X-ray-, Neutron- and Radio-imaging for Plant Systems Biology

Understanding the signaling and developmental mechanisms underlying processes in plants that control growth, biomass composition, and responses to environmental stresses, is of the utmost importance in improving plant traits for feed, fiber, and energy applications. However, there is a dearth of suitable approaches to study plant signaling mechanisms in vivo. Here we report results from development of three in vivo plant imaging techniques and demonstrate their application in studies of Populus, a model bioenergy crop.  Specifically, we adapted x-ray micro-CT technology to carry out in vivo imaging of plant structure, neutron imaging technology to carry out in vivo chemical imaging and carried out real-time monitoring of radiolabeled proteins. Neutron Imaging was used successfully to demonstrate water transport defects in auxin mutant plants. Morphometric and expression studies suggest that acute X-ray exposure does not trigger an acute stress response. Development of a plant radiochemical imager will facilitate dynamic studies of mobile biomolecules with relevance to plant systems biology. The combined capabilities of in vivo and ex situ molecular and phenotype profiling methods will provide an unprecedented capability to explore the fundamental processes underlying plant physiology as well as to help model plant growth and development.