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Drake JE, Vårhammar A, Aspinwall MJ, Pfautsch S, Ghannoum O, Tissue DT, Tjoelker MG. Pushing the envelope: do narrowly and widely distributed Eucalyptus species differ in response to climate warming? THE NEW PHYTOLOGIST 2024; 243:82-97. [PMID: 38666344 DOI: 10.1111/nph.19774] [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: 10/03/2023] [Accepted: 03/29/2024] [Indexed: 06/07/2024]
Abstract
Contemporary climate change will push many tree species into conditions that are outside their current climate envelopes. Using the Eucalyptus genus as a model, we addressed whether species with narrower geographical distributions show constrained ability to cope with warming relative to species with wider distributions, and whether this ability differs among species from tropical and temperate climates. We grew seedlings of widely and narrowly distributed Eucalyptus species from temperate and tropical Australia in a glasshouse under two temperature regimes: the summer temperature at seed origin and +3.5°C. We measured physical traits and leaf-level gas exchange to assess warming influences on growth rates, allocation patterns, and physiological acclimation capacity. Warming generally stimulated growth, such that higher relative growth rates early in development placed seedlings on a trajectory of greater mass accumulation. The growth enhancement under warming was larger among widely than narrowly distributed species and among temperate rather than tropical provenances. The differential growth enhancement was primarily attributable to leaf area production and adjustments of specific leaf area. Our results suggest that tree species, including those with climate envelopes that will be exceeded by contemporary climate warming, possess capacity to physiologically acclimate but may have varying ability to adjust morphology.
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Affiliation(s)
- John E Drake
- Department of Sustainable Resources Management, College of Environmental Science and Forestry, State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - Angelica Vårhammar
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | | | - Sebastian Pfautsch
- Urban Transformations Research Centre, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Oula Ghannoum
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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2
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Qu LP, Dong G, Chen J, Xiao J, De Boeck HJ, Chen J, Jiang S, Batkhishig O, Legesse TG, Xin X, Shao C. Soil environmental anomalies dominate the responses of net ecosystem productivity to heatwaves in three Mongolian grasslands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173742. [PMID: 38839012 DOI: 10.1016/j.scitotenv.2024.173742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/28/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024]
Abstract
Climate change is causing more frequent and intense heatwaves. Therefore, it is important to understand how heatwaves affect the terrestrial carbon cycle, especially in grasslands, which are especially susceptible to climate extremes. This study assessed the impact of naturally occurring, simultaneous short-term heatwaves on CO2 fluxes in three ecosystems on the Mongolia Plateau: meadow steppe (MDW), typical steppe (TPL), and shrub-grassland (SHB). During three heatwaves, net ecosystem productivity (NEP) was reduced by 86 %, 178 %, and 172 % at MDW, TPL, and SHB, respectively. The changes in ecosystem respiration, gross primary production, evapotranspiration, and water use efficiency were divergent, indicating the mechanisms underlying the observed NEP decreases among the sites. The impact of the heatwave in MDW was mitigated by the high soil water content, which enhanced evapotranspiration and subsequent cooling effects. However, at TPL, insufficient soil water led to combined thermal and drought stress and low resilience. At SHB, the ecosystem's low tolerance to an August heatwave was heavily influenced by species phenology, as it coincided with the key phenological growing phase of plants. The potential key mechanism of divergent NEP response to heatwaves lies in the divergent stability and varying importance of environmental factors, combined with the specific sensitivity of NEP to each factor in ecosystems. Furthermore, our findings suggest that anomalies in soil environment, rather than atmospheric anomalies, are the primary determinants of NEP anomalies during heatwaves. This challenges the conventional understanding of heatwaves as a discrete and ephemeral periods of high air temperatures. Instead, heatwaves should be viewed as chronologically variable, compound, and time-sensitive environmental stressors. The ultimate impact of heatwaves on ecosystems is co-determined by a complex interplay of environmental, biological, and heatwave features.
