• 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.

• Journal of Plant Biotechnology
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• 제45권4호
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• pp.306-314
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• 2018

Korean ginseng (Panax ginseng) has long been cultivated as an important economic medicinal plant. Owing to the seasonal and long-term agricultural cultivation methods of Korean ginseng, they are always vulnerable to various environmental stress conditions. ABSCISIC ACID (ABA) is an essential plant hormone associated with seed development and diverse abiotic stress responses including drought, cold and salinity stress. By modulating ABA responses, plants can regulate their immune responses and growth patterns to increase their ability to tolerate stress. With recent advances in genome sequencing technology, we first reported the functional features of genes related to canonical ABA signaling pathway in P. ginseng genome. Based on the protein sequences and functional genomic analysis of Arabidopsis thaliana, the ABA related genes were successfully identified. Our functional genomic characterizations clearly showed that the ABA signaling related genes consisting the ABA receptor proteins (PgPYLs), kinase family (PgSnRKs) and transcription factors (PgABFs, PgABI3s and PgABI5s) were evolutionary conserved in the P. ginseng genome. We confirmed that overexpressing ABA related genes of P. ginseng completely restored the ABA responses and stress tolerance in ABA defective Arabidopsis mutants. Finally, tissue and age specific spatio-temporal expression patterns of the identified ABA-related genes in P. ginseng tissues were also classified using various available RNA sequencing data. This study provides ABA signal transduction related genes and their functional genomic information related to the growth and development of Korean ginseng. Additionally, the results of this study could be useful in the breeding or artificial selection of ginseng which is resistant to various stresses.

• Journal of Plant Biotechnology
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• 제38권2호
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• pp.186-190
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• 2011

본 연구는 백합나무 배발생조직으로부터 체세포배 유도에 영향하는 ABA (abscisic acid)의 농도, 환원질소원 및 삼투압제의 종류 및 농도 효과를 조사하기 위해 수행되었다. ABA농도 비교에서는 0.5 mg/L 첨가구에서 가장 높은 체세포배 유도 수 (640/10 mg 조직)를 보였으나 0.5 mg/L 이상의 농도에서는 점차 체세포배 발생 수는 감소하는 경향을 보였으며, 20 mg/L 농도에서 가장 낮은 유도수 (250/5 mg 조직)를 나타냈다. 8종류 환원질소원 종류 및 농도에 대한 체세포배 유도 효과를 비교한 결과 최대 체세포배 유도는 500 mg/L casamino acid (223/5 mg 조직) 첨가구에서 나타났으나, 그 외 환원질소원 종류 및 농도에 따라 매우 다양하게 나타났다. 삼투압제 종류 및 농도 비교에서는 최고의 체세포배 발생 수 (317/5 mg 조직)는 4% sucrose 첨가 시 나타났으나 maltose 첨가배지에서는 농도에 상관없이 체세포배가 전혀 유도되지 않아 삼투압제 종류에 따라 큰 차이를 보였다.

• 생명과학회지
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• 제15권2호
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• pp.298-303
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• 2005

포도 '거봉'의 착색을 조장하기 위해 적절한 ABA의 처리시기와 처리 횟수를 알아보기 위하여 본 실험을 수행한 결과 다음과 같은 결과를 얻었다. PAL 효소의 활성은 변색기 처리구와 변색기 10일 후 처리구에서 활성이 높은 것으로 나타났으며, 변색기 10일후 처리구가 변색기 처리구보다 약간 더 높은 효소 활성을 나타냈다. 안토시아닌 함량은 각 처리구 공히 생육기간 동안 계속 증가하는 경향을 보였고, 모든 ABA 처리구는 무처리구에 비해 훨씬 높은 안토시아닌 함량을 나타내었으며, 변색기 10일후 처리구에서 가장 높은 안토시아닌 함량을 나타내었다. 가용성당 함량에 있어서 과당과 포도당만이 검출되었으며, 처리구간에 함량의 차가 그다지 크지 않았다. 처리 횟수에 있어서 PAL 효소의 활성은 각 처리구 공히 증가하다가 감소하는 경향을 보였으며, 2회 처리구는 변색기 10일후의 2회째 처리 이후에도 급속한 PAL 효소 활성 증가가 이어져 최종수확기에서도 비교적 상당히 높은 효소 활성을 보였다. 변색기와 변색기 10일 후의 2회 처리구에서 안토시아닌 함량 증가가 가장 높아 최종수확기에 가서는 무처리구에 비해 5배 이상, 1회 처리구에 비해서는 2배정도 많았다. 1회 및 2회 ABA 처리구 모두 과당과 포도당 함량 공히 무처리구에 비해 약간 높은 경향을 나타냈지만 그다지 큰 차이는 없었다.

