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Kupper P, Tullus A, Rohula-Okunev G. Night-time water relations and gas exchange in cut shoots of five boreal dwarf shrub species: impact of soil water availability. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2023; 29:1193-1203. [PMID: 37829697 PMCID: PMC10564692 DOI: 10.1007/s12298-023-01350-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/03/2023] [Accepted: 08/21/2023] [Indexed: 10/14/2023]
Abstract
Recent findings suggest that drought may affect plants' daytime and night-time stomatal regulation differently. However, knowledge of night-time stomatal behaviour in dwarf shrubs growing in boreal ecosystems is lacking. We sampled cut shoots from dwarf shrub species to elucidate their capacity to transpire at night and the effect of drought on stomatal regulation. The shoots' water relations and gas exchange were measured under controlled conditions in a growth chamber. The studied species demonstrated considerable differences in their diurnal water use. The night-time water use percentage of daytime water use (NWU) reached up to 90% in Andromeda polifolia and Vaccinium uliginosum. In Rhododendron tomentosum, Vaccinium myrtillus and Chamaedaphne calyculata, the NWU was 62, 27 and 26%, respectively. The shoots of C. calyculata showed a significant increase (P < 0.001) in the transpiration rate (E) during the night. However, in R. tomentosum, a decrease (P < 0.05) in nightly E was observed. The shoot conductance (g) at the end of the night was lower than daytime g in all studied species, but the difference was not significant for V. uliginosum. Across the species, NWU was negatively related (P < 0.001) to the soil volumetric water content (SWC) in the plant habitat. However, daytime E and g were positively related (P < 0.05) to the habitat SWC. Only in V. myrtillus was night-time E higher (P < 0.05) in dry conditions than in wet conditions. Our results demonstrate high variability in diurnal water relations in dwarf shrubs, which can keep stomata open in the dark even when drought limits daytime g and E.
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Affiliation(s)
- Priit Kupper
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - Arvo Tullus
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
| | - Gristin Rohula-Okunev
- Institute of Ecology and Earth Sciences, University of Tartu, Liivi 2, 50409 Tartu, Estonia
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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: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [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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de la Riva EG, Borden K, Ostonen I, Saengwilai P, Prieto I. Editorial: Root functional traits: From fine root to community-level variation. FRONTIERS IN PLANT SCIENCE 2023; 14:1152174. [PMID: 36875572 PMCID: PMC9977287 DOI: 10.3389/fpls.2023.1152174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Enrique G. de la Riva
- Ecology Department, Faculty of Biology and Environmental Sciences, Universidad de León, León, Spain
| | - Kira Borden
- School of the Environment, Trent University, Peterborough, ON, Canada
| | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Patompong Saengwilai
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Iván Prieto
- Ecology Department, Faculty of Biology and Environmental Sciences, Universidad de León, León, Spain
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Du Y, Lu R, Sun H, Cui E, Yan L, Xia J. Plant photosynthetic overcompensation under nocturnal warming: lack of evidence in subtropical evergreen trees. ANNALS OF BOTANY 2022; 130:109-119. [PMID: 35690359 PMCID: PMC9295921 DOI: 10.1093/aob/mcac075] [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: 03/30/2022] [Accepted: 06/09/2022] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND AIMS Increased plant photosynthesis under nocturnal warming is a negative feedback mechanism to overcompensate for night-time carbon loss to mitigate climate warming. This photosynthetic overcompensation effect has been observed in dry deciduous ecosystems but whether it exists in subtropical wet forest trees is unclear. METHODS Two subtropical evergreen tree species (Schima superba and Castanopsis sclerophylla) were grown in a greenhouse and exposed to ambient and elevated night-time temperature. The occurrence of the photosynthetic overcompensation effect was determined by measuring daytime and night-time leaf gas exchange and non-structural carbohydrate (NSC) concentration. KEY RESULTS A reduction in leaf photosynthesis for both species and an absence of persistent photosynthetic overcompensation were observed. The photosynthetic overcompensation effect was transient in S. superba due to respiratory acclimation and stomatal limitation. For S. superba, nocturnal warming resulted in insufficient changes in night-time respiration and NSC concentration to stimulate overcompensation and inhibited leaf stomatal conductance by increasing the leaf-to-air vapour pressure deficit. CONCLUSIONS The results indicate that leaf stomatal conductance is important for the photosynthetic overcompensation effect in different tree species. The photosynthetic overcompensation effect under nocturnal warming may be a transient occurrence rather than a persistent mechanism in subtropical forest ecosystems.
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Affiliation(s)
- Ying Du
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Ruiling Lu
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Huanfa Sun
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Erqian Cui
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Liming Yan
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
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5
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Lu R, Du Y, Sun H, Xu X, Yan L, Xia J. Nocturnal warming accelerates drought-induced seedling mortality of two evergreen tree species. TREE PHYSIOLOGY 2022; 42:1164-1176. [PMID: 34919711 DOI: 10.1093/treephys/tpab168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Extreme drought is one of the key climatic drivers of tree mortality on a global scale. However, it remains unclear whether the drought-induced tree mortality will increase under nocturnal climate warming. Here we exposed seedlings of two wide-ranging subtropical tree species, Castanopsis sclerophylla and Schima superba, with contrasting stomatal regulation strategies to prolonged drought under ambient and elevated night-time temperature by 2 °C. We quantified the seedling survival time since drought treatment by measuring multiple leaf traits such as leaf gas exchange, predawn leaf water potential and water-use efficiency. The results showed that all seedlings in the ambient temperature died within 180 days and 167 days of drought for C. sclerophylla and S. superba, respectively. Night warming significantly shortened the survival time of C. sclerophylla, by 31 days, and S. superba by 28 days, under the drought treatment. A survival analysis further showed that seedlings under night warming suffered a 1.6 times greater mortality risk than those under ambient temperature. Further analyses revealed that night warming suppressed net leaf carbon gain in both species by increasing the nocturnal respiratory rate of S. superba across the first 120 days of drought and decreasing the photosynthetic rate of both species generally after 46 days of drought. These effects on net carbon gain were more pronounced in S. superba than C. sclerophylla. After 60 days of drought, night warming decreased the predawn leaf water potential and leaf water-use efficiency of C. sclerophylla but not S. superba. These contrasting responses are partially due to variations in stomatal control between the two species. These findings suggest that stomatal traits can regulate the response of leaf gas exchange and plant water-use to nocturnal warming during drought. This study indicates that nocturnal warming can accelerate tree mortality during drought. Night warming accelerates the mortality of two subtropical seedlings under drought.Night warming differently affects the drought response of leaf gas exchange and plant water-use between the two species due to species-specific stomatal morphological traits.Carbon metabolism changes and hydraulic damage play differential roles in driving night-warming impacts on the drought-induced mortality between the two species.