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Affiliation(s)
- Lu-Ping Qu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Gang Dong
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; School of Life Science, Shanxi University, Taiyuan, China
| | - Jiquan Chen
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI 48823, USA
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Hans J De Boeck
- Research Group of Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium; School of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, China
| | - Jingyan Chen
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shicheng Jiang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Ochirbat Batkhishig
- Institute of Geography, Mongolian Academy of Sciences, Ulaanbaartar 210620, Mongolia
| | - Tsegaye Gemechu Legesse
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoping Xin
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Changliang Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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3
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Sun W, Maseyk K, Lett C, Seibt U. Restricted internal diffusion weakens transpiration-photosynthesis coupling during heatwaves: Evidence from leaf carbonyl sulphide exchange. PLANT, CELL & ENVIRONMENT 2024; 47:1813-1833. [PMID: 38321806 DOI: 10.1111/pce.14840] [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: 04/19/2023] [Revised: 11/13/2023] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Increasingly frequent and intense heatwaves threaten ecosystem health in a warming climate. However, plant responses to heatwaves are poorly understood. A key uncertainty concerns the intensification of transpiration when heatwaves suppress photosynthesis, known as transpiration-photosynthesis decoupling. Field observations of such decoupling are scarce, and the underlying physiological mechanisms remain elusive. Here, we use carbonyl sulphide (COS) as a leaf gas exchange tracer to examine potential mechanisms leading to transpiration-photosynthesis decoupling on a coast live oak in a southern California woodland in spring 2013. We found that heatwaves suppressed both photosynthesis and leaf COS uptake but increased transpiration or sustained it at non-heatwave levels throughout the day. Despite statistically significant decoupling between transpiration and photosynthesis, stomatal sensitivity to environmental factors did not change during heatwaves. Instead, midday photosynthesis during heatwaves was restricted by internal diffusion, as indicated by the lower internal conductance to COS. Thus, increased evaporative demand and nonstomatal limitation to photosynthesis act jointly to decouple transpiration from photosynthesis without altering stomatal sensitivity. Decoupling offered limited potential cooling benefits, questioning its effectiveness for leaf thermoregulation in xeric ecosystems. We suggest that adding COS to leaf and ecosystem flux measurements helps elucidate diverse physiological mechanisms underlying transpiration-photosynthesis decoupling.
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Affiliation(s)
- Wu Sun
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
| | - Kadmiel Maseyk
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Céline Lett
- Department of Environmental Research and Innovation, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
| | - Ulli Seibt
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA
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4
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Kim D, Guadagno CR, Ewers BE, Mackay DS. Combining PSII photochemistry and hydraulics improves predictions of photosynthesis and water use from mild to lethal drought. PLANT, CELL & ENVIRONMENT 2024; 47:1255-1268. [PMID: 38178610 DOI: 10.1111/pce.14806] [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: 02/04/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
Rising temperatures and increases in drought negatively impact the efficiency and sustainability of both agricultural and forest ecosystems. Although hydraulic limitations on photosynthesis have been extensively studied, a solid understanding of the links between whole plant hydraulics and photosynthetic processes at the cellular level under changing environmental conditions is still missing, hampering our predictive power for plant mortality. Here, we examined plant hydraulic traits and CO2 assimilation rate under progressive water limitation by implementing Photosystem II (PSII) dynamics with a whole plant process model (TREES). The photosynthetic responses to plant water status were parameterized based on measurements of chlorophyll a fluorescence, gas exchange and water potential for Brassica rapa (R500) grown in a greenhouse under fully watered to lethal drought conditions. The updated model significantly improved predictions of photosynthesis, stomatal conductance and leaf water potential. TREES with PSII knowledge predicted a larger hydraulic safety margin and a decrease in percent loss of conductivity. TREES predicted a slower decrease in leaf water potential, which agreed with measurements. Our results highlight the pressing need for incorporating PSII drought photochemistry into current process models to capture cross-scale plant water dynamics from cell to whole plant level.
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Affiliation(s)
- Dohyoung Kim
- Department of Geography, State University of New York at Buffalo, Buffalo, New York, USA
| | | | - Brent E Ewers
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
| | - D Scott Mackay
- Department of Geography, State University of New York at Buffalo, Buffalo, New York, USA
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5
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Bison NN, Michaletz ST. Variation in leaf carbon economics, energy balance, and heat tolerance traits highlights differing timescales of adaptation and acclimation. THE NEW PHYTOLOGIST 2024. [PMID: 38532535 DOI: 10.1111/nph.19702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
Multivariate leaf trait correlations are hypothesized to originate from natural selection on carbon economics traits that control lifetime leaf carbon gain, and energy balance traits governing leaf temperatures, physiological rates, and heat injury. However, it is unclear whether macroevolution of leaf traits primarily reflects selection for lifetime carbon gain or energy balance, and whether photosynthetic heat tolerance is coordinated along these axes. To evaluate these hypotheses, we measured carbon economics, energy balance, and photosynthetic heat tolerance traits for 177 species (157 families) in a common garden that minimizes co-variation of taxa and climate. We observed wide variation in carbon economics, energy balance, and heat tolerance traits. Carbon economics and energy balance (but not heat tolerance) traits were phylogenetically structured, suggesting macroevolution of leaf mass per area and leaf dry matter content reflects selection on carbon gain rather than energy balance. Carbon economics and energy balance traits varied along a common axis orthogonal to heat tolerance traits. Our results highlight a fundamental mismatch in the timescales over which morphological and heat tolerance traits respond to environmental variation. Whereas carbon economics and energy balance traits are constrained by species' evolutionary histories, photosynthetic heat tolerance traits are not and can acclimate readily to leaf microclimates.
