• 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.

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

• 한국작물학회지
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• 제37권3호
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• pp.288-298
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• 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.

• Applied Biological Chemistry
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• 제34권2호
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• pp.162-167
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• 1991

식물의 저온 스트레스와 이에 대한 방어체계의 기작론적 측면을 탐색하기 위하여, 냉해유발조건하에서 세워둔 식물(주로 3-4엽기의 벼 유묘)를 대상으로 하여 조직중 pyruvate 함량, superoxide$(O_{\overline{2}})$ 수준 및 항산소성 효소들의 활성을 경시적으로 측정하였다. 저온$(5^{\circ}C)$처리동안에 엽조직에는 현저한 pyruvate축적이 일어났으며, 그 상대적 축적량은 처리시간의 경과에 따라 증가하였다. 그러나 저온처리된 식물을 상온하에 옮겨 놓았을 때 축적된 pyruvate는 곧 소진하기 시작하였으며 이와 동시에 조직내 superoxide$(O_{\overline{2}})$수준이 상승하기 시작하였다. 아울러, 몇시간 정도의 lag time을 가지며 superoxide dismutase(SOD)와 catalase의 활성도 증가하였다. 이에 반하여 또 다른 항산소성 효소인 Glutathione peroxidase는 활성화 현상을 전혀 보이지 않았다. 뿌리를 통해서 외부로부터 공급된 superoxide$(O_{\overline{2}})$는 뿌리 조직내의 SOD와 catalase의 활성을 유도하였다. 한편 $H_2O_2$ 공급이 조직내 catalase는 활성화시켰으나, 역시 glutathione peroxidase에 대해서는 어떤 영향도 미치지 않았다. 위의 모든 결과들은 저온처리중에 일어난 pyruvate의 세포내 축적이 상온으로 환원된 조직내에서 superoxide$(O_{\overline{2}})$ 및 이로부터 이차적으로 생성된 활성산소를 과잉 발생시키는 직접적 원인이라는 사실과, 두 항산소성 효소(SOD와 catalase)가 활성산소를 중간매체로 하여 일어나는 것으로 해석되는 식물냉해로부터 세포를 보호함에 있어서 결정적인 역할을 담당하고 있다는 사실을 강력히 시사하였다.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2004년도 총회및 심포지움
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• pp.67-72
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• 2004

Quality of fresh-cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml $h^{-1}\;m^{-2}\;atm^{-1}$ at $5^{\circ}C\;and\;99\%$ RH, respectively. While slices in containers with an initial atmospheric composition of air, $4\%\;CO_2+1\;or\;20\%\;O_2,\;8\%\;CO_2+1\;or\;20\%\;O_2,\;or\;12\%\;CO_2+20\%\;O_2$ showed fungal growth, slices in containers with $12\%\;CO_2+1\%\;O_2$ did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf-life of 2 weeks or more at $5^{\circ}C$. Experiments were conducted to compare changes in quality of slices of red tomato (Lycopersicon esculentum Mill. 'Sunbeam') fruit from plants grown using black polyethylene or hairy vetch mulches under various foliar disease management systems including: no fungicide applications (NF), a disease forecasting model (Tom-Cast), and weekly fungicide applications (WF), during storage at $5^{\circ}C$ under a modified atmosphere. Slices were analyzed for firmness, soluble solids content (SSC), titratable acidity (TA), pH, electrolyte leakage, fungi, yeasts, and chilling injury. With both NF and Tom-Cast fungicide treatments, slices from tomato fruit grown with hairy vetch (Vicia villosa Roth) mulch were firmer than those from tomato fruit grown with black polyethylene mulch after 12 days storage. Ethylene production of slices from fruit grown using hairy vetch mulch under Tom-Cast was about 1.5- and 5-fold higher than that of slices from WF and NF fungicide treatments after 12 days, respectively. The percentage of water-soaked areas (chilling injury) for slices from tomato fruit grown using black polyethylene mulch under NF was over 7-fold that of slices from tomato fruit grown using hairy vetch under Tom-Cast. When stored at $20^{\circ}C$, slices from light-red tomato fruit grown with black polyethylene or hairy vetch mulches both showed a rapid increase in electrolyte leakage beginning 6 hours after slicing. However, slices from tomato fruit grown using the hairy vetch mulch tended to have lower electrolyte leakage than those grown with black polyethylene mulch. These results suggest that tomato fruit from plants grown using hairy vetch mulch may be more suitable for fresh-cut slices than those grown using black polyethylene mulch. Also, use of the disease forecasting model Tom-Cast, which can result in lower fungicide application than is currently used commercially, resulted in high quality fruit for fresh-cut processing. Experiments were conducted to determine if ethylene influences chilling injury, as measured by percentage of slices exhibiting water-soaked areas in fresh-cut tomato slices of 'Mountain Pride' and 'Sunbeam' tomato (Lycopersicon esculentum Mill.). Ethylene concentration in containers without ventilation significantly increased during storage at $5^{\circ}C$, whereas little or no accumulation of ethylene occurred in containers with one or six perforations. Chilling injury was greatest for slices in containers with six perforations, compared to slices in containers with one perforation, and was over 13-fold greater than that of slices in control containers with no perforations. An experiment was also performed to investigate the effectiveness of including an ethylene absorbent pad in containers on subsequent ethylene accumulation and chilling injury. While ethylene in the no-pad controls increased continually during storage of both 'Mountain Pride' and 'Sunbeam' tomatoes at $5^{\circ}C$ under modified atmosphere conditions, no increase in accumulation of ethylene was observed in containers containing ethylene absorbent pads throughout storage. The ethylene absorbent pad treatment resulted in a significantly higher percentage of chilling injury compared with the no-pad control. In studies aimed at inhibiting ethylene production using AVG during storage of slices, the concentration of ethylene in control containers (no AVG) remained at elevated levels throughout storage, compared to containers with slices treated with AVG. Chilling injury in slices treated with AVG was 5-fold greater than that of controls. Further, we tested the effect of ethylene pretreatment of slices on subsequent slice shelf-life and quality. In slices treated with ethylene (0, 0.1, 1, or $10\;{mu}L\;L^{-1}$) immediately after slicing, ethylene production in non-treated controls was greater than that of all other ethylene pre-treatments. However, pretreatment of slices 3 days after slicing resulted in a different pattern of ethylene production during storage. Ihe rate of ethylene production by slices treated with 1 L $L^{-1}$ ethylene 3 days after slicing was greater during storage than any of the other ethylene treatments. With slices pre-treated with ethylene, both immediately and 3 days after slicing, the rate of ethylene production tended to show an negative correlation with chilling injury. Chemical name used: 1-aminoethoxyvinylglycine (AVG).

