Recent laboratory studies revealed that root hairs may alter soil physical behaviour, influencing soil porosity and water retention on the small scale. However, the results are not consistent, and it is not known if structural changes at the small-scale have impacts at larger scales. Therefore, we evaluated the potential effects of root hairs on soil hydro-mechanical properties in the field using rhizosphere-scale physical measurements.
MethodsChanges in soil water retention properties as well as mechanical and hydraulic characteristics were monitored in both silt loam and sandy loam soils. Measurements were taken from plant establishment to harvesting in field trials, comparing three barley genotypes representing distinct phenotypic categories in relation to root hair length. Soil hardness and elasticity were measured using a 3-mm-diameter spherical indenter, while water sorptivity and repellency were measured using a miniaturized infiltrometer with a 0.4-mm tip radius.
ResultsOver the growing season, plants induced changes in the soil water retention properties, with the plant available water increasing by 21%. Both soil hardness (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.031) and elasticity (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.048) decreased significantly in the presence of root hairs in silt loam soil, by 50% and 36%, respectively. Root hairs also led to significantly smaller water repellency (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.007) in sandy loam soil vegetated with the hairy genotype (-49%) compared to the hairless mutant.
ConclusionsBreeding of cash crops for improved soil conditions could be achieved by selecting root phenotypes that ameliorate soil physical properties and therefore contribute to increased soil health.
", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "0106 biological sciences", "Supplementary Data", "QH301 Biology", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Soil Science", "Rural and Environmental Science and Analytical Services (RESAS)", "Plant Science", "01 natural sciences", "630", "QH301", "BBSRC BB/L025825/1", "Barley", "Soil health", "Soil structure", "Root hairs", "Soil hydromechanical properties", "BB/L025620/1", "580", "2. Zero hunger", "name=Soil Science", "ERCDMR-646809", "04 agricultural and veterinary sciences", "15. Life on land", "Soil water retention", "BBSRC BB/J00868/1", "6. Clean water", "Biotechnology and Biological Sciences Research Council (BBSRC)", "0401 agriculture", " forestry", " and fisheries", "Other", "name=Plant Science", "Research Article"]}, "links": [{"href": "https://eprints.soton.ac.uk/484590/2/s11104_022_05530_1.pdf"}, {"href": "https://link.springer.com/content/pdf/10.1007/s11104-022-05530-1.pdf"}, {"href": "https://doi.org/10.1007/s11104-022-05530-1"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-022-05530-1", "name": "item", "description": "10.1007/s11104-022-05530-1", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-022-05530-1"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-06-11T00:00:00Z"}}, {"id": "10.1007/s11104-019-04308-2", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:36Z", "type": "Journal Article", "created": "2019-12-06", "title": "Significance of root hairs at the field scale \u2013 modelling root water and phosphorus uptake under different field conditions", "description": "Abstract Background and aimsRoot hairs play a significant role in phosphorus (P) extraction at the pore scale. However, their importance at the field scale remains poorly understood.
MethodsThis study uses a continuum model to explore the impact of root hairs on the large-scale uptake of P, comparing root hair influence under different agricultural scenarios. High vs low and constant vs decaying P concentrations down the soil profile are considered, along with early vs late precipitation scenarios.
ResultsSimulation results suggest root hairs accounted for 50% of total P uptake by plants. Furthermore, a delayed initiation time of precipitation potentially limits the P uptake rate by over 50% depending on the growth period. Despite the large differences in the uptake rate, changes in the soil P concentration in the domain due to root solute uptake remains marginal when considering a single growth season. However, over the duration of 6\uffc2\uffa0years, simulation results showed that noticeable differences arise over time.
ConclusionRoot hairs are critical to P capture, with uptake efficiency potentially enhanced by coordinating irrigation with P application during earlier growth stages of crops.
", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "0106 biological sciences", "330", "550", "EP/M020355/1", "ERC 646809 DIMR", "QH301 Biology", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Soil Science", "A. B", "Field", "610", "Plant Science", "01 natural sciences", "NERC NE/L00237/1", "QH301", "Soil", "Plant roots", "Root hairs", "BBSRC SARIC BB/P004180/", "2. Zero hunger", "BBSRC SARISA BB/L025620/1. S. D.", "Mathematical modelling", "Natural Environment Research Council (NERC)", "name=Soil Science", "Water", "Phosphorus", "Regular Article", "04 agricultural and veterinary sciences", "15. Life on land", "6. Clean water", "Engineering and Physical Sciences Research Council (EPSRC)", "Rhizosphere", "Biotechnology and Biological Sciences Research Council (BBSRC)", "0401 agriculture", " forestry", " and fisheries", "name=Plant Science", "European Research Council"]}, "links": [{"href": "https://eprints.soton.ac.uk/434043/1/Manuscript_No_Tracked_Changes.pdf"}, {"href": "http://link.springer.com/content/pdf/10.1007/s11104-019-04308-2.pdf"}, {"href": "https://doi.org/10.1007/s11104-019-04308-2"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-019-04308-2", "name": "item", "description": "10.1007/s11104-019-04308-2", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-019-04308-2"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-12-06T00:00:00Z"}}, {"id": "10.1007/s11104-021-05133-2", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:37Z", "type": "Journal Article", "created": "2021-09-12", "title": "In situ laser manipulation of root tissues in transparent soil", "description": "AbstractAimsLaser micromanipulation such as dissection or optical trapping enables remote physical modification of the activity of tissues, cells and organelles. To date, applications of laser manipulation to plant roots grown in soil have been limited. Here, we show laser manipulation can be applied in situ when plant roots are grown in transparent soil.
MethodsWe have developed a Q-switched laser manipulation and imaging instrument to perform controlled dissection of roots and to study light-induced root growth responses. We performed a detailed characterisation of the properties of the cutting beams through the soil, studying dissection and optical ablation. Furthermore, we also studied the use of low light doses to control the root elongation rate of lettuce seedlings (Lactuca sativa) in air, agar, gel and transparent soil.
ResultsWe show that whilst soil inhomogeneities affect the thickness and circularity of the beam, those distortions are not inherently limiting. The ability to induce changes in root elongation or complete dissection of microscopic regions of the root is robust to substrate heterogeneity and microscopy set up and is maintained following the limited distortions induced by the transparent soil environment.
ConclusionsOur findings show that controlled in situ laser dissection of root tissues is possible with a simple and low-cost optical set-up. We also show that, in the absence of dissection, a reduced laser light power density can provide reversible control of root growth, achieving a precise \uffe2\uff80\uff9cpoint and shoot\uffe2\uff80\uff9d method for root manipulation.
", "keywords": ["Transparent soil", "/dk/atira/pure/subjectarea/asjc/1100/1111", "580", "0301 basic medicine", "570", "0303 health sciences", "Lactuca sativa", "name=Soil Science", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Regular Article", "15. Life on land", "Imaging", "Laser dissection", "03 medical and health sciences", "Root", "name=Plant Science"]}, "links": [{"href": "https://link.springer.com/content/pdf/10.1007/s11104-021-05133-2.pdf"}, {"href": "https://doi.org/10.1007/s11104-021-05133-2"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-021-05133-2", "name": "item", "description": "10.1007/s11104-021-05133-2", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-021-05133-2"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-09-12T00:00:00Z"}}, {"id": "10.1007/s11104-023-06151-y", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:37Z", "type": "Journal Article", "created": "2023-07-26", "title": "Smart soils track the formation of pH gradients across the rhizosphere", "description": "Abstract AimsOur understanding of the rhizosphere is limited by the lack of techniques for in situ live microscopy. Current techniques are either destructive or unsuitable for observing chemical changes within the pore space. To address this limitation, we have developed artificial substrates, termed smart soils, that enable the acquisition and 3D reconstruction of chemical sensors attached to soil particles.
MethodsThe transparency of smart soils was achieved using polymer particles with refractive index matching that of water. The surface of the particles was modified both to retain water and act as a local sensor to report on pore space pH via fluorescence emissions. Multispectral signals were acquired from the particles using a light sheet microscope, and machine learning algorithms predicted the changes and spatial distribution in pH at the surface of the smart soil particles.
ResultsThe technique was able to predict pH live and in situ within \uffc2\uffb1\uffe2\uff80\uff890.5 units of the true pH value. pH distribution could be reconstructed across a volume of several cubic centimetres around plant roots at 10\uffc2\uffa0\uffce\uffbcm resolution. Using smart soils of different composition, we revealed how root exudation and pore structure create variability in chemical properties.
ConclusionSmart soils captured the pH gradients forming around a growing plant root. Future developments of the technology could include the fine tuning of soil physicochemical properties, the addition of chemical sensors and improved data processing. Hence, this technology could play a critical role in advancing our understanding of complex rhizosphere processes.
", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "light sheet microscopy", "0301 basic medicine", "570", "0303 health sciences", "name=Soil Science", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Sensing soil", "live imaging", "15. Life on land", "root", "530", "[SDE.BE] Environmental Sciences/Biodiversity and Ecology", "03 medical and health sciences", "Root", "13. Climate action", "Rhizosphere", "Light sheet microscopy", "name=Plant Science", "rhizosphere", "[SDV.SA.SDS] Life Sciences [q-bio]/Agricultural sciences/Soil study", "Live imaging"]}, "links": [{"href": "https://doi.org/10.1007/s11104-023-06151-y"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11104-023-06151-y", "name": "item", "description": "10.1007/s11104-023-06151-y", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-023-06151-y"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2023-07-26T00:00:00Z"}}, {"id": "10.1016/j.plantsci.2023.111919", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:17:16Z", "type": "Journal Article", "created": "2023-11-20", "title": "Phytosiderophore pathway response in barley exposed to iron, zinc or copper starvation", "description": "Efficient micronutrient acquisition is a critical factor in selecting micronutrient dense crops for human consumption. Enhanced exudation and re-uptake of metal chelators, so-called phytosiderophores, by roots of graminaceous plants has been implicated in efficient micronutrient acquisition. We compared PS biosynthesis and exudation as a response mechanism to either Fe, Zn or Cu starvation. Two barley (Hordeum vulgare L.) lines with contrasting micronutrient grain yields were grown hydroponically and PS exudation (LC-MS) and root gene expression (RNAseq) were determined after either Fe, Zn, or Cu starvation. The response strength of the PS pathway was micronutrient dependent and decreased in the order Fe >\u00a0Zn >\u00a0Cu deficiency. We observed a stronger expression of PS pathway genes and greater PS exudation in the barley line with large micronutrient grain yield suggesting that a highly expressed PS pathway might be an important trait involved in high micronutrient accumulation. In addition to several metal specific transporters, we also found that the expression of IRO2 and bHLH156 transcription factors was not only induced under Fe but also under Zn and Cu deficiency. Our study delivers important insights into the role of the PS pathway in the acquisition of different micronutrients.", "keywords": ["2. Zero hunger", "Phytosiderophore", "/dk/atira/pure/subjectarea/asjc/1300/1311", "/dk/atira/pure/subjectarea/asjc/1100/1102", "Root exudation", "name=Genetics", "Iron", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Hordeum", "Copper deficiency", "Plant Roots", "630", "Mugineic acid", "name=Agronomy and Crop Science", "Zinc", "Barley", "Humans", "Micronutrients", "name=Plant Science", "Biofortification", "Copper"]}, "links": [{"href": "https://doi.org/10.1016/j.plantsci.2023.111919"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.plantsci.2023.111919", "name": "item", "description": "10.1016/j.plantsci.2023.111919", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.plantsci.2023.111919"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-01T00:00:00Z"}}, {"id": "10.1016/j.tplants.2023.01.008", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:17:54Z", "type": "Journal Article", "created": "2023-02-27", "title": "Heritage genetics for adaptation to marginal soils in barley", "description": "Future crops need to be sustainable in the face of climate change. Modern barley varieties have been bred for high productivity and quality; however, they have suffered considerable genetic erosion, losing crucial genetic diversity. This renders modern cultivars vulnerable to climate change and stressful environments. We highlight the potential to tailor crops to a specific environment by utilising diversity inherent in an adapted landrace population. Tapping into natural biodiversity, while incorporating information about local environmental and climatic conditions, allows targeting of key traits and genotypes, enabling crop production in marginal soils. We outline future directions for the utilisation of genetic resources maintained in landrace collections to support sustainable agriculture through germplasm development via the use of genomics technologies and big data.", "keywords": ["Crops", " Agricultural", "0301 basic medicine", "EFFICIENCY", "genetic resilience", "IMPACT", "/dk/atira/pure/subjectarea/asjc/1100/1110", "630", "12. Responsible consumption", "diversity", "Soil", "03 medical and health sciences", "FUTURE", "MANGANESE DEFICIENCY", "PLANTS", "2. Zero hunger", "580", "0303 health sciences", "barley landraces", "Hordeum", "Agriculture", "15. Life on land", "LANDRACES", "Adaptation", " Physiological", "CULTIVARS", "CLIMATE", "Plant Breeding", "climate change", "marginal soil", "13. Climate action", "name=Plant Science", "local adaptation", "RESISTANCE"]}, "links": [{"href": "https://doi.org/10.1016/j.tplants.2023.01.008"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Trends%20in%20Plant%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.tplants.2023.01.008", "name": "item", "description": "10.1016/j.tplants.2023.01.008", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.tplants.2023.01.008"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2023-05-01T00:00:00Z"}}, {"id": "10.1093/aob/mcaa181", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:19:03Z", "type": "Journal Article", "created": "2020-10-07", "title": "Significance of root hairs for plant performance under contrasting field conditions and water deficit", "description": "AbstractBackground and AimsPrevious laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale.
