Positron Emission Tomography (PET) Data

Fluoride Transport in Living Plants

Background

• Ion transport is a fundamental physiological process in plants.
• Fluoride is a phytotoxic pollutant; understanding its transport is crucial.
• Positron Emission Tomography (PET) is used to trace fluoride transport in Brassica oleracea after petiolar administration.
• This allows mathematical modeling of fluoride transport.

Methods

• [18F]fluoride administered via bisected petioles of Brassica oleracea.
• PET scanner used to monitor fluoride uptake and distribution in real-time.
• Time-activity curves (TACs) were obtained and mathematically modeled.
• Kinetic modeling described tracer movement with free- and trapped-compartment model.

Results

• Radioactivity climbed for 10 minutes, followed by washout and equilibration in leaves.
• Trapping rate: $1.5 \pm 0.3$ %/min.
• Velocity: $2.2 \pm 1.1$ cm/min.
• Trapping fraction: $0.8 \pm 0.5$ %/cm.

Discussion

• PET allows quantitative assessment of fluoride transport parameters.
• Free fluoride movement consistent with bulk flow in xylem.
• Trapping observed, likely in the apoplast.
• Petiolar administration allows observation of finite bolus activity.

Conclusion

• PET combined with petiolar administration enables quantitative assessment of fluoride transport.
• Allows compartmental kinetic modeling to measure fluoride velocity and trapping fraction.