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Affiliation(s)
- Ruiling Lu
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Ying Du
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Huanfa Sun
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Xiaoni Xu
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Liming Yan
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Jianyang Xia
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
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McAusland L, Smith KE, Williams A, Molero G, Murchie EH. Nocturnal stomatal conductance in wheat is growth-stage specific and shows genotypic variation. THE NEW PHYTOLOGIST 2021; 232:162-175. [PMID: 34143507 DOI: 10.1111/nph.17563] [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: 03/03/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
Nocturnal stomatal conductance (gsn ) represents a significant source of water loss, with implications for metabolism, thermal regulation and water-use efficiency. With increasing nocturnal temperatures due to climate change, it is vital to identify and understand variation in the magnitude and responses of gsn in major crops. We assessed interspecific variation in gsn and daytime stomatal conductance (gs ) in a wild relative and modern spring wheat genotype. To investigate intraspecific variation, we grew six modern wheat genotypes and two landraces under well watered, simulated field conditions. For the diurnal data, higher gsn in the wild relative was associated with significantly lower nocturnal respiration and higher daytime CO2 assimilation while both species exhibited declines in gsn post-dusk and pre-dawn. Lifetime gsn achieved rates of 5.7-18.9% of gs . Magnitude of gsn was genotype specific 'and positively correlated with gs . gsn and gs were significantly higher on the adaxial surface. No relationship was determined between harvest characteristics, stomatal morphology and gsn , while cuticular conductance was genotype specific. Finally, for the majority of genotypes, gsn declined with age. Here we present the discovery that variation in gsn occurs across developmental, morphological and temporal scales in nonstressed wheat, presenting opportunities for exploiting intrinsic variation under heat or water stressed conditions.
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Affiliation(s)
- Lorna McAusland
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Kellie E Smith
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Alexander Williams
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Gemma Molero
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera Mexico, El Batan, Texcoco, CP 56237, Mexico
| | - Erik H Murchie
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
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Wang Y, Anderegg WRL, Venturas MD, Trugman AT, Yu K, Frankenberg C. Optimization theory explains nighttime stomatal responses. THE NEW PHYTOLOGIST 2021; 230:1550-1561. [PMID: 33576001 DOI: 10.1111/nph.17267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Nocturnal transpiration is widely observed across species and biomes, and may significantly impact global water, carbon, and energy budgets. However, it remains elusive why plants lose water at night and how to model it at large scales. We hypothesized that plants optimize nighttime leaf diffusive conductance (gwn ) to balance potential daytime photosynthetic benefits and nocturnal transpiration benefits. We quantified nighttime benefits from respiratory reductions due to evaporative leaf cooling. We described nighttime costs in terms of a reduced carbon gain during the day because of water use at night. We measured nighttime stomatal responses and tested our model with water birch (Betula occidentalis) saplings grown in a glasshouse. The gwn of water birch decreased with drier soil, higher atmospheric CO2 , wetter air, lower leaf temperature, and lower leaf respiration rate. Our model predicted all these responses correctly, except for the response of gwn to air humidity. Our results also suggested that the slow decrease in gwn after sunset could be associated with decreasing leaf respiration. The optimality-based nocturnal transpiration model smoothly integrates with daytime stomatal optimization approaches, and thus has the potential to quantitatively predict nocturnal transpiration across space and time.
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Affiliation(s)
- Yujie Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - William R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Anna T Trugman
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kailiang Yu
- Le Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCECEA/CNRS/UVSQ Saclay, Gif-sur-Yvette, 91191, France
| | - Christian Frankenberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
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8
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Hafner BD, Hesse BD, Grams TEE. Friendly neighbours: Hydraulic redistribution accounts for one quarter of water used by neighbouring drought stressed tree saplings. PLANT, CELL & ENVIRONMENT 2021; 44:1243-1256. [PMID: 32683699 DOI: 10.1111/pce.13852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
Hydraulic redistribution (HR) can buffer drought events of tree individuals, however, its relevance for neighbouring trees remains unclear. Here, we quantified HR to neighbouring trees in single- and mixed-species combinations. We hypothesized that uptake of HR water positively correlates with root length, number of root tips and root xylem hydraulic conductivity and that neighbours in single-species combinations receive more HR water than in phylogenetic distant mixed-species combinations. In a split-root experiment, a sapling with its roots split between two pots redistributed deuterium labelled water from a moist to a dry pot with an additional tree each. We quantified HR water received by the sapling in the dry pot for six temperate tree species. After 7 days, one quarter of the water in roots (2.1 ± 0.4 ml), stems (0.8 ± 0.2 ml) and transpiration (1.0 ± 0.3 ml) of the drought stressed sapling originated from HR. The amount of HR water transpired by the receiving plant stayed constant throughout the experiment. While the uptake of HR water increased with root length, species identity did not affect HR as saplings of Picea abies ((L.) Karst) and Fagus sylvatica (L.) in single- and mixed-species combinations received the same amount of HR water.
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Affiliation(s)
- Benjamin D Hafner
- Ecophysiology of Plants, Technical University of Munich, Freising, Germany
- School of Integrated Plant Science, Cornell University, New York, New York, USA
| | - Benjamin D Hesse
- Ecophysiology of Plants, Technical University of Munich, Freising, Germany
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technical University of Munich, Freising, Germany
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Hafner BD, Hesse BD, Bauerle TL, Grams TEE. Water potential gradient, root conduit size and root xylem hydraulic conductivity determine the extent of hydraulic redistribution in temperate trees. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13508] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Benjamin D. Hafner
- Ecophysiology of Plants Technical University of Munich Freising Germany
- School of Integrative Plant Science Cornell University Ithaca NY USA
| | - Benjamin D. Hesse
- Ecophysiology of Plants Technical University of Munich Freising Germany
| | - Taryn L. Bauerle
- School of Integrative Plant Science Cornell University Ithaca NY USA
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10
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Sadok W, Schoppach R. Potential involvement of root auxins in drought tolerance by modulating nocturnal and daytime water use in wheat. ANNALS OF BOTANY 2019; 124:969-978. [PMID: 30918962 PMCID: PMC6881217 DOI: 10.1093/aob/mcz023] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 02/06/2019] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS The ability of wheat genotypes to save water by reducing their transpiration rate (TR) at times of the day with high vapour pressure deficit (VPD) has been linked to increasing yields in terminal drought environments. Further, recent evidence shows that reducing nocturnal transpiration (TRN) could amplify water saving. Previous research indicates that such traits involve a root-based hydraulic limitation, but the contribution of hormones, particularly auxin and abscisic acid (ABA), has not been explored to explain the shoot-root link. In this investigation, based on physiological, genetic and molecular evidence gathered on a mapping population, we hypothesized that root auxin accumulation regulates whole-plant water use during both times of the day. METHODS Eight double-haploid lines were selected from a mapping population descending from two parents with contrasting water-saving strategies and root hydraulic properties. These spanned the entire range of slopes of TR responses to VPD and TRN encountered in the population. We examined daytime/night-time auxin and ABA contents in the roots and the leaves in relation to hydraulic traits that included whole-plant TR, plant hydraulic conductance (KPlant), slopes of TR responses to VPD and leaf-level anatomical traits. KEY RESULTS Root auxin levels were consistently genotype-dependent in this group irrespective of experiments and times of the day. Daytime root auxin concentrations were found to be strongly and negatively correlated with daytime TR, KPlant and the slope of TR response to VPD. Night-time root auxin levels significantly and negatively correlated with TRN. In addition, daytime and night-time leaf auxin and ABA concentrations did not correlate with any of the examined traits. CONCLUSIONS The above results indicate that accumulation of auxin in the root system reduces daytime and night-time water use and modulates plant hydraulic properties to enable the expression of water-saving traits that have been associated with enhanced yields under drought.
