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Cs in river water榎本 一之*; 保科 宏行*; 笠井 昇*; 栗田 圭輔; 植木 悠二*; 長尾 悠人*; 尹 永根*; 鈴井 伸郎*; 河地 有木*; 瀬古 典明*
Chemical Engineering Journal, 460, p.141696_1 - 141696_9, 2023/03
被引用回数：1 パーセンタイル：49.6(Engineering, Environmental)本研究では、モリブドリン酸アンモニウム(AMP)を放射線グラフト重合した繊維状のCs吸着フィルターとCe:Gd
Al
GaO
シンチレータを用いた
線検出器を組み合わせて、連続水流中のCsの放射能濃度をその場で測定する方法を開発した。
尹 永根*; 森 欣順*; 鈴井 伸郎*; 栗田 圭輔; 山口 充孝*; 三好 悠太*; 長尾 悠人*; 芦苅 基行*; 永井 啓祐*; 河地 有木*
New Phytologist, 232(5), p.1974 - 1984, 2021/12
被引用回数：9 パーセンタイル：65.39(Plant Sciences)イネ植物(
)は中空の器官を持ち、これが水上の葉から水没した器官へ空気を供給する経路として機能すると推定される。しかし、イネにおけるガス移動はリアルタイムで可視化されていない。本研究では、部分的に水没したイネの葉に窒素13標識窒素([
N]N)トレーサーガスを供給し、葉身、葉鞘、節間に沿って下方に移動するガスの動きを経時的に観察した。
栗田 圭輔; 酒井 卓郎; 鈴井 伸郎*; 尹 永根*; 杉田 亮平*; 小林 奈通子*; 田野井 慶太朗*; 河地 有木*
Japanese Journal of Applied Physics, 60(11), p.116501_1 - 116501_4, 2021/11
被引用回数：1 パーセンタイル：7.86(Physics, Applied)本研究では、生きた植物におけるRI動態をイメージングするために、蛍光体粉末(ZnS:Ag)を用いたオートラジオグラフィシステム「Live-autoradiography」を開発した。このシステムは、無傷の植物における元素の移動と蓄積を、光環境下で連続的に可視化する。イメージングテストでは、10-100kBqのCs点線源を測定した。この結果から、画像強度とCsの放射能との間に良好な線形性が確認できた。さらに、無傷のダイズ植物中におけるCsの動態イメージングを4日間行った。その結果、植物の節,葉脈,成長点にCsが蓄積している様子を観察できた。今回開発したシステムは、植物の生理現象の研究に利用できるだけでなく、放射性核種の定量的な測定にも利用できる。
C-imaging revealed the spatiotemporal variability in the translocation of photosynthates into strawberry fruits in response to increasing daylight integrals at leaf surface三好 悠太*; 日高 功太*; 尹 永根*; 鈴井 伸郎*; 栗田 圭輔; 河地 有木*
Frontiers in Plant Science (Internet), 12, p.688887_1 - 688887_14, 2021/07
被引用回数：12 パーセンタイル：76.93(Plant Sciences)本研究では、イチゴ果実への光合成産物の輸送を陽電子放出トレーサーイメージング装置(PETIS)を用いて非侵襲的に繰り返し可視化し、日照時間の増加に伴う輸送動態の時空間的な変動を評価した。本研究は、C-放射性同位体を用いて、ソース葉から個々のシンク果実への光合成産物輸送の時空間変動を、高い時空間分解能で明らかにした初めての研究である。
栗田 圭輔; 三好 悠太*; 長尾 悠人*; 山口 充孝*; 鈴井 伸郎*; 尹 永根*; 石井 里美*; 河地 有木*; 日高 功太*; 吉田 英治*; et al.
QST-M-29; QST Takasaki Annual Report 2019, P. 106, 2021/03
Research on the distribution and dynamics of photoassimilates in plants, especially those in fruits, is important for improving food production. Positron emission tomography (PET) and carbon-11 (C) isotope technique are valuable to obtain 3-D images of photoassimilates. For plant experiments, however, it is important to adjust a system to plant's growth environment. General PET devices, even small-animal PET devices, are not suitable for plant studies. This can be solved by using a small OpenPET prototype which is a compact PET device that has an open space in its field of view (FOV). In this work, we upgraded the OpenPET system for the PET study of fruits and successfully realized the 3-D imaging of a photoassimilate labeled with CO in a fruit of a strawberry plant.
