1
|
Gifford ML, Xu G, Dupuy LX, Vissenberg K, Rebetzke G. Root architecture and rhizosphere-microbe interactions. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:503-507. [PMID: 38197460 PMCID: PMC10773993 DOI: 10.1093/jxb/erad488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 01/11/2024]
Abstract
Plant roots fulfil crucial tasks during a plant's life. As roots encounter very diverse conditions while exploring the soil for resources, their growth and development must be responsive to changes in the rhizosphere, resulting in root architectures that are tailor-made for all prevailing circumstances. Using multi-disciplinary approaches, we are gaining more intricate insights into the regulatory mechanisms directing root system architecture. This Special Issue provides insights into our advancement of knowledge on different aspects of root development and identifies opportunities for future research.
Collapse
Affiliation(s)
- Miriam L Gifford
- School of Life Sciences, The University of Warwick, Coventry, UK
| | - Guohua Xu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Lionel X Dupuy
- Department of Conservation of Natural Resources, Neiker, Derio, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
- Plant Biochemistry and Biotechnology Lab, Department of Agriculture, Hellenic Mediterranean University, Stavromenos PC 71410, Heraklion, Crete, Greece
| | - Greg Rebetzke
- CSIRO Agriculture and Food, PO Box 1700, Canberra ACT 2601, Australia
| |
Collapse
|
2
|
Xiao T, Li P, Fei W, Wang J. Effects of vegetation roots on the structure and hydraulic properties of soils: A perspective review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167524. [PMID: 37793452 DOI: 10.1016/j.scitotenv.2023.167524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/22/2023] [Accepted: 09/29/2023] [Indexed: 10/06/2023]
Abstract
This paper aims to provide a state-of-the-art review on the effects of vegetation roots on the soil structure and soil hydraulic properties. After a thorough review of current studies, the effects of vegetation roots are summarized into four: root exudation, root penetration, root water uptake and root decay. Root exudates alter the size and stability of aggregates, the contact angle of soil, and the viscosity and surface tension of pore fluid; root exudates of crops always increase the soil water retention capacity and decrease the soil saturated hydraulic conductivity. Root penetration creates new pores or clogs existing pores during root growth, and root parameters (e.g., root biomass density, root diameter and root length density) are well correlated to soil hydraulic properties. Root water uptake can apparently increase the soil water retention capacity by providing an additional negative pressure and induce micro-fissures and macropores in the rhizosphere soil. Root decay modifies the pore structure and water repellency of soil, resulting in the increase of soil macro-porosity, soil water retention, and the saturated hydraulic conductivity or steady infiltration rate. Some of the above four effects may be difficult to be distinguished, and most importantly each is highly time-dependent and influenced by a multitude of plant-related and soil-related factors. Therefore, it remains a significant challenge to comprehend and quantify the effects of vegetation roots on the soil structure and soil hydraulic properties. Unsolved questions and disputes that require further investigations in the future are summarized in this review.
Collapse
Affiliation(s)
- Tao Xiao
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
| | - Ping Li
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China; Water Cycle and Geological Environment Observation and Research Station for the Chinese Loess Plateau, Ministry of Education, Zhengning 745339, China.
| | - Wenbin Fei
- Department of Infrastructure Engineering, The University of Melbourne, Parkville, Australia.
| | - Jiading Wang
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
| |
Collapse
|
3
|
Gao J, Feng P, Zhang J, Dong C, Wang Z, Chen M, Yu Z, Zhao B, Hou X, Wang H, Wu Z, Jemim RS, Yu H, Sun D, Jing P, Chen J, Song W, Zhang X, Zhou Z, Wu J. Enhancing maize's nitrogen-fixing potential through ZmSBT3, a gene suppressing mucilage secretion. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:2645-2659. [PMID: 37929676 DOI: 10.1111/jipb.13581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 11/04/2023] [Indexed: 11/07/2023]
Abstract
Maize (Zea mays) requires substantial amounts of nitrogen, posing a challenge for its cultivation. Recent work discovered that some ancient Mexican maize landraces harbored diazotrophic bacteria in mucilage secreted by their aerial roots. To see if this trait is retained in modern maize, we conducted a field study of aerial root mucilage (ARM) in 258 inbred lines. We observed that ARM secretion is common in modern maize, but the amount significantly varies, and only a few lines have retained the nitrogen-fixing traits found in ancient landraces. The mucilage of the high-ARM inbred line HN5-724 had high nitrogen-fixing enzyme activity and abundant diazotrophic bacteria. Our genome-wide association study identified 17 candidate genes associated with ARM across three environments. Knockouts of one candidate gene, the subtilase family gene ZmSBT3, confirmed that it negatively regulates ARM secretion. Notably, the ZmSBT3 knockout lines had increased biomass and total nitrogen accumulation under nitrogen-free culture conditions. High ARM was associated with three ZmSBT3 haplotypes that were gradually lost during maize domestication, being retained in only a few modern inbred lines such as HN5-724. In summary, our results identify ZmSBT3 as a potential tool for enhancing ARM, and thus nitrogen fixation, in maize.
