• 농업기술회보
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• v.49 no.6
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• pp.35-35
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• 2012

비닐이나 유리로 피복되어 있는 원예재배시설은 저온, 강우 등의 불량환경을 극복하여 작물의 생산성을 높이는 데 크게 이바지해 왔다. 그러나 여름철 고온기에 강광의 유입은 직접적 작물 스트레스는 물론 시설 내 온도를 과도하게 상승시켜 작물생육에 악영향을 미친다. 이 때문에 일반적으로 환기와 차광에 의존하여 시설 내 온도상승을 억제하고 있으나 어려움이 많다. 이에 원예재배시설 내 온도 및 광환경을 개선하기 위하여 개발된 유동차광 냉각시스템을 소개하고자 한다.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.216-217
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.11a
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• pp.43-43
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• 2020

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.04a
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• pp.70-70
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• 2021

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.267-276
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• 2006

To investigate the physiological responses to winter freezing stress naturally occurring, the level of lipid peroxidation and enzymatic antioxidant responses were compared between zoysiagrass and creeping bentgrass during overwintering. Root mortality of creeping bentgrass was significantly higher than zoysiagrass at January. Root growth of creeping bentgrass was nearly parallel with temperature fluctuation, while zoysiagrass showed little changes in root growth until the end of April. Total nonstructural carbohydrate of zoysiauass was 10% higher than creeping bentgrass. Malondialdehyde(MDA) content in creeping bentgrass was 2-fold higher than that of zoysiagrass. The peroxidase(POD) activity of creeping bentgrass in January was 4.2 times higher, while superoxide(SOD) and catalase(CAT) activities lowered 22% and 67%, respectively, compared to zoysiagrass. These results suggest that zoysiagrass roots much properly operate cold tolerance mechanism and: are less susceptible to cold stress in comparison to creeping bentgrass.

• Research in Plant Disease
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• v.26 no.3
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• pp.144-158
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• 2020

Quantitative reverse transcription PCR is used for gene expression analysis as the accurate and sensitive method. To analyze quantification of gene expression changes in apple plants, 10 housekeeping genes (ACT, CKL, EF-1α, GAPDH, MDH, PDI, THFs, UBC, UBC10, and WD40) were evaluated for their stability of expression during infection by Apple stem grooving virus (ASGV) or in cold-stress apple plant buds. Five reference-gene validation programs were used to establish the order of the most stable genes for ASGV as CKL>THFs>GAPDH>ACT, and the least stable genes WD40CKL>UBC10, and the least stable genes were ACT

• Applied Biological Chemistry
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• v.43 no.4
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• pp.236-240
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• 2000

Correlations between mitochondrial respiration, glycolysis activity and overall growth activity of rice (Oryza sativa: cv. Dasan) seedlings during low temperature exposure were studied in order to provide insights into the underlying mechanism for the primary phase of chilling injury in plants. Among cellular membranes involved in energy metabolism, only the mitochondrial inner membrane showed not only physical phase transition at ca. $13^{\circ}C$, as monitored by ESR spin label, but also functional phase transition at the same temperature, as assessed by cytochrome c oxidase activity. The main regulatory enzyme of glycolysis, phosphofructokinase, in situ did not suffer phase transition of its activity at least in the $4{\sim}27^{\circ}C$ range. Low temperature caused a significant accumulation of glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P), which disappeared almost completely on rewarming of the seedlings. Temperature profiles of the steady state levels of G6P and F6P revealed the inflection point appearing at around phase transition temperature of the mitochondrial membrane. The results conform to our previous proposition on the mechanism for the early stage events of chilling injury that the accumulation of glycolytic metabolites in cells due to metabolic imbalance at low temperature gives rise to an excess supply of electrons during rewarming period, which, in turn, results in overproduction of active oxygen in mitochondria.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.554-564
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• 1994

