• 한국초지조사료학회지
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• 제39권1호
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• pp.39-44
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• 2019

Drought is one of the key limiting factors that adversely affects the growth and productivity of crop plants. For the enhancement of drought tolerance in crop plants, the identification of basic mechanisms of a plant to drought stress is necessary. In this study, we compared physiological and biochemical responses of five local Arundenilla hirta ecotypes to drought stress. These ecotypes were previously collected from various parts of Korean peninsula, including Youngduk, Gunsan, Jangsoo, Jinju-1 and Yecheon. A. hirta plants were exposed to drought stress for 14 and 17 days respectively, followed by re-watering for 3 days. The results showed that the lipid peroxidation (MDA), hydrogen peroxide ($H_2O_2$), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, and proline level were significantly increased while the chlorophyll content was decreased by drought stress in A. hirta leaves. The highest proline content and DPPH scavenging activity were shown in Ecotype of Youngduk with least MDA and $H_2O_2$ levels while the highest MDA and $H_2O_2$ contents, and least proline and DPPH levels were shown in Gunsan, respectvely. These results indicate that the Youngduk is the most tolerant and Gunsan is the most sensitive ecotype among the five different collections. Together, these results provide a new insight of overall physiological responses of A. hirta to drought stress.

• 대한원격탐사학회지
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• 제37권6_2호
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• pp.1803-1818
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• 2021

기후변화로 인해 가뭄의 발생 빈도가 증가함에 따라 광범위하게 발생하는 가뭄의 상황을 정확하게 판단할 수 있는 모니터링 체계를 갖추는 것이 매우 중요하다. 그러나 지상 관측 기상자료만으로는 한국의 전 지역에 대한 복잡한 가뭄을 모두 파악하기에는 한계가 존재하는 반면, 인공위성 원격탐사자료는 광범위한 지역에서의 가뭄의 공간적 특성을 파악하고 가뭄을 탐지하는 데 효과적으로 이용될 수 있다. 본 연구에서는 남한의 가뭄 식별을 위한 원격탐사자료의 활용 가능성을 분석하고자 하였다. 다양한 측면의 가뭄을 모니터링하기 위해 가뭄에 영향을 미치는 주요 변수인 강수량과 잠재증발산량의 원격탐사 및 지상 관측자료를 수집하였다. 원격탐사자료의 적용성 평가는 관측자료와의 비교를 중심으로 수행하였다. 먼저 원격탐사자료의 적용성과 정확성을 평가하기 위하여 관측자료와의 상관관계를 분석하고, 기상학적 가뭄 모니터링을 위해 강수량과 잠재증발산량을 이용하여 다양한 측면의 가뭄지수들을 산정하였다. 이후 원격탐사자료의 가뭄 모니터링 능력을 평가하기 위해 가뭄지수에 대한 ROC 분석을 적용하여 과거 가뭄 재현성을 확인하였다. 마지막으로 원격탐사자료를 이용한 고해상도의 가뭄 지도를 작성하여 남한의 실제 가뭄에 대한 원격탐사자료의 모니터링 활용 가능성을 평가하였다. 원격탐사자료의 적용을 통해 향후 미 계측 유역을 포함한 남한 전 지역에서 다양하게 발생하는 가뭄 상황을 파악하고 이해할 수 있을 것으로 판단되었다.

• 한국수자원학회논문집
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• 제56권1호
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• pp.11-21
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• 2023

최근 발생하는 극한가뭄에 대비하고자 본 연구는 실제 운영에서 수자원 시설물의 가뭄 취약도 및 가뭄대책별 우선순위를 파악할 수 있는 가뭄대응력 지표로 S-day를 제안하였다. 여기서 가뭄대책이란 용수공급 조정, 시설간 연계운영, 비상용량 고려 등이 대표적이며, 각 댐별로 그 구성에 차이가 있다. 본 연구에서는 국내 15개 다목적댐 및 용수댐에 대하여 가뭄대응력을 산정하였으며, 그 결과 20년 빈도의 가뭄이 지속될 시 15개 댐 모두 전반적으로 용수공급 조정이라는 가뭄대책을 통해 안정적인 가뭄대응력을 보였다. 하지만 다른 대책에서는 2년 이상 지속되는 다년 가뭄을 대비하지 못하였으며, 횡성댐과 안동·임하댐은 100년 빈도 가뭄 발생 시 대부분의 대책에서 S-day가 1년을 넘기지 못하였다. 특히, 횡성댐, 안동·임하댐, 군위댐, 운문댐, 대청댐, 주암댐은 20년 빈도 가뭄 발생 시, 가뭄대책을 적용하지 않으면 1년 내로 정상적인 용수공급이 불가능할 것으로 나타났다. 이에 본 연구에서는 S-day를 통해 가뭄대책별 최적 공급 용량을 제안하고 대책별 가뭄단계에 따른 가동시기를 변경해 가뭄대응 효과를 평가하였다. 마지막으로 미래 사회·경제적 변동에 따른 수요변화를 반영하고자 현행 공급 계약량에 대해 10%씩 증감하여 전체 15개 댐의 가뭄대응력을 재평가하였다. 그 결과 공급계약량이 10% 감소할 경우, 대부분의 댐에서 용수공급 조정만으로도 심각한 가뭄에 대한 대비가 가능할 것으로 분석되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.25-25
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• 2022