Collapse
Affiliation(s)
- Jingyang Gao
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Peijiang Feng
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jingli Zhang
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Chaopei Dong
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhao Wang
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Mingxiang Chen
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhongliang Yu
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Bowen Zhao
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xin Hou
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Huijuan Wang
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhaokun Wu
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Razia Sultana Jemim
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Haidong Yu
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Doudou Sun
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Pei Jing
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jiafa Chen
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Weibin Song
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Xuecai Zhang
- International Maize and Wheat Improvement Center (CIMMYT), El Batan, Texcoco, 56237, Mexico
| | - Zijian Zhou
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jianyu Wu
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450002, China
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, China
| |
Collapse
|
4
|
Diehl D, Knott M, Schaumann GE. Purification effects show seed and root mucilage's ability to respond to changing rhizosphere conditions. Biopolymers 2023; 114:e23561. [PMID: 37435955 DOI: 10.1002/bip.23561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 06/11/2023] [Accepted: 06/26/2023] [Indexed: 07/13/2023]
Abstract
Mucilage, a polysaccharide-containing hydrogel, is hypothesized to play a key role in the rhizosphere as a self-organized system because it may vary its supramolecular structure with changes in the surrounding solution. However, there is currently limited research on how these changes are reflected in the physical properties of real mucilage. This study examines the role of solutes in maize root, wheat root, chia seed, and flax seed mucilage in relation to their physical properties. Two purification methods, dialysis and ethanol precipitation, were applied to determine the purification yield, cation content, pH, electrical conductivity, surface tension, viscosity, transverse 1 H relaxation time, and contact angle after drying of mucilage before and after purification. The two seed mucilage types contain more polar polymers that are connected to larger assemblies via multivalent cation crosslinks, resulting in a denser network. This is reflected in higher viscosity and water retention ability compared to root mucilage. Seed mucilage also contains fewer surfactants, making them better wettable after drying compared to the two root mucilage types. The root mucilage types, on the other hand, contain smaller polymers or polymer assemblies and become less wettable after drying. However, wettability not only depends on the amount of surfactants but also on their mobility, as well as the strength and mesh size of the network structure. The changes in physical properties and cation composition observed after ethanol precipitation and dialysis suggest that the polymer network of seed mucilage is more stable and specialized in protecting the seeds from unfavorable environmental conditions. In contrast, root mucilage is characterized by fewer cationic interactions and its network relies more on hydrophobic interactions. This allows root mucilage to be more flexible in responding to changing environmental conditions, facilitating nutrient and water exchange between root surfaces and the rhizosphere soil.
