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Lu Y, Fricke W. Salt Stress-Regulation of Root Water Uptake in a Whole-Plant and Diurnal Context. Int J Mol Sci 2023; 24:ijms24098070. [PMID: 37175779 PMCID: PMC10179082 DOI: 10.3390/ijms24098070] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/25/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
This review focuses on the regulation of root water uptake in plants which are exposed to salt stress. Root water uptake is not considered in isolation but is viewed in the context of other potential tolerance mechanisms of plants-tolerance mechanisms which relate to water relations and gas exchange. Plants spend between one third and half of their lives in the dark, and salt stress does not stop with sunset, nor does it start with sunrise. Surprisingly, how plants deal with salt stress during the dark has received hardly any attention, yet any growth response to salt stress over days, weeks, months and years is the integrative result of how plants perform during numerous, consecutive day/night cycles. As we will show, dealing with salt stress during the night is a prerequisite to coping with salt stress during the day. We hope to highlight with this review not so much what we know, but what we do not know; and this relates often to some rather basic questions.
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Affiliation(s)
- Yingying Lu
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, D04 N2E5 Dublin, Ireland
| | - Wieland Fricke
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, D04 N2E5 Dublin, Ireland
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Fricke W. Energy costs of salinity tolerance in crop plants: night-time transpiration and growth. New Phytol 2020; 225:1152-1165. [PMID: 30834533 DOI: 10.1111/nph.15773] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/25/2019] [Indexed: 05/28/2023]
Abstract
Plants grow and transpire during the night. The aim of the present work was to assess the relative flows of carbon, water and solutes, and the energy involved, in sustaining night-time transpiration and leaf expansive growth under control and salt-stress conditions. Published and unpublished data were used, for barley plants grown in presence of 0.5-1 mM NaCl (control) and 100 mM NaCl. Night-time leaf growth presents a more efficient use of taken-up water compared with day-time growth. This efficiency increases several-fold with salt stress. Night-time transpiration cannot be supported entirely through osmotically driven uptake of water through roots under salt stress. Using a simple three- (root medium/cytosol/vacuole) compartment approach, the energy required to support cell expansion during the night is in the lower percentage region (0.03-5.5%) of the energy available through respiration, under both, control and salt-stress conditions. Use of organic (e.g. hexose equivalents) rather than inorganic (e.g. Na+ , Cl- , K+ ) solutes for generation of osmotic pressure in growing cells, increases the energy demand by orders of magnitude, yet requires only a small portion of carbon assimilated during the day. Night-time transpiration and leaf expansive growth should be considered as a potential acclimation mechanism to salinity.
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Affiliation(s)
- Wieland Fricke
- School of Biology and Environmental Sciences, University College Dublin (UCD), Belfield, Dublin 4, Ireland
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Abstract
Plants grow and transpire water during the day and night. Recent work highlights the idea that night-time transpirational water loss is a consequence of allowing respiratory CO2 to escape at sufficiently high rates through stomata. Respiration fuels night-time leaf expansion and requires carbohydrates produced during the day. As carbohydrate availability and growth are under the control of the plants' internal clock, so is night-time transpiration. The cost of night-time transpiration is that water is lost without carbon being gained, the benefit is a higher efficiency of taken up water for use in leaf expansion. This could provide a stress acclimation process.
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Affiliation(s)
- Wieland Fricke
- School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Ireland; https://people.ucd.ie/wieland.fricke.
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Even M, Sabo M, Meng D, Kreszies T, Schreiber L, Fricke W. Night-time transpiration in barley (Hordeum vulgare) facilitates respiratory carbon dioxide release and is regulated during salt stress. Ann Bot 2018; 122:569-582. [PMID: 29850772 PMCID: PMC6153476 DOI: 10.1093/aob/mcy084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/26/2018] [Indexed: 05/24/2023]
Abstract
Background and Aims Night-time transpiration accounts for a considerable amount of water loss in crop plants. Despite this, there remain many questions concerning night-time transpiration - its biological function, regulation and response to stresses such as salinity. The aim of the present study was to address these questions on 14- to 18-d-old, hydroponically grown barley plants. Methods Plants were either stressed for the last 4-7 d prior to, and during subsequent continuous (24 h), diurnal gravimetric transpiration analyses; or subjected to salt stress just before analyses; or stressed for 4-7 d and then transferred to control medium before analyses. The idea behind this experimental setup was to distinguish between a longer- (cuticle, stomata) and shorter-term (stomata) response of transpiration to treatments. Cuticular conductance was assessed through residual transpiration measurements in detached leaves. Cuticle wax load and dark respiration rate of leaves were determined. Leaf conductance to CO2 was calculated. Key Results Night-time and daytime transpiration rates were highly, and positively, correlated with each other, across all treatments. Night-time transpiration rates accounted for 9-17 % of daytime rates (average: 13.8 %). Despite minor changes in the ratio of night- to daytime transpiration rates, the contribution of cuticular and stomatal conductance to leaf (epidermal) conductance to water vapour differed considerably between treatments. Salt stress did not affect cuticle wax load. The conductance for CO2 of the cuticle was insufficient to support rates of dark respiratory CO2 release. Conclusions The main biological function of night-time transpiration is the release of respiratory CO2 from leaves. Night-time transpiration is regulated in the short and long term, also under salt stress. Stomata play a key role in this process. We propose to refer, in analogy to water use efficiency (WUE) during the day, to a CO2 release efficiency ('CORE') during the night.
