• The Plant Pathology Journal
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• 제19권6호
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• pp.301-304
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• 2003

Gamma-ray irradiation is known to induce various mutations in plants caused by chromosome alterations. This study investigated disease responses of selected gamma-ray induced rice mutants generated from seven Japonica-type rice cultivars against three plant diseases. Among the tested 22 mutants, three gain-of-function mutants and six loss-of-function mutants against rice blast were obtained, as well as three loss-of-function mutants against bacterial leaf blight (BLB). Two of the loss-of-function mutants were susceptible to both rice blast and BLB. Gain-of-function mutation has not been frequently observed in rice plants, thus, the mutants can be used to identify loci of novel genes for the regulation of disease resistant response.

• 한국작물학회지
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• 제49권2호
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• pp.126-130
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• 2004

This study is to identify the physiological traits of submergence-tolerant varieties of rice plants (Oryza sativa L.) in Yeongnam area, southeastern part of Korea, where the reduction of rice yield due to submergence is remarkably severe. In the present study, two tolerant varieties of rice plants were selected from over 30 rice varieties grown in under a 10-day period. The tolerant varieties selected from a submerged paddy field. As a control, one intolerant variety of rice plant was chosen. Of the tolerant variety Samgangbyeo, rather than Haepyungbyeo, had a lower dissolved oxygen consumption and maintained a higher dry weight than the intolerant variety. The leaf photosynthetic rates (LPS) of the two tolerant varieties were significantly higher than that of the intolerant-variety after four days of submergence treatment. These results indicate that lower dissolved oxygen consumption in a limited pool is prevented by ethylene formation in the tolerant varieties, which may be a mechanism of submergence tolerance.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.163-168
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• 2003

A routine system based on particle bombardment of embryogenic callus for recovery of fertile transgenic rice (Oryza sativa L.) plants was developed. Embryogenic callus was established within 2-3 months from calli derived from mature seeds of Korean rice cultivar, Nagdongbyeo. The callus was bombarded with the plasmid pRQ6 containing the $\beta$-glucuronidase gene (gusA) and hygromycin phosphotransferase gene (hph, conferring resistance to hygromycin B), both driven by CaMV 35S promoter. Placement of cells on an osmoticum-containing medium (0.2 M sorbitol and 0.2 M mannitol) 4 hrs prior to and 16 hrs after bombardment resulted in a statistically significant increase with 3.2-fold in transient expression frequency gusA. In five independent experiments, the average frequency of transformation showing GUS activities was $8.86\%$. A large number of morphologically normal, fertile transgenic rice plants were obtained. Integration of foreign gene into the genome of $R_0$ transgenic plants was confirmed by Southern blot analysis. GUS and HPT were detected in $R_1$ progeny and Mendelian segregation of these genes was observed in $R_1$ progeny.

• 식물조직배양학회지
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• 제28권1호
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• pp.37-40
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• 2001

벼의 약배양 배지 내에 콜히친 첨가에 의한 염색체 배가 방법을 확립하기 위하여, 콜히친의 농도를 0.001∼0.1 mg/L까지 조절하여 약배양하였을 때 콜히친의 농도가 증가할수록 캘러스 형성률과 식물체 분화율은 점점 감소하였으며, 그 감소폭은 농도가 증가됨에 따라 점점 커지는 경향이었다. 자포니카 3품종과 통일형 1품종을 콜히친이 첨가되지 않은 배지에 약배양하였을 때 반수체의 출현빈도가 50%이상 높게 나타난 반면, 이배체는 40% 이하의 낮은 발생빈도를 나타내었다. 그러나 0.001 mg/L의 콜히친이 약배양 배지에 첨가될 경우 품종에 따라 다소간의 차이는 있으나, 반수체의 출현빈도는 상대적으로 감소되고 이배체의 발생 비율이 54.3∼60%로 증가하였다.

