Abstract
The mechanisms controlling the genesis of rhizosheaths are not well understood, despite their importance in controlling the flux of nutrients and water from soil to root. Here, we examine the development of rhizosheaths from drought-tolerant and drought-sensitive chickpea varieties; focusing on the three-dimensional characterization of the pore volume (> 16 μm voxel spatial resolution) obtained from X-ray microtomography, along with the characterization of mucilage and root hairs, and water sorption. We observe that drought-tolerant plants generate a larger diameter root, and a greater and more porous mass of rhizosheath, which also has a significantly increased water sorptivity, as compared with bulk soil. Using lattice Boltzmann simulations of soil permeability, we find that the root activity of both cultivars creates an anisotropic structure in the rhizosphere, in that its ability to conduct water in the radial direction is significantly higher than in the axial direction, especially in the drought-tolerant cultivar. We suggest that significant differences in rhizosheath architectures are sourced not only by changes in structure of the volumes, but also from root mucilage, and further suggest that breeding for rhizosheath architectures and function may be a potential future avenue for better designing crops in a changing environment.
Original language | English (US) |
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Pages (from-to) | 542-550 |
Number of pages | 9 |
Journal | New Phytologist |
Volume | 219 |
Issue number | 2 |
DOIs | |
State | Published - Jul 2018 |
Bibliographical note
Funding Information:The work at Rothamsted Research forms part of the Soil to Nutrient (S2N) strategic programme (BBS/E/C/00010320) funded by the Biotechnology and Biological Sciences Research Council (BBSRC) of UK.
Publisher Copyright:
© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust
Keywords
- chickpea
- microtomography
- mucilage
- rhizosheath
- rhizosphere
- root hairs
- soil structure
- water uptake
ASJC Scopus subject areas
- Physiology
- Plant Science