• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 춘계학술대회
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• pp.110-110
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• 2022

Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

• Natural Product Sciences
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• 제13권4호
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• pp.373-377
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• 2007

Antiscratching behavioral effects of the water extract of two black colored rice (BCR) varieties [Oryza sativa L. cv. Heugjinjubyeo (HJ) and Josaengheugchalbyeo (JH)], major pigment of which is cyanindin 3-glucoside, were investigated. Orally administered BCRs' extracts exhibited potent inhibitory activity against scratching behaviors which were induced by compound 48/80 and histamine. The inhibitory effect of Josaengheugchalbyeo in vivo and in vitro were more potent than those of Heugjinjubyeo. These finding suggest that black colored rice, especially Josaengheugchalbyeo, may inhibit scratching behaviors and anaphylaxis reaction by stabilizing membrane.

• Journal of Applied Biological Chemistry
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• 제42권2호
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• pp.66-70
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• 1999

Effects of the enhanced level of L-ascorbic acid (AA) on the water deficit-induced oxidative damage were studied in rice (Oryza sativa L.) seedlings. The seedlings sprayed with 20 to 80 mM L-galactono-${\gamma}$-lactone (GL), a putative precursor of AA, showed 2 to 5-fold higher levels of AA compared with controls. Pretreatment of the seedlings with GL prior to water stress imposition caused virtually no effect on dehydration of tissues during water deficit but substantially mitigated oxidative injury, as accessed by 2-thiobarbituric acid-reactive substances, ${\alpha}$-tocopherol, chlorophylls and ${\beta}$-carotene. Proline accumulation during water stress was also significantly lowered in the treated seedlings. In a complementary experiment, AA retarded photodegradation of ${\alpha}$-tocopherol in isolated thylakoids far more efficiently than glutathione. GL in itself did not show any noticeable reactivity toward ${\alpha}$-tocopheroxyl radical. The results demonstrate the antioxidative function of AA in rice seedlings encountering water-limited environments, suggesting a critical role of AA as a defense against oxidative stress in plants.

• 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.

• The Plant Pathology Journal
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• 제21권2호
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• pp.149-157
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• 2005

A novel rice (Oryza sativa L.) gene, homologous to Arabidopsis pathogenesis-related NDR1 gene, was cloned from cDNA library prepared from 30 min Magnaporthe grisea -treated rice seedling leaves, and named as OsNDR1. OsNDR1 encoded a 220-aminoacid polypeptide and was highly similar to the Arabidopsis AtNDR1 protein. OsNDR1 is a plasma membrane (PM)-localized protein, and presumes through sequence analysis and protein localization experiment. Overexpression of OsNDR1 promotes the expression of PBZ1 that is essential for the activation of defense/stressrelated gene. The OsNDR1 promoter did not respond significantly to treatments with either SA, PBZ, or ETP. Exogenously applied BTH induces the same set of SAR genes as biological induction, providing further evidence for BTH as a signal. Presumably, BTH is bound by a receptor and the binding triggers a signal transduction cascade that has an ultimate effect on transcription factors that regulate SAR gene expression. Thus OsNDR1 may act as a transducer of pathogen signals and/or interact with the pathogen and is indeed another important step in clarifying the component participating in the defense response pathways in rice.

• 한국환경농학회지
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• 제21권2호
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• pp.156-161
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• 2002

냉해나 한발등의 환경스트레스에 대해 저항성을 유발하는 유전자를 환경스트레스에 강한 잡초성벼로부터 선발하고 이들 유전자를 재배벼에 도입하여 도입유전자 산물의 과량 발현을 통해 냉해나 한발 등에 대한 저항성이 향상된 벼를 선발하고자 하였다. 잡초성벼인 Bhutan 14Ad로부터 냉해 및 한발 저항성 유전자로 알려진 superoxide dismutase (SOD) cDNA를 분리하고자 mRNA를 분리하고 이 분리된 mRNA를 이용해 reverse transcriptase PCR방법으로 SOD cDNA를 cloning 하였다. 그 결과 2종의 SOD cDNA가 cloning되어 SOD-A, SOD-B로 명명하였다. 이들 cDNA의 염기서열을 결정한 결과 이들은 아미노산 서열 상동성이 88.4%를 나타내었으며, SOD-A는 Oryza sativa 계열의 Cu/Zn SOD유전자인 GenBank accession No. L36320와 99.3% 동일하였으며, SOD-B는 accession No. D01000과 100% 동일하였다. 이들 SOD-A와 SOD-B cDNA를 재배벼인 낙동벼에 형질전환하여 형질전환체 벼를 선발하였으며, 이들 형질전환체 벼의 냉해저항성및 한발저항성 검정을 통해 저항성이 향상된 형질전환체 벼를 선발하고 있다.

• 한국토양비료학회지
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• 제50권4호
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• pp.203-214
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• 2017

Environmental toxicity due to cadmium (Cd) pollution in croplands causes critical problems worldwide. Rice (Oryza sativa L.) is an important crop in Asia, including South Korea, and numerous studies have evaluated the relationship between Cd and antioxidants to alleviate Cd uptake from the soil into plants. However, information about the relationship between phosphorus (P) and antioxidants in rice seedlings is still limited with regard to Cd phytotoxicity. We therefore investigated the physiological responses of rice (Oryza sativa L. cv 'Dongjin') seedlings to Cd toxicity and the effect of P application on reactive oxygen species (ROS) and antioxidant changes. The exposure of rice seedlings to $30{\mu}M$ Cd inhibited plant growth; increased the contents of superoxide, hydrogen peroxide, and malondialdehyde; and induced Cd uptake by the roots and leaves. Application of P to Cd-exposed seedlings decreased Cd-induced oxidative stress by enhancing the capacity of ascorbate (AsA) production and ROS-scavenging, and decreased Cd transfer from the roots to the leaves. These results suggest that P application alleviated Cd-induced growth inhibition and oxidative damage by restricting Cd translocation from the roots to the leaves and maintaining sufficient levels of AsA.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1990년도 춘계 학술대회지
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• pp.58-59
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• 1990

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.202.1-202
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• 2003

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• 한국작물학회:학술대회논문집
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• 한국작물학회 1988년도 춘계 학술대회지
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• pp.12-13
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• 1988