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Affiliation(s)
- Nicole N Bison
- Department of Botany, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Biodiversity Research Centre, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Sean T Michaletz
- Department of Botany, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Biodiversity Research Centre, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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6
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Cook AM, Rezende EL, Petrou K, Leigh A. Beyond a single temperature threshold: Applying a cumulative thermal stress framework to plant heat tolerance. Ecol Lett 2024; 27:e14416. [PMID: 38549256 DOI: 10.1111/ele.14416] [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: 08/28/2023] [Accepted: 02/27/2024] [Indexed: 04/02/2024]
Abstract
Most plant thermal tolerance studies focus on single critical thresholds, which limit the capacity to generalise across studies and predict heat stress under natural conditions. In animals and microbes, thermal tolerance landscapes describe the more realistic, cumulative effects of temperature. We tested this in plants by measuring the decline in leaf photosynthetic efficiency (FV/FM) following a combination of temperatures and exposure times and then modelled these physiological indices alongside recorded environmental temperatures. We demonstrate that a general relationship between stressful temperatures and exposure durations can be effectively employed to quantify and compare heat tolerance within and across plant species and over time. Importantly, we show how FV/FM curves translate to plants under natural conditions, suggesting that environmental temperatures often impair photosynthetic function. Our findings provide more robust descriptors of heat tolerance in plants and suggest that heat tolerance in disparate groups of organisms can be studied with a single predictive framework.
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Affiliation(s)
- Alicia M Cook
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
| | - Enrico L Rezende
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
| | - Andy Leigh
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
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7
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Kullberg AT, Coombs L, Soria Ahuanari RD, Fortier RP, Feeley KJ. Leaf thermal safety margins decline at hotter temperatures in a natural warming 'experiment' in the Amazon. THE NEW PHYTOLOGIST 2024; 241:1447-1463. [PMID: 37984063 DOI: 10.1111/nph.19413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/28/2023] [Indexed: 11/22/2023]
Abstract
The threat of rising global temperatures may be especially pronounced for low-latitude, lowland plant species that have evolved under stable climatic conditions. However, little is known about how these species may acclimate to elevated temperatures. Here, we leveraged a strong, steep thermal gradient along a natural geothermal river to assess the ability of woody plants in the Amazon to acclimate to elevated air temperatures. We measured leaf traits in six common tropical woody species along the thermal gradient to investigate whether individuals of these species: acclimate their thermoregulatory traits to maintain stable leaf temperatures despite higher ambient temperatures; acclimate their photosynthetic thermal tolerances to withstand hotter leaf temperatures; and whether acclimation is sufficient to maintain stable leaf thermal safety margins (TSMs) across different growth temperatures. Individuals of three species acclimated their thermoregulatory traits, and three species increased their thermal tolerances with growth temperature. However, acclimation was generally insufficient to maintain constant TSMs. Notwithstanding, leaf health was generally consistent across growth temperatures. Acclimation in woody Amazonian plants is generally too weak to maintain TSMs at high growth temperatures, supporting previous findings that Amazonian plants will be increasingly vulnerable to thermal stress as temperatures rise.
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Affiliation(s)
- Alyssa T Kullberg
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Lauren Coombs
- Hussman Institute of Human Genomics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Roy D Soria Ahuanari
- Herbario Regional de Ucayali IVITA, Pucallpa (HRUIP), Universidad Nacional Mayor de San Marcos, Pucallpa, 25001, Peru
| | - Riley P Fortier
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Kenneth J Feeley
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
- Fairchild Tropical Botanic Garden, Coral Gables, FL, 33156, USA
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8
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O'Connell BP, Wiley E. Heatwaves do not limit recovery following defoliation but alter leaf drought tolerance traits. PLANT, CELL & ENVIRONMENT 2024; 47:482-496. [PMID: 37877185 DOI: 10.1111/pce.14750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/20/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
As heatwave frequency increases, they are more likely to coincide with other disturbances like insect defoliation. But it is unclear if high temperatures after defoliation impact canopy recovery or leaf traits which may affect response to further stressors like drought. To examine these stressor interactions, we subjected defoliated (DEF) and undefoliated (UNDEF) oak saplings to a simulated spring heatwave of +10°C for 25 days. We measured gas exchange, leaf area recovery, carbohydrate storage, turgor loss point (ΨTLP ), and minimum leaf conductance (gmin ). During the heatwave, stem respiration exhibited stronger thermal acclimation in DEF than UNDEF saplings, while stomatal conductance and net photosynthesis increased. The heatwave did not affect leaf area recovery or carbohydrate storage of DEF saplings, but reflush leaves had higher gmin than UNDEF leaves, and this was amplified by the heatwave. Across all treatments, higher gmin was associated with higher daytime stomatal conductance and a lower ΨTLP . The results suggest defoliation stress may not be exacerbated by higher temperatures. However, reflush leaves are less conservative in their water use, limiting their ability to minimise water loss. While lower ΨTLP could help DEF trees maintain gas exchange under mild drought, they may be more vulnerable to dehydration under severe drought.