세균이 세포내 공생하는 xD strain과 모 세포주인 tD strain Amoeba proteus의 열충격 대응의 차이를 알아 보기 위하여 방사선 동위원소로 표지된 아미노산을 Ca2+_less Chalkley's 용액에서 음작용 경로를 통하여 90분 동안 흡수하게 하고, 저온 및 고온 스트레스에 대하여 새로 합성되는 스트레스 대응 단백질의 양상을 1, 2차원 전기영동 및 자기방사 사진법에 의해서 비교하였다 저온(10"C) 충격에 대응하여 아메바는 두 strain 모두 56.0 kDa, pl 6.0 단백질을 강하게 발현하였으며, xD strain에서는 tD strain과 달리 저온 충격 초기에 66 0 kDa, pl 5.5 단백질의 발현이 중단되었다. 한편 고온(33"C) 열충격에 대하여 두 strain 아메바에서 모두 10여종의 단백질이 새합성되는 것으로 확인되었으며, tD 아메바에는 이들 단백질의 새합성이 완만하게 이루어지는데 비하여 xD 아메바에서는 그중 66.0 kDa 단백질이 고온 대응 단백질로서 신속하게 새합성되는 것으로 나타났다. 이외에도 2차원 전기 영동 분석을 통하여 열충격에 의해서 발현이 촉진되는 다수의 단백질들을 탐지하였다 탐지된 아메바의 열충격 단백질은 분자량에 따라 hsp100군 2종, hsp90군, 3종, hsp70군 및 hsp60군 각 1종, 그리고 small csp군 4종으로 분류해 볼 수 있었다 두 분석의 결과를 종합해 보면 tD 아메바에는 저온 및 고온 충격에 대하여 열충격 단백질의 합성이 완만하게 상승하는 데 비하여 xD strain에서는 신속하게 이루어졌다. 이상의 결과로 보아 아메바의 세포내 공생 세균은 숙주의 열충격 대응기작에 변화를 야기한 것으로 판단된다한 것으로 판단된다. 10mg과 20mg의 estrogen 처리구 사이에 유두 직경, 길이 그리고 용적의 증가량에 있어서는 차이가 없었다. 10mg 및 20mg의 estrogen 처리는 초발정일령을 각각 20일 및 124일 단축시켰다. 전체적으로 이러한 결과는 송아지에 estradiol의 삽입은 성장과 유선 발달을 촉진시키고 초발정일령을 단축시킬수 있다는 것을 강력하게 지적한다. 일치하지 않으므로 더욱 정밀한 조사를 실시하여 분류학상의 위치를 정확히 밝혀 볼 필요가 있을 것으로 생각되었다.연한 도구이자 정신활동으로 보게함으로써, 주제 및 연구방법에서 획일성보다 다양성과 창조성이 강조되고 있다. 그리고 연구에 있어서 주제 의 다양성을 통해 보다 현실생활에 밀접하게 연결되어야 할 필요성은 학문이나 과학의 사회 성에 대한 새로운 인식을 가져다 주고 있다. 이러한 지리교육과정의 좌표의 변화된 측면들 을 고려하여, 지리교육과정의 새로운 방향은 다음의 세가지로 모색될 수 있다. 첫째, 爭點中 心 地理敎育課程이다. 사회쟁점에 대한 접근은 쟁점의 이해와 문제해결에의 지리적 관점의 활용을 통해 학습내용의 시사성과 사실성을 높힐 수 있다. 이때 문제해결능력을 통해 현대 시민의 자질 및 능력을 기를 수 있음은 물론, 다른 한편으로 실제세계 즉 학생의 실생활, 사 회, 국가, 세계에서 일어나는 일들과의 관련성을 갖게 함으로써, 내적 동기화와 외적인 자극 을 강력하게 결합할 수 있을 것이다. 이는 개인적 유관적합성과 사회적 유관적합성을 동시 에 확보하는 데 유리할 것이다. 둘째, 思考中心 地理敎育課程이다. 지리교육은 학생들을 지 식 및 기능의 숙달자가 되도록 할 것이 아니라 기본적 문장해독력의 수준을 넘어 능력있는 사고자로 길러내는 것을 목표로 하여야 한다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.246-253
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• 2012

