• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.43-43
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• 2014

The rice blast disease caused by of Magnaporthe oryzae is one of the most destructive diseases of rice. By the microarray analysis, we profiled expression changes of genes during conidiation and found out many putative genes that are up-regulated. Among those, we first selected MGG_06399 encoding a dual-specificity tyrosine-regulated protein kinase (DYRK), homologous to YAK1 in yeast. To investigate functional roles of MoYAK1, We made ${\Delta}Moyak1$ mutants by homology dependent gene replacement. The deletion mutant showed a remarkable reduction in conidiation and produced abnormally shaped conidia smaller than those of wild type. The conidia form ${\Delta}Moyak1$ were able to develop a germ tube, but failed to form apppressoria on a hydrophobic coverslip. The ${\Delta}Moyak1$ formed appressria on a hydrophobic cover slip when exogenous cAMP was induced, but the appressoria shape was abnormal. The ${\Delta}Moyak1$ also formed appressoria abberent in shape on onion epidermis and rice sheaths and failed to penetrate the surface of the plants. These data indicate that MoYAK1 is associated with cAMP/PKA pathway and important for conidiation, appressorial formation and pathogenic development in Magnaporthe oryzae. Detailed characterization of MoYAK1 will be presented.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6541-6548
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• 2013

Pigmented rice is mainly black, red, and dark purple, and contains a variety of flavones, tannin, polyphenols, sterols, tocopherols, ${\gamma}$-oryzanols, amino acids, and essential oils. The present study evaluated the cytotoxic effects of purple rice extracts (PREs) combined with chemotherapeutic drugs on human cancer cells and mechanisms of cell death. Methanolic (MeOH) and dichloromethane (DCM) extracts of three cultivars of purple rice in Thailand: Doisaket (DSK), Nan and Payao (PYO), were tested and compared with white rice (KK6). Cytotoxicity was determined by 3-(4, 5-dimethyl)-2, 5-diphenyltetrazolium bromide (MTT) assay in human hepatocellular carcinoma HepG2, prostate cancer LNCaP and murine normal fibroblast NIH3T3 cells. MeOH-PYO-PRE was the most cytotoxic and inhibited HepG2 cell growth more than that of LNCaP cells but was not toxic to NIH3T3 cells. When PREs were combined with paclitaxel or vinblastine, they showed additive cytotoxic effects on HepG2 and LNCaP cells, except for MeOH-PYO-PRE which showed synergistic effects on HepG2 cells when combined with vinblastine. MeOH-PYO-PRE plus vinblastine induced HepG2 cell apoptosis with loss of mitochondrial transmembrane potential (MTP) but no ROS production. MeOH-PYO-PRE-treated HepG2 cells underwent apoptosis via caspase-9 and-3 activation. The level of ${\gamma}$-oryzanol was highest in DCM-PYO-PRE (44.17 mg/g) whereas anthocyanin content was high in MeOH-PYO-PRE (5.80 mg/g). In conclusion, methanolic Payao purple rice extract was mostly toxic to human HepG2 cells and synergistically enhanced the cytotoxicity of vinblastine. Human HepG2 cell apoptosis induced by MeOH-PYO-PRE and vinblastine was mediated through a mitochondrial pathway.

• Journal of Crop Science and Biotechnology
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• 제10권4호
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• pp.281-286
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• 2007

Gibberellins are growth hormones that play a pivotal role in the growth and development of plants. Present investigations were carried to check the effect of nitrogen(N) and silicon(Si) on bioactive $GA_1$ and its immediate precursor $GA_{20}$ at different growth stages of two rice cultivars with different maturity traits. It was observed that the endogenous bioactive $GA_1$ level gradually increased during vegetative stage and anthesis stage of both Junghwabyeo(early flowering cultivar) and Daesanbyeo(late flowering cultivar). However, the $GA_1$ and $GA_{20}$ content start decreasing during the seed filling stage in both rice cultivars, which indicated a possible relationship of bioactive $GA_1$ and floral development. Our results also confirmed that early 13-hydroxylation pathway was operated at all developmental stages of rice plant. Variation in the levels of the endogenous gibberellins in rice shoots were measured by GCMS-SIM using $^2H_2$-labeled gibberellins as internal standards. Combined application of N and Si enhanced growth parameters and reduced lodging index of both rice cultivars. It was thus concluded that the level of physiologically active $GA_1$ increased during vegetative and early reproductive stage, but starts declining at seed filling stage.

• 생명과학회지
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• 제12권3호
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• pp.274-280
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• 2002

Phenylpropanoid pathway 생성물질은 식물의 self-defense에 관계하며 이러한 물질들은 UV뿐 아니라 wounding, pathogen과 같은 environmental stress에 의해 생성되는 것으로 알려져 있다. 벼에서 PAL mRNA 는 UV 조사 후 12시간에서 48시간까지는 증가하였으나 48시간부터 60시간까지는 점점 줄어드는 경향을 보였다. 한편 PAL의 활성은 UV조사 후 24시간에서 가장 높았지만 상처에 의해서는 PAL의 활성이 벼에서는 증가하지 않았다. 그러나 고추에서는 UV조사와 상처를 준 후 24시간과 10시간에서 각각 높은 활성을 나타내었다. 벼와 고추 모두 cinnamic acid 4-hydroxylase의 활성은 상처를 준 후 12시간에서 증가하였지만 UV 조사는 C4H 활성에 영향을 주지 않았다. 이러한 결과로 볼 때 벼와 고추에서는 UV 조사와 상처가 모두 PAL, C4H 효소활성에 영향을 주는 것으로 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.121-121
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• 2017

