1
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Duan H, Shao C, Zhao N, Wang D, Resco de Dios V, Tissue DT. The role of leaf superoxide dismutase and proline on intra-specific photosynthesis recovery of Schima superba following drought. Sci Rep 2024; 14:8824. [PMID: 38627563 PMCID: PMC11021533 DOI: 10.1038/s41598-024-59467-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/11/2024] [Indexed: 04/19/2024] Open
Abstract
Understanding the physiological and biochemical responses of tree seedlings under extreme drought stress, along with recovery during rewatering, and potential intra-species differences, will allow us to more accurately predict forest responses under future climate change. Here, we selected seedlings from four provenances (AH (Anhui), JX (Jiangxi), HN (Hunan) and GX (Guangxi)) of Schima superba and carried out a simulated drought-rewatering experiment in a field-based rain-out shelter. Seedlings were progressively dried until they reached 50% and 88% loss of xylem hydraulic conductivity (PLC) (i.e. P50 and P88), respectively, before they were rehydrated and maintained at field capacity for 30 days. Leaf photosynthesis (Asat), water status, activity of superoxide dismutase (SOD), and proline (Pro) concentration were monitored and their associations were determined. Increasing drought significantly reduced Asat, relative water content (RWC) and SOD activity in all provenances, and Pro concentration was increased to improve water retention; all four provenances exhibited similar response patterns, associated with similar leaf ultrastructure at pre-drought. Upon rewatering, physiological and biochemical traits were restored to well-watered control values in P50-stressed seedlings. In P88-stressed seedlings, Pro was restored to control values, while SOD was not fully recovered. The recovery pattern differed partially among provenances. There was a progression of recovery following watering, with RWC firstly recovered, followed by SOD and Pro, and then Asat, but with significant associations among these traits. Collectively, the intra-specific differences of S. superba seedlings in recovery of physiology and biochemistry following rewatering highlight the need to consider variations within a given tree species coping with future more frequent drought stress.
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Affiliation(s)
- Honglang Duan
- Institute for Forest Resources & Environment of Guizhou, College of Forestry, Guizhou University, Guiyang, 550025, China.
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, 330099, China.
| | - Changchang Shao
- Institute for Forest Resources & Environment of Guizhou, College of Forestry, Guizhou University, Guiyang, 550025, China
| | - Nan Zhao
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, 330099, China
| | - Defu Wang
- Research Center of Sichuan Old Revolutionary Areas Development, Sichuan University of Arts and Science, Dazhou, 635000, China
| | - Víctor Resco de Dios
- Department of Crop and Forest Sciences, University of Lleida, 25198, Lleida, Spain
| | - David T Tissue
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Richmond, NSW, 2753, Australia
- Global Centre for Land-Based Innovation, Hawkesbury Campus, Western Sydney University, Richmond, NSW, 2753, Australia
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2
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Stefanski A, Butler EE, Bermudez R, Montgomery RA, Reich PB. Stomatal behaviour moderates the water cost of CO 2 acquisition for 21 boreal and temperate species under experimental climate change. PLANT, CELL & ENVIRONMENT 2023; 46:3102-3119. [PMID: 36756817 DOI: 10.1111/pce.14559] [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: 09/12/2022] [Revised: 01/26/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
The linkage of stomatal behaviour with photosynthesis is critical to understanding water and carbon cycles under global change. The relationship of stomatal conductance (gs ) and CO2 assimilation (Anet ) across a range of environmental contexts, as represented in the model parameter (g1 ), has served as a proxy of the marginal water cost of carbon acquisition. We use g1 to assess species differences in stomatal behaviour to a decade of open-air experimental climate change manipulations, asking whether generalisable patterns exist across species and climate contexts. Anet -gs measurements (17 727) for 21 boreal and temperate tree species under ambient and +3.3°C warming, and ambient and ~40% summer rainfall reduction, provided >2700 estimates of g1 . Warming and/or reduced rainfall treatments both lowered g1 because those treatments resulted in lower soil moisture and because stomatal behaviour changed more in warming when soil moisture was low. Species tended to respond similarly, although, in species from warmer and drier habitats, g1 tended to be slightly higher and to be the least sensitive to the decrease in soil water. Overall, both warming and rainfall reduction consistently made stomatal behaviour more conservative in terms of water loss per unit carbon gain across 21 species and a decade of experimental observation.
