Mathematical Analysis of Moving Images of Transportation in a Living Plant Captured by the Positron Emitting Tracer Imaging System (PETIS)

Abstract

The Positron Emitting Tracer Imaging System (PETIS) is a non-invasive tool to present moving images of transportation of positron-emitting radioactive tracers in an intact plant body. The movies have been helping understand the dynamics of uptake and transportation of nutrients in living plants. In this report, we show a new aspect that quantitative information such as a speed of transportation can be lead from the PETIS data through a mathematical analysis.
We employed transfer function analysis for time-course profiles of tracer activity on selected regions in the image. A transfer function is a mathematical model which converts inputs into outputs, which describes dynamics of natural or artificial systems with unknown mechanisms. We calculated the flow speeds and leakage ratios through the path of ¹⁸F^- or ¹³NO₃^- in chinese chive and soybean plants. Our recent results on the dynamics of photoassimilates transportation in a living plant supplied ¹¹CO₂ are also presented.