High resolution NMR microscopy of plants and fungi

Nuclear magnetic resonance (NMR) microscopy is a completely noninvasive technique that can be used to acquire images with high spatial resolution through opaque objects such as plant organs and tissue parts. The image contrast can be chosen to represent the anatomical details or to visualize the spatial distribution of a range of physico-chemical parameters such as the apparent diffusion constant of water or the velocity of water flow within plants in vivo. In addition, images can be generated which show the spatial distribution of metabolites. Furthermore, it is possible to detect chemical compounds labelled with the stable isotope C-13 and to generate images showing the spatial distribution of the C-13 label in the intact plant. The ability to monitor water flow and transport of C-13-labelled tracer in intact plants with NMR microscopy favours the use of this technique in the investigation of long-distance transport processes in plants. A short introduction into the technical principles of NMR microscopy is provided and the problems associated with applications to plants are summarized. The potential of the technique is explained with applications to Zinnia elegans plants, wheat grains and Brassica napus siliques.