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Affiliation(s)
- Walid Sadok
- Department of Agronomy and Plant Genetics, Upper Buford Circle, University of Minnesota, St. Paul, MN, USA
| | - Rémy Schoppach
- Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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11
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Fricke W. Night-Time Transpiration - Favouring Growth? TRENDS IN PLANT SCIENCE 2019; 24:311-317. [PMID: 30770287 DOI: 10.1016/j.tplants.2019.01.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 05/16/2023]
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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12
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Brito C, Dinis LT, Ferreira H, Moutinho-Pereira J, Correia C. The role of nighttime water balance on Olea europaea plants subjected to contrasting water regimes. JOURNAL OF PLANT PHYSIOLOGY 2018; 226:56-63. [PMID: 29702427 DOI: 10.1016/j.jplph.2018.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/13/2018] [Accepted: 04/08/2018] [Indexed: 05/16/2023]
Abstract
The climate change scenarios besides foreseeing a severe drought imposition also emphasize the temperature rising in the Mediterranean region, with special prominence at nighttime. Despite the high olive tree tolerance to severe environmental conditions, stomatal nighttime water loss can change plant water relations, and the related consequences and opportunities, especially under water scarcity, must be clarified. A set of 3-year-old potted olive trees were subjected to three cycles of drought, imposed by withholding irrigation, while another group were continuously irrigated. At the end of the latter and more severe drought cycle, daytime gas exchange parameters, water status and membrane integrity was negatively affected by drought imposition. Moreover, the nighttime transpiration rate was far above cuticular water loss, suggesting sustained stomatal aperture during nighttime, leading to substantial water losses, which was higher under drought in the first hours of darkness. The higher nighttime stomatal conductance of droughted plants were related with higher starch concentration in their leaves, a thicker trichome layer and a lower intercellular CO2 concentration, in a closely association with an inferior nighttime respiration. Still, whole-plant transpiration on droughted plants were much lower than leaf transpiration-based estimates, which is interpreted as compensation by water inputs due to dew deposition on leaves. Although unexpected, the increased of stomatal conductance in the first hours of the night, until a certain level of water deficit intensity, could be linked with potential benefits to the plants.
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Affiliation(s)
- Cátia Brito
- CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Apt. 1013, 5000-801, Vila Real, Portugal
| | - Lia-Tânia Dinis
- CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Apt. 1013, 5000-801, Vila Real, Portugal
| | - Helena Ferreira
- CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Apt. 1013, 5000-801, Vila Real, Portugal
| | - José Moutinho-Pereira
- CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Apt. 1013, 5000-801, Vila Real, Portugal
| | - Carlos Correia
- CITAB - Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Apt. 1013, 5000-801, Vila Real, Portugal.
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Yu T, Feng Q, Si J, Mitchell PJ, Forster MA, Zhang X, Zhao C. Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement. Ecol Evol 2018; 8:2607-2616. [PMID: 29531680 PMCID: PMC5838069 DOI: 10.1002/ece3.3875] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/20/2017] [Accepted: 01/02/2018] [Indexed: 11/15/2022] Open
Abstract
During the night, plant water loss can occur either through the roots, as hydraulic redistribution (HR), or through the leaves via the stoma, as nocturnal transpiration (En), which was methodologically difficult to separate from stem refilling (Re). While HR and En have been reported across a range of species, ecosystem, and climate zone, there is little understanding on the interactions between En and/or Re and HR. As water movement at night occurs via gradients of water potential, it is expected that during periods of high atmospheric vapor pressure deficit (VPD), water loss via En will override water loss via HR. To test this hypothesis, sap flow in stems and roots of Populus euphratica Oliv. trees, growing in a riparian zone in a hyperarid climate, was measured once in a year. Nocturnal stem sap flow was separated into En and Re using the "forecasted refilling" method. Substantial nocturnal sap flow (38% of 24-hr flux on average) was observed and positively correlated with VPD; however, the strength of the correlation was lower (R2 = .55) than diurnal sap flow (Ed) (R2 = .72), suggesting that nocturnal stem sap flow was attributed to both water loss through the canopy and replenishment of water in stem tissues. Partitioning of nocturnal sap flow shows that Re constituted approximately 80%, and En ~20%, of nocturnal sap flow. The amount of root sap flow attributed to redistribution was negatively related to Ed (R2 = .69) and the amount of acropetally sap flow in stems, Re (R2 = .41) and En (R2 = .14). It was suggested that the magnitude of HR is more strongly depressed by Re that was recharge to the water loss via Ed than by En. It was consistent with whole-tree water balance theory, that the nighttime upward sap flow to xylem, stem refilling and transpiration, may depress hydraulic redistribution of roots.
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Affiliation(s)
- Tengfei Yu
- Alxa Desert Ecohydrology Experimental Research StationNorthwest Institute of Eco‐Environment and ResourcesChinese Academy of SciencesLanzhouChina
- Key Laboratory of Ecohydrology of Inland River BasinChinese Academy of SciencesLanzhouChina
| | - Qi Feng
- Alxa Desert Ecohydrology Experimental Research StationNorthwest Institute of Eco‐Environment and ResourcesChinese Academy of SciencesLanzhouChina
- Key Laboratory of Ecohydrology of Inland River BasinChinese Academy of SciencesLanzhouChina
| | - Jianhua Si
- Alxa Desert Ecohydrology Experimental Research StationNorthwest Institute of Eco‐Environment and ResourcesChinese Academy of SciencesLanzhouChina
- Key Laboratory of Ecohydrology of Inland River BasinChinese Academy of SciencesLanzhouChina
| | | | - Michael A. Forster
- Edaphic Scientific Pty LtdPort MacquarieNSWAustralia
- School of Agriculture and Food ScienceThe University of QueenslandBrisbaneAustralia
| | - Xiaoyou Zhang
- Alxa Desert Ecohydrology Experimental Research StationNorthwest Institute of Eco‐Environment and ResourcesChinese Academy of SciencesLanzhouChina
- Key Laboratory of Ecohydrology of Inland River BasinChinese Academy of SciencesLanzhouChina
| | - Chunyan Zhao
- Alxa Desert Ecohydrology Experimental Research StationNorthwest Institute of Eco‐Environment and ResourcesChinese Academy of SciencesLanzhouChina
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14
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Bazihizina N, Veneklaas EJ, Barrett-Lennard EG, Colmer TD. Hydraulic redistribution: limitations for plants in saline soils. PLANT, CELL & ENVIRONMENT 2017; 40:2437-2446. [PMID: 28707352 DOI: 10.1111/pce.13020] [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: 01/10/2017] [Accepted: 06/25/2017] [Indexed: 06/07/2023]
Abstract
Hydraulic redistribution (HR), the movement of water from wet to dry patches in the soil via roots, occurs in different ecosystems and plant species. By extension of the principle that HR is driven by gradients in soil water potential, HR has been proposed to occur for plants in saline soils. Despite the inherent spatial patchiness and salinity gradients in these soils, the lack of direct evidence of HR in response to osmotic gradients prompted us to ask the question: are there physical or physiological constraints to HR for plants in saline environments? We propose that build-up of ions in the root xylem sap and in the leaf apoplast, with the latter resulting in a large predawn disequilibrium of water potential in shoots compared with roots and soil, would both impede HR. We present a conceptual model that illustrates how processes in root systems in heterogeneous salinity with water potential gradients, even if equal to those in non-saline soils, will experience a dampened magnitude of water potential gradients in the soil-plant continuum, minimizing or preventing HR. Finally, we provide an outlook for understanding the relevance of HR for plants in saline environments by addressing key research questions on plant salinity tolerance.