MethodsA field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield.
Key ResultsMeasurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in a less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought.
ConclusionsSelecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder\uffe2\uff80\uff99s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.Bacterial attachment on root surfaces is an important step preceding the colonization or internalization and subsequent infection of plants by pathogens. Unfortunately, bacterial attachment is not well understood because the phenomenon is difficult to observe. Here we assessed whether this limitation could be overcome using optical trapping approaches. We have developed a system based on counter-propagating beams and studied its ability to guide Pectobacterium atrosepticum (Pba) cells to different root cell types within the interstices of transparent soils. Bacterial cells were successfully trapped and guided to root hair cells, epidermal cells, border cells, and tissues damaged by laser ablation. Finally, we used the system to quantify the bacterial cell detachment rate of Pba cells on root surfaces following reversible attachment. Optical trapping techniques could greatly enhance our ability to deterministically characterize mechanisms linked to attachment and formation of biofilms in the rhizosphere.Rhizobial infection of legume roots during development of nitrogen fixing root nodules occurs either intracellularly though plant derived infection threads traversing the epidermal and cortical cell layers to deliver the bacteria or intercellularly via bacterial entry between epidermal plant cells. Although, around 25% of all legume genera are postulated to be intercellularly infected, the pathways and mechanisms supporting this process has remained virtually unexplored due to lack of genetically amenable legumes that have this infection mode. In this study, we report that the model legume Lotus japonicus is infected intercellularly by Rhizobium sp. IRBG74 and demonstrate that the resources available in Lotus enable insight into the genetic requirements and the fine-tuning of the pathway governing intercellular infection. Inoculation of Lotus mutants shows that Ern1 and RinRK1 are dispensable for intercellular infection in contrast to intracellular infection. Other symbiotic genes, including Nfr5, SymRK, CCaMK, Epr3, Cyclops, Nin, Nsp1, Nsp2, Cbs and Vpy1 are equally important for both entry modes. Comparative RNAseq analysis of roots inoculated with IRBG74 revealed a distinctive transcriptome response compared to intracellular colonization. In particular, a number of cytokinin-related genes were differentially regulated. Corroborating this observation cyp735A and ipt4 cytokinin biosynthesis mutants were significantly affected in their nodulation with IRBG74 while lhk1 cytokinin receptor mutants did not form any nodules. These results indicate that a differential requirement for cytokinin signalling conditions intercellular rhizobial entry and highlight the distinct modalities of the inter- and intra-cellular infection mechanisms.
