Previous 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.
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.
In this paper, we provide direct evidence of the importance of root hairs on pore structure development at the root\uffe2\uff80\uff93soil interface during the early stage of crop establishment.
This was achieved by use of high\uffe2\uff80\uff90resolution (c. 5\uffc2\uffa0\uffce\uffbcm) synchrotron radiation computed tomography (SRCT) to visualise both the structure of root hairs and the soil pore structure in plant\uffe2\uff80\uff93soil microcosms. Two contrasting genotypes of barley (Hordeum vulgare), with and without root hairs, were grown for 8\uffc2\uffa0d in microcosms packed with sandy loam soil at 1.2\uffc2\uffa0g\uffc2\uffa0cm\uffe2\uff88\uff923 dry bulk density. Root hairs were visualised within air\uffe2\uff80\uff90filled pore spaces, but not in the fine\uffe2\uff80\uff90textured soil regions.
We found that the genotype with root hairs significantly altered the porosity and connectivity of the detectable pore space (>\uffc2\uffa05\uffc2\uffa0\uffce\uffbcm) in the rhizosphere, as compared with the no\uffe2\uff80\uff90hair mutants. Both genotypes showed decreasing pore space between 0.8 and 0.1\uffc2\uffa0mm from the root surface. Interestingly the root\uffe2\uff80\uff90hair\uffe2\uff80\uff90bearing genotype had a significantly greater soil pore volume\uffe2\uff80\uff90fraction at the root\uffe2\uff80\uff93soil interface.
Effects of pore structure on diffusion and permeability were estimated to be functionally insignificant under saturated conditions when simulated using image\uffe2\uff80\uff90based modelling.
The effects of predicted climate change on aphid\uffe2\uff80\uff93natural enemy interactions have principally considered the effects of elevated carbon dioxide concentration and air temperature. However, increased incidence of summer droughts are also predicted in Northern Europe, which could affect aphid\uffe2\uff80\uff93plant interactions and aphid antagonists. We investigated how simulated summer drought affected the bird cherry\uffe2\uff80\uff93oat aphid, Rhopalosiphum padi L., and its natural enemy the parasitoid wasp Aphidius ervi. Drought and, to a greater extent, aphids reduced barley ( Hordeum vulgare) dry mass by 33% and 39%, respectively. Drought reduced leaf and root nitrogen concentrations by 13% and 28%, respectively, but foliar amino acid concentrations and composition remained similar. Aphid numbers were unaffected by drought, but population demography changed significantly; adults constituted 41% of the population on drought\uffe2\uff80\uff90treated plants, but only 26% on those receiving ambient irrigation. Nymphs constituted 56% and 69% of the population on these plants, respectively, suggesting altered aphid development rates on drought\uffe2\uff80\uff90stressed plants. Parasitism rates were significantly lower on drought\uffe2\uff80\uff90stressed plants (9\uffc2\uffa0attacks\uffc2\uffa0h\uffe2\uff88\uff921 compared with 35 attacks h\uffe2\uff88\uff921 on ambient\uffe2\uff80\uff90irrigated plants), most likely because of lower incidence of nymphs and more adults, the latter being more difficult to parasitize. Any physiological changes in individual aphids did not affect parasitoid preferences, suggesting that attacks were postponed because of drought\uffe2\uff80\uff90induced changes in aphid demography. This study demonstrates the potential for sporadic climate change events, such as summer drought, to be disruptive to herbivore\uffe2\uff80\uff93antagonist interactions.", "keywords": ["580", "2. Zero hunger", "0106 biological sciences", "droughts", "Aphidius ervi", "820501 - Barley", "15. Life on land", "01 natural sciences", "6. Clean water", "climatic changes", "Rhopalosiphum padi", "13. Climate action", "060202 - Community Ecology", "Hordeum vulgare"]}, "links": [{"href": "https://doi.org/10.1111/j.1439-0418.2012.01747.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Applied%20Entomology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1439-0418.2012.01747.x", "name": "item", "description": "10.1111/j.1439-0418.2012.01747.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1439-0418.2012.01747.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-07-23T00:00:00Z"}}, {"id": "10.1111/ppl.70363", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-21T16:17:55Z", "type": "Journal Article", "created": "2025-07-13", "title": "Belowground Interactions in a Barley Cultivar Mixture: Root Distribution and Arbuscular Mycorrhizal Contributions to Uptake of Heterogeneous Phosphorus", "description": "ABSTRACTCultivar mixtures have the potential to mitigate abiotic stress and stabilize crop yields, but their belowground dynamics remain poorly understood. We evaluated phosphorus (P) uptake by two contrasting spring barley (Hordeum vulgare L.) cultivars (\uffe2\uff80\uff9cAnneli\uffe2\uff80\uff9d and \uffe2\uff80\uff9cFeedway\uffe2\uff80\uff9d), grown either in 50:50 mixture or as pure stand. The cultivars were grown in mesocosms under four P fertilization treatments: low\uffe2\uff80\uff90P, homogeneous high\uffe2\uff80\uff90P (90\uffe2\uff80\uff89mg P/kg), and localized P hotspots (100\uffe2\uff80\uff89mg P) placed either in the topsoil (5\uffe2\uff80\uff89cm) or subsoil (35\uffe2\uff80\uff89cm). To trace P uptake pathways, the hotspots were labeled with 33P and enclosed in mesh bags allowing only mycorrhizal hyphae (25\uffe2\uff80\uff89\uffce\uffbcm) or both roots and hyphae (2\uffe2\uff80\uff89mm) to access the hotspot. After 35\uffe2\uff80\uff89days, we measured aboveground biomass, total