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Affiliation(s)
- Nadia Bazihizina
- Department of Agrifood Production and Environmental Sciences, Università degli Studi di Firenze, Viale delle Idee 30, 50019 Sesto Fiorentino, Florence, Italy
- School of Land and Food, University of Tasmania, Hobart, TAS, 7001, Australia
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Erik J Veneklaas
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
- School of Biological Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
- The UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Edward G Barrett-Lennard
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
- Department of Agriculture and Food, Western Australia, 3 Baron-Hay Court, South, Perth, Western Australia, 6151, Australia
- School of Veterinary and Life Science, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia
| | - Timothy D Colmer
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
- The UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
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15
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Hafner BD, Tomasella M, Häberle KH, Goebel M, Matyssek R, Grams TEE. Hydraulic redistribution under moderate drought among English oak, European beech and Norway spruce determined by deuterium isotope labeling in a split-root experiment. TREE PHYSIOLOGY 2017; 37:950-960. [PMID: 28541559 DOI: 10.1093/treephys/tpx050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 05/02/2017] [Indexed: 06/07/2023]
Abstract
Hydraulic redistribution (HR) of soil water through plant roots is a crucial phenomenon improving the water balance of plants and ecosystems. It is mostly described under severe drought, and not yet studied under moderate drought. We tested the potential of HR under moderate drought, hypothesizing that (H1) tree species redistribute soil water in their roots even under moderate drought and that (H2) neighboring plants are supported with water provided by redistributing plants. Trees were planted in split-root systems with one individual (i.e., split-root plant, SRP) having its roots divided between two pots with one additional tree each. Species were 2- to 4-year-old English oak (Quercus robur L.), European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst). A gradient in soil water potential (ψsoil) was established between the two pots (-0.55 ± 0.02 MPa and -0.29 ± 0.03 MPa), and HR was observed by labeling with deuterium-enriched water. Irrespective of species identity, 93% of the SRPs redistributed deuterium enriched water from the moist to the drier side, supporting H1. Eighty-eight percent of the plants in the drier pots were deuterium enriched in their roots, with 61 ± 6% of the root water originating from SRP roots. Differences in HR among species were related to their root anatomy with diffuse-porous xylem structure in both beech and-opposing the stem structure-oak roots. In spruce, we found exclusively tracheids. We conclude that water can be redistributed within roots of different tree species along a moderate ψsoil gradient, accentuating HR as an important water source for drought-stressed plants, with potential implications for ecohydrological and plant physiological sciences. It remains to be shown to what extent HR occurs under field conditions in Central Europe.
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Affiliation(s)
- Benjamin D Hafner
- Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Martina Tomasella
- Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Karl-Heinz Häberle
- Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Marc Goebel
- Department of Natural Resources, Cornell University, Ithaca, NY 14853, USA
| | - Rainer Matyssek
- Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
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16
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Eller F, Jensen K, Reisdorff C. Nighttime stomatal conductance differs with nutrient availability in two temperate floodplain tree species. TREE PHYSIOLOGY 2017; 37:428-440. [PMID: 27974652 DOI: 10.1093/treephys/tpw113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
Nighttime water flow varies between plant species and is a phenomenon for which the magnitude, purpose and consequences are widely discussed. A potential benefit of nighttime stomata opening may be increased nutrient availability during the night since transpiration affects the mass flow of soil water towards plant roots. We investigated how nitrogen (N) and phosphorus (P) fertilization, and short-term drought affected stomatal conductance of Fraxinus excelsior L. and Ulmus laevis Pallas during the day (gs) and night (gn), and how these factors affected growth for a period of 18 weeks. Both species were found to open their stomata during the night, and gn responded to nutrients and water in a different manner than gs. Under N-deficiency, F. excelsior had higher gn, especially when P was sufficient, and lower pre-dawn leaf water potential (Ψpd), supporting our assumption that nutrient limitation leads to increases in nighttime water uptake. Under P-deficiency, F. excelsior had higher relative root production and, thus, adjusted its biomass allocation under P shortage, while sufficient N but not P contributed to overall higher biomasses. In contrast, U. laevis had higher gn and lower root:shoot ratio under high nutrient (especially N) availability, whereas both sufficient N and P produced higher biomasses. Compared with well-watered trees, the drought treatment did not affect any growth parameter but it resulted in lower gn, minimum stomatal conductance and Ψpd of F. excelsior. For U. laevis, only gs during July was lower when drought-treated. In summary, the responses of gs and gn to nutrients and drought depended on the species and its nutrient uptake strategy, and also the timing of measurement during the growing season. Eutrophication of floodplain forests dominated by F. excelsior and U. laevis may, therefore, considerably change nighttime transpiration rates, leading to ecosystem-level changes in plant-water dynamics. Such changes may have more severe consequences in the future as a higher frequency of drought events is predicted under climate change.
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Affiliation(s)
- Franziska Eller
- Hamburg University, Biocenter Klein Flottbek, Ohnhorststr. 18, 22609 Hamburg, Germany
- Aarhus University, Department of Bioscience, Ole Worms Alle 1, 8000 Aarhus C, Denmark
| | - Kai Jensen
- Hamburg University, Biocenter Klein Flottbek, Ohnhorststr. 18, 22609 Hamburg, Germany
| | - Christoph Reisdorff
- Hamburg University, Biocenter Klein Flottbek, Ohnhorststr. 18, 22609 Hamburg, Germany
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17
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An assessment of diurnal water uptake in a mesic prairie: evidence for hydraulic lift? Oecologia 2017; 183:963-975. [PMID: 28154965 DOI: 10.1007/s00442-017-3827-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 01/22/2017] [Indexed: 01/05/2023]
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18
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Huang CW, Domec JC, Ward EJ, Duman T, Manoli G, Parolari AJ, Katul GG. The effect of plant water storage on water fluxes within the coupled soil-plant system. THE NEW PHYTOLOGIST 2017; 213:1093-1106. [PMID: 27870064 DOI: 10.1111/nph.14273] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/10/2016] [Indexed: 05/14/2023]
Abstract
In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil-plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. The model numerically resolves soil-plant hydrodynamics by coupling them to leaf-level gas exchange and soil-root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (Fe,night) on hydraulic redistribution (HR) in the soil. The model results suggest that daytime PWS usage and Fe,night generate a residual water potential gradient (Δψp,night) along the plant vascular system overnight. This Δψp,night represents a non-negligible competing sink strength that diminishes the significance of HR. Considering the co-occurrence of PWS usage and HR during a single extended dry-down, a wide range of plant attributes and environmental/soil conditions selected to enhance or suppress plant drought resilience is discussed. When compared with HR, model calculations suggest that increased root water influx into plant conducting-tissues overnight maintains a more favorable water status at the leaf, thereby delaying the onset of drought stress.
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Affiliation(s)
- Cheng-Wei Huang
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Jean-Christophe Domec
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Bordeaux Sciences Agro, UMR 1391 INRA-ISPA, 33175, Gradignan Cedex, France
| | - Eric J Ward
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Tomer Duman
- Department of Biological Sciences, Rutgers University, Newark, NJ, 07102, USA
| | - Gabriele Manoli
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Anthony J Parolari
- Department of Civil, Construction, and Environmental Engineering, Marquette University, Milwaukee, WI, 53233, USA
| | - Gabriel G Katul
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA
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19
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Paoletti E, Materassi A, Fasano G, Hoshika Y, Carriero G, Silaghi D, Badea O. A new-generation 3D ozone FACE (Free Air Controlled Exposure). THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:1407-1414. [PMID: 27717567 DOI: 10.1016/j.scitotenv.2016.09.217] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 06/06/2023]
Abstract
To artificially simulate the impacts of ground-level ozone (O3) on vegetation, ozone FACE (Free Air Controlled Exposure) systems are increasingly recommended. We describe here a new-generation, three-dimensional ozone FACE, with O3 diffusion through laser-generated micro-holes, pre-mixing of air and O3, O3 generator with integral oxygen generator, continuous (day/night) exposure and full replication. Based on three O3 levels and assumptions on the pre-industrial O3 levels, we describe principles to calculate relative yield/biomass and estimate impacts even at lower-than-ambient O3 levels. The case study is called FO3X, and is at present the only ozone FACE in Mediterranean climate and one of the very few ozone FACEs investigating more than one stressor at a time. The results presented here will give further impulse to the research on O3 impacts on vegetation all over the world.