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Affiliation(s)
- Artur Stefanski
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Ethan E Butler
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Raimundo Bermudez
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Rebecca A Montgomery
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
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3
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Pohl F, Werban U, Kumar R, Hildebrandt A, Rebmann C. Observational evidence of legacy effects of the 2018 drought on a mixed deciduous forest in Germany. Sci Rep 2023; 13:10863. [PMID: 37407831 DOI: 10.1038/s41598-023-38087-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/03/2023] [Indexed: 07/07/2023] Open
Abstract
Forests play a major role in the global carbon cycle, and droughts have been shown to explain much of the interannual variability in the terrestrial carbon sink capacity. The quantification of drought legacy effects on ecosystem carbon fluxes is a challenging task, and research on the ecosystem scale remains sparse. In this study we investigate the delayed response of an extreme drought event on the carbon cycle in the mixed deciduous forest site 'Hohes Holz' (DE-HoH) located in Central Germany, using the measurements taken between 2015 and 2020. Our analysis demonstrates that the extreme drought and heat event in 2018 had strong legacy effects on the carbon cycle in 2019, but not in 2020. On an annual basis, net ecosystem productivity was [Formula: see text] higher in 2018 ([Formula: see text]) and [Formula: see text] lower in 2019 ([Formula: see text]) compared to pre-drought years ([Formula: see text]). Using spline regression, we show that while current hydrometeorological conditions can explain forest productivity in 2020, they do not fully explain the decrease in productivity in 2019. Including long-term drought information in the statistical model reduces overestimation error of productivity in 2019 by nearly [Formula: see text]. We also found that short-term drought events have positive impacts on the carbon cycle at the beginning of the vegetation season, but negative impacts in later summer, while long-term drought events have generally negative impacts throughout the growing season. Overall, our findings highlight the importance of considering the diverse and complex impacts of extreme events on ecosystem fluxes, including the timing, temporal scale, and magnitude of the events, and the need to use consistent definitions of drought to clearly convey immediate and delayed responses.
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Affiliation(s)
- Felix Pohl
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
| | - Ulrike Werban
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Rohini Kumar
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Anke Hildebrandt
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
- Friedrich Schiller University Jena, Institute of Geoscience, Burgweg 11, 07749, Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstrasse 4, 04103, Leipzig, Germany
| | - Corinna Rebmann
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
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4
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Li J, Nie K, Wang L, Zhao Y, Qu M, Yang D, Guan X. The Molecular Mechanism of GhbHLH121 in Response to Iron Deficiency in Cotton Seedlings. PLANTS (BASEL, SWITZERLAND) 2023; 12:1955. [PMID: 37653872 PMCID: PMC10224022 DOI: 10.3390/plants12101955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 09/02/2023]
Abstract
Iron deficiency caused by high pH of saline-alkali soil is a major source of abiotic stress affecting plant growth. However, the molecular mechanism underlying the iron deficiency response in cotton (Gossypium hirsutum) is poorly understood. In this study, we investigated the impacts of iron deficiency at the cotton seedling stage and elucidated the corresponding molecular regulation network, which centered on a hub gene GhbHLH121. Iron deficiency induced the expression of genes with roles in the response to iron deficiency, especially GhbHLH121. The suppression of GhbHLH121 with virus-induced gene silence technology reduced seedlings' tolerance to iron deficiency, with low photosynthetic efficiency and severe damage to the structure of the chloroplast. Contrarily, ectopic expression of GhbHLH121 in Arabidopsis enhanced tolerance to iron deficiency. Further analysis of protein/protein interactions revealed that GhbHLH121 can interact with GhbHLH IVc and GhPYE. In addition, GhbHLH121 can directly activate the expression of GhbHLH38, GhFIT, and GhPYE independent of GhbHLH IVc. All told, GhbHLH121 is a positive regulator of the response to iron deficiency in cotton, directly regulating iron uptake as the upstream gene of GhFIT. Our results provide insight into the complex network of the iron deficiency response in cotton.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center (the Ministry of Education), College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China;
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; (K.N.); (L.W.); (Y.Z.)
| | - Ke Nie
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; (K.N.); (L.W.); (Y.Z.)