• 한국산림과학회지
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• 제99권4호
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• pp.633-637
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• 2010

본 연구는 낙엽송의 4가지 배발생조직(LL-L, LL-K, LL-P 및 LL-N)으로 체세포배 유도에 영향하는 배지종류, 엡시식산(abscisic acid, ABA)의 농도, 삼투압제의 종류 및 농도의 효과를 평가하기 위해 수행되었다. 배지종류 비교에서 1/2LM 배지에 배양한 LL-P 조직라인(134.9개/90 mg조직)에서 가장 높은 자엽단계의 체세포배가 유도되었으나 BLG 배지의 경우 LL-P라인(32.9개)을 제외하고는 체세포배가 전혀 유도되지 않았다. 2가지 ABA농도(60 혹은 100 ${\mu}M$)에 대한 4가지 배발생조직의 체세포배 유도 효과를 비교 한 바 최대 체세포배는 60 ${\mu}M$ ABA농도(142.9개)에서 나타났으나 LL-N 라인을 제외하고는 체세포배 발생에 ABA영향은 그리 크지 않은 것으로 나타났다. 삼투압제 종류 및 농도 비교에서 최고의 체세포배 발생은 LL-K 조직라인을 0.2 M maltose 첨가배지(540.5개)에 배양하였을 때 나타났다. 결론적으로 체세포배 발생 효과는 배지의 종류, 혹은 배지에 첨가된 ABA 및 삼투압제 농도보다는 배발생 조직 라인에 따라 크게 좌우되었다.

• Current Research on Agriculture and Life Sciences
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• 제10권
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• pp.99-108
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• 1992

천연형(天然形) ABA가 갖는 생물(生物) 활성(活性)을 향상(向上)시키기 위하여 합성(合成)된 ABA 유도체(誘導體)들의 생물활성(生物活性)과 아울러 초기생장(初期生長)과 밀접(密接)한 관계(關係)가 있는 peroxidase 활성도(活性度) 변화(變化)를 조사(調査)한 결과(結果)는 다음과 같다. $26{\pm}1^{\circ}C$, 암실(暗室)에서 7일간(日間) 생장(生長)시킨 보리 유묘(幼苗)의 지상부(地上部) 신장(伸張)은 3.2ppm의 (${\pm}$)-ABA, 1.2ppm의 (S)-(+)-ABA, 0.6ppm의 ABA-methyl cinnamate ester 화합물(化合物)(AC) 및 0.08ppm의 ABA-umbelliferone ester 화합물(化合物)(AU)에서 대조구(對照區)에 비(比)해 80% 이상의 저해(沮害)를 보여 (S)-(+)-ABA가 racemic ABA보다 약(約) 3배(倍), AC와 AU는 (S)-(+)-ABA보다 각각(各各) 약(約) 2.5배(倍), 16배(倍) 더 강(强)한 활성(活性)을 나타내었다. 발아(發芽) 후(後) 생장(生長)이 진행(進行)됨에 따른 보리 유묘(幼苗)의 지상부(地上部)의 peroxidase 활성도(活性度)는 대조구(對照區)에서는 큰 변화(變化)는 없었으나, ABA와 그 유도체(誘導體)를 처리(處理)한 보리 유묘(幼苗)의 지상부(地上部)에서는 계속 증가(增加)하였다. 생장(生長) 저해(沮害) 활성(活性)이 강(强)하게 나타난 고농도(高濃度) [3.2ppm의 (${\pm}$)-ABA, 1.2ppm의 (S)-(+)-ABA, 0.6ppm의 AC 및 0.08ppm의 AU]의 처리(處理)가 저농도(低濃度) [3.0ppm의 (${\pm}$)-ABA, 1.0ppm의 (S)-(+)-ABA, 0.4ppm의 AC 및 0.06ppm의 AU]의 처리(處理)보다 더 높은 peroxidase 활성도(活性度)를 나타내었으며, ABA 유도체들은 ABA보다 저농도(低濃度)에서 더 높은 peroxidase 활성도(活性度)를 나타내었다.