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Affiliation(s)
- Elena Paoletti
- IPSP-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
| | | | | | - Yasutomo Hoshika
- IPSP-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | | | | | - Ovidiu Badea
- INCDS, B-dul Eroilor 128, Voluntari, Ilfov, Romania
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20
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Méndez-Alonzo R, López-Portillo J, Moctezuma C, Bartlett MK, Sack L. Osmotic and hydraulic adjustment of mangrove saplings to extreme salinity. TREE PHYSIOLOGY 2016; 36:1562-1572. [PMID: 27591440 DOI: 10.1093/treephys/tpw073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 05/16/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
Salinity tolerance in plant species varies widely due to adaptation and acclimation processes at the cellular and whole-plant scales. In mangroves, extreme substrate salinity induces hydraulic failure and ion excess toxicity and reduces growth and survival, thus suggesting a potentially critical role for physiological acclimation to salinity. We tested the hypothesis that osmotic adjustment, a key type of plasticity that mitigates salinity shock, would take place in coordination with declines in whole-plant hydraulic conductance in a common garden experiment using saplings of three mangrove species with different salinity tolerances (Avicennia germinans L., Rhizophora mangle L. and Laguncularia racemosa (L.) C.F. Gaertn., ordered from higher to lower salinity tolerance). For each mangrove species, four salinity treatments (1, 10, 30 and 50 practical salinity units) were established and the time trajectories were determined for leaf osmotic potential (Ψs), stomatal conductance (gs), whole-plant hydraulic conductance (Kplant) and predawn disequilibrium between xylem and substrate water potentials (Ψpdd). We expected that, for all three species, salinity increments would result in coordinated declines in Ψs, gs and Kplant, and that the Ψpdd would increase with substrate salinity and time of exposure. In concordance with our predictions, reductions in substrate water potential promoted a coordinated decline in Ψs, gs and Kplant, whereas the Ψpdd increased substantially during the first 4 days but dissipated after 7 days, indicating a time lag for equilibration after a change in substratum salinity. Our results show that mangroves confront and partially ameliorate acute salinity stress via simultaneous reductions in Ψs, gs and Kplant, thus developing synergistic physiological responses at the cell and whole-plant scales.
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Affiliation(s)
- Rodrigo Méndez-Alonzo
- Departamento de Biología de la Conservación, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas, Ensenada, B.C., 22860, México
| | - Jorge López-Portillo
- Red de Ecología Funcional, Instituto de Ecología, A.C., Xalapa, Veracruz, 91070, México
| | - Coral Moctezuma
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, 58190 , México
| | - Megan K Bartlett
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA 90095-1606, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA 90095-1606, USA
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21
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22
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McNellis B, Howard AR. Phylogenetic and ecological patterns in nighttime transpiration among five members of the genus Rubus co-occurring in western Oregon. Ecol Evol 2015; 5:3557-69. [PMID: 26380686 PMCID: PMC4567861 DOI: 10.1002/ece3.1608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 05/19/2015] [Accepted: 05/27/2015] [Indexed: 11/22/2022] Open
Abstract
Nighttime transpiration is a substantial portion of ecosystem water budgets, but few studies compare water use of closely related co-occurring species in a phylogenetic context. Nighttime transpiration can range up to 69% of daytime rates and vary between species, ecosystem, and functional type. We examined leaf-level daytime and nighttime gas exchange of five species of the genus Rubus co-occurring in the Pacific Northwest of western North America in a greenhouse common garden. Contrary to expectations, nighttime transpiration was not correlated to daytime water use. Nighttime transpiration showed pronounced phylogenetic signals, but the proportion of variation explained by different phylogenetic groupings varied across datasets. Leaf osmotic water potential, water potential at turgor loss point, stomatal size, and specific leaf area were correlated with phylogeny but did not readily explain variation in nighttime transpiration. Patterns in interspecific variation as well as a disconnect between rates of daytime and nighttime transpiration suggest that variation in nighttime water use may be at least partly driven by genetic factors independent of those that control daytime water use. Future work with co-occurring congeneric systems is needed to establish the generality of these results and may help determine the mechanism driving interspecific variation in nighttime water use.
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Affiliation(s)
- Brandon McNellis
- Department of Biology, Western Oregon UniversityMonmouth, Oregon, 97361
- Department of Biology, University of California-RiversideRiverside, California, 92507
| | - Ava R Howard
- Department of Biology, Western Oregon UniversityMonmouth, Oregon, 97361
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23
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Borland AM, Wullschleger SD, Weston DJ, Hartwell J, Tuskan GA, Yang X, Cushman JC. Climate-resilient agroforestry: physiological responses to climate change and engineering of crassulacean acid metabolism (CAM) as a mitigation strategy. PLANT, CELL & ENVIRONMENT 2015; 38:1833-49. [PMID: 25366937 DOI: 10.1111/pce.12479] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 10/16/2014] [Accepted: 10/27/2014] [Indexed: 05/20/2023]
Abstract
Global climate change threatens the sustainability of agriculture and agroforestry worldwide through increased heat, drought, surface evaporation and associated soil drying. Exposure of crops and forests to warmer and drier environments will increase leaf:air water vapour-pressure deficits (VPD), and will result in increased drought susceptibility and reduced productivity, not only in arid regions but also in tropical regions with seasonal dry periods. Fast-growing, short-rotation forestry (SRF) bioenergy crops such as poplar (Populus spp.) and willow (Salix spp.) are particularly susceptible to hydraulic failure following drought stress due to their isohydric nature and relatively high stomatal conductance. One approach to sustaining plant productivity is to improve water-use efficiency (WUE) by engineering crassulacean acid metabolism (CAM) into C3 crops. CAM improves WUE by shifting stomatal opening and primary CO2 uptake and fixation to the night-time when leaf:air VPD is low. CAM members of the tree genus Clusia exemplify the compatibility of CAM performance within tree species and highlight CAM as a mechanism to conserve water and maintain carbon uptake during drought conditions. The introduction of bioengineered CAM into SRF bioenergy trees is a potentially viable path to sustaining agroforestry production systems in the face of a globally changing climate.
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Affiliation(s)
- Anne M Borland
- School of Biology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
- Biosciences Division, Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6407, USA
| | - Stan D Wullschleger
- Climate Change Science Institute, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6301, USA
| | - David J Weston
- Biosciences Division, Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6407, USA
| | - James Hartwell
- Department of Plant Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Gerald A Tuskan
- Biosciences Division, Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6407, USA
| | - Xiaohan Yang
- Biosciences Division, Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6407, USA
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, MS330, University of Nevada, Reno, NV, 89557-0330, USA
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24
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Hatier JHB, Faville MJ, Hickey MJ, Koolaard JP, Schmidt J, Carey BL, Jones CS. Plant vigour at establishment and following defoliation are both associated with responses to drought in perennial ryegrass (Lolium perenne L.). JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:5823-34. [PMID: 25104762 PMCID: PMC4203121 DOI: 10.1093/jxb/eru318] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Periodic drought events present a significant and, with climate change, increasing constraint on temperate forage plants' production. Consequently, improving plants' adaptive response to abiotic stress is a key goal to ensure agricultural productivity in these regions. In this study we developed a new methodology, using both area-based comparison and soil water content measurements of individual non-irrigated and irrigated clones, to assess performance of perennial ryegrass (Lolium perenne L.) genotypes subjected to moisture stress in a simulated competitive environment. We applied this method to the evaluation of a full-sibling population from a pair cross between genotypes from a New Zealand cultivar and a Moroccan ecotype. Our hypothesis was that: (i) both leaf lamina regrowth after defoliation (LR) and plant vigour affect plant performance during drought and rehydration; and (ii) quantitative trait loci (QTLs) associated with plant performance under moisture stress could be identified. Differences amongst genotypes in dry matter (DM) production, early vigour at establishment, leaf elongation rate and LR were measured. LR explained most of the variation in DM production during exposure to moisture deficit and rehydration followed by plant vigour, indicated by initial DM production in both treatments and subsequent measures of DM production of irrigated clones. We identified two main QTL regions associated with DM production and LR, both during drought exposure and rehydration. Further research focused on these regions should improve our understanding of the genetic control of drought response in this forage crop and potentially other grass species with significant synteny, and support improvement in performance through molecular breeding approaches.