Cs tracer鈴井 伸郎*; 柴田 卓弥; 尹 永根*; 船木 善仁*; 栗田 圭輔; 保科 宏行*; 山口 充孝*; 藤巻 秀*; 瀬古 典明*; 渡部 浩司*; et al.
Scientific Reports (Internet), 10, p.16155_1 - 16155_9, 2020/10
被引用回数：2 パーセンタイル：24.28(Multidisciplinary Sciences)Visualizing the dynamics of cesium (Cs) is desirable to understand the impact of radiocesium when accidentally ingested or inhaled by humans. The positron-emitting nuclide Cs was produced using the I (
, 4n) Cs reaction, which was induced by irradiation of sodium iodide with a 
He
beam from a cyclotron. We excluded sodium ions by using a material that specifically adsorbs Cs as a purification column and successfully eluted Cs by flowing a solution of ammonium sulfate into the column. We injected the purified Cs tracer solution into living rats and the dynamics of Cs were visualized using positron emission tomography; the distributional images showed the same tendency as the results of previous studies using disruptive methods. Thus, this method is useful for the non-invasive investigation of radiocesium in a living animal.
尹 永根*; 鈴井 伸郎*; 栗田 圭輔; 三好 悠太*; 海野 佑介*; 藤巻 秀*; 中村 卓司*; 信濃 卓郎*; 河地 有木*
Scientific Reports (Internet), 10, p.8446_1 - 8446_11, 2020/06
被引用回数：11 パーセンタイル：59.51(Multidisciplinary Sciences)根系からの放出物は根の位置によって異なり、同化炭素(C)の供給と密接に関係している。したがって、短時間での炭素の動きを定量化することで、根と土壌における炭素の代謝を明らかにできる可能性がある。CO
と陽電子放出トレーサーイメージングシステムを使用し、根箱内における同化炭素の根系への移行を可視化するための非侵襲的な方法を確立した。C-光合成産物の移動と根系および土壌への放出の様子を、白ルーピンとダイズについて観察した。本手法により、根と土壌に分布する炭素配分の定量化が可能になった。これは、比較的短期間の環境条件に応じて、根-土壌系の特定の場所での炭素代謝と栄養循環の関係を解明するのに役立つ可能性がある。
N]N gas for visualization of nitrogen fixation and translocation in nodulated soybean尹 永根*; 石井 里美*; 鈴井 伸郎*; 井倉 将人*; 栗田 圭輔; 三好 悠太*; 長澤 尚胤*; 田口 光正*; 河地 有木*
Applied Radiation and Isotopes, 151, p.7 - 12, 2019/09
被引用回数：6 パーセンタイル：55.67(Chemistry, Inorganic & Nuclear)マメ科作物の窒素固定を正確に解析するためには、無傷の植物体内での窒素利用を測定する必要がある。しかしながら、ほとんどのアプローチでは組織の解体が必要である。我々は、高純度かつ高収率の[N]Nガスを簡便かつ迅速に生成する技術を開発し、無傷のダイズ植物体内における窒素固定をリアルタイムで画像化することに成功した。減衰補正後の精製効率は約81.6%であった。
尹 永根; 河地 有木; 鈴井 伸郎; 石井 里美; 吉原 利一*; 渡部 浩司*; 山本 誠一*; 藤巻 秀
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 112, 2016/02
Large areas of agricultural fields were contaminated with radiocesium (
Cs and Cs) in Japan by the accident of The Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station in March 2011. Many agricultural studies, such as fertilizer management and plant breeding, are undertaken for reducing radiocesium uptake in crops or enhancing of uptake and transportation via phytoremediation. These studies examine the control of radiocesium transport into/within plant bodies from the viewpoint of plant physiology. Radiotracer imaging is one of the few methods that enable the observation of the movement of substances in a living plant, like a video camera, without sampling of the plant tissues. In this study, we performed the imaging of Cs uptake and transport from root to aerial part by using a new gamma camera in intact soybean plants because contamination of soybean by radiocesium has currently become a major problem in agriculture in Fukushima.