", "keywords": ["name=Physiology", "580", "0301 basic medicine", "/dk/atira/pure/subjectarea/asjc/1300/1314", "0303 health sciences", "/dk/atira/pure/subjectarea/asjc/1300/1311", "571", "Regular Issue", "name=Genetics", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Plant Roots", "03 medical and health sciences", "Gene Expression Regulation", " Plant", "Calcium-Calmodulin-Dependent Protein Kinases", "Lotus", "name=Plant Science", "Root Nodules", " Plant", "Plant Proteins", "Rhizobium", "Signal Transduction"]}, "links": [{"href": "http://academic.oup.com/plphys/article-pdf/185/3/1131/37166752/kiaa049.pdf"}, {"href": "https://doi.org/10.1093/plphys/kiaa049"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20Physiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1093/plphys/kiaa049", "name": "item", "description": "10.1093/plphys/kiaa049", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/plphys/kiaa049"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-05-31T00:00:00Z"}}, {"id": "10.1101/2020.05.29.124313", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:19:11Z", "type": "Journal Article", "created": "2020-05-31", "title": "Distinct signalling routes mediates intercellular and intracellular rhizobial infection in Lotus japonicus", "description": "AbstractRhizobial infection of legume roots during development of nitrogen fixing root nodules occurs either intracellularly though plant derived infection threads traversing the epidermal and cortical cell layers to deliver the bacteria or intercellularly via bacterial entry between epidermal plant cells. Although, around 25% of all legume genera are postulated to be intercellularly infected, the pathways and mechanisms supporting this process has remained virtually unexplored due to lack of genetically amenable legumes that have this infection mode. In this study, we report that the model legume Lotus japonicus is infected intercellularly by Rhizobium sp. IRBG74 and demonstrate that the resources available in Lotus enable insight into the genetic requirements and the fine-tuning of the pathway governing intercellular infection. Inoculation of Lotus mutants shows that Ern1 and RinRK1 are dispensable for intercellular infection in contrast to intracellular infection. Other symbiotic genes, including Nfr5, SymRK, CCaMK, Epr3, Cyclops, Nin, Nsp1, Nsp2, Cbs and Vpy1 are equally important for both entry modes. Comparative RNAseq analysis of roots inoculated with IRBG74 revealed a distinctive transcriptome response compared to intracellular colonization. In particular, a number of cytokinin-related genes were differentially regulated. Corroborating this observation cyp735A and ipt4 cytokinin biosynthesis mutants were significantly affected in their nodulation with IRBG74 while lhk1 cytokinin receptor mutants did not form any nodules. These results indicate that a differential requirement for cytokinin signalling conditions intercellular rhizobial entry and highlight the distinct modalities of the inter- and intra-cellular infection mechanisms.
Limitation to root growth results from forces required to overcome soil resistance to deformation. The variations in individual particle forces affects root development and often deflects the growth trajectory.
We have developed transparent soil and optical projection tomography microscopy systems where measurements of growth trajectory and particle forces can be acquired in a granular medium at a range of confining pressures. We developed image\uffe2\uff80\uff90processing pipelines to analyse patterns in root trajectories and a stochastic\uffe2\uff80\uff90mechanical theory to establish how root deflections relate to particle forces and thickening of the root.
Root thickening compensates for the increase in mean particle forces but does not prevent deflections from 5% of most extreme individual particle forces causing root deflection. The magnitude of deflections increases with pressure but they assemble into helices of conserved wavelength in response linked to gravitropism.
The study reveals mechanisms for the understanding of root growth in mechanically impeding soil conditions and provides insights relevant to breeding of drought\uffe2\uff80\uff90resistant crops.
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\uffe2\uff80\uff90dimensional 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\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm 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.
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\uffe2\uff80\uff90dimensional 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\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm 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.
Root hairs play a significant role in phosphorus (P) extraction at the pore scale. However, their importance at the field scale remains poorly understood. MethodsThis study uses a continuum model to explore the impact of root hairs on the large-scale uptake of P, comparing root hair influence under different agricultural scenarios. High vs low and constant vs decaying P concentrations down the soil profile are considered, along with early vs late precipitation scenarios.
ResultsSimulation results suggest root hairs accounted for 50% of total P uptake by plants. Furthermore, a delayed initiation time of precipitation potentially limits the P uptake rate by over 50% depending on the growth period. Despite the large differences in the uptake rate, changes in the soil P concentration in the domain due to root solute uptake remains marginal when considering a single growth season. However, over the duration of 6\uffc2\uffa0years, simulation results showed that noticeable differences arise over time.
ConclusionRoot hairs are critical to P capture, with uptake efficiency potentially enhanced by coordinating irrigation with P application during earlier growth stages of crops.
", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "0106 biological sciences", "330", "550", "EP/M020355/1", "ERC 646809 DIMR", "QH301 Biology", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Soil Science", "A. B", "Field", "610", "Plant Science", "01 natural sciences", "NERC NE/L00237/1", "QH301", "Soil", "Plant roots", "Root hairs", "BBSRC SARIC BB/P004180/", "2. Zero hunger", "BBSRC SARISA BB/L025620/1. S. D.", "Mathematical modelling", "Natural Environment Research Council (NERC)", "name=Soil Science", "Water", "Phosphorus", "Regular Article", "04 agricultural and veterinary sciences", "15. Life on land", "6. Clean water", "Engineering and Physical Sciences Research Council (EPSRC)", "Rhizosphere", "Biotechnology and Biological Sciences Research Council (BBSRC)", "0401 agriculture", " forestry", " and fisheries", "name=Plant Science", "European Research Council"]}, "links": [{"href": "https://eprints.soton.ac.uk/434043/1/Manuscript_No_Tracked_Changes.pdf"}, {"href": "http://link.springer.com/content/pdf/10.1007/s11104-019-04308-2.pdf"}, {"href": "https://doi.org/2164/13582"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "2164/13582", "name": "item", "description": "2164/13582", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/2164/13582"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-12-06T00:00:00Z"}}, {"id": "2164/17159", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:26:42Z", "type": "Journal Article", "created": "2020-10-07", "title": "Significance of root hairs for plant performance under contrasting field conditions and water deficit", "description": "AbstractBackground and AimsPrevious laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale.