The productivity of rice has been influenced by various abiotic factors including temperature which cause to limitations to rice yield and quality. Rice yield and quality are adversely affected by high temperature globally. In the present study, four Korean four cultivars such as Dongan, Ilpum, Samkwang, Chucheong were investigated in order to explore molecular mechanisms of high temperature at seedling stage. Rice seedlings grown at $28/20^{\circ}C$ (day/night) were subjected to 7-day exposure to $38/28^{\circ}C$ for high-temperature stress, followed by 2-D based proteomic analysis on biological triplicates of each treatment. The growth characteristics demonstrated that Dongan is tolerant while Ilpum is sensitive to high-temperature stress. High temperature has an adverse effect in the seedling stage both in high temperature sensitive and tolerant cultivar. Two-dimensional gels stained with silver staining, a total of 722 differential expressed protein spots (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. However, a total of 38 differentially expressed protein spots were analyzed by LTQ-FT-ICR MS. Of these, 9 proteins were significantly increased while 10 decreased under high-temperature treatment. Significant changes were associated with the proteins involved in the carbohydrate metabolism, photosynthesis, and stress responses. Proteome results revealed that high-temperature stress had an inhibitory effect on carbon fixation, ATP production, and photosynthetic machinery pathway. The expression level of mRNA is significantly correlated with the results obtained in the proteome investigation. Taken together, these findings provide a better understanding of the high-temperature resistance by proteomic approaches, providing valuable insight into improving the high-temperature stress tolerance in the global warming epoch.

• 한국작물학회지
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• 제10권
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• pp.51-56
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• 1971

청도군이서면과 김제군죽산면에서 발생된 수도심고선충을 분리하여 그 병실과 병원선충의 형태를 조사하고 그 전염경로와 온탕처리방제에 관한 약간의 실험을 실시하였는데 그 지과를 요약하면 다음과 같다. 1. 발병되었던 포장에서는 매년발병된다. 즉 포장전염을 한다. 2. 발병되었던 벼 종자는 그 종자를 통해서 전염한다. 3. 관개수를 통해서 전염한다. 4. 토양중에서 선충이 생존하고 있다가 토양의 이동으로 선충이 전염된다. 5. 선충은 이삭과 뿌리에 많이 분포되어 있지만 성숙식물전체부분에 널리 분포되여 있다가 그것을 통해서 전염된다. 6. 5$0^{\circ}C$, 55$^{\circ}C$, 6$0^{\circ}C$의 온탕에서 5분간격으로 60분까지 종자처리를 하여 살선충효과와 발아와의 관계를 조사하였던 바 5$0^{\circ}C$에서는 60분간 처리하여도 효과가 없고 55$^{\circ}C$에서는 15~20분간, 6$0^{\circ}C$에서는 10~15분간만 처리하여도 효과가 있음을 알았다.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.179-179
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• 2005

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3249-3252
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• 2013

We have explored the potential energy surface for the isomerization of the aniline (AN) radical cation to the 2-, 3-, and 4-methylpyridine (picoline, MP) radical cations using G3 model calculations. The isomerization may occur through the 1H-azepine (7-aza-cycloheptatriene) radical cation. A quantitative kinetic analysis has been performed using the Rice-Ramsperger-Kassel-Marcus theory, based on the potential energy surface. The result shows that isomerization between $AN^{+\bullet}$ and each $MP^{+\bullet}$ hardly occurs before their dissociations.

• Molecules and Cells
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• 제19권2호
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• pp.212-218
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• 2005

A full-length 1.1 kb cDNA, designated Oryza sativa Dehydrin 1 (OsDhn1), was isolated from the seed coat of rice. The deduced protein is hydrophilic and has three K-type and one S-type motifs (SK3-type), indicating that OsDhn1 belongs to the acidic dehydrin family, which includes wheat WCOR410 and Arabidopsis COR47. Expression of OsDhn1 was strongly induced by low temperature as well as by drought. Induction of OsDhn1 by cold stress was clearcut in the roots of seedlings and the epidermis of palea and lemma. OsDhn1 was also up-regulated in UBI::CBF1/DREB1b transgenic plants indicating that it is regulated by the CBF/DREB stress signaling pathway.

• Natural Product Sciences
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• 제26권3호
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• pp.221-229
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• 2020

This study was undertaken to investigate the protective effect of rice bran oil (RBO) on amyloid β protein (Aβ) (25-35)-induced memory impairment and brain damage in an ICR mouse model. Memory impairment was produced by intracerebroventricular microinjection of 15 nmol Aβ (25-35) and assessed using the passive avoidance test. Treatment with RBO at 0.1, 0.5, or 1 mL/kg (p.o. daily for 8 days) protected against Aβ (25-35)-induced memory impairment. Furthermore, Aβ (25-35)-induced decreases in glutathione and increases in lipid peroxidation and cholinesterase activity in brain tissue were inhibited by RBO, and Aβ (25-35)-induced increases of phosphorylated mitogen-activated protein kinases (MAPKs) and inflammatory factors, and changes in the levels of apoptosis-related proteins were significantly inhibited by RBO. Furthermore, Aβ (25-35) suppressed the PI3K/Akt pathway and the phosphorylation of CREB, but increased phosphorylation of tau (p-tau) in mice brain; these effects were significantly inhibited by administration of RBO. These results suggest that RBO inhibits Aβ (25-35)-induced memory impairment by inducing anti-apoptotic and anti-inflammatory effects, promoting PI3K/Akt/CREB signaling, and thus, inhibiting p-tau formation.