• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.105-105
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• 2017

Our previous study for developing seeds of Iksan 526 (I.526), an inbred line of resveratrol-producing transgenic rice line, showed that, in 20 days after heading (DAH) seeds, resveratrol was almost saturated and accumulation of piceid was highest though the expression of Arachis hypogaea resveratrol synthase 3 (AhRS3, GenBank DQ124938) was highest in 31 DAH seeds. In this study, it was investigated how the overexpression of AhRS3 affects phenylpropanoid pathway genes. p-Coumaroyl-CoA is derived from phenylpropanoid pathway and used as a substrate of AhRS3 reaction for resveratrol production. In 6, 13, 20, 31 and 41 (45 for Dongjin) DAH seeds of I526 and Dongjin, a wild type of I.526, respectively, the expression pattern of phenylpropanoid pathway genes, including phenylalanine ammonia-lyase (PAL: LOC_Os02g41630.2, LOC_Os04g43760.1), cinnamate 4-hydroxylase (C4H: LOC_Os05g25640.1), 4-coumarate-CoA ligase (4CL: LOC_Os02g08100.1), cinnamoyl-CoA reductase (CCR: LOC_Os09g25150.1, LOC_Os08g34280.1), hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT: LOC_Os04g42250.2, LOC_Os02g39850.1) and cinnamyl alcohol dehydrogenase (CAD: LOC_Os02g09490.1), was examined using real time (RT)-PCR. Compared to developing seeds of Dongjin, RT-PCR results showed that the expression pattern of phenylpropanoid pathway genes was modified in developing seeds of I.526. In most genes, except for CAD, of I.526 developing seeds, the gene expression was highest in 20 DAH corresponding to biosynthesis of resveratrol and piceid, i.e. the expression of phenylpropanoid pathway genes was gradually increased by 20 DAH and decreased as seeds develop. Especially, in Dongjin, the highest expression of PALs and 4CL was in 6 DAH and their expression was gradually decreased as seeds develop. These genes expression data also exhibited that, in developing seeds of I.526, phenylpropanoid pathway genes were slightly or significantly (in some genes) upregulated compared to Dongjin. Therefore, the overexpression of AhRS3 changed the expression pattern of phenylpropanoid pathway genes in I.526 developing seeds and this modification for gene expression is closely related to biosynthesis of resveratrol and piceid.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.172-172
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• 2023

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.176-176
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• 2005

• Journal of Photoscience
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• v.9 no.2
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• pp.162-165
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• 2002

Rice is widely cultivated in various regions throughout Asia. Over a five-year period, we investigated the effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars in the field. The findings of that study indicated that supplemental UVB radiation has inhibitory effects on the growth and grain development. Furthermore, we investigated the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, and found that rice cultivars vary widely in UVB sensitivity. The aim of our study is improving UVB resistance in plants by bioengineering or breeding programs. In order to make it, there is need to find the molecular origin of the sensitivity to UVB. Cyclobutane pyrimidine dimer (CPD) is major UV-induced DNA lesions. Plants possess two mechanisms to cope with such DNA damage. The first is the accumulation of UV-absorbing compounds. Our previous data showed that the steady-state CPD levels in leaves of rice grown under chronic radiation in any culture were not so greatly influenced by the increased UV-absorbing compounds content, although there was a significant positive correlation between the CPD levels induced by challenge UVB exposure and the UV-absorbing compounds content. The other is the repair of DNA damage. Photorepair is the major pathway in plants for repairing CPD. We found that the sensitivity to UVB could seriously correlate with the low ability in CPD photorepair in rice plants. These results suggest that photo lyase might be an excellent candidate for restoration by way of selective breeding or engineering in rice.

• Journal of Plant Biotechnology
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• v.5 no.1
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• pp.33-41
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• 2003

Microspore-derived cell lines resistant to 5-methyltryptophan (5MT, a tryptophan analog) or S-(2-aminoethyl)-L-cysteine (AEC, a Iysine analog) were selected in rice by in vitro mutagenesis. For selection of 5MT or AEC resistant cell lines, suspension-cultured cells were irradiated with gamma rays. Thirteen 5MT resistant cell lines were selected and they were able to grow stably at 2 times higher 5MT concentration. A feedback insensitive form of anthranilate synthesis, the pathway specific control enzyme for tryptophan synthesis, was detected from the 5MT resistant lines. Contents of the free amino acids in five resistant lines (MR12-1 to MR12-5) showed a 7.4 to 46.6 times greater level than that in the control culture. Tryptophan, phenylalanine, and tyrosine levels in the shikimate pathway were 28.1 and 22.5 times higher in MR12-3 and MR12 4, respectively, than that measured in the control cells. Four AEC resistant cell lines were isolated from cultures grown on medium containing 1 mM AEC, They were able to grow stably with 2 mM AEC, while sensitive calli were inhibited by 0.5 mM AEC. Aspartate kinase activities of the resistant lines were insensitive to the natural inhibitor, Iysine, and accumulated 2.2 to 12.9-fold higher levels of free Iysine than that of the control cells. Especially, the levels of aspartate, asparagine, and methionine in the aspartate pathway showed higher accumulation in the AEC resistant lines than that in the control cells.