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Affiliation(s)
- Margaux Even
- School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Marine Sabo
- School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Delong Meng
- School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Tino Kreszies
- Ecophysiology of Plants, IZMB, University of Bonn, Bonn, Germany
| | - Lukas Schreiber
- Ecophysiology of Plants, IZMB, University of Bonn, Bonn, Germany
| | - Wieland Fricke
- School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Republic of Ireland
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Peters RL, Fonti P, Frank DC, Poyatos R, Pappas C, Kahmen A, Carraro V, Prendin AL, Schneider L, Baltzer JL, Baron-Gafford GA, Dietrich L, Heinrich I, Minor RL, Sonnentag O, Matheny AM, Wightman MG, Steppe K. Quantification of uncertainties in conifer sap flow measured with the thermal dissipation method. New Phytol 2018; 219:1283-1299. [PMID: 29862531 DOI: 10.1111/nph.15241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Trees play a key role in the global hydrological cycle and measurements performed with the thermal dissipation method (TDM) have been crucial in providing whole-tree water-use estimates. Yet, different data processing to calculate whole-tree water use encapsulates uncertainties that have not been systematically assessed. We quantified uncertainties in conifer sap flux density (Fd ) and stand water use caused by commonly applied methods for deriving zero-flow conditions, dampening and sensor calibration. Their contribution has been assessed using a stem segment calibration experiment and 4 yr of TDM measurements in Picea abies and Larix decidua growing in contrasting environments. Uncertainties were then projected on TDM data from different conifers across the northern hemisphere. Commonly applied methods mostly underestimated absolute Fd . Lacking a site- and species-specific calibrations reduced our stand water-use measurements by 37% and induced uncertainty in northern hemisphere Fd . Additionally, although the interdaily variability was maintained, disregarding dampening and/or applying zero-flow conditions that ignored night-time water use reduced the correlation between environment and Fd . The presented ensemble of calibration curves and proposed dampening correction, together with the systematic quantification of data-processing uncertainties, provide crucial steps in improving whole-tree water-use estimates across spatial and temporal scales.
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Affiliation(s)
- Richard L Peters
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Patrick Fonti
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - David C Frank
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Laboratory of Tree-Ring Research, 1215 E. Lowell Street, Tucson, AZ, 8572, USA
- Oeschger Centre for Climate Change Research, Falkenplatz 16, CH-3012, Bern, Switzerland
| | - Rafael Poyatos
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Faculty of Bioscience Engineering, Department of Plants and Crops, Laboratory of Plant Ecology, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
| | - Christoforos Pappas
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, H2V 2B8, Canada
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Vinicio Carraro
- Department TeSAF Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020, Legnaro, PD, Italy
| | - Angela Luisa Prendin
- Department TeSAF Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020, Legnaro, PD, Italy
- Department of Bioscience, Ecoinformatic & Biodiversity, Aarhus University, Ny Munkegade 116, Building 1540, DK-8000, Aarhus C, Denmark
| | - Loïc Schneider
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Jennifer L Baltzer
- Biology Department, Wilfrid Laurier University, 75 University Ave. W, Waterloo, ON, N2L 3C5, Canada
| | - Greg A Baron-Gafford
- School of Geography and Development, University of Arizona, 1064 E Lowell St, Tucson, AZ, 85719, USA
| | - Lars Dietrich
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Ingo Heinrich
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Telegrafenberg, 14473, Potsdam, Germany
| | - Rebecca L Minor
- School of Geography and Development, University of Arizona, 1064 E Lowell St, Tucson, AZ, 85719, USA
| | - Oliver Sonnentag
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, H2V 2B8, Canada
| | - Ashley M Matheny
- Department of Geological Sciences, Jackson School of Geosciences, 2305 Speedway Stop, C1160, Austin, TX, USA
| | - Maxwell G Wightman
- College of Forestry, Oregon State University, 1500 SW Jefferson St, Corvallis, OR, 97331, USA
| | - Kathy Steppe
- Faculty of Bioscience Engineering, Department of Plants and Crops, Laboratory of Plant Ecology, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