Cs movement in a plant body河地 有木; 尹 永根; 鈴井 伸郎; 石井 里美; 吉原 利一*; 渡部 浩司*; 山本 誠一*; 藤巻 秀
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 94, 2016/02
We developed an original gamma camera system to image radiocesium in a plant. The gamma camera was designed for high-energy gamma photons from Cs radiocesium (662 keV). We performed tests to evaluate the position resolution and quantitative linearity of the gamma camera. The best spatial resolution of this gamma camera was determined to be 19.1 mm in full width at half maximum at the center of the field-of-view. And a result shows a quantitative linearity of the image data with a correlation of 
= 0.9985 between the source activity and the count rate. We conclude the gamma camera system has sufficiently high capability to obtain quantitative and dynamic images of Cs movement in intact plants.
in a greenhouse for tomato cultivation石井 里美; 山崎 治明*; 鈴井 伸郎; 尹 永根; 河地 有木; 島田 浩章*; 藤巻 秀
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 93, 2016/02
Tomato is popularly grown in environmentally controlled system such as a greenhouse for improvement of bioproduction. It is important to control the condition in the greenhouse for increasing the translocation of fixed carbon from the leaves to the growing fruits. Elevation of COconcentration is widely employed for that purpose; however, it is difficult to estimate its effect quantitatively because tomato plants have too large inter-individual variations with developing fruits. In this study, we employed a PETIS which is a live-imaging system of nutrients in plant body using short-lived radioisotopes including C. We also established a closed cultivation system to feed a test plant with CO at set concentrations of 400, 1,500 and 3,000 ppm and a pulse of CO.
河地 有木; 尹 永根; 鈴井 伸郎; 石井 里美; 吉原 利一*; 渡部 浩司*; 山本 誠一*; 藤巻 秀
Journal of Environmental Radioactivity, 151(Part 2), p.461 - 467, 2016/01
被引用回数：14 パーセンタイル：41.64(Environmental Sciences)We developed a new gamma camera specifically for plant nutritional research and successfully performed live imaging of the uptake and partitioning of Cs in intact plants. The gamma camera was specially designed for high-energy photons from Cs (662 keV). To obtain reliable images, a pinhole collimator made of tungsten heavy alloy was used to reduce penetration and scattering of photons. The array block of the GAGG scintillator was coupled to a high-quantum efficiency position sensitive photomultiplier tube to obtain accurate images. The completed gamma camera had a sensitivity of 0.83 count s
MBq for Cs, and a spatial resolution of 23.5 mm. We used this gamma camera to study soybean plants that were hydroponically grown and fed with 2.0 MBq of Cs for 6 days to visualize and investigate the transport dynamics in aerial plant parts. Cs gradually appeared in the shoot several hours after feeding, and then accumulated preferentially and intensively in growing pods and seeds; very little accumulation was observed in mature leaves. Our results also suggested that this gamma-camera method may serve as a practical analyzing tool for breeding crops and improving cultivation techniques resulting in low accumulation of radiocesium into the consumable parts of plants.
concentration in a closed cultivation system for the improvement of bioproduction in tomato fruits山崎 治明*; 鈴井 伸郎; 尹 永根; 河地 有木; 石井 里美; 島田 浩章*; 藤巻 秀
Plant Biotechnology, 32(1), p.31 - 37, 2015/04
被引用回数：16 パーセンタイル：53.52(Biotechnology & Applied Microbiology)To maximize fruit yield of tomatoes cultivated in a controlled, closed system such as a greenhouse or a plant factory at a limited cost, it is important to raise the translocation rate of fixed carbon to fruits by tuning the cultivation conditions. Elevation of atmospheric CO concentration is a good candidate. In this study, we employed a positron-emitting tracer imaging system (PETIS), which is a live-imaging technology for plant studies, and a short-lived radioisotope C to quantitatively analyze immediate responses of carbon fixation and translocation in tomatoes in elevated CO conditions. We also developed a closed cultivation system to feed a test plant with CO at concentrations of 400, 1500 and 3000 ppm and a pulse of CO. As a result, we obtained serial images of C fixation by leaves and subsequent translocation into fruits. Carbon fixation was enhanced steadily by increasing the CO concentration, but the amount translocated into fruits saturated at 1500 ppm on average. The translocation rate had larger inter-individual variation and showed less consistent responses to external CO conditions compared with carbon fixation.