P content, 33P specific activity, and root biomass, length, diameter, and arbuscular mycorrhiza fungi (AMF) root colonization. In the mixture, reduced P uptake by \uffe2\uff80\uff9cFeedway\uffe2\uff80\uff9d led to lower overall performance compared to pure stand. Root modifications in the mixture did not enhance biomass or P acquisition, potentially due to decreased AMF colonization. Although different P placements altered P uptake patterns, they did not increase total P uptake. Roots accessed the P hotspots and acquired 33P without notable proliferation in the enriched zones. Our findings underscore the complexity of belowground interactions involving root distribution, competition for P, and AMF, and highlight the need for future research to optimize nutrient acquisition and performance in cultivar mixtures.In Northern Europe, inter\uffe2\uff80\uff90row hoeing has become a popular tactic for controlling weeds in organic cereals. Hoeing is highly effective and can be implemented from crop emergence until stem elongation to maintain a nearly weed\uffe2\uff80\uff90free inter\uffe2\uff80\uff90row zone. However, hoeing has a lesser effect on weeds growing in the intra\uffe2\uff80\uff90row zone, where crop\uffe2\uff80\uff93weed proximity results in heightened competition. In the hoed cereal system, it is investigated whether tall\uffe2\uff80\uff90growing, competitive, cruciferous weeds in the intra\uffe2\uff80\uff90row zone affect crop biomass, yield and thousand kernel weight (TKW). An additive experimental design is employed to enable the fitting of rectangular hyperbolas, describing and quantifying the effects of increasing intra\uffe2\uff80\uff90row surrogate weed density on crop growth parameters. Regressions were studied under the influence of crop (spring barley and spring wheat), row spacing (narrow [12.5 or 15.0\uffc2\uffa0cm] and wide [25.0\uffc2\uffa0cm]) and nitrogen rate (50 and 100\uffc2\uffa0kg NH4\uffe2\uff80\uff90N/ha). Cruciferous surrogate weeds were found to impact crop yield and quality severely. For example, ten intra\uffe2\uff80\uff90row plants/m2 of surrogate weed Sinapis alba reduced grains yields by 7%\uffe2\uff80\uff9314% in spring barley and by 7%\uffe2\uff80\uff9332% in spring wheat with yield losses becoming markedly greater in wheat compared to barley as weed density increases. Compared to wheat, barley limited yield and quality losses and suppressed intra\uffe2\uff80\uff90row weed growth more. Row spacing did not have a consistent effect on crop or weed parameters; in one of six experiments, the 25\uffc2\uffa0cm row spacing reduced yields and increased intra\uffe2\uff80\uff90row weed biomass in wheat. Nitrogen rate did not affect crop or weed parameters. Results warrant the implementation of additional tactics to control intra\uffe2\uff80\uff90row weeds and limit crop losses.
", "keywords": ["2. Zero hunger", "Hordeum vulgare L.", "thousand kernel weight", "nitrogen rate", "Hordeum vulgare L.", " Triticum aestivum L.", " inter-row hoeing", " nitrogen rate", " inter-row spacing", " thousand kernel weight", " crop-weed competition.", "0401 agriculture", " forestry", " and fisheries", "crop", "Weed management", "04 agricultural and veterinary sciences", "weed competition", "inter-row hoeing", "inter-row spacing", "Triticum aestivum L."]}, "links": [{"href": "https://doi.org/10.1111/wre.12452"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Weed%20Research", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/wre.12452", "name": "item", "description": "10.1111/wre.12452", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/wre.12452"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-11-05T00:00:00Z"}}, {"id": "2164/11950", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-21T16:22:44Z", "type": "Journal Article", "created": "2018-10-06", "title": "Imaging microstructure of the barley rhizosphere: particle packing and root hair influences", "description": "Summary
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.
Previous 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.
In this paper, we provide direct evidence of the importance of root hairs on pore structure development at the root\uffe2\uff80\uff93soil interface during the early stage of crop establishment.
This was achieved by use of high\uffe2\uff80\uff90resolution (c. 5\uffc2\uffa0\uffce\uffbcm) synchrotron radiation computed tomography (SRCT) to visualise both the structure of root hairs and the soil pore structure in plant\uffe2\uff80\uff93soil microcosms. Two contrasting genotypes of barley (Hordeum vulgare), with and without root hairs, were grown for 8\uffc2\uffa0d in microcosms packed with sandy loam soil at 1.2\uffc2\uffa0g\uffc2\uffa0cm\uffe2\uff88\uff923 dry bulk density. Root hairs were visualised within air\uffe2\uff80\uff90filled pore spaces, but not in the fine\uffe2\uff80\uff90textured soil regions.
We found that the genotype with root hairs significantly altered the porosity and connectivity of the detectable pore space (>\uffc2\uffa05\uffc2\uffa0\uffce\uffbcm) in the rhizosphere, as compared with the no\uffe2\uff80\uff90hair mutants. Both genotypes showed decreasing pore space between 0.8 and 0.1\uffc2\uffa0mm from the root surface. Interestingly the root\uffe2\uff80\uff90hair\uffe2\uff80\uff90bearing genotype had a significantly greater soil pore volume\uffe2\uff80\uff90fraction at the root\uffe2\uff80\uff93soil interface.
Effects of pore structure on diffusion and permeability were estimated to be functionally insignificant under saturated conditions when simulated using image\uffe2\uff80\uff90based modelling.