Investigating belowground dynamics with Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET)

Investigating belowground dynamics with Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET)Ralf Metzner*, Dagmar van Dusschoten and Siegfried JahnkeInstitute of Bio- and Geosciences IBG 2: Plant Sciences, Forschungszentrum Jülich GmbH, Germany*Presenting author: r.metzner@fz-juelich.deThe development of a root system adequate for supplying a plant with water and nutrients under dynamic growing conditions is critical for survival, performance and yield. Particularly for “Root Crops” where the storage organs are developing belowground, the dynamics of the carbon storage of the roots are also highly relevant. The opaque nature of soil prevents direct observation and while a number of approaches for observing 2D root development such as rhizotrons have been applied successfully, roots naturally develop in interaction with the 3D soil environment and form themselves complex 3D structures. Therefore the ability to deep-phenotype the 3D structure and function of roots and other belowground structures non-invasively yields a high potential for gaining new insights into root development, its regulation and responses to stress. Here we present two approaches that allow this kind of investigation: Magnetic resonance imaging (MRI) allows for visualization and quantification of root system architecture traits in soil such as root length and mass, but also of internal structures of storage organs. Positron emission tomography (PET) using short-lived radiotracer 11C provides additional 3D imaging of the photoassimilate distribution. Photoassimilate flow characteristics can be extracted from these data with a model-based analysis. We show here application of both techniques for repeated visualization and quantification of root system architecture, anatomy and photoassimilate allocation of a number of species and developmental stages, including barley, pea and sugar beet