Visualising spatio-temporal distributions of assimilated carbon translocation and release in root systems of leguminous plants

Yin, Y.-G.*; Suzui, Nobuo*; Kurita, Keisuke  ; Miyoshi, Yuta*; Unno, Yusuke*; Fujimaki, Shu*; Nakamura, Takuji*; Shinano, Takuro*; Kawachi, Naoki*

The release of rhizodeposits differs depending on the root position and is closely related to the assimilated carbon (C) supply. Therefore, quantifying the C partitioning over a short period may provide crucial information for clarifying root-soil carbon metabolism. A non-invasive method for visualising the translocation of recently assimilated C into the root system inside the rhizobox was established using CO labelling and the positron-emitting tracer imaging system. The spatial distribution of recent C-photoassimilates translocated and released in the root system and soil were visualised for white lupin () and soybean (). Our method enabled the quantification of the spatial C allocations in roots and soil, which may help to elucidate the relationship between C metabolism and nutrient cycling at specific locations of the root-soil system in response to environmental conditions over relatively short periods.