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Kamata A.,Saitama Prefectural Agriculture and Forestry Research Center | Honda Y.,The Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center | Miyazaki Y.,The Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center
Soil Science and Plant Nutrition | Year: 2015

We investigated radiocesium distribution in tea plants (Camellia sinensis L. var. sinensis) of Saitama Prefecture, located approximately 200–250 km away from Tokyo Electric Power Company’s Fukushima Daiichi nuclear power plant. In 2012, more than 2500 samples of tea plants were analyzed. We found differences in radiocesium concentration among tea plant cultivars, which appeared to be attributable mainly to the leaf morphology and depth of the leaf layer in tea plants. Furthermore, the radiocesium concentration in the first tea crop showed a strong correlation with that in spring skiffing. © 2015 Japanese Society of Soil Science and Plant Nutrition


Hayashi N.,Japan National Agriculture and Food Research Organization | Ujihara T.,Japan National Agriculture and Food Research Organization | Tanaka E.,Saitama Prefectural Agriculture and Forestry Research Center | Kishi Y.,Saitama Prefectural Agriculture and Forestry Research Center | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2011

To obtain basic knowledge about the relationship between the application of organic fertilizers and the δ 15N values of leaves of organically grown tea plants, annual variations in the δ 15N values of the tea leaves were investigated. Although variations did not immediately arise after the application of organic fertilizers, differences in the δ 15N values between organic and conventional cultivations appeared basically after three years from the beginning of the organic cultivation except when an organic fertilizer with a low δ 15N value was applied, and the variation depended on the δ 15N values of the fertilizers. In addition, the effectiveness of the δ 15N values as a practical indicator of organic teas was examined. The tea leaves collected from organic farms did not always have higher δ 15N values than the commercially available nonorganic teas. This result demonstrates that it is not easy to discriminate organic teas from nonorganic teas simply by their δ 15N values. © 2011 American Chemical Society.


Yanagi Y.,Kyoto University | Hirooka H.,Kyoto University | Oishi K.,Kyoto University | Choumei Y.,Ryukoku University | And 6 more authors.
Food Chemistry | Year: 2012

A pilot study was conducted to evaluate the suitability of stable isotope analysis for inferring the feeding histories of cattle fed known feeds. Stable isotope ratios of carbon and nitrogen (δ 13C and δ 15N) were measured in meat and hair from cattle and in their feeds at five farms in different regions of Japan, and the correlations of the isotope ratios between meat and hair were analysed. The results showed that δ 13C values in feed depend on the photosynthesis type: C 3 or C 4. The values of δ 15N in feeds varied widely, indicating divergent feeds made from plant materials that have different nitrogen origins, such as soil, chemical fertilizer, manure and air. In both cattle meat and hair, the farms differed significantly in the values of δ 13C and δ 15N. Both δ 13C and δ 15N were significantly higher in hair than in meat, and high correlations between meat and hair in both δ 13C and δ 15N were found. The results suggested that stable carbon and nitrogen isotope analysis for cattle meat and hair could be used to trace the feeding histories of cattle in Japan, and that hair samples would be used as an alternative to meat. © 2012 Elsevier Ltd. All rights reserved.


Abe K.,Japan National Institute for Agro - Environmental Sciences | Nakamura K.,Sumika Chemical Analysis Service Ltd | Arao T.,Japan National Institute for Agro - Environmental Sciences | Sakurai Y.,Japan National Institute for Agro - Environmental Sciences | And 4 more authors.
Journal of the Science of Food and Agriculture | Year: 2011

A simple and quick on-site test for trace levels of cadmium (Cd) in food is needed because of the human toxicity of this heavy metal. We developed an immunochromatography kit which uses the antigen-antibody complex reaction between the Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex and an anti-Cd-EDTA antibody. We previously reported the successful use of this kit to determine Cd concentrations in brown rice with respect to the international standard: 0.4 mg kg -1. Here, we measured, using this immunochromatography kit, Cd concentrations in crops with lower international standards than rice. RESULTS: Cadmium extracted with 0.1 mol L -1 HCl from wheat grain and fresh eggplant was purified sufficiently using an ion-exchange column treatment. Appropriate HCl extraction rates and dilution rates for the column eluate were selected; Cd concentrations in wheat grain and fresh eggplant were determined successfully by immunochromatography with respect to the international standards of 0.2 mg kg -1 and 0.05 mg kg -1 fresh weight, respectively. CONCLUSION: Approximate Cd concentrations in wheat grain and fresh eggplant can be monitored easily and quickly by this method at locations where facilities for acid digestion and precision analysis are not available. © 2011 Society of Chemical Industry.