MethodsA field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield.
Key ResultsMeasurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in a less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought.
ConclusionsSelecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder\uffe2\uff80\uff99s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.Recent laboratory studies revealed that root hairs may alter soil physical behaviour, influencing soil porosity and water retention on the small scale. However, the results are not consistent, and it is not known if structural changes at the small-scale have impacts at larger scales. Therefore, we evaluated the potential effects of root hairs on soil hydro-mechanical properties in the field using rhizosphere-scale physical measurements.
MethodsChanges in soil water retention properties as well as mechanical and hydraulic characteristics were monitored in both silt loam and sandy loam soils. Measurements were taken from plant establishment to harvesting in field trials, comparing three barley genotypes representing distinct phenotypic categories in relation to root hair length. Soil hardness and elasticity were measured using a 3-mm-diameter spherical indenter, while water sorptivity and repellency were measured using a miniaturized infiltrometer with a 0.4-mm tip radius.
ResultsOver the growing season, plants induced changes in the soil water retention properties, with the plant available water increasing by 21%. Both soil hardness (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.031) and elasticity (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.048) decreased significantly in the presence of root hairs in silt loam soil, by 50% and 36%, respectively. Root hairs also led to significantly smaller water repellency (P\uffe2\uff80\uff89=\uffe2\uff80\uff890.007) in sandy loam soil vegetated with the hairy genotype (-49%) compared to the hairless mutant.
ConclusionsBreeding of cash crops for improved soil conditions could be achieved by selecting root phenotypes that ameliorate soil physical properties and therefore contribute to increased soil health.
", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "0106 biological sciences", "Supplementary Data", "QH301 Biology", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Soil Science", "Rural and Environmental Science and Analytical Services (RESAS)", "Plant Science", "01 natural sciences", "630", "QH301", "BBSRC BB/L025825/1", "Barley", "Soil health", "Soil structure", "Root hairs", "Soil hydromechanical properties", "BB/L025620/1", "580", "2. Zero hunger", "name=Soil Science", "ERCDMR-646809", "04 agricultural and veterinary sciences", "15. Life on land", "Soil water retention", "BBSRC BB/J00868/1", "6. Clean water", "Biotechnology and Biological Sciences Research Council (BBSRC)", "0401 agriculture", " forestry", " and fisheries", "Other", "name=Plant Science", "Research Article"]}, "links": [{"href": "https://eprints.soton.ac.uk/484590/2/s11104_022_05530_1.pdf"}, {"href": "https://link.springer.com/content/pdf/10.1007/s11104-022-05530-1.pdf"}, {"href": "https://doi.org/2164/19751"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "2164/19751", "name": "item", "description": "2164/19751", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/2164/19751"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-06-11T00:00:00Z"}}, {"id": "2988521966", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:27:03Z", "type": "Journal Article", "created": "2019-11-06", "title": "The helical motions of roots are linked to avoidance of particle forces in soil", "description": "SummaryLimitation to root growth results from forces required to overcome soil resistance to deformation. The variations in individual particle forces affects root development and often deflects the growth trajectory.
We have developed transparent soil and optical projection tomography microscopy systems where measurements of growth trajectory and particle forces can be acquired in a granular medium at a range of confining pressures. We developed image\uffe2\uff80\uff90processing pipelines to analyse patterns in root trajectories and a stochastic\uffe2\uff80\uff90mechanical theory to establish how root deflections relate to particle forces and thickening of the root.
Root thickening compensates for the increase in mean particle forces but does not prevent deflections from 5% of most extreme individual particle forces causing root deflection. The magnitude of deflections increases with pressure but they assemble into helices of conserved wavelength in response linked to gravitropism.
The study reveals mechanisms for the understanding of root growth in mechanically impeding soil conditions and provides insights relevant to breeding of drought\uffe2\uff80\uff90resistant crops.