Drought becomes frequent and severe because of continuous global warming, leading to a significant loss of crop yield. In soybean (Glycine max [L.]), most of quantitative trait loci (QTLs) analyses for drought tolerance have conducted by investigating yield changes under water-restricted conditions at the reproductive stages. More recently, the necessity of QTL studies to use physiological indices responding to drought at the early growth stages besides the reproductive ones has arisen due to the unpredictable and prevalent occurrence of drought throughout the soybean growing season. In this study, we thus identified QTLs conferring wilting scores and moisture contents of soybean subjected to drought stress in the early vegetative stage using an recombinant inbred line (RIL) population derived from a cross between Taekwang (drought-sensitive) and SS2-2 (drought-tolerant). For the two traits, the same major QTL was located on chromosome 10, accounting for up to 11.5% of phenotypic variance explained with LOD score of 12.5. This QTL overlaps with a reported QTL for the limited transpiration trait in soybean and harbors an ortholog of the Arabidopsis ABA and drought-induced RING-D UF1117 gene. Meanwhile, one of important features of plant drought tolerance is their ability to limit transpiration rates under high vapor pressure deficiency in response to mitigate water loss. However, monitoring their transpiration rates is time-consuming and laborious. Therefore, only a few population-level studies regarding transpiration rates under the drought condition have been reported so far. Via employing an Arduino-based platform, for the reasons addressed, we are measuring and recording total pot weights of soybean plants every hour from the 1^st day after water restriction to the days when the half of the RILs exhibited permanent tissue damage in at least one trifoliate. Gradual decrease in moisture of soil in pots as time passes refers increase in the severity of drought stress. By tracking changes in the total pot weights of soybean plants, we will infer transpiration rates of the mapping parents and their RILs according to different levels of VPD and drought stress. The profile of transpiration rates from different levels of severity in the stresses facilitates a better understanding of relationship between transpiration-related features, such as limited maximum transpiration rates, to water saving performances, as well as those to other drought-responsive phenotypes. Our findings will provide primary insights on drought tolerance mechanisms in soybean and useful resources for improvement of soybean varieties tolerant to drought stress.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.306-306
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• 2017

Screening for drought and salinity tolerance was undertaken for selected Philippine upland rice landraces during germinative and seedling stages to identify varieties which can potentially be grown in marginally dry and saline soils. While increasing PEG and NaCl concentrations caused obvious signs of injury to all rice genotypes, considerable varietal differences were noted in the nature of responses providing evidence that these genotypes possess broad intraspecific genetic variations for drought and salt tolerance. Inconsistent responses of these varieties during both growth stages highlight complexities involved in stress responses and underscore the futility of utilizing a single stage in the rice plant's life cycle for physiological screening. Notwithstanding these perplexing responses, G_Katiil and Ml-Pilit Tapul were observed to thrive relatively well despite increased salt and drought stress during early growth stages and may therefore possess genes needed in crop improvement efforts for drought and salinity tolerance. While these results do not reflect the entire spectrum of adaptive expression to drought and salinity stress during the life cycle of the upland rice plant, they nonetheless provide an easy, reliable and reproducible method for preliminary identification of drought and salt tolerant rice varieties.

• 한국작물학회지
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• 제64권4호
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• pp.432-440
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• 2019

Global climate change exerts adverse effects on maize production. Among abiotic stresses, drought stress during the tasseling stage (VT) can increase anthesis-silking intervals (ASI) and decrease yield. We performed an evaluation of ASI and yield using a drought-sensitive line (Ki3) and a drought-tolerant line (Ki11) to analyze the correlation with ASI and yield. Moreover, the de novo data of Ki11 were analyzed to find putative novel transcripts related todrought stress in tropical maize. A total of 182 transcripts, with a log2 ratio >1.5, were found by comparing drought conditions to a control. The top 40 transcripts of high expression levels in the de novo analysis were selected and analyzed with PCR. Of the 40 transcripts, six novel transcripts were detected by quantitative real-time PCR (qRT-PCR) using seedling and VT stage samples. Five transcripts (transcripts_1, 12, 34, 35, and 40) were up-regulated in the Ki11 shoot at seedling stage, and transcripts_1, 12, and 40 were up-regulated at the re-watering stage after 12 h of drought stress. The transcripts_32 and 34 were up-regulated at the VT stage. Hence, transcript_34 possibly plays a significant role in drought tolerance during the seedling and VT stages. The transcript_32 was identified as chloramphenicol acetyltransferase (CAT) by Pfam domain analysis. The function of the other transcripts remained unknown. Further characterization of these novel transcripts in genetic regulation will be of great value for the improvement of maize production.