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• Molecules and Cells
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• 제27권4호
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• pp.409-416
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• 2009

ADAP is an AP2-domain protein that interacts with ARIA, which, in turn, interacts with ABF2, a bZIP class transcription factor. ABF2 regulates various aspects of the abscisic acid (ABA) response by controlling the expression of a subset of ABA-responsive genes. Our expression analyses indicate that ADAP is expressed in roots, emerging young leaves, and flowers. We found that adap knockout mutant lines germinate more efficiently than wild-type plants and that the mutant seedlings grow faster. This suggests that ADAP is involved in the regulation of germination and seedling growth. Both germination and post-germination growth of the knockout mutants were partially insensitive to ABA, which indicates that ADAP is required for a full ABA response. The survival rates for mutants from which water was withheld were low compared with those for wild-type plants. The result shows that ADAP is necessary for the response to stress induced by water deprivation. Together, our data indicate that ADAP is a positive regulator of the ABA response and is also involved in regulating seedling growth. The role of ADAP is similar to that of ARIA, which is also a positive regulator of the ABA response. It appears that ADAP acts through the same ABA response pathway as ARIA.

• 원예과학기술지
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• 제29권1호
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• pp.1-9
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• 2011

본 연구는 한지형 마늘인 '의성마늘'을 이용하여 장일과 단일 조건에서 재배하여 마늘의 인경 분화 및 비대에 미치는 식물 생장 물질의 역할에 대해서 조사하였다. 한지형 마늘의 인경 분화기(4월 16)부터 인경 비대기(4월 24일, 5월 18일)에 엽신과 엽초내 식물내생호르몬 abscisic acid (ABA), jamonic acid(JA) 및 당 함량변화는 장일조건에서 ABA 함량이 단일조건에서 ABA 함량보다 높았고, 엽초내 ABA 함량이 엽신내 ABA 함량보다 높은 것으로 조사되었다. 마늘생육시기별 ABA 함량은 인편 분화기에서 인경 비대개시기까지는 큰 변화가 없다가 인경 비대개시기(5월 2일) 이후부터 인경이 비대 되는(5월 18일) 동안 그 함량이 현저히 증가하는 것으로 조사되었다. 반면 단일조건에서는 내생 JA 함량은 변화가 없었으나, 장일조건에서는 인편 분화기(4월 16일)부터 인경 비대개시기(5월 2일)까지 JA 함량은 증가되었다. 엽초내 JA 함량($30.19-53.19ng{\cdot}g^{-1}$ DW)은 엽신내 JA 함량($12.82-20.41ng{\cdot}g^{-1}$ DW)보다 높은 것으로 조사되어 엽초 내 JA 함량에 의해 마늘의 인경 비대가 유도되는 것으로 조사되었다. 장일 조건에서 엽신내 당 함량은 인편 분화기(4월 16일)부터 인경 비대개시기(5월 4일)까지 증가되었고, 인경 비대기(5월 4일에서 5월 8일) 동안 감소하였으나, 엽초내 당 함량은 인편 분화기(4월 16일)부터 인경 비대기(5월 18일)까지 서서히 증가되었다. 결론적으로 한지형 의성마늘 생장양상에 따라 엽초내 호르몬도 변화하는 경향을 보여 호르몬 변화가 마늘 생장과 밀접한 연관이 있음을 보여주었다.

• Molecules and Cells
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• 제40권8호
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• pp.577-586
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• 2017

Phytocystatins (PhyCYSs) are plant-specific proteinaceous inhibitors that are implicated in protein turnover and stress responses. Here, we characterized a PhyCYS from Arabidopsis thaliana, which was designated AtCYS5. RT-qPCR analysis showed that the expression of AtCYS5 in germinating seeds was induced by heat stress (HS) and exogenous abscisic acid (ABA) treatment. Analysis of the expression of the ${\beta}-glucuronidase$ reporter gene under the control of the AtCYS5 promoter showed that AtCYS5 expression during seed germination was induced by HS and ABA. Constitutive overexpression of AtCYS5 driven by the cauliflower mosaic virus 35S promoter led to enhanced HS tolerance in transgenic Arabidopsis, which was characterized by higher fresh weight and root length compared to wild-type (WT) and knockout (cys5) plants grown under HS conditions. The HS tolerance of AtCYS5-overexpressing transgenic plants was associated with increased insensitivity to exogenous ABA during both seed germination and post-germination compared to WT and cys5. Although no HS elements were identified in the 5'-flanking region of AtCYS5, canonical ABA-responsive elements (ABREs) were detected. AtCYS5 was upregulated in ABAtreated protoplasts transiently co-expressing this gene and genes encoding bZIP ABRE-binding factors (ABFs and AREB3). In the absence of ABA, ABF1 and ABF3 directly bound to the ABREs in the AtCYS5 promoter, which activated the transcription of this gene in the presence of ABA. These results suggest that an ABA-dependent pathway plays a positive role in the HS-responsive expression of AtCYS5 during seed germination and post-germination growth.