• 한국작물학회지
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• 제29권4호
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• pp.321-327
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• 1984

벼 재배시에 나타나는 주연효과의 품종간 차이와 생장해석을 통한 주연효과의 원인을 알고져 3품종을 공시하여 시험한 결과를 요약하면 다음과 같다. 1. 논의 외연 1∼2 열에 심겨진 벼의 수량은 내부열에 비하여 평균 30％ 정도 많았는데 주연효과는 품종에 따라서 최대 35％, 최소 21％이었다. 2. 주연효과에 의한 수량증가는 논의 외부 1∼2열에서만 나타났으나 한강찰벼는 외연으로부터 4열까지도 주연효과가 나타났다. 30 주연효과는 주당수수와 수당입수에서 현저하게 나타났다. 4. 수건물중과 엽면적은 이앙후 30∼60일경부터 외열과 내열간에 차이가 나타났는데 조생종은 중만생종보다 주연효과에 의한 건물중과 엽면적의 차이가 빨리 나타났다. 5. 개체군생장속도, 상대생장율, 순동화율 및 엽면적비 등에 있어서도 주연효과를 나타내는 시기가 많았다.

• 한국작물학회지
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• 제51권1호
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• pp.32-40
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• 2006

The nitrogen (N) absorption and partition of the rice plants are important indicators that can be used to improve the N use efficiency (NUE) of the plants. Improving the plant NUE can help to avoid nutrient waste that may cause environmental pollution. To investigate the N absorption and partition of the rice plants, Hwaseongbyeo (Japonica) and Dasanbyeo (indica/japonica) were applied with N fertilizers at the rates of 60, 120, and 180 kg N per ha in paddy field. Also micro plots of $0.81m^2$ were established inside each plot for application of $^{15}N-labeled$ fertilizer. The differences in N utilization of the rice plants were associated with the total N absorption and partitioning after the heading stage. In the grain filling period, the increase of nitrogen content in the total and leaf blades of Dasanbyeo was higher than that of Hwaseongbyeo. Soil N was the main contributor for the increase of total N of Dasanbyeo during the grain filling period. The N fertilizer uptake rate of Hwaseongbyeo rapidly increased with the increment of N fertilization rate. In Dasanbyeo, N fertilizer uptakes were similar under all rates and times of N application. From heading stage to harvest, Dasanbyeo continued accumulating nitrogen, whereas Hwaseongbyeo had small changes. In conclusion, the difference in nitrogen absorption and partition after heading of the two cultivars was caused by the ability of Dasanbyeo to accumulate and remobilize soil nitrogen to the grains during the grain filling period.

• 한국잡초학회지
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• 제13권2호
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• pp.75-80
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• 1993

수도(水稻)와 너도방동사니간의 Bensulfuron 선택성(選擇性) 기작(機作)을 밝히고자 $^{14}C$-bensulfuron을 공시(供試)하여 식물체(植物體)간 Bensulfuron의 흡수(吸收), 移行(이행) 및 대사(代謝)를 연구(硏究)하였다. 1. Bensulfuron 흡수량(吸收量)은 줄기보다 뿌리에서 월등히 많았으며 너도방동사니보다 수도(水稻)에서 현저하게 높았다. 2. 뿌리로 부터 줄기로의 Bensulfuron 이행속도(移行速度)는 수도(水稻)보다 너도방동사니에서 빨랐으며 이행량(移行量)도 많았다. 3. Bensulfuron의 대사속도(代謝速度)는 수도(水稻)에서는 현저하게 빨랐으나 너도방동사니에서는 매우 느린 경향이었다. 4. 따라서 수도(水稻)의 내성(耐性)은 빠른 대사속도(代謝速度)에 주로 기인(基因)하며 부분적으로 느린 이행속도(移行速度)와도 관련이 있으며 너도방동사니의 감수성(感受性)은 느린 대사속도(代謝速度)와 빠른 이행속도(移行速度)와 관련이 있을 것으로 사료(思料)되었다.