- Hainan Institute, Zhejiang University, Yongyou Industry Park, Yazhou Bay Sci-Tech City, Sanya 572000, China
| | - Luyao Wang
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; (K.N.); (L.W.); (Y.Z.)
- Hainan Institute, Zhejiang University, Yongyou Industry Park, Yazhou Bay Sci-Tech City, Sanya 572000, China
| | - Yongyan Zhao
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; (K.N.); (L.W.); (Y.Z.)
| | - Mingnan Qu
- Hainan Yazhou Bay Seed Lab, Yazhou Bay Science and Technology City, Yazhou District, Sanya 572025, China;
| | - Donglei Yang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center (the Ministry of Education), College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China;
| | - Xueying Guan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center (the Ministry of Education), College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China;
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 300058, China; (K.N.); (L.W.); (Y.Z.)
- Hainan Institute, Zhejiang University, Yongyou Industry Park, Yazhou Bay Sci-Tech City, Sanya 572000, China
- Hainan Yazhou Bay Seed Lab, Yazhou Bay Science and Technology City, Yazhou District, Sanya 572025, China;
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5
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Lu Y, Zhang B, Li L, Zeng F, Li X. Negative effects of long-term exposure to salinity, drought, and combined stresses on halophyte Halogeton glomeratus. PHYSIOLOGIA PLANTARUM 2021; 173:2307-2322. [PMID: 34625966 DOI: 10.1111/ppl.13581] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
Plants are subjected to salt and drought stresses concurrently but our knowledge about the effects of combined stress on plants is limited, especially on halophytes. We aim to study if some diverse drought and salt tolerance traits in halophyte may explain their tolerance to salinity and drought stresses, individual and in combination, and identify key traits that influence growth under such stress conditions. Here, the halophyte Halogeton glomeratus was grown under control, single or combinations of 60 days drought and salt treatments, and morphophysiological responses were tested. Our results showed that drought, salinity, and combination of these two stressors decreased plant growth (shoot height, root length, and biomass), leaf photosynthetic pigments content (chlorophyll a, b, a + b and carotenoids), gas exchange parameters (Net photosynthesis rate [PN ], transpiration rate [E], stomatal conductance [gs ]), and water potential (ψw ), and the decreases were more prominent under combined drought and salinity treatment compared with these two stressors individually performed. Similarly, combined drought and salinity treatment induced more severe oxidative stress as indicated by more hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA) accumulated. Nevertheless, H. glomeratus is equipped with specific mechanisms to protect itself against drought and salt stresses, including upregulation of superoxide dismutases (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities and accumulation of osmoprotectants (Na+ , Cl- , and soluble sugar). Our results indicated that photosynthetic pigments content, gas exchange parameters, water potential, APX activity, CAT activity, soluble sugar, H2 O2 , and MDA are valuable screening criteria for drought and salt, alone or combined, and provide the tolerant assessment of H. glomeratus.
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Affiliation(s)
- Yan Lu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China
| | - Bo Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China
| | - Lei Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China
| | - Fanjiang Zeng
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China
| | - Xiangyi Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
- Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China
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6
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D'Odorico P, Schönbeck L, Vitali V, Meusburger K, Schaub M, Ginzler C, Zweifel R, Velasco VME, Gisler J, Gessler A, Ensminger I. Drone-based physiological index reveals long-term acclimation and drought stress responses in trees. PLANT, CELL & ENVIRONMENT 2021; 44:3552-3570. [PMID: 34462922 PMCID: PMC9292485 DOI: 10.1111/pce.14177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/19/2021] [Accepted: 08/19/2021] [Indexed: 05/07/2023]
Abstract
Monitoring early tree physiological responses to drought is key to understanding progressive impacts of drought on forests and identifying resilient species. We combined drone-based multispectral remote sensing with measurements of tree physiology and environmental parameters over two growing seasons in a 100-y-old Pinus sylvestris forest subject to 17-y of precipitation manipulation. Our goal was to determine if drone-based photochemical reflectance index (PRI) captures tree drought stress responses and whether responses are affected by long-term acclimation. PRI detects changes in xanthophyll cycle pigment dynamics, which reflect increases in photoprotective non-photochemical quenching activity resulting from drought-induced photosynthesis downregulation. Here, PRI of never-irrigated trees was up to 10 times lower (higher stress) than PRI of irrigated trees. Long-term acclimation to experimental treatment, however, influenced the seasonal relationship between PRI and soil water availability. PRI also captured diurnal decreases in photochemical efficiency, driven by vapour pressure deficit. Interestingly, 5 years after irrigation was stopped for a subset of the irrigated trees, a positive legacy effect persisted, with lower stress responses (higher PRI) compared with never-irrigated trees. This study demonstrates the ability of remotely sensed PRI to scale tree physiological responses to an entire forest and the importance of long-term acclimation in determining current drought stress responses.