Collapse
Affiliation(s)
- Doerte Diehl
- Environmental and Soil Chemistry Group, Rheinland-Pfälzische Technische Universität Kaiserslautern Landau, RPTU in Landau, iES Institute for Environmental Sciences, Landau, Germany
| | - Mathilde Knott
- Environmental and Soil Chemistry Group, Rheinland-Pfälzische Technische Universität Kaiserslautern Landau, RPTU in Landau, iES Institute for Environmental Sciences, Landau, Germany
| | - Gabriele E Schaumann
- Environmental and Soil Chemistry Group, Rheinland-Pfälzische Technische Universität Kaiserslautern Landau, RPTU in Landau, iES Institute for Environmental Sciences, Landau, Germany
| |
Collapse
|
5
|
Berauer BJ, Akale A, Schweiger AH, Knott M, Diehl D, Wolf M, Sawers RJH, Ahmed MA. Differences in mucilage properties and stomatal sensitivity of locally adapted Zea mays in relation with precipitation seasonality and vapour pressure deficit regime of their native environment. PLANT DIRECT 2023; 7:e519. [PMID: 37600238 PMCID: PMC10435965 DOI: 10.1002/pld3.519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/05/2023] [Accepted: 07/27/2023] [Indexed: 08/22/2023]
Abstract
With ongoing climate change and the increase in extreme weather events, especially droughts, the challenge of maintaining food security is becoming ever greater. Locally adapted landraces of crops represent a valuable source of adaptation to stressful environments. In the light of future droughts-both by altered soil water supply and increasing atmospheric water demand (vapor pressure deficit [VPD])-plants need to improve their water efficiency. To do so, plants can enhance their access to soil water by improving rhizosphere hydraulic conductivity via the exudation of mucilage. Furthermore, plants can reduce transpirational water loss via stomatal regulation. Although the role of mucilage and stomata regulation on plant water management have been extensively studied, little is known about a possible coordination between root mucilage properties and stomatal sensitivity as well as abiotic drivers shaping the development of drought resistant trait suits within landraces. Mucilage properties and stomatal sensitivity of eight Mexican landraces of Zea mays in contrast with one inbred line were first quantified under controlled conditions and second related to water demand and supply at their respective site of origin. Mucilage physical properties-namely, viscosity, contact angle, and surface tension-differed between the investigated maize varieties. We found strong influences of precipitation seasonality, thus plant water availability, on mucilage production (R 2 = .88, p < .01) and mucilage viscosity (R 2 = .93, p < .01). Further, stomatal sensitivity to increased atmospheric water demand was related to mucilage viscosity and contact angle, both of which are crucial in determining mucilage's water repellent, thus maladaptive, behavior upon soil drying. The identification of landraces with pre-adapted suitable trait sets with regard to drought resistance is of utmost importance, for example, trait combinations such as exhibited in one of the here investigated landraces. Our results suggest a strong environmental selective force of seasonality in plant water availability on mucilage properties as well as regulatory stomatal effects to avoid mucilage's maladaptive potential upon drying and likely delay critical levels of hydraulic dysfunction. By this, landraces from highly seasonal climates may exhibit beneficial mucilage and stomatal traits to prolong plant functioning under edaphic drought. These findings may help breeders to efficiently screen for local landraces with pre-adaptations to drought to ultimately increase crop yield resistance under future climatic variability.
Collapse
Affiliation(s)
- Bernd J. Berauer
- Institute of Landscape and Plant Ecology, Department of Plant EcologyUniversity of HohenheimStuttgartGermany
| | - Asegidew Akale
- Root‐Soil Interaction, TUM School of Life SciencesTechnical University of MunichFreisingGermany
| | - Andreas H. Schweiger
- Institute of Landscape and Plant Ecology, Department of Plant EcologyUniversity of HohenheimStuttgartGermany
| | - Mathilde Knott
- Institute for Environmental Sciences, Group of Environmental and Soil ChemistryRPTU in LandauLandauGermany
| | - Dörte Diehl
- Institute for Environmental Sciences, Group of Environmental and Soil ChemistryRPTU in LandauLandauGermany
| | - Marc‐Philip Wolf
- Institute for Environmental Sciences, Group of Environmental and Soil ChemistryRPTU in LandauLandauGermany
| | - Ruairidh J. H. Sawers
- Department of Plant ScienceThe Pennsylvania State UniversityState CollegePennsylvaniaUSA
| | - Mutez A. Ahmed
- Root‐Soil Interaction, TUM School of Life SciencesTechnical University of MunichFreisingGermany
| |
Collapse
|
6
|
