In this paper, we provide the first direct evidence of the importance of root hairs on pore structure development at the root-soil interface during the early stage of crop establishment. This was achieved by use of high resolution (~5 µm) synchrotron radiation computed tomography (SRCT) to visualise both the structure of root hairs and the soil pore structure in plant-soil microcosms. Two contrasting genotypes of barley (Hordeum vulgare L.), with and without root hairs, were grown for 8 days in microcosms packedwith sandy loam soil at 1.2 g cm-3 35 dry bulk density. Root hairs were visualised within air filled pore spaces, but not in the fine-textured soil regions. We found that the genotype with root hairs significantly altered the porosity and connectivity of the detectable pore space (> 5 µm) in the rhizosphere, as compared with the no-hair mutants. Both genotypes showed decreasing pore-space between 0.8 mm and 0.1 mm from the root surface. Interestingly the root-hair-bearing genotype had a significantly greater soil pore volume-fraction at the root-soil interface. Effects of pore structure on diffusion and permeability were estimated to be functionally insignificant under saturated conditions when simulated using image based modelling.
- image-based modelling
- non-invasive imaging
- root hairs
- soil structure
Koebernik, N., Daly, K. R., Keyes, S. D., George, T. S., Brown, L. . K., Raffan, A., ... Roose, T. (2017). High-resolution synchrotron imaging shows that root hairs influence rhizosphere soil structure formation. New Phytologist, 216(1), 124-135. https://doi.org/10.1111/nph.14705