Yamamoto A.,Japan National Institute for Agro - Environmental Sciences | Akiyama H.,Japan National Institute for Agro - Environmental Sciences | Naokawa T.,Denki Kagaku Kogyo Kabushiki Kaisha | Miyazaki Y.,Saitama Prefectural Agriculture and Forestry Research Center | And 4 more authors.
Biology and Fertility of Soils | Year: 2014

Lime-N (calcium cyanamide, CaCN2) acts as both fertilizer and pesticide. Lime-N may reduce nitrous oxide (N2O) emission from soil, although its effectiveness and the relative mechanisms are not well understood. The aim of the study was to quantify the effect of lime-N on N2O emission from the acidic soil of tea fields. The study design consisted of two treatments: conventional fertilizer (CF) (application of conventional organo-chemical fertilizer) and lime-N (LN) (application of approximately 53 % of the applied N as lime-N and the remaining as conventional organo-chemical fertilizer). Both treatments had the same amount of N, P2O5, and K2O applied to soil between plant canopies; fertilizer was incorporated into soil. We measured N2O emissions and environmental and microbial parameters of soil between plant canopies and under the canopy of tea plants, including the concentrations of dicyandiamide and cyanamide derived from lime-N. Nitrous oxide emission from soil between plant canopies was lower in the LN treatment than in the CF treatment, and soil ammonium oxidation activity and soil denitrification rate decreased after lime-N application. We applied the acetylene inhibition technique and analyzed isotopomer ratios of N2O; the results of both techniques suggested that denitrification was the major process of N2O production in the soil between plant canopies, despite relatively low water-filled pore space. Cumulative N2O emission over the 366 days of the experiment was 36.0 % lower in the LN treatment than in the CF treatment (P < 0.05). Our results suggest that lime-N application decreases N2O emission by inhibiting both nitrification and denitrification processes in the acidic soil. © 2013 Springer-Verlag Berlin Heidelberg.


Inami K.,Tokyo University of Agriculture and Technology | Yoshioka C.,Tokyo University of Agriculture and Technology | Hirano Y.,Saitama Prefectural Agriculture and Forestry Research Center | Kawabe M.,Japan National Agricultural Research Center | And 3 more authors.
Journal of General Plant Pathology | Year: 2010

Five primer/probe sets to identify the tomato wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL), and its three races selectively were designed based on the rDNA-intergenic spacer and avirulence genes. Real-time PCR using genomic DNA from mycelia and soil DNA with the primer/probe sets allowed the successful identification of FOL and its races. © 2010 The Phytopathological Society of Japan and Springer.


Kase C.,Azabu University | Eguchi Y.,National Agriculture Research Center for Western Region | Furuya M.,Saitama Prefectural Agriculture and Forestry Research Center | Uetake K.,Azabu University | Tanaka T.,Azabu University
Mammal Study | Year: 2011

To prevent damage to houses, we investigated the particular size and shape of gap that 12 masked palm civets (six subadults and six adults weighing 2.2-3.4 kg) could enter. After the animals were humanely killed, we measured the body parts of civets and compared those of animals that could and could not enter the gaps. The minimum sizes for different shapes of gaps that masked palm civets could enter were the H6 × W20 cm horizontally long rectangle, H20 × W6 cm vertically long rectangle, 8 cm square, and 9 cm diameter circle. There were no significant differences in most body parts sizes between individuals that went through the minimum-size rectangular gaps and individuals that did not. In contrast, differences in the sizes of body parts affected the minimum sizes of square and circular gaps that they entered. The minimum sizes of square and circular gaps that they entered could be predicted by the regression line of their body weight (square: y = 0.98x + 5.75, r 2 = 0.76, P < 0.01, circle: y = 0.93x + 6.84, r 2 = 0.72, P < 0.01). © the Mammalogical Society of Japan.


