title: Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera.
abstract: We developed a new gamma camera specifically for plant nutritional research and successfully performed live imaging of the uptake and partitioning of (137)Cs in intact plants. The gamma camera was specially designed for high-energy gamma photons from (137)Cs (662 keV). To obtain reliable images, a pinhole collimator made of tungsten heavy alloy was used to reduce penetration and scattering of gamma photons. A single-crystal scintillator, Ce-doped Gd3Al2Ga3O12, with high sensitivity, no natural radioactivity, and no hygroscopicity was used. The array block of the 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(-1) MBq(-1) for (137)Cs with an energy window from 600 keV to 730 keV, 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 (137)Cs for 6 days to visualize and investigate the transport dynamics in aerial plant parts. (137)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.
authors.affiliation: Radiotracer Imaging Group, Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan. Electronic address: kawachi.naoki@jaea.go.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kawachi
authors.affiliation: Radiotracer Imaging Group, Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
authors.forename: Yong-Gen
authors.initials: YG
authors.lastname: Yin
authors.affiliation: Radiotracer Imaging Group, Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Suzui
authors.affiliation: Radiotracer Imaging Group, Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Ishii
authors.affiliation: Laboratory of Environmental Science, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Chiba 270-1194, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yoshihara
authors.affiliation: Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watabe
authors.affiliation: Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Radiotracer Imaging Group, Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Fujimaki
mesh_terms: D002588:Cesium Radioisotopes / Q000378:metabolism*; D015902:Gamma Cameras; D018521:Plant Physiological Phenomena; D011834:Radiation Monitoring / Q000295:instrumentation / Q000379:methods*; D013025:Glycine max / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D002588:Cesium Radioisotopes
keywords: (137)Cs; Gamma camera; Imaging; Plant; Radiocesium; Soybean