Rhizobial infection of legume roots during development of nitrogen fixing root nodules occurs either intracellularly though plant derived infection threads traversing the epidermal and cortical cell layers to deliver the bacteria or intercellularly via bacterial entry between epidermal plant cells. Although, around 25% of all legume genera are postulated to be intercellularly infected, the pathways and mechanisms supporting this process has remained virtually unexplored due to lack of genetically amenable legumes that have this infection mode. In this study, we report that the model legume Lotus japonicus is infected intercellularly by Rhizobium sp. IRBG74 and demonstrate that the resources available in Lotus enable insight into the genetic requirements and the fine-tuning of the pathway governing intercellular infection. Inoculation of Lotus mutants shows that Ern1 and RinRK1 are dispensable for intercellular infection in contrast to intracellular infection. Other symbiotic genes, including Nfr5, SymRK, CCaMK, Epr3, Cyclops, Nin, Nsp1, Nsp2, Cbs and Vpy1 are equally important for both entry modes. Comparative RNAseq analysis of roots inoculated with IRBG74 revealed a distinctive transcriptome response compared to intracellular colonization. In particular, a number of cytokinin-related genes were differentially regulated. Corroborating this observation cyp735A and ipt4 cytokinin biosynthesis mutants were significantly affected in their nodulation with IRBG74 while lhk1 cytokinin receptor mutants did not form any nodules. These results indicate that a differential requirement for cytokinin signalling conditions intercellular rhizobial entry and highlight the distinct modalities of the inter- and intra-cellular infection mechanisms.Limitation to root growth results from forces required to overcome soil resistance to deformation. The variations in individual particle forces affects root development and often deflects the growth trajectory.
We have developed transparent soil and optical projection tomography microscopy systems where measurements of growth trajectory and particle forces can be acquired in a granular medium at a range of confining pressures. We developed image\uffe2\uff80\uff90processing pipelines to analyse patterns in root trajectories and a stochastic\uffe2\uff80\uff90mechanical theory to establish how root deflections relate to particle forces and thickening of the root.
Root thickening compensates for the increase in mean particle forces but does not prevent deflections from 5% of most extreme individual particle forces causing root deflection. The magnitude of deflections increases with pressure but they assemble into helices of conserved wavelength in response linked to gravitropism.
The study reveals mechanisms for the understanding of root growth in mechanically impeding soil conditions and provides insights relevant to breeding of drought\uffe2\uff80\uff90resistant crops.
Laser micromanipulation such as dissection or optical trapping enables remote physical modification of the activity of tissues, cells and organelles. To date, applications of laser manipulation to plant roots grown in soil have been limited. Here, we show laser manipulation can be applied in situ when plant roots are grown in transparent soil.MethodsWe have developed a Q-switched laser manipulation and imaging instrument to perform controlled dissection of roots and to study light-induced root growth responses. We performed a detailed characterisation of the properties of the cutting beams through the soil, studying dissection and optical ablation. Furthermore, we also studied the use of low light doses to control the root elongation rate of lettuce seedlings (Lactuca sativa) in air, agar, gel and transparent soil.
ResultsWe show that whilst soil inhomogeneities affect the thickness and circularity of the beam, those distortions are not inherently limiting. The ability to induce changes in root elongation or complete dissection of microscopic regions of the root is robust to substrate heterogeneity and microscopy set up and is maintained following the limited distortions induced by the transparent soil environment.
