• 한국토양비료학회지
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• 제35권5호
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• pp.314-325
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• 2002

페레니얼 라이그라스의 가뭄스트레스 저항성과 관련하여 균근균(mycorrhiza) 접종이 작물생장 및 질소대사 산물에 미치는 영향을 조사하였다. 균근균 접종에 의한 잎의 수분퍼텐셜, 건물량 및 인의 함량의 유의적인 증가가 인정되었다. 가뭄스트레스 상태에서 뿌리의 질산염 농도는 증가하였으며, 균근균 비접종구가 접종구에 비하여 현저하였다. 잎의 수용성 단백질 함량은 가뭄 스트레스 하에서 균근균 비접종구가 접종구에 비해 현저히 감소하였다. 전 실험기간 동안 가뭄 스트레스 처리구의 암모니아와 proline의 농도는 현저히 증가하였으며, 균근균 접종구에서는 증가가 현저히 완화되었다. 가뭄 스트레스 하에서 잎의 건물량 감소는 암모니아(p<0.01)와 proline(p<0.001) 농도의 증가와 부의 유의적인 상관성을 보였다. 이상의 결과로 볼 때, 균근균의 접종 효과는 가뭄 스트레스 하에서 작물의 성장 억제를 완화시켰으며, 인의 함량과 질소의 동화 작용을 증가 시켰다.

• 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.

• Journal of Plant Biotechnology
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• 제47권1호
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• pp.1-14
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• 2020

Drought and salinity are significant stressors for crop plants, including wheat. The relationship between physiological mechanisms and gene expression is important for stress tolerance. NAC transcription factors (TFs) play vital roles in abiotic stress. In this study, we assessed the expression of four TaNAC genes with some physiological traits of nine Egyptian wheat genotypes under different concentrations of PEG and NaCl. All the physiological traits that we assessed declined under both stress conditions in all genotypes. In addition, all the genes that we measured were induced under both stress conditions in young leaves. Shandaweel 1, Bani Seuf 7, Sakha 95, and Misr 2 genotypes showed higher gene expression and were linked with a better genotypic performance in physiological traits under both stress conditions. In addition, we found an association between the expression of NAC genes and physiological traits. Overall, NAC genes may act as beneficial markers for selecting for genotypic tolerance to these stress conditions in wheat.

• 식물병연구
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• 제24권3호
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• pp.242-247
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• 2018

Pseudomonas chlororaphis O6 induces systemic tolerance in plants against drought stress. A volatile, 2R, 3R-butanediol, produced by the bacterium causes partial stomatal closure, thus, limiting water loss from the plant. In this study, we report that applications of extracellular polymeric substances (EPS) from P. chlororaphis O6 to epidermal peels of leaves of Arabidopsis thaliana also reduce the size of stomatal openings. Growth of A. thaliana seedlings with applications of the EPS from P. chlororaphis O6 reduced the extent of wilting when water was withheld from the plants. Fluorescence measurements showed photosystem II was protected in the A. thaliana leaves in the water stressed EPS-exposed plants. These findings indicate that P. chlororaphis O6 has redundancy in traits associated with induction of mechanisms to limit water stress in plants.

• 한국토양비료학회지
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• 제35권4호
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• pp.232-242
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• 2002

Mycorrhiza 접종이 페레니얼 라이그라스가 가뭄 스트레스 저항성에 대한 효과를 검증하기 위해 mycorrhiza 접종구(AM)와 mycorrhiza를 접종하지 않은 비접종구 (non-AM)를 정상적 토양 수분 (-0.04Mpa) 및 가뭄 스트레스 (-0.12MPa)를 각각 처리한 후 0.14 및 28일에 잎의 수분포텐셜, 인의 함량, 작물의 성장 및 탄수화물 농도를 분석하였다. 가뭄 스트레스구에서 잎의 수분포텐셜, 클로로필, 인의 함량 및 잎의 성장이 유의적으로 감소되었다. 가뭄에 의한 이러한 생리적 장해요인들은 mycorrhiza 접종에 의해 완화되었다. 가뭄 스트레스하에서 잎의 soluble sugar 농도는 감소 되었으며, AM 처리구는 non-AM 처리구보다 soluble sugar 농도는 높게 나타났다. 가뭄 스트레스하에서 지상부의 starch와 fructan의 축적은 가뭄 스트레스 하에서 감소되는 반면 뿌리에서는 증가하였다. 가뭄 스트레스 하에서 뿌리에서 starch의 농도는 non-AM 처리구에서 AM처리구보다 더 높게 나타났다. 가뭄 스트레스 하에서 잎의 fructan 농도는 약간 감소하였으나 뿌리에서는 현저히 증가하였다. 가뭄 스트레스 하에서 처리 후 28일째 fructan의 농도는 정상적 수분공급구와 비교해 볼 때 non-AM과 AM 잎에서 각각 18.7% 와 13.3% 낮았다. 뿌리에서 가뭄스트레스에 의한 fructan의 축적은 mycorrhiza 접종에 의해 약 14% 감소되었다. 이상의 결과들은 mycorrhiza 접종은 잎의 수분 포텐셜과 인의 함량을 더 높게 유지하게 하고, soluble sugar의 함량을 더 많이 보유하게 함으로써 작물의 가뭄에 대한 내성을 증가 시킴을 잘 보여 주었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2020년도 추계학술대회
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• pp.133-133
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• 2020

