Mn translocation in barley monitored using a positron-emitting tracer imaging system

オオムギにおけるMn移行のポジトロンイメージング技術による計測

塚本 崇志*; 中西 啓仁*; 清宮 正一郎*; 渡辺 智; 松橋 信平; 西澤 直子*; 森 敏*

Tsukamoto, Takashi*; Nakanishi, Hiromi*; Kiyomiya, Shoichiro*; Watanabe, Satoshi; Matsuhashi, Shimpei; Nishizawa, Naoko*; Mori, Satoshi*

Until now, the real-time uptake and movement of Mn, has not been documented in plants. In this study, the real-time translocation of Mn in barley was visualized using Mn and PETIS. In all cases, Mn first accumulated in the discrimination center (DC), suggesting that this region may play an important role in Mn distribution in graminaceous plants. Mn deficient barley showed greater translocation of Mn from roots to shoots than did Mn-sufficient barley. In contrast, the translocation of Mn from roots to shoots was suppressed in Mn-excess barley. In Mn-sufficient barley, the dark treatment did not suppress the translocation of Mn to the youngest leaf, suggesting that the translocation of Mn to the youngest leaf is independent of the transpiration stream. Our results show that the translocation of Mn from the roots to the DC depends passively on water flow, but actively on the Mn transporter(s).