ConclusionsOur findings show that controlled in situ laser dissection of root tissues is possible with a simple and low-cost optical set-up. We also show that, in the absence of dissection, a reduced laser light power density can provide reversible control of root growth, achieving a precise \uffe2\uff80\uff9cpoint and shoot\uffe2\uff80\uff9d method for root manipulation.Bacterial attachment on root surfaces is an important step preceding the colonization or internalization and subsequent infection of plants by pathogens. Unfortunately, bacterial attachment is not well understood because the phenomenon is difficult to observe. Here we assessed whether this limitation could be overcome using optical trapping approaches. We have developed a system based on counter-propagating beams and studied its ability to guide Pectobacterium atrosepticum (Pba) cells to different root cell types within the interstices of transparent soils. Bacterial cells were successfully trapped and guided to root hair cells, epidermal cells, border cells, and tissues damaged by laser ablation. Finally, we used the system to quantify the bacterial cell detachment rate of Pba cells on root surfaces following reversible attachment. Optical trapping techniques could greatly enhance our ability to deterministically characterize mechanisms linked to attachment and formation of biofilms in the rhizosphere.\u00a0Zn >\u00a0Cu deficiency. We observed a stronger expression of PS pathway genes and greater PS exudation in the barley line with large micronutrient grain yield suggesting that a highly expressed PS pathway might be an important trait involved in high micronutrient accumulation. In addition to several metal specific transporters, we also found that the expression of IRO2 and bHLH156 transcription factors was not only induced under Fe but also under Zn and Cu deficiency. Our study delivers important insights into the role of the PS pathway in the acquisition of different micronutrients.", "keywords": ["2. Zero hunger", "Phytosiderophore", "/dk/atira/pure/subjectarea/asjc/1300/1311", "/dk/atira/pure/subjectarea/asjc/1100/1102", "Root exudation", "name=Genetics", "Iron", "/dk/atira/pure/subjectarea/asjc/1100/1110", "Hordeum", "Copper deficiency", "Plant Roots", "630", "Mugineic acid", "name=Agronomy and Crop Science", "Zinc", "Barley", "Humans", "Micronutrients", "name=Plant Science", "Biofortification", "Copper"]}, "links": [{"href": "https://doi.org/37992897"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "37992897", "name": "item", "description": "37992897", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/37992897"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-01T00:00:00Z"}}, {"id": "PMC8133683", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:29:49Z", "type": "Journal Article", "created": "2020-05-31", "title": "Distinct signalling routes mediates intercellular and intracellular rhizobial infection in Lotus japonicus", "description": "Abstract
Rhizobial infection of legume roots during development of nitrogen fixing root nodules occurs either intracellularly though plant derived infection threads traversing the epidermal and cortical cell layers to deliver the bacteria or intercellularly via bacterial entry between epidermal plant cells. Although, around 25% of all legume genera are postulated to be intercellularly infected, the pathways and mechanisms supporting this process has remained virtually unexplored due to lack of genetically amenable legumes that have this infection mode. In this study, we report that the model legume Lotus japonicus is infected intercellularly by Rhizobium sp. IRBG74 and demonstrate that the resources available in Lotus enable insight into the genetic requirements and the fine-tuning of the pathway governing intercellular infection. Inoculation of Lotus mutants shows that Ern1 and RinRK1 are dispensable for intercellular infection in contrast to intracellular infection. Other symbiotic genes, including Nfr5, SymRK, CCaMK, Epr3, Cyclops, Nin, Nsp1, Nsp2, Cbs and Vpy1 are equally important for both entry modes. Comparative RNAseq analysis of roots inoculated with IRBG74 revealed a distinctive transcriptome response compared to intracellular colonization. In particular, a number of cytokinin-related genes were differentially regulated. Corroborating this observation cyp735A and ipt4 cytokinin biosynthesis mutants were significantly affected in their nodulation with IRBG74 while lhk1 cytokinin receptor mutants did not form any nodules. These results indicate that a differential requirement for cytokinin signalling conditions intercellular rhizobial entry and highlight the distinct modalities of the inter- and intra-cellular infection mechanisms.Laser micromanipulation such as dissection or optical trapping enables remote physical modification of the activity of tissues, cells and organelles. To date, applications of laser manipulation to plant roots grown in soil have been limited. Here, we show laser manipulation can be applied in situ when plant roots are grown in transparent soil.
MethodsWe have developed a Q-switched laser manipulation and imaging instrument to perform controlled dissection of roots and to study light-induced root growth responses. We performed a detailed characterisation of the properties of the cutting beams through the soil, studying dissection and optical ablation. Furthermore, we also studied the use of low light doses to control the root elongation rate of lettuce seedlings (Lactuca sativa) in air, agar, gel and transparent soil.
ResultsWe show that whilst soil inhomogeneities affect the thickness and circularity of the beam, those distortions are not inherently limiting. The ability to induce changes in root elongation or complete dissection of microscopic regions of the root is robust to substrate heterogeneity and microscopy set up and is maintained following the limited distortions induced by the transparent soil environment.
ConclusionsOur findings show that controlled in situ laser dissection of root tissues is possible with a simple and low-cost optical set-up. We also show that, in the absence of dissection, a reduced laser light power density can provide reversible control of root growth, achieving a precise \uffe2\uff80\uff9cpoint and shoot\uffe2\uff80\uff9d method for root manipulation.