• 원예과학기술지
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• 제34권1호
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• pp.102-111
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• 2016

본 연구의 목적은 BrDSR(Drought Stress Resistance in B. rapa) 유전자의 기능을 명확히 밝히고, 배추에서 건조 스트레스 반응 유전자들을 분석하는데 있다. 내혼계배추('CT001')와 BrDSR 완전장(438bp의 오픈리딩프레임)을 지닌 pSL100 vector를 재료로 아그로박테리아를 이용한 배추 형질전환을 수행하였다. PCR 분석을 통해 4개체의 형질전환체를 확보하였고, 이들의 BrDSR 발현량은 건조 스트레스 조건에서 비형질전환체 대비 약 1.9-3.4배 정도 더 큰 것으로 분석되었다. 또한 표현형 분석에서도 BrDSR이 과발현된 형질전환체들은 건조 스트레스에 저항성을 보이며 정상적인 생장을 하였다. 기 구축된 건조 스트레스 반응 유전자의 상호발현 네트워크를 기반으로 BrDSR과 밀접한 관련이 있는 유전자들을 분석하기 위해 B. rapa 135K cDNA microarray 데이터를 분석하였다. 그 결과, 환경 스트레스와 관련하여 식물체에서 잎의 노화와 자가소화에 관련된 것으로 보고된 'dark inducible 2(DIN2, AT3G60140)'와 'autophagy 8h(ATG8H, AT3G06420)' 유전자가 확인되었다. 위 결과들을 근거로 BrDSR 유전자는 건조 스트레스에 대한 저항성 향상에 중요한 역할을 할 것으로 판단되었다.

• 한국작물학회지
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• 제62권1호
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• pp.24-31
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• 2017

We screened the drought tolerant maize using seventeen maize genotypes from different sources, nine inbred genotypes from United States Department of Agriculture (USDA) (B73, CML103, CML228, CML277, CML322, CML69, Ki3, Ki11, and NC350), three Southeast Asian genotypes (DK9955, LVN-4, and 333), and five Korean hybrids (Cheongdaok, Gangdaok, Ilmichal, Kwangpyeongok, and Pyeonganok). We evaluated anthesis-silking interval (ASI), leaf senescence (LS), ears per plant (EPP), tassel length (TL), and fresh weight (FW) at silking date. According to ASI and LS examination, CML103 and Kill were drought tolerant genotypes, wheareas Ki3 and 333 were drought susceptible. EPP, TL, and FW differed according to drought resistance. Grain yield was correlated strongly with ASI, but moderately with LS. Difference in ASI between drought-stressed (DS) and well-watered (WW) conditions was less than three days in CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok, whereas that of Ki3, Pyeonganok, and Gangdaok was more than 6.5 days. We concluded that CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok are drought tolerant genotypes, whereas Ki3, Pyeonganok, and Gangdaok are drought susceptible.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.341-341
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• 2017

Abiotic stress adversely affects crop growth worldwide. Drought of the major abiotic stresses have the most significant impact on all of the crop. The main objective of this study was to assess the effects of drought stress on photochemical performance and vitality of maize (Zea mays L.). The photochemical characteristics were analyzed in the context of period of drought stress during the maize growth. Drought experiment was carried out for four weeks, thereafter, the drought treated maize was re-watered. The polyphasic OJIP fluorescence transient was used to evaluate the behavior of photosystem II (PSII) and photosystem I (PSI) during the entire experiment period. In drought stress, the performance Index (PI) level was reached earlier when compared to the controls. For the screening of drought stress tolerance the drought factor index (DFI) of each variety was calculated as follow DFI= log(A) + 2log(B). All the fourteen cultivars show DFI ranged from -0.69 to 0.30, meaning less useful in selection of drought tolerant cultivars. PI and electron transport flux values of fourteen cultivars were to indicate reduction of photosynthetic performance during the early vegetative stage under drought stress. In conclusion, DFI and energy flux parameters can be used as photochemical and physiological index.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.110-110
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• 2017

Stomata are the main gateways for water and air transport between leaves and the environment. Inward-rectifying potassium channels regulate photo-induced stomatal opening. Rice contains three inward rectifying shaker-like potassium channel proteins, OsKAT1, OsKAT2 and OsKAT3. Among these, only OsKAT2 is specifically expressed in guard cells. Here, we investigated the functions of OsKAT2 in stomatal regulation using three dominant negative mutant proteins, OsKAT2(T235R), OsKAT2(T285A) and OsKAT2(T285D), which are altered in amino acids in the channel pore and at a phosphorylation site. Yeast complementation and patch clamp assays showed that all three mutant proteins lost channel activity. However, among plants overexpressing these mutant proteins, only plants overexpressing OsKAT2(T235R) showed significantly less water loss than the control. Moreover, overexpression of this mutant protein led to delayed photo-induced stomatal opening and increased drought tolerance. Our results indicate that OsKAT2 is an inward-rectifying shaker-like potassium channel that mainly functions in stomatal opening. Interestingly, overexpression of OsKAT2(T235R) did not cause serious defects in growth or yield in rice, suggesting that OsKAT2 is a potential target for engineering plants with improved drought tolerance without yield penalty.