收動態)와 내산도(耐酸度)를 검토(檢討)하였다. 1. 강산성역(强酸性域)에서의 영양흡수동태(營養吸收動態)를 pH 3구(區)를 기준(基準)으로 건물증가율(乾物增加率)로서 보면 리기다소나무>소나무>해송 이었고 따라서 내산도(耐酸度)도 같은 순위(順位)라고 할 수 있다. 2. 알카리성역(性域)인 pH 9구(區)에서의 영양흡수동태(營養吸收動態)를 건물증가율(乾物增加率)로서 보면 해송>리기다소나무>소나무>잣나무>전나무>낙엽송이었음으로 내(耐)알카리 도(度)도 같은 순위(順位)라고 할 수 있다. 3. 본(本) 실험(實驗)에서 K와 Ca의 흡수동태(吸收動態)로 보아 그 흡수동태(吸收動態)로서 내산도(耐酸度)를 판정(判定)할 수 있으며 흡수량(吸收量)이 K>Ca이면 내산성(耐酸性)이 강(强)하고 K

• Applied Biological Chemistry
• /
• 제36권1호
• /
• pp.38-44
• /
• 1993

1) OBT mutant는 Clostridium saccharoperbutylacetonicum ATCC 13564(N1-4주(株))로부터 UV light와 butanol tolerance에 의해 분리했다. 동 돌연변이주(株)는 16.46g/l(1.4배 증가)의 부타놀과 4.6g/l(1.5배 증가)의 아세톤을 생산하고 전체 용매는 21.47g/l를 생산했다. 이 결과는 n-butanol을 생산하는 clostridial bacteria에서 error-prone pathway를 통한 misrepair의 약한 효과가 UV light와 butanol tolerance에 의해서 극복되었다는 것을 제시했다. 2) glucose 발효에 비교해서 mannitol 발효에서 OBT mutant는 acetone과 acetic acid는 생산되지 않았다. 전체용매에 대한 n-butanol과 ethanol의 비는 각각 10.3%와 10.6%씩 증가되었고 전체적으로는20.9% 증가된 반면, acetone의 비는 21.2%가 감소되었다. 또한 전체 용매에 대한 n-butanol의 최대비는 94.8%까지 증가하였다. 이들 결과는 산화합물(acetone, acetic acid, butyric acid)이 환원화합물(n-butanol, ethanol)로 전환된 것을 의미했다. 따라서 mannitol은 부산물인 산화합물을 제거하는데 사용할 수 있다.