• Journal of Plant Biotechnology
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• 제41권1호
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• pp.26-32
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• 2014

Recent genome annotation revealed that Populus trichocarpa contains 81 glutathione S-transferase (GST) genes. GST genes play important and varying roles in plants, including conferring tolerance to various abiotic stresses. Little information is available on the relationship - if any - between drought/salt stresses and GSTs in woody plants. In this study, we screened the PatgGST genes in hybrid poplar (Populus alba ${\times}$ Populus tremula var. glandulosa) that were predicted to confer drought tolerance based on our expression analysis of all members of the poplar GST superfamily following exposure to salt (NaCl) and drought (PEG) stresses, respectively. Exposure to the salt stress resulted in the induction of eight PatgGST genes and down-regulation of one PatgGST gene, and the level of induction/repression was different in leaf and stem tissues. In contrast, 16 PatgGST genes were induced following exposure to the drought (PEG) stress, and two were down-regulated. Taken together, we identified seven PatgGSTs (PatgGSTU15, PatgGSTU18, PatgGSTU22, PatgGSTU27, PatgGSTU46, PatgGSTU51 and PatgGSTU52) as putative drought tolerance genes based on their induction by both salt and drought stresses.

• 원예과학기술지
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• 제33권4호
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• pp.575-584
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• 2015

건조 스트레스는 작물의 생존과 생산성을 결정하는데 매우 중요한 환경요인이다. 본 연구의 목적은 배추에서 신규 건조 스트레스 저항성 유전자를 동정 검정하는 것이다. 건조 스트레스 하에서 생육된 지부('Chiifu') 배추를 이용하여 제작된 KBGP-24K 마이크로어레이 데이터 분석을 통해 738개의 건조 반응 유전자 중 기능은 밝혀져 있지 않지만, 건조 스트레스 하에서 발현량이 6배 이상 크게 증가한 1개의 유전자를 선발하여 BrDSR(B. rapa Drought Stress Resistance)이라 명명하였다. 이의 검정을 위해 내혼계배추('CT001')에서 BrDSR을 동정한 결과 438bp의 오픈리딩프레임과 145개의 아미노산을 가지고 있음을 확인하였고, 동정된 완전장의 cDNA 염기서열은 형질전환용 과발현 vector인 'pSL100' 제작에 이용하였다. BrDSR이 식물체에서 건조 스트레스 저항성을 향상시켜줄 수 있는지 분석하기 위해 담배 형질전환을 수행하였다. PCR과 DNA 블롯 분석으로 선발된 T1 세대 담배 형질전환체들을 대상으로 quantitative real-time RT PCR 분석을 수행한 결과, 형질전환체의 BrDSR 발현량은 비형질 전환체 보다 2.6배까지 증가하였다. 또한 건조처리 10일째 수행한 표현형 분석에서 BrDSR이 발현되는 담배 형질전환체들이 비형질전환체들 보다 우수한 건조 저항성을 보였다. 연구 결과들을 종합하면 BrDSR은 건조 스트레스 하에서 식물의 생장과 생존에 효과적인 저항성 기능을 할 것으로 기대된다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.101.1-101
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• 2003

Lipopolysaccharide, siderophore, and cyclic dipeptide have been shown to be necessary for ISR induction by pseudomnads. However, there is no report on cloning of genes or generating specific mutants involving in ISR activity. A biological control bacteium P. chlororaphis O6 induces resistance to Erwinia carotovora subsp. carotovara SCCI in tobacco and induces drought resistance in Arabidopsis. To isolate genes involved in ISR activity and induction of drough resistance of O6, we constructed Tn5 mutants and were used to screen for ISR activity and drought resistance activity using microtiter assay with tobacco and Arabidopsis. Thirty-three ISR-deficient mutants were selected, and the nine ISR-deficient mutants were also lost activity of drought resistance. The flanking sequence analysis of the ISR and drought resistance-deficient mutants showed that a gacS gene encoding a two-component sensor kinase, and a mce gene encoding a protein involved in mycobacterial cell entry were mutated. The flanking sequence of each Tn5 mutant altered ISR activity is currently under investigation. These results indicate that gacS and mce are important genes in induction of ISR activity and drought resistance of P. chlororaphis O6. Our works will open opportunities for identification of bacterial genes or traits that are involved in ISR activity and induced drought resistance of P. chlororaphis O6.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.103-103
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• 2017

Vigorous root growth at the seedling stage in dry direct-seeded conditions is considered as a critical trait because it is involved in seedling emergence, early vegetative vigour, nutrient uptake as well as drought tolerance. In this study, we performed QTL mapping using the recombinant inbred lines obtained from the cross between Tongil-type Dasan and temperate japonica TR22183 (DT-RILs) to identify QTL underlying early root development. TR22183, which was previously reported to have high nitrogen utility and cold tolerance, showed vigorous root growth at the seedling stage in semi-drought conditions. Root length, fresh weight and dry weight of TR22183 were significantly higher than in Dasan. By QTL analysis with genotyping-by-sequencing method, we identified two QTLs for root fresh weight (RFW) in chromosome 7 and root dry weight (RDW) in chromosome 8, explaining phenotypic variances of 13.5% and 10.6%, respectively. These QTLs would be used to develop rice varieties adapted to direct-seeded cultivating system.