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Affiliation(s)
- Petra D'Odorico
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Leonie Schönbeck
- Plant Ecology Research LaboratorySchool of Architecture, Civil and Environmental Engineering, EPFLLausanneSwitzerland
- Community Ecology UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLLausanneSwitzerland
| | - Valentina Vitali
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Katrin Meusburger
- Biogeochemistry UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Marcus Schaub
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Christian Ginzler
- Land Change Science UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Roman Zweifel
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | | | - Jonas Gisler
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Arthur Gessler
- Forest Dynamics Research UnitSwiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
- Department of Environmental Systems ScienceETH ZürichZürichSwitzerland
| | - Ingo Ensminger
- Department of BiologyUniversity of Toronto MississaugaMississaugaOntarioCanada
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7
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Salvi AM, Smith DD, Adams MA, McCulloh KA, Givnish TJ. Mesophyll photosynthetic sensitivity to leaf water potential in Eucalyptus: a new dimension of plant adaptation to native moisture supply. THE NEW PHYTOLOGIST 2021; 230:1844-1855. [PMID: 33630331 DOI: 10.1111/nph.17304] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic sensitivity to drought is a fundamental constraint on land-plant evolution and ecosystem function. However, little is known about how the sensitivity of photosynthesis to nonstomatal limitations varies among species in the context of phylogenetic relationships. Using saplings of 10 Eucalyptus species, we measured maximum CO2 -saturated photosynthesis using A-ci curves at several different leaf water potentials (ψleaf ) to quantify mesophyll photosynthetic sensitivity to ψleaf (MPS), a measure of how rapidly nonstomatal limitations to carbon uptake increase with declining ψleaf . MPS was compared to the macroclimatic moisture availability of the species' native habitats, while accounting for phylogenetic relationships. We found that species native to mesic habitats have greater MPS but higher maximum photosynthetic rates during non-water-stressed conditions, revealing a trade-off between maximum photosynthesis and drought sensitivity. Species with lower turgor loss points have lower MPS, indicating coordination among photosynthetic and water-relations traits. By accounting for phylogenetic relationships among closely related species, we provide the first compelling evidence that MPS in Eucalyptus evolved in an adaptive fashion with climatically determined moisture availability, opening the way for further study of this poorly explored dimension of plant adaptation to drought.
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Affiliation(s)
- Amanda M Salvi
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Duncan D Smith
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Vic., 3363, Australia
- Swinburne University of Technology, John Street, Hawthorn, Vic., 3122, Australia
| | - Mark A Adams
- Swinburne University of Technology, John Street, Hawthorn, Vic., 3122, Australia
| | | | - Thomas J Givnish
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53705, USA
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8
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Jiang M, Kelly JWG, Atwell BJ, Tissue DT, Medlyn BE. Drought by CO 2 interactions in trees: a test of the water savings mechanism. THE NEW PHYTOLOGIST 2021; 230:1421-1434. [PMID: 33496969 DOI: 10.1111/nph.17233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
Elevated atmospheric CO2 (eCa ) may benefit plants during drought by reducing stomatal conductance (gs ) but any 'water savings effect' could be neutralized by concurrent stimulation of leaf area. We investigated whether eCa enhanced water savings, thereby ameliorating the impact of drought on carbon and water relations in trees. We report leaf-level gas exchange and whole-plant and soil water relations during a short-term dry-down in two Eucalyptus species with contrasting drought tolerance. Plants had previously been established for 9 to 11 months in steady-state conditions of ambient atmospheric CO2 (aCa ) and eCa , with half of each treatment group exposed to sustained drought for 5 to 7 months. The lower stomatal conductance under eCa did not lead to soil moisture savings during the dry-down due to the counteractive effect of increased whole-plant leaf area. Nonetheless, eCa -grown plants maintained higher photosynthetic rates and leaf water potentials, making them less stressed during the dry-down, despite being larger. These effects were more pronounced in the xeric species than the mesic species, and in previously water-stressed plants. Our findings indicate that eCa may enhance plant performance during drought despite a lack of soil water savings, especially in species with more conservative growth and water-use strategies.
