EngSci-BIO-142: A fusion of in vivo Neutron and X-ray Computed Tomography to understand water dynamics in biological systems

One of the essential functions of plant roots is the uptake of water. Due to increasing water restraints on agriculture, there is increasing motivation to truly understand plant water uptake. This requires new methods to allow the measurement of water fluxes in roots and the soils that surround them. This studentship provides the opportunity to work in a world leading group which develops sophisticated methods for non-destructive 3D imaging at the single root scale in vivo. The X-ray computed tomography (XCT) approaches usually applied are not well- suited to visualising water distributions, however, the high neutron attenuation coefficient of hydrogen makes neutron radiography and tomography (NCT) very attractive techniques for measuring water dynamics in plant soil systems. We seek a student with a good technical background in engineering, physics, computer science (or similar discipline) who wants to conduct exciting interdisciplinary research across two world-leading institutions.

This fully-funded project will develop methods to fuse X-ray and neutron computed tomography, combining the strengths of both methods to synthesise greater understanding of hydrological processes in biological systems. It provides a unique opportunity to use the new IMAT neutron imaging beamline at the UK’s national spallation neutron source, as well as the I13 X-ray micro-tomography beamline at the UK’s synchrotron light source, both less than an hour from the University of Southampton. Using these facilities, you will develop tools to elucidate the 3D structure of complex soil pore networks using XCT, then quantify the corresponding 3D water distributions of the same samples using NCT. You will carry out experiments using both i) in vivo plant root assays, and ii) hydrodynamic validation assays which use microfluidic approaches to deliver precise fluxes of water at a point source in a soil matrix.

The techniques you develop will allow: i) quantification of the dynamics of water transport and uptake from soil by roots, ii) quantification of the diffusion rates of water-rich gels (exudates) from root tips into the surrounding soil, iii) the comparison of NT measurements of water fluxes with those estimated by image-based mathematical models parameterised using 3D soil-structure data from XCT.
The nature of the project will require time to be spent embedded working at the STFC campus at Harwell (year 1 and year 3), which is <1 h from Southampton University, with good road and rail links. A vibrant community of postgraduate students exists at both the University and the Harwell campus.

If you wish to discuss any details of the project informally, please contact Dr Samuel Keyes, Bioengineering research group, Email: [Email Address Removed]