C-photoassimilate flow using positron-emitting tracer imaging system鈴井 伸郎; 河地 有木; 石井 里美; 尹 永根; 岩崎 郁*; 小川 健一*; 藤巻 秀
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 105, 2015/03
In this study, we developed an analytical method to evaluate velocity of photoassimilate flow using C-tracer and the positron-emitting tracer imaging system (PETIS). CO gas tracer was fed to the compound leaves of the soybean plant, and serial images of C distribution were obtained by PETIS. Regions of interests (ROIs) were set in the node of the first compound leaf (ROI-1) and the stem base (ROI-2). Time course of C-radioactivity (Time-Activity Curve: TAC) in each ROI was generated from the serial images. Initial slope of the rising C-radioactivity was estimated by a linear least-square method using the TAC data. The value of the intercept of approximated line to the background line (X-intercept) was defined as "C-arrival time" to the ROIs. In order to determine X-intercept with a fair criterion, we developed an analytical program. The velocities of C-photoassimilate flows of 18 individual soybean plants were estimated by the values of C-arrival time and the distance between ROI-1 and ROI-2. As a result, the average value of the velocity was 113 cm h and the standard deviation was 20 cm h. This result indicates the newly developed method is a reliable tool for the quantitative analysis of photoassimilate flow through the phloem.
山本 誠一*; 緒方 良至*; 河地 有木; 鈴井 伸郎; 尹 永根; 藤巻 秀
Nuclear Instruments and Methods in Physics Research A, 777, p.102 - 109, 2015/03
被引用回数：3 パーセンタイル：25.85(Instruments & Instrumentation)After the nuclear disaster in Fukushima, radiocesium contamination became a serious scientific concern and research of its effects on plants increased. In such plant studies, high resolution images of radiocesium are required without contacting the subjects. Cherenkov light imaging of beta radionuclides has inherently high resolution and is promising for plant research. Since Cs and Cs emit beta particles, Cherenkov light imaging will be useful for the imaging of radiocesium distribution. Consequently, we developed and tested a Cherenkov light imaging system. We used a high sensitivity cooled charge coupled device (CCD) camera for imaging Cherenkov light from Cs and Cs. A bright lens was mounted on the camera and placed in a black box. With a 100-
m Cs point source, we obtained 220-m spatial resolution in the Cherenkov light image. With a 1-mm diameter, 320-kBq Cs point source, the source was distinguished within 2-s. We successfully obtained Cherenkov light images of a plant whose root was dipped in a Cs solution, radiocesium-containing samples as well as line and character phantom images with our imaging system. Cherenkov light imaging is promising for the high resolution imaging of radiocesium distribution without contacting the subject.
中村 進一*; 近藤 ひかり*; 鈴井 伸郎; 尹 永根; 石井 里美; 河地 有木; 頼 泰樹*; 服部 浩之*; 藤巻 秀
Molecular Physiology and Ecophysiology of Sulfur, p.253 - 259, 2015/00
被引用回数：3 パーセンタイル：71.1(Plant Sciences)Glutathione is a sulfur-containing peptide involved in various aspects of plant metabolism. Glutathione is also known to have effects on heavy metal responses in plants. In our previous work, we have found glutathione, applied to roots site- specifically, inhibited cadmium (Cd) translocation from roots to shoots and Cd accumulation in shoots in oilseed rape plants. In addition, we succeeded in visualizing inhibition of root-to-shoot translocation of Cd by using a positron-emitting tracer imaging system (PETIS). In this work, the effects of glutathione concentration in the root zone (hydroponic solution) and the glutathione treatment period on Cd partitioning in oilseed rape plants were investigated. Our experimental results demonstrated that glutathione, exceeding a certain concentration in the root zone, is needed to trigger inhibition of Cd translocation, and that treatment time from the start of glutathione application had different effects on Cd partitioning in oilseed rape plants.
-knockdown rice is a promising candidate for Cd phytoremediation in paddy fields高橋 竜一*; 石丸 泰寛*; Shimo, H.*; Bashir, K.*; 瀬野浦 武志*; 杉本 和彦*; 小野 和子*; 鈴井 伸郎; 河地 有木; 石井 里美; et al.
