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Koebernick N, Daly KR, Keyes SD, Bengough AG, Brown LK, Cooper LJ, George TS, Hallett PD, Naveed M, Raffan A, Roose T. Imaging microstructure of the barley rhizosphere: particle packing and root hair influences. New Phytol 2019; 221:1878-1889. [PMID: 30289555 DOI: 10.1111/nph.15516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/23/2018] [Indexed: 05/10/2023]
Abstract
Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three-dimensional pore structure at a fine scale is scarce and often contradictory. Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (<250 μm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron-based X-ray computed tomography to visualise pore structure at the soil-root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1 mm of the root surface. Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions. A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.
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Affiliation(s)
- Nicolai Koebernick
- Bioengineering Sciences Research Group, Engineering Sciences Academic Unit, Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ, UK
- Soil Science and Soil Protection, Martin Luther University Halle-Wittenberg, von-Seckendoff-Platz 3, 06120, Halle (Saale), Germany
| | - Keith R Daly
- Bioengineering Sciences Research Group, Engineering Sciences Academic Unit, Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ, UK
| | - Samuel D Keyes
- Bioengineering Sciences Research Group, Engineering Sciences Academic Unit, Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ, UK
| | - Anthony G Bengough
- Ecological Sciences Group, The James Hutton Institute, Dundee, DD2 5DA, UK
- School of Science and Engineering, University of Dundee, Dundee, DD1 4HN, UK
| | - Lawrie K Brown
- Ecological Sciences Group, The James Hutton Institute, Dundee, DD2 5DA, UK
| | - Laura J Cooper
- Bioengineering Sciences Research Group, Engineering Sciences Academic Unit, Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ, UK
- Mathematics Institute, University of Warwick, Warwick, CV4 7AL, UK
| | - Timothy S George
- Ecological Sciences Group, The James Hutton Institute, Dundee, DD2 5DA, UK
| | - Paul D Hallett
- Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen, AB24 3FX, UK
| | - Muhammad Naveed
- Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen, AB24 3FX, UK
- School of Computing and Engineering, University of West London, London, W5 5RF, UK
| | - Annette Raffan
- Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen, AB24 3FX, UK
| | - Tiina Roose
- Bioengineering Sciences Research Group, Engineering Sciences Academic Unit, Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ, UK
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