Translocation of 133Cs administered to Cryptomeria japonica wood

To reveal the in planta behaviour of caesium (Cs), the stable isotope Cs-133 was administered into 3-year-old Cryptomeria japonica seedlings by the application of (CsCI)-Cs-133 aqueous solution to the bark surface. The administered Cs-133 was quantified by ICP-MS measurements, which showed transportation of Cs-133 in an ascending direction in the stem. Distribution of Cs-133 was visualized using freeze-fixed C japonica woody stem samples and cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. Cryo-TOF-SIMS/SEM visualization suggested that Cs-133 was rapidly transported radially by ray parenchyma cells followed by axial transportation by pith and axial parenchyma cells. Adsorption experiments using powdered C japonica wood samples and X-ray absorption fine structure (XAFS) analysis suggested that Cs-133 was in the hydrated state following its deposition into tracheid cell walls. (C) 2017 Elsevier B.V. All rights reserved.