Non-invasive estimation of phloem flow velocity under cadmium stress using the positron emitting tracer imaging system

ポジトロンイメージング技術を用いたカドミウムストレス下における転流速度の解析

鈴井 伸郎; 河地 有木; 石井 里美; 中村 進一*; 松橋 信平; 藤巻 秀

Suzui, Nobuo; Kawachi, Naoki; Ishii, Satomi; Nakamura, Shinichi*; Matsuhashi, Shimpei; Fujimaki, Shu

In this study, we estimated a phloem flow under Cd stress using the positron emitting tracer imaging system (PETIS), quantitatively and non-invasively. In an experiment, CO was supplied to leaves of rice plants and the translocations of C-photoassimilates were monitored. We performed 6 sets of PETIS experiments using 56 different rice plants treated with 0, 1, 10, 100 M of Cd. The arrival times of C-photoassimilates to the basal region of each plant were analyzed. Phloem flow velocities were also estimated using the C-arrival time and the distance from the bottom of gas-cell to the basal region. Arrival time of 100 M Cd-treated plants was significantly different from that of control and 10 M Cd-treated plants (p 0.05). This result indicates that Cd exposure to the root for 1 day causes the decrease of phloem flow velocity in rice plant.