Glutathione, applied to roots specifically, has effects on Cd behavior in oilseed rape plants

アブラナの根に与えたグルタチオンは地上部へのカドミウムの移行を選択的に阻害する

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

Nakamura, Shinichi*; Kondo, Hikari*; Suzui, Nobuo; Yin, Y.-G.; Ishii, Satomi; Kawachi, Naoki; Rai, Hiroki*; Hattori, Hiroyuki*; Fujimaki, Shu

We proved that application of glutathione (GSH) to roots reduced Cd accumulation in the shoot of oilseed rape plants selectively. The effects of GSH application to roots on Cd behavior in the whole plant body was visualized and analyzed by using PETIS (positron-emitting tracer imaging system). Further research was performed to investigate the molecular mechanisms of this phenomenon. Oilseed rape plants were grown hydroponically. Four-week old seedlings were used in Cd and GSH treatment experiments. After harvest, Cd content in each part of seedling was measured by using an inducitively coupled plasma atomic emission spectrometer. And time-series images of the Cd distribution were obtained using PETIS. As a result, there were differences in Cd contents in shoots of plants which were treated in different GSH concentration. 10 M GSH in hydroponic solution had little effect on Cd behavior although 1 mM GSH had obvious effect. We also succeeded to obtain fine serial images of Cd behavior in oilseed rape plants by using PETIS. Strong Cd signals were observed in the shoot base. Our experimental results suggested that some signals, triggered by GSH, might operate in roots and play an important role in distributing Cd in the plant body. Some level of GSH is required to induce these signals.