PLOS ONE (Internet), 9(6), p.e98816_1 - e98816_7, 2014/06
被引用回数：51 パーセンタイル：86.7(Multidisciplinary Sciences)Previously, we reported that OsNRAMP5 functions as a manganese, iron, and cadmium (Cd) transporter. The shoot Cd content in RNAi plants was higher than that in wild-type (WT) plants, whereas the total Cd content (roots plus shoots) was lower. For efficient Cd phytoremediation, we produced RNAi plants using the natural high Cd-accumulating cultivar Anjana Dhan (A5i). Using a positron-emitting tracer imaging system, we assessed the time-course of Cd absorption and accumulation in A5i plants. Enhanced 
Cd translocation from the roots to the shoots was observed in A5i plants. To evaluate the phytoremediation capability of A5i plants, we performed a field experiment in a Cd-contaminated paddy field. The biomass of the A5i plants was unchanged by the suppression of expression; the A5i plants accumulated twice as much Cd in their shoots as WT plants. Thus, A5i plants could be used for rapid Cd extraction and the efficient phytoremediation of Cd from paddy fields, leading to safer food production.
and tobacco plants吉原 利一*; 鈴井 伸郎; 石井 里美; 北崎 真由*; 山崎 治明*; 北崎 一義*; 河地 有木; 尹 永根; 七夕 小百合*; 橋田 慎之介*; et al.
Plant, Cell & Environment, 37(5), p.1086 - 1096, 2014/05
被引用回数：24 パーセンタイル：65.61(Plant Sciences)Cadmium (Cd) accumulations in a Cd hyper-accumulator fern, (
), and tobacco, 
(
), were kinetically analysed using the positron-emitting tracer imaging system under two medium conditions (basal and no-nutrient). In , maximumly 50% and 15% of the total Cd accumulated in the distal roots and the shoots under the basal condition, respectively. Interestingly, a portion of the Cd in the distal roots returned to the medium. In comparison with , a little fewer Cd accumulations in the distal roots and clearly higher Cd migration to the shoots were observed in under the basal condition (maximumly 40% and 70% of the total Cd, respectively). The no-nutrient condition down-regulated the Cd migration in both species, although the regulation was highly stricter in than in (almost no migration in and around 20% migration in ). In addition, the present work enabled to estimate physical and physiological Cd accumulation capacities in the distal roots, and demonstrated condition-dependent changes especially in . These results clearly suggested occurrences of species-/condition-specific regulations in each observed parts. It is probable that integration of these properties govern the specific Cd tolerance/accumulation in and .
Cd distribution using positron-emitting tracer imaging system鈴井 伸郎; 尹 永根; 井倉 将人*; 石井 里美; 河地 有木; 石川 覚*; 藤巻 秀
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 101, 2014/03
We have conducted noninvasive imaging of cadmium (Cd) in intact plants using a positron-emitting tracer imaging system (PETIS) and Cd for the purpose of understanding the mechanism of Cd translocation in plants. In our typical imaging experiment, Cd tracer has been fed to the root of large plants such as rice, and obtain the serial images of Cd distribution in the underground parts (roots and culture solutions) or the aerial parts (shoots or grains). However, whole-plant images of Cd distribution in both underground and aerial parts have not been obtained because the field of view (FOV) of PETIS is limited. In this study, we fed Cd to dwarf plants, 
and visualized Cd dynamics in a whole plant within the FOV of PETIS. As a result, the whole physiological process, i.e., uptake from culture solution, translocation from root to shoot and accumulation in shoot, were successfully visualized in the single imaging experiment. The time courses of Cd amounts demonstrated that the half amount of Cd fed to the solution was taken up by the root within 2 hours, and the two-thirds amount was accumulated in the shoot after 30 hours. These results imply the whole-plant imaging represents a reliable tool for the quantitative analysis of Cd dynamics.
N-labeled nitrogen gas tracer for the imaging of nitrogen fixation in soybean nodules石井 里美; 井倉 将人*; 尹 永根; Hung, N. V. P.*; 鈴井 伸郎; 河地 有木; 小柳 淳*; 大山 卓爾*; 藤巻 秀
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 98, 2014/03
Nitrogen is the most important nutrient for the plants. Soybean can utilize nitrogen from atmospheric N fixed by nodules which are symbiotic organs of leguminous plants with rhizobia. In the beginning of this research project, we set our methodological goal to visualize and analyze the nitrogen fixation in the nodules and subsequent nitrogen transport to the aerial part in a plant using N and PETIS. Previously, we have developed a method of production of highly purified N-labelled nitrogen gas tracer using gas chromatography and successfully visualized nitrogen fixation in intact nodules. However, the yields of the tracer were only a few ten megabecquerels and too low to visualize the transport of fixed nitrogen to the aerial part. Therefore, we have been trying to improve the production method to gain much higher radioactivity with consideration of the very short half-life of [N]N. In this study, we tested a new technique to turn the main by-product [N]NO into the desired product [N]N directly.