Despite frequent freezing injury to tea trees due low temperature, drought, and strong wind during wintertime, no comprehensive measurements have been taken. We selected and examined 9 locations in Hwagae-myeon and 4 places in Agyang-myeon, Hadong-gun, Gyeonsanggnam-do where low temperature damage had occurred between December 2010 and February 2011. Our objective is to examine the effect of frost damage on the morphological symptom and harvest of a tea tree exposed to a constant low temperature environment during wintertime. The results of our analyses on meteorological environment, tea leaf chromaticity, water content and trypan blue are as follows: (1) the number of days with temperature of $-10^{\circ}C$ or less, which were subject to frost damage to a tea tree were 8 and 13.6% during the winterization period in 2011; (2) the accumulated time was 1,308 minutes, and the longest duration at $-10^{\circ}C$ was 588 minutes from 21:08 p.m. 15 January to 7:30 a.m. $16^{th}$ January. The rainfall was only 104 mm which was 306 mm less than the previous year; (3) the lightness L values in 2011 were higher than in 2012 due to dehydration and necrosis by blue discoloration and red discoloration at all areas in chromaticity measurement; (4) the water content in a tea leaf in 2011 was higher than in 2012 due to low rainfall and strong wind, and almost no cell death phenomenon was observed from normal tea leaves subject to no low temperature stress in a trypan blue analysis; and (5) partial coloration due to cell death, however, took place in the leaves damaged by blue discoloration subject to low temperature stress, and most coloration due to cell death took place in the leaves damaged by red discoloration.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.170-179
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• 2022

Glutamic acid is a precursor of essential amino acids that play an important role in plant growth and development. It is one of the biostimulants that reduce cold stress damage by stimulating biosynthetic pathways leading to cryoprotectants. This study evaluated the effects of glutamic acid foliar application on Kimchi cabbage under low-temperature stress. There were six treatments, combining three photo-/dark periods temperature levels (11/-1℃ extremely low, E; 16/4℃ moderately low, M; and 21/9℃ optimal, O) with and without glutamic acid foliar application (0 and 10 mg·L^-1; Glu 0 and Glu 10). Glutamic acid foliar application was sprayed once 10 days after transplanting, and then temperature treatment immediately after glutamic acid foliar application was conducted for up to four days. After four days of treatment, abscisic acid (ABA), phaseic acid (PA), dihydrophaseic acid (DPA), and abscisic acid-glucose ester (ABA-GE) contents were higher with Glu 10 treatment than Glu 0 treatment in M treatment. Glucose content was highest in E with Glu 10 treatment (52.1 mg·100 g^-1 dry weight), while fructose content was highest in O with Glu 0 treatment (134.6 mg·100 g^-1 dry weight). The contents of glucolepiddin (GLP), glucobrassicin (GBS), 4-methoxyglucobrassicin (4MGBS), neoglucobrassicin (GNBS), and gluconasturtiin (GNS) were highest among all treatments in E with Glu 10 treatments (0.72, 2.05, 1.67, 9.40 and 0.85 µmol·g^-1 dry weight). After two days of treatment, rapid changes in PA and DPA contents of E with Glu 10 treatments were confirmed, and several individual glucosinolate contents (GLP, GBS, 4MGBS, GNBS, and GNS) were significantly different depending on low temperature and glutamic acid treatment. In addition, the content of fructose was significantly lower than that of O treatment in E and M treatments after four days of treatment. Therefore, although the changes in PA, DPA, glucose, fructose, and individual glucosinolates according to low temperature and glutamic acid foliar treatment were shown. A clear correlation between low temperature and glutamic acid effects could not be evaluated. Results indicated that Brassica crops are cryophilic vegetables, do not react sensitively to low temperatures, and mostly have cold resistance.