• Applied Biological Chemistry
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• 제37권6호
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• pp.433-440
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• 1994

상온에서 배양된 녹색조류 Clamydomonas reinhardtii를 $5^{\circ}C$의 저온에 세워두었을 때 세포내에는 괄목할 만한 pyruvate의 축적이 일어났다. 그러나 저온처리된 세포를 다시 상온으로 옮기면 세포내 pyruvate 수준은 감소하기 시작하며 이에 수반하여 superoxide radicals$(O_2^-)$의 발생수준이 증가하였다. 일정기간 후 최고치에 도달한 $O_2^-$ 수준은 다시 비교적 빠르게 떨어지기 시작하였는데, 이때를 전후하여 세포내 superoxide dismutase(SOD)가 현저하게 활성화 되었다. 이러한 결과는 벼의 냉해와 관련하여 얻었던 기존(본 연구실)의 관찰 사실과 매우 유사한 것으로서 고등식물이나 조류가 공히 냉해의 초기과정에 관한한 동일한 기작의 지배를 받고 있음을 시사한다. 아울러 본 연구에서는 저온처리에 의해 야기된 SOD의 활성 증가가 대부분 Mn-SOD의 활성화에 기인하는 것으로 관찰되었다. Mn-SOD는 세포 소기관 중 미토콘드리아에만 존재하므로, 이러한 관찰은 독성이 큰 산소화학종이 과생성되는 부정적 상황 즉 냉해유발 상황에 대처하기 위해 항산소성 효소가 냉해의 초기과정이 진행되는 미토콘드리아에서 유도된다는 개념과 부합된다.

• Applied Biological Chemistry
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• 제30권4호
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• pp.364-370
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• 1987

