Incorporation and translocation of 2-deoxy-2-[18F]fluoro-d-glucose in Sorghum bicolor (L.) Moench monitored using a planar positron imaging system

Abstract

[(18)F]FDG (2-deoxy-2-[(18)F]fluoro-D-glucose) was fed to a sorghum plant [Sorghum bicolor (L.) Moench] from the tip of a leaf and its movement was monitored using a planar positron imaging system (PPIS). [(18)F]FDG was uptaken from the leaf tip and it was translocated to the basal part of the shoots from where it moved to the roots, the tillers and the sheaths. Autoradiographic analysis of the distribution of (18)F, [(18)F]FDG and/or its metabolites showed translocation to the roots, tillers, and to the leaves that were younger than the supplied leaf. Strong labelling was observed in the basal part of the shoots, in the sheaths, the youngest leaf and the root tips. Our results indicate that [(18)F]FDG and/or its metabolites were absorbed from the leaf and translocated to the sites where nutrients are required. This strongly suggests that [(18)F]FDG can be utilised as a tracer to study photoassimilate translocation in the living plant. This is the first report on the use of [(18)F]FDG, which is routinely used as a probe for clinical diagnosis, to study source to sink translocation of metabolites in whole plants in real time.

Imaging of photoassimilates transport in plant tissues by positron emission tomography

“…In the literature focused on the analysis of uptake and translocation of compounds in plant tissues using PET, the application of radiotracer on the cut leaf tip of plants represents a relatively common method. For example, Hattori et al (2008) using this approach found that 2-[ 18 F]FDG was uptaken from the leaf tip and it wastranslocated to the basal part of the shoots from where it moved further to the roots, the tillers and the sheaths of sorghum plant. As it can be seen in the Fig.…”

“…Previously, Hattori et al (2008) and Karve et al (2015) applied the PET in the analysis of the uptake and distribution of radioindicator in the tissues of sorghum (Sorghum bicolour L.) plants also belonging to Poaceae like giant reed plants. (Fig.…”

It Was Found That Amino Sugar Nitrogen Was a New Source of Energy for Plant

“…We injected 2.425 mCi 18 F-FDG into every treated substrate solution. Five hours after injection, the plants were washed with deionized water and fixed on the Explore Vista Micro PET System for imaging.…”

“…The root was cut for radioactivity measurements with a well-type detector. The data were corrected using 109.77 min as the 18 F half-life and according to the same count time.…”

“…To identify whether ASN is directly absorbed by plants, the specific activity of the roots of tomatoes and rice that had been dipped in 18 F-FDG substrate solution was assayed. The specific activity of tomato roots showed an approximately linear increase with time from application of the tracer, within the first 30 min (Figure 2A).…”