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Affiliation(s)
- Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Jeff W G Kelly
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Brian J Atwell
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
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9
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Peters W, Bastos A, Ciais P, Vermeulen A. A historical, geographical and ecological perspective on the 2018 European summer drought. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190505. [PMID: 32892723 DOI: 10.1098/rstb.2019.0505] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Wouter Peters
- Department of Meteorology and Air Quality, Wageningen University, Wageningen, The Netherlands.,Centre for Isotope Research Groningen, Groningen University, Groningen, The Netherlands
| | - Ana Bastos
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette, France
| | - Alex Vermeulen
- Integrated Carbon Observing System (ICOS ERIC), Carbon Portal, Lund, Sweden
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10
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Gourlez de la Motte L, Beauclaire Q, Heinesch B, Cuntz M, Foltýnová L, Šigut L, Kowalska N, Manca G, Ballarin IG, Vincke C, Roland M, Ibrom A, Lousteau D, Siebicke L, Neiryink J, Longdoz B. Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190527. [PMID: 32892725 DOI: 10.1098/rstb.2019.0527] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Severe drought events are known to cause important reductions of gross primary productivity (GPP) in forest ecosystems. However, it is still unclear whether this reduction originates from stomatal closure (Stomatal Origin Limitation) and/or non-stomatal limitations (Non-SOL). In this study, we investigated the impact of edaphic drought in 2018 on GPP and its origin (SOL, NSOL) using a dataset of 10 European forest ecosystem flux towers. In all stations where GPP reductions were observed during the drought, these were largely explained by declines in the maximum apparent canopy scale carboxylation rate VCMAX,APP (NSOL) when the soil relative extractable water content dropped below around 0.4. Concurrently, we found that the stomatal slope parameter (G1, related to SOL) of the Medlyn et al. unified optimization model linking vegetation conductance and GPP remained relatively constant. These results strengthen the increasing evidence that NSOL should be included in stomatal conductance/photosynthesis models to faithfully simulate both GPP and water fluxes in forest ecosystems during severe drought. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
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Affiliation(s)
- Louis Gourlez de la Motte
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Quentin Beauclaire
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Bernard Heinesch
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
| | - Mathias Cuntz
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, 54000 Nancy, France
| | | | - Ladislav Šigut
- Global Change Research Institute CAS, Brno, Czech Republic
| | | | - Giovanni Manca
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | | | - Caroline Vincke
- Earth and Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Marilyn Roland
- Plants and Ecosystems, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Andreas Ibrom
- Department of Environmental Engineering, Technical University of Denmark (DTU), Bygningstorvet 115, 2800 Lyngby, Denmark
| | | | - Lukas Siebicke
- Bioclimatology, University of Goettingen, Büsgenweg 2, 37077 Goettingen, Germany
| | - Johan Neiryink
- Institute for Nature and Forest Research, INBO, Havenlaan 88 Box 73, 1000 Brussels, Belgium
| | - Bernard Longdoz
- Terra Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
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Ye ZP, Ling Y, Yu Q, Duan HL, Kang HJ, Huang GM, Duan SH, Chen XM, Liu YG, Zhou SX. Quantifying Light Response of Leaf-Scale Water-Use Efficiency and Its Interrelationships With Photosynthesis and Stomatal Conductance in C 3 and C 4 Species. FRONTIERS IN PLANT SCIENCE 2020; 11:374. [PMID: 32411151 PMCID: PMC7199201 DOI: 10.3389/fpls.2020.00374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