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Affiliation(s)
- Jean-Hugues B Hatier
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Marty J Faville
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Michael J Hickey
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - John P Koolaard
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Jana Schmidt
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Brandi-Lee Carey
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Chris S Jones
- AgResearch Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
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25
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Zeppel MJB, Lewis JD, Phillips NG, Tissue DT. Consequences of nocturnal water loss: a synthesis of regulating factors and implications for capacitance, embolism and use in models. TREE PHYSIOLOGY 2014; 34:1047-55. [PMID: 25413023 DOI: 10.1093/treephys/tpu089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Total daily water use is a key factor influencing the growth of many terrestrial plants, and reflects both day-time and nocturnal water fluxes. However, while nocturnal sap flow (En) and stomatal conductance (gs,n) have been reported across a range of species, ecosystems and microclimatic conditions, the regulation of these fluxes remains poorly understood. Here, we present a framework describing the role of abiotic and biotic factors in regulating En and gs,n highlighting recent developments in this field. Across ecosystems, En and gs,n generally increased with increasing soil water content and vapor pressure deficit, but the interactive effects of these factors and the potential roles of wind speed and other abiotic factors remain unclear. On average, gs,n and En are higher in broad-leaved compared with needle-leaved plants, in C3 compared with C4 plants, and in tropical compared with temperate species. We discuss the impacts of leaf age, elevated [CO2] and refilling of capacitance on night-time water loss, and how nocturnal gs,n may be included in vegetation models. Younger leaves may have higher gs,n than older leaves. Embolism refilling and recharge of capacitance may affect sap flow such that total plant water loss at night may be less than estimated solely from En measurements. Our estimates of gs,n for typical plant functional types, based on the published literature, suggest that nocturnal water loss may be a significant fraction (10-25%) of total daily water loss. Counter-intuitively, elevated [CO2] may increase nocturnal water loss. Assumptions in process-based ecophysiological models and dynamic global vegetation models that gs is zero when solar radiation is zero are likely to be incorrect. Consequently, failure to adequately consider nocturnal water loss may lead to substantial under-estimation of total plant water use and inaccurate estimation of ecosystem level water balance.
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Affiliation(s)
- M J B Zeppel
- Macquarie University, Sydney, NSW 2109, Australia
| | - J D Lewis
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia Louis Calder Center-Biological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY 10504, USA
| | - N G Phillips
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia Department of Earth and Environment, Boston University, Boston, MA 02215, USA
| | - D T Tissue
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia
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26
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Schoppach R, Claverie E, Sadok W. Genotype-dependent influence of night-time vapour pressure deficit on night-time transpiration and daytime gas exchange in wheat. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:963-971. [PMID: 32481049 DOI: 10.1071/fp14067] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/07/2014] [Indexed: 06/11/2023]
Abstract
In crop plants, accumulating evidence indicates non-marginal night-time transpiration (TRNight) that is responsive to environmental conditions, especially in semiarid areas. However, the agronomical advantages resulting from such phenomenon remain obscure. Recently, drought-tolerance strategies directly stemming from daytime TR (TRDay) responses to daytime vapour pressure deficit VPD (VPDDay) were identified in wheat (Triticum spp.), but the existence of similar strategies resulting from TRNight response to night-time VPD (VPDNight) remains to be investigated, especially that preliminary evidence on this species indicates that TRNight might be responsive to VPDNight. Our study aims at investigating such strategies among a group of diverse lines including drought-tolerant genotypes. The study revealed that: (i) TRNight can be as high as 55% that of the maximal TRDay; (ii) VPDNight is the major driver of TRNight in a genotype-dependent fashion and has an impact on following daytime gas exchange; and (iii) a strong correlation exists between TR sensitivities to VPD under night-time and daytime conditions, revealing that tolerance strategies such as conservative water use do also exist under night-time environments. Overall, this report opens the way to further phenotyping and modelling work aiming at assessing the potential of using TRNight as a trait in breeding new drought-tolerant germplasm.
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Affiliation(s)
- Rémy Schoppach
- Stress Agronomy Group, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Elodie Claverie
- Stress Agronomy Group, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Walid Sadok
- Stress Agronomy Group, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
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Matimati I, Verboom GA, Cramer MD. Do hydraulic redistribution and nocturnal transpiration facilitate nutrient acquisition in Aspalathus linearis? Oecologia 2014; 175:1129-42. [PMID: 24972698 DOI: 10.1007/s00442-014-2987-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 05/29/2014] [Indexed: 11/28/2022]
Abstract
The significance of soil water redistribution by roots and nocturnal transpiration for nutrient acquisition were assessed for deep-rooted 3-year-old leguminous Aspalathus linearis shrubs of the Cape Floristic Region (South Africa). We hypothesised that hydraulic redistribution and nocturnal transpiration facilitate nutrient acquisition by releasing moisture in shallow soil to enable acquisition of shallow-soil nutrients during the summer drought periods and by driving water fluxes from deep to shallow soil powering mass-flow nutrient acquisition, respectively. A. linearis was supplied with sub-surface (1-m-deep) irrigation rates of 0, 2 or 4 L day(-1 )plant(-1). Some plants were unfertilized, whilst others were surface- or deep-fertilized (1 m depth) with Na(15)NO3 and CaP/FePO4. We also supplied deuterium oxide ((2)H2O) at 1 m depth at dusk and measured its predawn redistribution to shallow soil and plant stems. Hydraulic redistribution of deep water was substantial across all treatments, accounting for 34-72 % of surface-soil predawn moisture. Fourteen days after fertilization, the surface-fertilized plants exhibited increased hydraulic redistribution and increased (15)N and P acquisition with higher rates of deep-irrigation. Deep-fertilization also increased hydraulic redistribution to surface soils, although these plants additionally accumulated (2)H2O in their stem tissue overnight, probably due to nocturnal transpiration. Plants engaged in nocturnal transpiration also increased (15)N and P acquisition from deep fertilizer sources. Thus, both nocturnal transpiration and hydraulic redistribution increased acquisition of shallow soil N and P, possibly through a combination of increased nutrient availability and mobility.
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Affiliation(s)
- Ignatious Matimati
- Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, 7701, South Africa
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28
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Neumann RB, Cardon ZG, Teshera-Levye J, Rockwell FE, Zwieniecki MA, Holbrook NM. Modelled hydraulic redistribution by sunflower (Helianthus annuus L.) matches observed data only after including night-time transpiration. PLANT, CELL & ENVIRONMENT 2014; 37:899-910. [PMID: 24118010 DOI: 10.1111/pce.12206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/05/2013] [Accepted: 09/09/2013] [Indexed: 06/02/2023]
Abstract
The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical and ecological consequences of HR depend on the amount of redistributed water, whereas the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two ecotypes of sunflower (Helianthus annuus L.) in split-pot experiments, we examined how well the widely used HR modelling formulation developed by Ryel et al. matched experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive night-time transpiration, and although over the last decade it has become more widely recognized that night-time transpiration occurs in multiple species and many ecosystems, the original Ryel et al. formulation does not include the effect of night-time transpiration on HR. We developed and added a representation of night-time transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and night-time stomatal behaviour changed, both influencing HR.