Pauwels R, Graefe J, Bitterlich M. An arbuscular mycorrhizal fungus alters soil water retention and hydraulic conductivity in a soil texture specific way. MYCORRHIZA 2023; 33:165-179. [PMID: 36976365 DOI: 10.1007/s00572-023-01106-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/14/2023] [Indexed: 06/08/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) alter plant water relations and contribute to soil structure. Although soil hydraulic properties depend on soil structure and may limit plant water uptake, little is known about how AMF influence soil water retention (the relation between the soil water content and soil water potential) and hydraulic conductivity in different soils. Instead, these soil hydraulic properties often are considered to be independent of AMF presence in experiments. We asked if this assumption holds true for both sand and loam. We grew maize plants either inoculated with Rhizophagus irregularis or with autoclaved inoculum in pots filled with quartz sand or loam soil until extraradical spread of the fungus throughout the pots was achieved. Each pot contained a hyphal compartment made of a soil sampling core (250 cm3) covered with a 20-µm nylon mesh to encourage fungus ingrowth but to exclude root ingrowth. We measured soil water retention and unsaturated hydraulic conductivity in these undisturbed root-free soil volumes. We observed that in loam harboring the mycorrhizal fungus, the soil water retention decreased, while in sand, it increased without detectable changes in the soil bulk density. The effects of the fungus on the soil water potential were strongest at low soil water contents in both soils. As a consequence of the altered water potentials in soils with the mycorrhizal fungus, soil hydraulic conductivity increased in loam but decreased in sand after fungus ingrowth. We conclude that in our study, the mycorrhizal fungus acted as a soil conditioner even distant from roots, which encouraged drainage in loams prone to sogginess but enhanced water storage in sands prone to quick desiccation. We recommend considering soil hydraulic properties as being dynamic in future studies on water relations of mycorrhizal plants.
Collapse
Affiliation(s)
- Richard Pauwels
- Leibniz Institute of Vegetable and Ornamental Crops e.V. (IGZ), Grossbeeren, Germany
| | - Jan Graefe
- Leibniz Institute of Vegetable and Ornamental Crops e.V. (IGZ), Grossbeeren, Germany
| | - Michael Bitterlich
- Division Urban Plant Ecophysiology, Thaer-Institute, Humboldt-Universität zu Berlin, Berlin, Germany.
| |
Collapse
|
7
|
Hallett PD, Marin M, Bending GD, George TS, Collins CD, Otten W. Building soil sustainability from root-soil interface traits. TRENDS IN PLANT SCIENCE 2022; 27:688-698. [PMID: 35168900 DOI: 10.1016/j.tplants.2022.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 01/06/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Great potential exists to harness plant traits at the root-soil interface, mainly rhizodeposition and root hairs, to 'build' soils with better structure that can trap more carbon and resources, resist climate stresses, and promote a healthy microbiome. These traits appear to have been preserved in modern crop varieties, but scope exists to improve them further because they vary considerably between genotypes and respond to environmental conditions. From emerging evidence, rhizodeposition can act as a disperser, aggregator, and/or hydrogel in soil, and root hairs expand rhizosheath size. Future research should explore impacts of selecting these traits on plants and soils concurrently, expanding from model plants to commercial genotypes, and observing whether impacts currently limited to glasshouse studies occur in the field.
Collapse
Affiliation(s)
- Paul D Hallett
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK.
| | - Maria Marin
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
| | - Gary D Bending
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Timothy S George
- Ecological Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Chris D Collins
- Department of Geography and Environmental Science, University of Reading, Reading RG6 6DW, UK
| | - Wilfred Otten
- Cranfield Soil and Agrifood Institute, College Road, Cranfield, MK43 0AL, UK
| |
Collapse
|
8
|
Oburger E, Schmidt H, Staudinger C. Harnessing belowground processes for sustainable intensification of agricultural systems. PLANT AND SOIL 2022; 478:177-209. [PMID: 36277079 PMCID: PMC9579094 DOI: 10.1007/s11104-022-05508-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/18/2022] [Indexed: 06/16/2023]
Abstract
Increasing food demand coupled with climate change pose a great challenge to agricultural systems. In this review we summarize recent advances in our knowledge of how plants, together with their associated microbiota, shape rhizosphere processes. We address (molecular) mechanisms operating at the plant-microbe-soil interface and aim to link this knowledge with actual and potential avenues for intensifying agricultural systems, while at the same time reducing irrigation water, fertilizer inputs and pesticide use. Combining in-depth knowledge about above and belowground plant traits will not only significantly advance our mechanistic understanding of involved processes but also allow for more informed decisions regarding agricultural practices and plant breeding. Including belowground plant-soil-microbe interactions in our breeding efforts will help to select crops resilient to abiotic and biotic environmental stresses and ultimately enable us to produce sufficient food in a more sustainable agriculture in the upcoming decades.