Light intensity (I) is the most dynamic and significant environmental variable affecting photosynthesis (A n), stomatal conductance (g s), transpiration (T r), and water-use efficiency (WUE). Currently, studies characterizing leaf-scale WUE-I responses are rare and key questions have not been answered. In particular, (1) What shape does the response function take? (2) Are there maximum intrinsic (WUEi; WUEi-max) and instantaneous WUE (WUEinst; WUEinst-max) at the corresponding saturation irradiances (I i-sat and I inst-sat)? This study developed WUEi-I and WUEinst-I models sharing the same non-asymptotic function with previously published A n-I and g s-I models. Observation-modeling intercomparison was conducted for field-grown plants of soybean (C3) and grain amaranth (C4) to assess the robustness of our models versus the non-rectangular hyperbola models (NH models). Both types of models can reproduce WUE-I curves well over light-limited range. However, at light-saturated range, NH models overestimated WUEi-max and WUEinst-max and cannot return I i-sat and I inst-sat due to its asymptotic function. Moreover, NH models cannot describe the down-regulation of WUE induced by high light, on which our models described well. The results showed that WUEi and WUEinst increased rapidly within low range of I, driven by uncoupled photosynthesis and stomatal responsiveness. Initial response rapidity of WUEi was higher than WUEinst because the greatest increase of A n and T r occurred at low g s. C4 species showed higher WUEi-max and WUEinst-max than C3 species-at similar I i-sat and I inst-sat. Our intercomparison highlighted larger discrepancy between WUEi-I and WUEinst-I responses in C3 than C4 species, quantitatively characterizing an important advantage of C4 photosynthetic pathway-higher A n gain but lower T r cost per unit of g s change. Our models can accurately return the wealth of key quantities defining species-specific WUE-I responses-besides A n-I and g s-I responses. The key advantage is its robustness in characterizing these entangled responses over a wide I range from light-limited to light-inhibitory light intensities, through adopting the same analytical framework and the explicit and consistent definitions on these responses. Our models are of significance for physiologists and modelers-and also for breeders screening for genotypes concurrently achieving maximized photosynthesis and optimized WUE.
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Affiliation(s)
- Zi-Piao Ye
- Maths & Physics College, Jinggangshan University, Ji’an, China
| | - Yu Ling
- College of Agricultural Sciences, Guangdong Ocean University, Zhanjiang, China
| | - Qiang Yu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia
- College of Resources and Environment, University of Chinese Academy of Science, Beijing, China
| | - Hong-Lang Duan
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Hua-Jing Kang
- Department of Landscape Architecture, Wenzhou Vocational College of Science & Technology, Wenzhou, China
| | - Guo-Min Huang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Shi-Hua Duan
- School of Life Sciences, Jinggangshan University, Ji’an, China
| | - Xian-Mao Chen
- Soil Fertilizer and Environmental Resources Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, China
| | - Yu-Guo Liu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China
| | - Shuang-Xi Zhou
- The New Zealand Institute for Plant and Food Research Limited, Havelock North, New Zealand
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Responses to Water Deficit and Salt Stress in Silver Fir (Abies alba Mill.) Seedlings. FORESTS 2020. [DOI: 10.3390/f11040395] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Forest ecosystems are frequently exposed to abiotic stress, which adversely affects their growth, resistance and survival. For silver fir (Abies alba), the physiological and biochemical responses to water and salt stress have not been extensively studied. Responses of one-year-old seedlings to a 30-day water stress (withholding irrigation) or salt stress (100, 200 and 300 mM NaCl) treatments were analysed by determining stress-induced changes in growth parameters and different biochemical markers: accumulation of ions, different osmolytes and malondialdehyde (MDA, an oxidative stress biomarker), in the seedlings, and activation of enzymatic and non-enzymatic antioxidant systems. Both salt and water stress caused growth inhibition. The results obtained indicated that the most relevant responses to drought are based on the accumulation of soluble carbohydrates as osmolytes/osmoprotectants. Responses to high salinity, on the other hand, include the active transport of Na+, Cl− and Ca2+ to the needles, the maintenance of relatively high K+/Na+ ratios and the accumulation of proline and soluble sugars for osmotic balance. Interestingly, relatively high Na+ concentrations were measured in the needles of A. alba seedlings at low external salinity, suggesting that Na+ can contribute to osmotic adjustment as a ‘cheap’ osmoticum, and its accumulation may represent a constitutive mechanism of defence against stress. These responses appear to be efficient enough to avoid the generation of high levels of oxidative stress, in agreement with the small increase in MDA contents and the relatively weak activation of the tested antioxidant systems.
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