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Affiliation(s)
- Rebecca B Neumann
- Department of Civil and Environmental Engineering, University of Washington, 201 More Hall, Seattle, WA, 98195, USA; Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave, Cambridge, MA, 02138, USA
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29
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Adhikari A, White JD. Plant water use characteristics of five dominant shrub species of the Lower Rio Grande Valley, Texas, USA: implications for shrubland restoration and conservation. CONSERVATION PHYSIOLOGY 2014; 2:cou005. [PMID: 27293626 PMCID: PMC4806726 DOI: 10.1093/conphys/cou005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 01/14/2014] [Accepted: 01/20/2014] [Indexed: 05/30/2023]
Abstract
The biogeographic distribution of plant species is inherently associated with the plasticity of physiological adaptations to environmental variation. For semi-arid shrublands with a legacy of saline soils, characterization of soil water-tolerant shrub species is necessary for habitat restoration given future projection of increased drought magnitude and persistence in these ecosystems. Five dominant native shrub species commonly found in the Lower Rio Grande Valley, TX, USA, were studied, namely Acacia farnesiana, Celtis ehrenbergiana, Forestiera angustifolia, Parkinsonia aculeata and Prosopis glandulosa. To simulate drought conditions, we suspended watering of healthy, greenhouse-grown plants for 4 weeks. Effects of soil salinity were also studied by dosing plants with 10% NaCl solution with suspended watering. For soil water deficit treatment, the soil water potential of P. glandulosa was the highest (-1.20 MPa), followed by A. farnesiana (-4.69 MPa), P. aculeata (-5.39 MPa), F. angustifolia (-6.20 MPa) and C. ehrenbergiana (-10.02 MPa). For the soil salinity treatment, P. glandulosa also had the highest soil water potential value (-1.60 MPa), followed by C. ehrenbergiana (-1.70 MPa), A. farnesiana (-1.84 MPa), P. aculeata (-2.04 MPa) and F. angustifolia (-6.99 MPa). Within the species, only C. ehrenbergiana and F. angustifolia for soil water deficit treatment and A. farnesiana for the salinity treatment had significantly lower soil water potential after 4 weeks of treatment (P < 0.05). We found that soil water potential, stomatal conductance and net photosynthesis of the species significantly reduced over time for both treatments (P < 0.05). We conclude that while all species exhibited capacities to withstand current water availability, some species demonstrated limited tolerance for extreme water stress that may be important for management of future shrub diversity in Lower Rio Grande Valley.
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Affiliation(s)
- Arjun Adhikari
- The Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Joseph D. White
- The Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
- The Institute of Ecological, Earth, and Environmental Sciences, Baylor University, One Bear Place #97205, Waco, TX 76798, USA
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Neumann RB, Cardon ZG. The magnitude of hydraulic redistribution by plant roots: a review and synthesis of empirical and modeling studies. THE NEW PHYTOLOGIST 2012; 194:337-352. [PMID: 22417121 DOI: 10.1111/j.1469-8137.2012.04088.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hydraulic redistribution (HR) - the movement of water from moist to dry soil through plant roots - occurs worldwide within a range of different ecosystems and plant species. The proposed ecological and hydrologic impacts of HR include increasing dry-season transpiration and photosynthetic rates, prolonging the life span of fine roots and maintaining root-soil contact in dry soils, and moving rainwater down into deeper soil layers where it does not evaporate. In this review, we compile estimates of the magnitude of HR from ecosystems around the world, using representative empirical and modeling studies from which we could extract amounts of water redistributed by plant root systems. The reported average magnitude of HR varies by nearly two orders of magnitude across ecosystems, from 0.04 to 1.3 mm H(2)O d(-1) in the empirical literature, and from 0.1 to 3.23 mm H(2)O d(-1) in the modeling literature. Using these synthesized data, along with other published studies, we examine this variation in the magnitude of upward and downward HR, considering effects of plant, soil and ecosystem characteristics, as well as effects of methodological details (in both empirical and modeling studies) on estimates of HR. We take both ecological and hydrologic perspectives.
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Affiliation(s)
- Rebecca B Neumann
- Department of Civil and Environmental Engineering, 201 More Hall, University of Washington, Seattle, WA 98195, USA
| | - Zoe G Cardon
- The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
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Zeppel MJB, Lewis JD, Chaszar B, Smith RA, Medlyn BE, Huxman TE, Tissue DT. Nocturnal stomatal conductance responses to rising [CO2], temperature and drought. THE NEW PHYTOLOGIST 2012; 193:929-938. [PMID: 22150067 DOI: 10.1111/j.1469-8137.2011.03993.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The response of nocturnal stomatal conductance (g(s,n)) to rising atmospheric CO(2) concentration ([CO(2)]) is currently unknown, and may differ from responses of daytime stomatal conductance (g(s,d)). Because night-time water fluxes can have a significant impact on landscape water budgets, an understanding of the effects of [CO(2)] and temperature on g(s,n) is crucial for predicting water fluxes under future climates. Here, we examined the effects of [CO(2)] (280, 400 and 640 μmol mol(-1)), temperature (ambient and ambient + 4°C) and drought on g(s,n,) and g(s,d) in Eucalyptus sideroxylon saplings. g(s,n) was substantially higher than zero, averaging 34% of g(s,d). Before the onset of drought, g(s,n) increased by 85% when [CO(2)] increased from 280 to 640 μmol mol(-1), averaged across both temperature treatments. g(s,n) declined with drought, but an increase in [CO(2)] slowed this decline. Consequently, the soil water potential at which g(s,n) was zero (Ψ(0)) was significantly more negative in elevated [CO(2)] and temperature treatments. g(s,d) showed inconsistent responses to [CO(2)] and temperature. g (s,n) may be higher in future climates, potentially increasing nocturnal water loss and susceptibility to drought, but cannot be predicted easily from g(s,d). Therefore, predictive models using stomatal conductance must account for both g(s,n) and g(s,d) when estimating ecosystem water fluxes.
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Affiliation(s)
- Melanie J B Zeppel
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - James D Lewis
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia
- Louis Calder Center - Biological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY 10504, USA
| | - Brian Chaszar
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| | - Renee A Smith
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia
| | - Belinda E Medlyn
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Travis E Huxman
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
- Biosphere 2, University of Arizona, Tucson, AZ 85721, USA
| | - David T Tissue
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW 2753, Australia
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Prieto I, Armas C, Pugnaire FI. Water release through plant roots: new insights into its consequences at the plant and ecosystem level. THE NEW PHYTOLOGIST 2012; 193:830-841. [PMID: 22250761 DOI: 10.1111/j.1469-8137.2011.04039.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Hydraulic redistribution (HR) is the passive movement of water between different soil parts via plant root systems, driven by water potential gradients in the soil-plant interface. New data suggest that HR is a heterogeneous and patchy process. In this review we examine the main biophysical and environmental factors controlling HR and its main implications at the plant, community and ecosystem levels. Experimental evidence and the use of novel modelling approaches suggest that HR may have important implications at the community scale, affecting net primary productivity as well as water and vegetation dynamics. Globally, HR may influence hydrological and biogeochemical cycles and, ultimately, climate.