Hasegawa T.,Saitama University | Akutsu K.,Saitama University | Kishi Y.,Saitama University | Nakamura K.,Saitama Prefectural Agriculture and Forestry Research Center
Natural Product Communications | Year: 2011

Green tea (Camellia sinensis) leaves are known to contain active ingredients such as catechins and caffeine, and are widely useful materials. Recently, green tea flowers also have been in the spotlight. However, little attention has been paid to the tea seeds. In this work, the constituents of green tea seeds and green tea leaves were compared. Caffeine was found in the seeds, whereas catechins (usually obtained from green tea leaves) were not observed. Next, we investigated the constituents of hexane extracts and methanol extracts of green tea seeds. We found that the hexane extracts contained high amounts of oleic glyceride (79.9%) in addition to linoleic glyceride (20%). We confirmed the structures of these glycerides by NMR spectroscopy and by synthesis from a fatty acid and glycerol. The methanol extract was found to contain naringenin glucosides by mass spectrometry and NMR spectroscopic analysis.


Takahashi A.,Research Institute for Clinical Oncology | Takahashi A.,Saitama University | Takahashi A.,Saitama Prefectural Agriculture and Forestry Research Center | Watanabe T.,Research Institute for Clinical Oncology | And 4 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2014

Green tea is a popular world-wide beverage with health benefits that include preventive effects on cancer as well as cardiovascular, liver and Alzheimer's diseases (AD). This study will examine the preventive effects on AD of a unique aroma of Japanese green tea. First, a transgenic Caenorhabditis elegans (C. elegans) CL4176 expressing human β-amyloid peptide (Aβ) was used as a model of AD. A hexane extract of processed green tea was further fractionated into volatile and non-volatile fractions, named roasty aroma and green tea aroma fractions depending on their aroma, by microscale distillation. Both hexane extract and green tea aroma fraction were found to inhibit Aβ-induced paralysis, while only green tea aroma fraction extended lifespan in CL4176. We also found that green tea aroma fraction has antioxidant activity. This paper indicates that the green tea aroma fraction is an additional component for prevention of AD. © 2014 Japan Society for Bioscience, Biotechnology, and Agrochemistry.


Takahashi A.,Research Institute for Clinical Oncology | Takahashi A.,Saitama University | Takahashi A.,Saitama Prefectural Agriculture and Forestry Research Center | Watanabe T.,Research Institute for Clinical Oncology | And 9 more authors.
Biochemical and Biophysical Research Communications | Year: 2014

Cell motility and cell stiffness are closely related to metastatic activity of cancer cells. (-)-Epigallocatechin gallate (EGCG) has been shown to inhibit spontaneous metastasis of melanoma cell line into the lungs of mice, so we studied the effects of EGCG on cell motility, cell stiffness, and expression of vimentin and Slug, which are molecular phenotypes of epithelial-mesenchymal transition (EMT). Treatments of human non-small cell lung cancer cell lines H1299 and Lu99 with 50 and 100 μM EGCG reduced cell motility to 67.5% and 43.7% in H1299, and 71.7% and 31.5% in Lu99, respectively in in vitro wound healing assay. Studies on cell stiffness using atomic force microscope (AFM) revealed that treatment with 50 μM EGCG increased Young's modulus of H1299 from 1.24 to 2.25. kPa and that of Lu99 from 1.29 to 2.28. kPa, showing a 2-fold increase in cell stiffness, i.e. rigid elasticity of cell membrane. Furthermore, treatment with 50 μM EGCG inhibited high expression of vimentin and Slug in the cells at a leading edge of scratch. Methyl-β-cyclodextrin, a reagent to deplete cholesterol in plasma membrane, showed inhibition of EMT phenotypes similar that by EGCG, suggesting that EGCG induces inhibition of EMT phenotypes by alteration of membrane organization. © 2013 Elsevier Inc.

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