본연구의 근간이 되는 기본적 가정은, (1) 식물냉해기작에서 2차과정은 반응성이 강한 $O_2^-$의 체내 축적이다. (2) $O_2^-$는 식물체가 저온(低溫)처리를 받고 있는 도중이 아니라 상온(常溫)으로 환원된 뒤에 축적되기 시작한다. (3) $O_2^-$의 축적은 미토콘드리아 막의 상전이가 야기한 세포대사(細胞代謝)$(glycolysis{\rightarrow}TCA\;cycle{\rightarrow}respiratory\;electron\;transport)$의 균형파괴에 기인 한다. 이와 같은 가정을 뒷받침할 수 있는 중요한 연구 결과는 다음과 같다. 먼저 $O_2^-$의 상대적(相對的) 수준(水準)을 측정하는 방법을 확립하였다. 저온처리를 받은 벼 유묘는 처리하지 않은 유묘보다 그 조직 추출액중의 $O_2^-$수준이 높게 나타났다. 48시간의 저온처리중에는 $O_2^-$의 축적이 거의 일어나지 않았으나, 상온(常溫)으로 환원시킨 후 축적되기 시작하여 약 8시간후에 최고치에 도달하였다. Model system을 이용한 연구 결과, 호흡기질을 공급했을 때 미토콘드리아 membrane(SMP)에서 $O_2^-$의 생성이 증가하였다. 효소적으로 발생시킨 $O_2^-$가 존재하는 조건하에서 미토콘드리아막의 전자전달 활성이 저해를 받았다. $O_2^-$의 축적이 최고치에 도달한 후 급격히 감소되는 사실이 관찰되었으며, 이는 Superoxide dismutase(SOD)에 의한 $O_2^-$의 dismutation 결과로 해석되었다.

• 한국농림기상학회지
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• 제6권3호
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• pp.177-182
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• 2004

기온의 공간변이가 심한 넓은 지역에서 Chill Unit 축적량과 휴면해제일의 공간분포를 얻기 위해서 Utah Chill Unit 모형을 지리정보시스템과 결합하여 Chill Unit 공간적산기(CUMAP)을 개발하였다. CUMAP은 Grid 형태의 일 최고, 최저기온을 입력받아 시간내삽법에 의해 매시기온을 추정하고, Utah 모형에 의해 매시 Chill Unit을 계산한다. 하루 단위로 Chill Unit이 누적되면 Grid파일로 저장되며, 사용자가 정하는 저온요구량(임계값)에 도달하는 날짜를 역시 Grid파일로 생성한다. 전라북도 김제시 백구면 일대 포도재배지역에 대해 CUMAP을 적용하여 10m 해상도의 Chill Unit 일별 적산값과 휴면해제일 추정분포도를 작성하였다.

• Weed & Turfgrass Science
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• 제1권4호
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• pp.50-56
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• 2012

본 연구의 목적은 bar 유전자를 발현한 형질전환벼에 대한 글루타민 합성효소 저해제인 glufosinate-ammonium, L-metionine sulfoximine과 광합성저해제인 paraquat에 저항성 수준과 형질전환벼와 비형질전환벼의 암모늄 축적량, 저온반응 및 수량을 비교하는데 있다. 형질전환벼 계통은 비형질전환벼에 비해 glufosinate-ammonium에 45~95배 높은 저항성을 보였다. 한편 형질전환벼 계통은 L-metionine sulfoximine을 처리했을 때도 형질전환벼 계통이 비형질전환벼에 비해 18배 이상의 저항성을 보여 교차저항성이 있음을 확인할 수 있었다. 그러나 glufosinate-ammonium과 작용기작이 다른 제초제인 paraquat에 대한 다중저항성은 없었다. Glufosinate-ammonium 처리에 의해 ammonium 축적은 비형질전환벼에서 증가하였으나 모든 형질전환벼의 계통에서는 적거나 효과가 없었다. 형질전환벼 계통 258, 411, 607 및 608을 제외한 계통은 비형질전환벼에 비해 저온 내성 및 저온 후 회복정도가 유의적으로 낮은 경향을 보였다. 형질전환벼 계통 142, 144, 258 및 608의 수량은 비형질전환벼와 유사하거나 높았다.

• 농업과학연구
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• 제41권2호
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• pp.75-83
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• 2014

Recently, a quick drop of air temperature in plastic film houses by adverse weather conditions leads to the occurrence of low temperature damages to growing crops. Chilling injury, defined as a variety of growth restriction occurring below the optimal temperature, is one of environmental factors strongly affecting crop growth and yield. Low temperature causes the restricted evapotranspiration, reduced mineral uptake (P > K > $NO_3{^-}$), and an increase in electrolyte leakage such as K. Despite being different with plant species, an accumulation of soluble carbohydrates such as glucose, fructose, sucrose and starch under chilling condition is well known. A variety of environmental stresses are known to cause oxidative damage to plants either directly or indirectly by triggering an increased level of production of reactive oxygen species (ROS), and, to combat the oxidative damage, plants have the antioxidant defense systems comprising of enzymes, SOD, POD, CAT, GPX and APX, and non-enzymes, ascorbate, gluthathione, ${\alpha}$-tocopherol, phenolic compounds, carotenoid and flavonoids. The aim of this review is to provide basic information to build chilling-indicators and optimal nutrition management under adverse temperature conditions as broadly considering mineral uptake, carbohydrate metabolism and antioxidative defense system.