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Affiliation(s)
- Iván Prieto
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
| | - Cristina Armas
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
| | - Francisco I Pugnaire
- Estación Experimental de Zonas Áridas - Consejo Superior de Investigaciones Científicas (EEZA-CSIC), Carretera de Sacramento s/n, E-04120 La Cañada de San Urbano, Almería, Spain
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Pfautsch S, Keitel C, Turnbull TL, Braimbridge MJ, Wright TE, Simpson RR, O'Brien JA, Adams MA. Diurnal patterns of water use in Eucalyptus victrix indicate pronounced desiccation-rehydration cycles despite unlimited water supply. TREE PHYSIOLOGY 2011; 31:1041-1051. [PMID: 21908853 DOI: 10.1093/treephys/tpr082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Knowledge about nocturnal transpiration (E(night)) of trees is increasing and its impact on regional water and carbon balance has been recognized. Most of this knowledge has been generated in temperate or equatorial regions. Yet, little is known about E(night) and tree water use (Q) in semi-arid regions. We investigated the influence of atmospheric conditions on daytime (Q(day)) and nighttime water transport (Q(night)) of Eucalyptus victrix L.A.S. Johnson & K.D. Hill growing over shallow groundwater (not >1.5 m in depth) in semi-arid tropical Australia. We recorded Q(day) and Q(night) at different tree heights in conjunction with measurements of stomatal conductance (g(s)) and partitioned E(night) from refilling processes. Q of average-sized trees (200-400 mm diameter) was 1000-3000 l month(-1), but increased exponentially with diameter such that large trees (>500 mm diameter) used up to 8000 l month(-1). Q was remarkably stable across seasons. Water flux densities (J(s)) varied significantly at different tree heights during day and night. We show that g(s) remained significantly different from zero and E(night) was always greater than zero due to vapor pressure deficits (D) that remained >1.5 kPa at night throughout the year. Q(night) reached a maximum of 50% of Q(day) and was >0.03 mm h(-1) averaged across seasons. Refilling began during afternoon hours and continued well into the night. Q(night) eventually stabilized and closely tracked D(night). Coupling of Q(night) and D(night) was particularly strong during the wet season (R2 = 0.95). We suggest that these trees have developed the capacity to withstand a pronounced desiccation-rehydration cycle in a semi-arid environment. Such a cycle has important implications for local and regional hydrological budgets of semi-arid landscapes, as large nighttime water fluxes must be included in any accounting.
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Affiliation(s)
- Sebastian Pfautsch
- Faculty of Agriculture, Food and Natural Resources, University of Sydney, 1 Central Avenue, Eveleigh, NSW 2015, Australia.
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Zeppel MJB, Lewis JD, Medlyn B, Barton CVM, Duursma RA, Eamus D, Adams MA, Phillips N, Ellsworth DS, Forster MA, Tissue DT. Interactive effects of elevated CO2 and drought on nocturnal water fluxes in Eucalyptus saligna. TREE PHYSIOLOGY 2011; 31:932-944. [PMID: 21616926 DOI: 10.1093/treephys/tpr024] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nocturnal water flux has been observed in trees under a variety of environmental conditions and can be a significant contributor to diel canopy water flux. Elevated atmospheric CO(2) (elevated [CO(2)]) can have an important effect on day-time plant water fluxes, but it is not known whether it also affects nocturnal water fluxes. We examined the effects of elevated [CO(2)] on nocturnal water flux of field-grown Eucalyptus saligna trees using sap flux through the tree stem expressed on a sapwood area (J(s)) and leaf area (E(t)) basis. After 19 months growth under well-watered conditions, drought was imposed by withholding water for 5 months in the summer, ending with a rain event that restored soil moisture. Reductions in J(s) and E(t) were observed during the severe drought period in the dry treatment under elevated [CO(2)], but not during moderate- and post-drought periods. Elevated [CO(2)] affected night-time sap flux density which included the stem recharge period, called 'total night flux' (19:00 to 05:00, J(s,r)), but not during the post-recharge period, which primarily consisted of canopy transpiration (23:00 to 05:00, J(s,c)). Elevated [CO(2)] wet (EW) trees exhibited higher J(s,r) than ambient [CO(2)] wet trees (AW) indicating greater water flux in elevated [CO(2)] under well-watered conditions. However, under drought conditions, elevated [CO(2)] dry (ED) trees exhibited significantly lower J(s,r) than ambient [CO(2)] dry trees (AD), indicating less water flux during stem recharge under elevated [CO(2)]. J(s,c) did not differ between ambient and elevated [CO(2)]. Vapour pressure deficit (D) was clearly the major influence on night-time sap flux. D was positively correlated with J(s,r) and had its greatest impact on J(s,r) at high D in ambient [CO(2)]. Our results suggest that elevated [CO(2)] may reduce night-time water flux in E. saligna when soil water content is low and D is high. While elevated [CO(2)] affected J(s,r), it did not affect day-time water flux in wet soil, suggesting that the responses of J(s,r) to environmental factors cannot be directly inferred from day-time patterns. Changes in J(s,r) are likely to influence pre-dawn leaf water potential, and plant responses to water stress. Nocturnal fluxes are clearly important for predicting effects of climate change on forest physiology and hydrology.
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Affiliation(s)
- Melanie J B Zeppel
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
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35
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Water-use strategies of six co-existing Mediterranean woody species during a summer drought. Oecologia 2011; 166:45-57. [DOI: 10.1007/s00442-011-1922-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 01/13/2011] [Indexed: 11/26/2022]
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Hydraulic lift through transpiration suppression in shrubs from two arid ecosystems: patterns and control mechanisms. Oecologia 2010; 163:855-65. [DOI: 10.1007/s00442-010-1615-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Accepted: 03/13/2010] [Indexed: 10/19/2022]
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Donovan LA, Ludwig F, Rosenthal DM, Rieseberg LH, Dudley SA. Phenotypic selection on leaf ecophysiological traits in Helianthus. THE NEW PHYTOLOGIST 2009; 183:868-879. [PMID: 19552693 DOI: 10.1111/j.1469-8137.2009.02916.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Habitats that differ in soil resource availability are expected to differ for selection on resource-related plant traits. Here, we examined spatial and temporal variation in phenotypic selection on leaf ecophysiological traits for 10 Helianthus populations, including two species of hybrid origin, Helianthus anomalus and Helianthus deserticola, and artificial hybrids of their ancestral parents. Leaf traits assessed were leaf size, succulence, nitrogen (N) concentration and water-use efficiency (WUE). Biomass and leaf traits of artificial hybrids indicate that the actively moving dune habitat of H. anomalus was more growth limiting, with lower N availability but higher relative water availability than the stabilized dune habitat of H. deserticola. Habitats differed for direct selection on leaf N and WUE, but not size or succulence, for the artificial hybrids. However, within the H. anomalus habitat, direct selection on WUE also differed among populations. Across years, direct selection on leaf traits did not differ. Leaf N was the only trait for which direct selection differed between habitats but not within the H. anomalus habitat, suggesting that nutrient limitation is an important selective force driving adaptation of H. anomalus to the active dune habitat.
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Affiliation(s)
- L A Donovan
- Department of Plant Biology, University of Georgia, Athens GA 30606, USA
| | - F Ludwig
- Department of Plant Biology, University of Georgia, Athens GA 30606, USA
| | - D M Rosenthal
- Department of Plant Biology, University of Georgia, Athens GA 30606, USA
| | - L H Rieseberg
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - S A Dudley
- Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
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