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Schoppach R, Taylor JD, Majerus E, Claverie E, Baumann U, Suchecki R, Fleury D, Sadok W. High resolution mapping of traits related to whole-plant transpiration under increasing evaporative demand in wheat. J Exp Bot 2016; 67:2847-60. [PMID: 27001921 PMCID: PMC4861027 DOI: 10.1093/jxb/erw125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Atmospheric vapor pressure deficit (VPD) is a key component of drought and has a strong influence on yields. Whole-plant transpiration rate (TR) response to increasing VPD has been linked to drought tolerance in wheat, but because of its challenging phenotyping, its genetic basis remains unexplored. Further, the genetic control of other key traits linked to daytime TR such as leaf area, stomata densities and - more recently - nocturnal transpiration remains unknown. Considering the presence of wheat phenology genes that can interfere with drought tolerance, the aim of this investigation was to identify at an enhanced resolution the genetic basis of the above traits while investigating the effects of phenology genes Ppd-D1 and Ppd-B1 Virtually all traits were highly heritable (heritabilities from 0.61 to 0.91) and a total of mostly trait-specific 68 QTL were detected. Six QTL were identified for TR response to VPD, with one QTL (QSLP.ucl-5A) individually explaining 25.4% of the genetic variance. This QTL harbored several genes previously reported to be involved in ABA signaling, interaction with DREB2A and root hydraulics. Surprisingly, nocturnal TR and stomata densities on both leaf sides were characterized by highly specific and robust QTL. In addition, negative correlations were found between TR and leaf area suggesting trade-offs between these traits. Further, Ppd-D1 had strong but opposite effects on these traits, suggesting an involvement in this trade-off. Overall, these findings revealed novel genetic resources while suggesting a more direct role of phenology genes in enhancing wheat drought tolerance.
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Affiliation(s)
- Rémy Schoppach
- Earth and Life Institute, Université Catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Julian D Taylor
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB 1, Glen Osmond, South Australia SA 5064, Australia
| | - Elisabeth Majerus
- Earth and Life Institute, Université Catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Elodie Claverie
- Earth and Life Institute, Université Catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Ute Baumann
- Australian Centre for Plant Functional Genomics (ACPFG), University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Radoslaw Suchecki
- Australian Centre for Plant Functional Genomics (ACPFG), University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Delphine Fleury
- Australian Centre for Plant Functional Genomics (ACPFG), University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Walid Sadok
- Department of Agronomy and Plant Genetics, University of Minnesota, 411 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN 55108, USA
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Cirelli D, Equiza MA, Lieffers VJ, Tyree MT. Populus species from diverse habitats maintain high night-time conductance under drought. Tree Physiol 2016; 36:229-242. [PMID: 26420792 DOI: 10.1093/treephys/tpv092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 08/17/2015] [Indexed: 06/05/2023]
Abstract
We investigated the interspecific variability in nocturnal whole-plant stomatal conductance under well-watered and drought conditions in seedlings of four species of Populus from habitats characterized by abundant water supply (mesic and riparian) or from drier upland sites. The study was carried out to determine whether (i) nocturnal conductance varies across different species of Populus according to their natural habitat, (ii) nocturnal conductance is affected by water stress similarly to daytime conductance based on species habitat and (iii) differences in conductance among species could be explained partly by differences in stomatal traits. We measured whole-plant transpiration and conductance (G) of greenhouse-grown seedlings using an automated high-resolution gravimetric technique. No relationship was found between habitat preference and daytime G (GD), but night-time G (GN) was on average 1.5 times higher in riparian and mesic species (P. deltoides Bartr. ex Marsh. and P. trichocarpa Torr. & Gray) than in those from drier environments (P. tremuloides Michx. and P. × petrowskyana Schr.). GN was not significantly reduced under drought in riparian species. Upland species restricted GN significantly in response to drought, but it was still at least one order of magnitude greater that the cuticular conductance until leaf death was imminent. Under both well-watered and drought conditions, GN declined with increasing vapour pressure deficit (D). Also, a small increase in GN towards the end of the night period was observed in P. deltoides and P. × petrowskyana, suggesting the involvement of endogenous regulation. The anatomical analyses indicated a positive correlation between G and variable stomatal pore index among species and revealed that stomata are not likely to be leaky but instead seem capable of complete occlusion, which raises the question of the possible physiological role of the significant GN observed under drought. Further comparisons among closely related species that occupy ecologically diverse habitats may provide a better understanding of the genetic versus environmental regulations of nocturnal water loss.