• Molecules and Cells
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• 제40권11호
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• pp.828-836
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• 2017

Eukaryotic cells consist of a complex network of thousands of proteins present in different organelles where organelle-specific cellular processes occur. Identification of the subcellular localization of a protein is important for understanding its potential biochemical functions. In the post-genomic era, localization of unknown proteins is achieved using multiple tools including a fluorescent-tagged protein approach. Several fluorescent-tagged protein organelle markers have been introduced into dicot plants, but its use is still limited in monocot plants. Here, we generated a set of multicolored organelle markers (fluorescent-tagged proteins) based on well-established targeting sequences. We used a series of pGWBs binary vectors to ameliorate localization and co-localization experiments using monocot plants. We constructed different fluorescent-tagged markers to visualize rice cell organelles, i.e., nucleus, plastids, mitochondria, peroxisomes, golgi body, endoplasmic reticulum, plasma membrane, and tonoplast, with four different fluorescent proteins (FPs) (G3GFP, mRFP, YFP, and CFP). Visualization of FP-tagged markers in their respective compartments has been reported for dicot and monocot plants. The comparative localization of the nucleus marker with a nucleus localizing sequence, and the similar, characteristic morphology of mCherry-tagged Arabidopsis organelle markers and our generated organelle markers in onion cells, provide further evidence for the correct subcellular localization of the Oryza sativa (rice) organelle marker. The set of eight different rice organelle markers with four different FPs provides a valuable resource for determining the subcellular localization of newly identified proteins, conducting co-localization assays, and generating stable transgenic localization in monocot plants.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.82-83
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• 2003

Plants have evolved differently from animals having mobile activities. Thus, plants should have developed unique defense mechanisms against biotic/abiotic stresses to which plants are differently exposed, according to seasons. Most organisms have an conserved signaling network using mitogen-activated protein kinase (MAPK) cascade(s). The phenomenon implied that they are functionally very important in all organisms. In fact, they constitute one of the major components of signaling pathways involved in regulating a wide range of cellular activities from growth and development to cell death. Recently, complete MAPK cascade was first characterized in Arabidopsis from the receptor kinase (FLS2) through fellowing MEKKI -MKK4/MKK5-MPK3/MPK6-WRKY22/MRKY29 pathway. Whereas, MAPK cascade signaling pathway in monocot plant including rice (0ryza sativa L.), the most important of all food crops and an established monocot plant research model, MAPKinase kinase kinases (MAPKKK) of rice are the first upstream component of the MAPK cascade, but MAPKKK has been first identified and characterized in our lab and designated as, OsEDRl based on its homology with the Arabidopsis EDRI. The Arabidopsis EDRl was regarded as a negative regulator of defense response and the role of rice OsEDRl was analyzed. Transcriptional regulation of OsEDRl was detected under various stresses and immunoblotting analysis is going on to detect the level of OsEDRl protein in the mutants showing unique phenotype. We also introduced the constitutively active and the dominant negative forms of the OsEDRl for characterizing biological function.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.115-115
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• 2017

Zinc finger proteins constitute a large family which has been studied to have various functions in different organisms. Tandem CCCH zinc finger proteins (TZFs), members of the zinc finger protein family, are known to participate as post-transcriptional regulators of gene expression in eukaryotes. Here, we showed that the OsZn15, a gene for tandem CCCH zinc finger protein, is induced by abiotic stress and its overexpression in transgenic rice plants (PGD1:OsZn15) gains higher drought tolerance. Gene expression analysis of promoter:GFP plants revealed that OsZn15 is specifically expressed in anther and embryo, but not in vegetative organs. In-field evaluation, grain yield was higher in the PGD1:OsZn15 than nontransgenic plants under drought conditions. Interestingly, OsZn15 is shown to not only localize at nucleus but also co-localize with both processing bodies (PB) and stress granules (SG), two messenger ribo-nucleoprotein complexes which are known to activate by forming cytoplasmic foci under stress conditions. In sum, these results suggest that OsZn15 increases drought stress tolerance of rice probably by participating in RNA turnover in PB and SG.