Collapse
Affiliation(s)
- Eva Oburger
- Department of Forest and Soil Science, Institute of Soil Research, University of Natural Resources and Life Sciences, Konrad Lorenzstrasse 24, 3430 Tulln an der Donau, Austria
| | - Hannes Schmidt
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Christiana Staudinger
- Department of Forest and Soil Science, Institute of Soil Research, University of Natural Resources and Life Sciences, Konrad Lorenzstrasse 24, 3430 Tulln an der Donau, Austria
- Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima, Japan
| |
Collapse
|
9
|
Oh S, Kim DY. Characterization, Antioxidant Activities, and Functional Properties of Mucilage Extracted from Corchorus olitorius L. Polymers (Basel) 2022; 14:polym14122488. [PMID: 35746064 PMCID: PMC9228403 DOI: 10.3390/polym14122488] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 02/07/2023] Open
Abstract
This study extracted the mucilage from Corchorus olitorius L. to observe its chemical and functional properties and suggest its possible applications in various fields. Corchorus olitorius L. mucilage was isolated by hot water extraction. FT-IR and HPAEC-PAD were used to describe the chemical composition, and the functional properties and antioxidant activities of the mucilage were also examined. The mucilage was mainly composed of uronic acid (34.24%, w/w). The solubility was 79.48 ± 1.08% at 65 °C, the swelling index was 29.01 ± 2.54% at 25 °C, and the water-holding capacity and oil-binding capacity were 28.66 ± 1.48 and 8.423 ± 0.23 g/g, respectively. The mucilage viscosity increased from 4.38 to 154.97 cP in a concentration-dependent manner. Increasing the concentration decreased the emulsion activity and increased the emulsion stability, most likely because of the corresponding increase in surface tension and viscosity. Results from antioxidant assays confirmed that the in-vitro radical scavenging activity of the mucilage increased with concentration. This study shows that C. olitorius L. can be utilized as a new hydrocolloid source, with potential applications in fields ranging from foods to cosmetics and pharmaceuticals.
Collapse
|
10
|
Marin M, Hallett PD, Feeney DS, Brown LK, Naveed M, Koebernick N, Ruiz S, Bengough AG, Roose T, George TS. Impact of root hairs on microscale soil physical properties in the field. PLANT AND SOIL 2022; 476:491-509. [PMID: 35992246 PMCID: PMC9381483 DOI: 10.1007/s11104-022-05530-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
AIMS 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. METHODS Changes 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. RESULTS Over the growing season, plants induced changes in the soil water retention properties, with the plant available water increasing by 21%. Both soil hardness (P = 0.031) and elasticity (P = 0.048) 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 = 0.007) in sandy loam soil vegetated with the hairy genotype (-49%) compared to the hairless mutant. CONCLUSIONS Breeding 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. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s11104-022-05530-1.
Collapse
Affiliation(s)
- M. Marin
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU UK
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
| | - P. D. Hallett
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU UK
| | - D. S. Feeney
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
- School of Science and Engineering, University of Dundee, Dundee, DD1 4HN UK
| | - L. K. Brown
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
| | - M. Naveed
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU UK
- Present Address: School of Computing and Engineering, University of West London, London, W5 5RF UK
| | - N. Koebernick
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ UK
- Present Address: Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06108 Halle (Saale), Germany
| | - S. Ruiz
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ UK
| | - A. G. Bengough
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
- School of Science and Engineering, University of Dundee, Dundee, DD1 4HN UK
| | - T. Roose
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ UK
| | - T. S. George
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA UK
| |
Collapse
|
11
|
Tsai AYL, McGee R, Dean GH, Haughn GW, Sawa S. Seed Mucilage: Biological Functions and Potential Applications in Biotechnology. PLANT & CELL PHYSIOLOGY 2021; 62:1847-1857. [PMID: 34195842 DOI: 10.1093/pcp/pcab099] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/16/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
In plants, the diaspore (seed dispersal unit) may include a seed coat and/or pericarp to protect the embryo and assist in dispersion. In many species, the seed coat and/or pericarp secrete a gelatinous mixture of cell wall polysaccharides known as mucilage. In several species, mucilage synthesis, secretion and modification have been studied extensively as model systems for the investigation of plant cell wall structure and function. Despite this, efforts toward understanding the role of mucilage have received less attention. Mucilage has been hypothesized to impact seed dispersal through interaction with soil, protecting the seed in the gut following ingestion by animals or affecting the ability of seeds to sink or float in water. Mucilage has been found to influence seed germination and seedling establishment, most often during abiotic stress, probably by maintaining seed hydration when water is scarce. Finally, mucilage has been documented to mediate interactions with various organisms. Advances in transgenic technology should enable the genetic modification of mucilage structure and function in crop plants. Cells synthesizing mucilage may also be a suitable platform for creating custom polysaccharides or proteins with industrial applications. Thus, in the near future, it is likely that research on seed mucilage will expand well beyond the current focus. Here we summarize our understanding of the biological functions of mucilage and provide an outlook on the future of mucilage research.
