Application of positron emission tomography and 2-[18F]fluoro-2-deoxy-d-glucose for visualization and quantification of solute transport in plant tissues

The aim of the presented work was to evaluate the uptake and distribution of 2-fluoro-2-deoxy-d-glucose spiked with ¹⁸F (2-[¹⁸F]FDG) in tissues of tobacco plants (Nicotiana tabacum L.) by positron emission tomography and multivariate data analysis after the immersion of the petiole of excised leaf or root of a tobacco plant in a glucose solution. From individual experiments it was found that increasing glucose concentration (c _glu) in the applied solution resulted in significantly higher 2-[¹⁸F]FDG diffusion and translocation within the leaf parenchyma. More than a four times increase of the 2-[¹⁸F]FDG translocation into the aboveground parts of the tobacco plant in case of the root immersion in solution with 100-times higher c _glu in comparison with the control (c _glu = 0.00762 mg cm^?3) was determined. These facts were not confirmed only visually on basis of the obtained 3D images, but also by the increasing coincidence transfer factor (TF_c) values defined by the ratio of the number of analyzed coincidences in the non-immersed parts of leaf or plant to coincidences in leaf petiole or root immersed in the solution. Cluster and principal component analysis suggest that the 2-[¹⁸F]FDG uptake by the petiole of excised leaf and root system was realized by different mechanisms; also, the 3D image quality is influenced by the initial radioactivity of the applied solution.