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Affiliation(s)
- Damián Cirelli
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
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Eller CB, Burgess SSO, Oliveira RS. Environmental controls in the water use patterns of a tropical cloud forest tree species, Drimys brasiliensis (Winteraceae). Tree Physiol 2015; 35:387-399. [PMID: 25716877 DOI: 10.1093/treephys/tpv001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/04/2015] [Indexed: 06/04/2023]
Abstract
Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.
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Affiliation(s)
- Cleiton B Eller
- Department of Plant Biology, Institute of Biology, University of Campinas - UNICAMP, CP6109, Campinas, SP, Brazil
| | - Stephen S O Burgess
- School of Plant Biology, The University of Western Australia - UWA, Perth, WA 6009, Australia
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas - UNICAMP, CP6109, Campinas, SP, Brazil School of Plant Biology, The University of Western Australia - UWA, Perth, WA 6009, Australia
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Doronila AI, Forster MA. Performance measurement via sap flow monitoring of three eucalyptus species for mine site and dryland salinity phytoremediation. Int J Phytoremediation 2015; 17:101-108. [PMID: 25237720 DOI: 10.1080/15226514.2013.850466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Monitoring of trees with reliable technology is essential in phytoremediation. Sap flow instrumentation on three Eucalyptus species at a mine site in western Victoria, Australia, was used to determine which species is best suited to meet the goals of a phytoremediation project. Specifically, the aim of the monitoring was to determine which species could better tolerate the hypersaline soil, potentially lower saline ground water, and cope with expected hotter and drier weather given climate change scenarios. Over a summer period, average daily water use of E. cladocalyx was approximately six times greater than E. melliodora and four times greater than E. polybractea. During a three day heat wave event, E. cladocalyx was found to have a higher tolerance to extreme temperature. The optimal VPD/temperature for tree transpiration was 2.6 kPa/26.2 °C for E. cladocalyx, 2.1 kPa/23.9 °C for E. melliodora, and 2.0 kPa/23.2 °C for E. polybractea. Through sap flow monitoring, it was determined that E. cladocalyx could better tolerate saline soils, hotter and drier weather, and had greater potential to lower saline ground water.
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Affiliation(s)
- Augustine I Doronila
- a School of Chemistry , The University of Melbourne , Parkville , VIC , Australia
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Knipfer T, Fricke W. Water uptake by seminal and adventitious roots in relation to whole-plant water flow in barley (Hordeum vulgare L.). J Exp Bot 2011; 62:717-33. [PMID: 20974734 PMCID: PMC3003818 DOI: 10.1093/jxb/erq312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 09/10/2010] [Accepted: 09/10/2010] [Indexed: 05/02/2023]
Abstract
Prior to an assessment of the role of aquaporins in root water uptake, the main path of water movement in different types of root and driving forces during day and night need to be known. In the present study on hydroponically grown barley (Hordeum vulgare L.) the two main root types of 14- to 17-d-old plants were analysed for hydraulic conductivity in dependence of the main driving force (hydrostatic, osmotic). Seminal roots contributed 92% and adventitious roots 8% to plant water uptake. The lower contribution of adventitious compared with seminal roots was associated with a smaller surface area and number of roots per plant and a lower axial hydraulic conductance, and occurred despite a less-developed endodermis. The radial hydraulic conductivity of the two types of root was similar and depended little on the prevailing driving force, suggesting that water uptake occurred along a pathway that involved crossing of membrane(s). Exudation experiments showed that osmotic forces were sufficient to support night-time transpiration, yet transpiration experiments and cuticle permeance data questioned the significance of osmotic forces. During the day, 90% of water uptake was driven by a tension of about -0.15 MPa.
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Affiliation(s)
- Thorsten Knipfer
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Ireland.
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