Collapse
Affiliation(s)
- Allen Yi-Lun Tsai
- International Research Center for Agricultural & Environmental Biology, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto 860-8555, Japan
| | - Robert McGee
- L'Institut National de la Recherche Scientifique Centre Armand-Frappier Santé Biotechnologie (INRS-CAFSB), 531 des Prairies Blvd, Laval, QC H7V 1B7, Canada
| | - Gillian H Dean
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
| | - George W Haughn
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
| | - Shinichiro Sawa
- International Research Center for Agricultural & Environmental Biology, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto 860-8555, Japan
| |
Collapse
|
12
|
Nazari M, Riebeling S, Banfield CC, Akale A, Crosta M, Mason-Jones K, Dippold MA, Ahmed MA. Mucilage Polysaccharide Composition and Exudation in Maize From Contrasting Climatic Regions. FRONTIERS IN PLANT SCIENCE 2020; 11:587610. [PMID: 33363554 PMCID: PMC7752898 DOI: 10.3389/fpls.2020.587610] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/18/2020] [Indexed: 05/28/2023]
Abstract
Mucilage, a gelatinous substance comprising mostly polysaccharides, is exuded by maize nodal and underground root tips. Although mucilage provides several benefits for rhizosphere functions, studies on the variation in mucilage amounts and its polysaccharide composition between genotypes are still lacking. In this study, eight maize (Zea mays L.) genotypes from different globally distributed agroecological zones were grown under identical abiotic conditions in a randomized field experiment. Mucilage exudation amount, neutral sugars and uronic acids were quantified. Galactose (∼39-42%), fucose (∼22-30%), mannose (∼11-14%), and arabinose (∼8-11%) were the major neutral sugars in nodal root mucilage. Xylose (∼1-4%), and glucose (∼1-4%) occurred only in minor proportions. Glucuronic acid (∼3-5%) was the only uronic acid detected. The polysaccharide composition differed significantly between maize genotypes. Mucilage exudation was 135 and 125% higher in the Indian (900 M Gold) and Kenyan (DH 02) genotypes than in the central European genotypes, respectively. Mucilage exudation was positively associated with the vapor pressure deficit of the genotypes' agroecological zone. The results indicate that selection for environments with high vapor pressure deficit may favor higher mucilage exudation, possibly because mucilage can delay the onset of hydraulic failure during periods of high vapor pressure deficit. Genotypes from semi-arid climates might offer sources of genetic material for beneficial mucilage traits.
Collapse
Affiliation(s)
- Meisam Nazari
- Division of Biogeochemistry of Agroecosystems, Georg-August University of Göttingen, Göttingen, Germany
| | - Sophie Riebeling
- Division of Biogeochemistry of Agroecosystems, Georg-August University of Göttingen, Göttingen, Germany
| | - Callum C. Banfield
- Division of Biogeochemistry of Agroecosystems, Georg-August University of Göttingen, Göttingen, Germany
| | - Asegidew Akale
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Margherita Crosta
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Kyle Mason-Jones
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Michaela A. Dippold
- Division of Biogeochemistry of Agroecosystems, Georg-August University of Göttingen, Göttingen, Germany
| | - Mutez Ali Ahmed
- Division of Biogeochemistry of Agroecosystems, Georg-August University of Göttingen, Göttingen, Germany
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| |
Collapse
|