• Mycobiology
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• v.44 no.2
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• pp.67-78
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• 2016

Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.64-72
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• 1989

Near full length cDNA clones encoding the rice seed storage protein, prolamine, were isolated and divided into two homology classes based on cross-hybridization and DNA sequencing analysis. These cDNA clones contain a single open reading frame encoding a putative rice prolamine precursor(M.W.=17,200) possessing atypical 14 amino acid signal peptide. Clones of these two homology classes diverge mainly by insertions/deletions of short nucleotide stretches and point mutations. The deduced primary structures of both types of prolamine polypeptides are devoid of any major tandem repetitive sequences, a feature prevalent in other cereal prolamines. No significant homology teas detected between the rice prolamine and other cereal prolamines, indicating that the rice gene evolved from a different ancestor that gave rise to other cereal prolamine genes. Developing wheat and rice endosperms were examined using ultrathin sections prepared from tissues harvested at various days after flowering. By immunocytochemical localization techniques, wheat prolamines are localized within vesicles from Golgi apparatus and in homogeneous regions of protein bodies. The involvement of the goli apparatus in the packaging of wheat prolamines into protein bodies indicates a pathway which differs from the mode of other cereal prolamines and resembles the mechanism employed for the storage of rice glutelin and legume globulins.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.334-347
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• 2000

The present experiment was carried out to study the utilization of glucose in the mammary gland of crossbred Holstein cattle during feeding with different types of roughage. Sixteen first lactating crossbred Holstein cattle which comprised eight animals of two breed types, Holstein Friesian${\times}$Red Sindhi ($50{\times}50=50%$ HF) and Holstein Friesian${\times}$Red Sindhi ($87.5{\times}12.5=87.5%$ HF). They were divided into four groups of 4 animals each of the same breed. The utilization of glucose in the mammary gland was determined by measuring rates of glucose uptake and the incorporation of glucose into milk components in both groups of 50% HF and 87.5% HF animals feeding on either hay or urea treated rice straw. In early lactation, there were no significant differences of the total glucose entry rate and glucose carbon recycling among groups of crossbred animals feeding on either hay or urea treated rice straw. During lactation advance, the total glucose turnover rates and recycling of carbon glucose of crossbred HF animals feeding on urea treated rice straw were markedly higher than those of crossbred HF animals feeding on hay as roughage, whereas there were no significant changes for both groups of crossbred animals feeding on hay. The percentages and values of non-mammary glucose utilization showed an increase during lactation advance in the same group of both 50% HF and 87.5% HF animals. The percentage of glucose uptake for utilization in the synthesis of milk lactose by the mammary gland was approximately 62% for both groups of 87.5% HF and by approximately 55% for both groups of 50% HF animals feeding on either hay or urea treated rice straw. Intracellular glucose 6-phosphate metabolized via the pentose phosphate pathway accounted for the NADPH (reducing equivalent) of fatty acid synthesis in the mammary gland being higher in 87.5% HF animals during mid-lactation. A large proportion of metabolism of glucose via the Embden-Meyerhof pathway in the mammary gland was more apparent in both groups of 50% HF animals than those of 87.5 % HF animals during early and mid-lactation while it markedly increased for both groups of 87.5% HF animals during late lactation. It can be concluded that utilization of glucose in the mammary gland occurs in a different manner for 50% HF and 87.5% HF animals feeding on either hay or urea treated rice straw. The glucose utilization for biosynthetic pathways in the mammary gland of 50% HF animals is maintained in a similar pattern throughout the periods of lactation. A poorer lactation persistency in both groups of 87.5% HF animals occurs during lactation advance, which is related to a decrease in the lactose biosynthetic pathway.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.38-47
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• 2011

This study focused on health risk assessment via multi-routes of As exposure to establish a target cleanup level (TCL) in abandoned mines. Soil, ground water, and rice samples were collected near ten abandoned mines in November 2009. The As contaminations measured in all samples were used for determining the probabilistic health risk by Monte-Carlo simulation techniques. The human exposure to As compound was attributed to ground water ingestion. Cancer risk probability (R) via ground water and rice intake exceeded the acceptable risk range of $10^{-6}{\sim}10^{-4}$ in all selected mines. In particular, the MB mine showed the higher R value than other mines. The non-carcinogenic effects, estimated by comparing the average As exposure with corresponding reference dose were determined by hazard quotient (HQ) values, which were less than 1.0 via ground water and rice intake in SD, NS, and MB mines. This implied that the non-carcinogenic toxic effects, due to this exposure pathway had a greater possibility to occur than those in other mines. Besides, hazard index (HI) values, representing overall toxic effects by summed the HQ values were also greater than 1.0 in SD, NS, JA, and IA mines. This revealed that non-carcinogenic toxic effects were generally occurred. The As contaminants in all selected mines exceeded the TCL values for target cancer risk ($10^{-6}$) through ground water ingestion and rice intake. However, the As level in soil was greater than TCL value for target cancer risk via inadvertent soil ingestion pathway, except for KK mine. In TCL values for target hazard quotient (THQ), the As contaminants in soil did not exceed such TCL value. On the contrary, the As levels in ground water and polished rice in SD, NS, IA, and MB mines were also beyond the TCL values via ground water and rice intake. This study concluded that the health risks through ground water and rice intake were greater than those though soil inadvertent ingestion and dermal contact. In addition, it suggests that the abandoned mines to exceed the risk-based TCL values are carefully necessary to monitor for soil remediation.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.67-74
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• 1991

Parameter uncertainty and sensitivity of KFOOD model for calculating the ingestion dose via terrestrial food-chain pathway was analyzed with using Monte-Carlo approach. For the rice ingestion pathway, estimated values from KFOOD code were very conservative. Most sensitive input parameters in model were deposition velocities and soil-to-plant transfer coefficient of radionuclides.