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Affiliation(s)
| | - Erin Wiley
- Department of Biology, University of Central Arkansas, Conway, Arkansas, USA
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9
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Qu LP, Chen J, Xiao J, De Boeck HJ, Dong G, Jiang SC, Hu YL, Wang YX, Shao CL. The complexity of heatwaves impact on terrestrial ecosystem carbon fluxes: Factors, mechanisms and a multi-stage analytical approach. ENVIRONMENTAL RESEARCH 2024; 240:117495. [PMID: 37890820 DOI: 10.1016/j.envres.2023.117495] [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: 08/25/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 10/29/2023]
Abstract
Extreme heatwaves have become more frequent and severe in recent decades, and are expected to significantly influence carbon fluxes at regional scales across global terrestrial ecosystems. Nevertheless, accurate prediction of future heatwave impacts remains challenging due to a lack of a consistent comprehension of intrinsic and extrinsic mechanisms. We approached this knowledge gap by analyzing the complexity factors in heatwave studies, including the methodology for determining heatwave events, divergent responses of individual ecosystem components at multiple ecological and temporal scales, and vegetation status and hydrothermal environment, among other factors. We found that heatwaves essentially are continuously changing compound environmental stress that can unfold into multiple chronological stages, and plant physiology and carbon flux responses differs in each of these stages. This approach offers a holistic perspective, recognizing that the impacts of heatwaves on ecosystems can be better understood when evaluated over time. These stages include instantaneous, post-heatwave, legacy, and cumulative effects, each contributing uniquely to the overall impact on the ecosystem carbon cycle. Next, we investigated the importance of the timing of heatwaves and the possible divergent consequences caused by different annual heatwave patterns. Finally, a conceptual framework is proposed to establish a united foundation for the study and comprehension of the consequences of heatwaves on ecosystem carbon cycle. This instrumental framework will assist in guiding regional assessments of heatwave impacts, shedding light on the underlying mechanisms responsible for the varied responses of terrestrial ecosystems to specific heatwave events, which are imperative for devising efficient adaptation and mitigation approaches.
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Affiliation(s)
- Lu-Ping Qu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
| | - Jiquan Chen
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI, 48823, USA.
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, 03824, USA.
| | - Hans J De Boeck
- Research Group of Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium.
| | - Gang Dong
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; School of Life Science, Shanxi University, Taiyuan, China.
| | | | - Ya-Lin Hu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
| | - Yi-Xuan Wang
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Chang-Liang Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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10
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Zhu L, Scafaro AP, Vierling E, Ball MC, Posch BC, Stock F, Atkin OK. Heat tolerance of a tropical-subtropical rainforest tree species Polyscias elegans: time-dependent dynamic responses of physiological thermostability and biochemistry. THE NEW PHYTOLOGIST 2024; 241:715-731. [PMID: 37932881 DOI: 10.1111/nph.19356] [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: 10/26/2022] [Accepted: 10/01/2023] [Indexed: 11/08/2023]
Abstract
Heat stress interrupts physiological thermostability and triggers biochemical responses that are essential for plant survival. However, there is limited knowledge on the speed plants adjust to heat in hours and days, and which adjustments are crucial. Tropical-subtropical rainforest tree species (Polyscias elegans) were heated at 40°C for 5 d, before returning to 25°C for 13 d of recovery. Leaf heat tolerance was quantified using the temperature at which minimal chl a fluorescence sharply rose (Tcrit ). Tcrit , metabolites, heat shock protein (HSP) abundance and membrane lipid fatty acid (FA) composition were quantified. Tcrit increased by 4°C (48-52°C) within 2 h of 40°C exposure, along with rapid accumulation of metabolites and HSPs. By contrast, it took > 2 d for FA composition to change. At least 2 d were required for Tcrit , HSP90, HSP70 and FAs to return to prestress levels. The results highlight the multi-faceted response of P. elegans to heat stress, and how this response varies over the scale of hours to days, culminating in an increased level of photosynthetic heat tolerance. These responses are important for survival of plants when confronted with heat waves amidst ongoing global climate change.
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Affiliation(s)
- Lingling Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Marilyn C Ball
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
- Department of Research, Conservation, and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - Frederike Stock
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
- Australian Plant Phenomics Facility, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
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11
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Chieppa J, Feller IC, Harris K, Dorrance S, Sturchio MA, Gray E, Tjoelker MG, Aspinwall MJ. Thermal acclimation of leaf respiration is consistent in tropical and subtropical populations of two mangrove species. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:3174-3187. [PMID: 36882067 DOI: 10.1093/jxb/erad093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 05/21/2023]
Abstract
Populations from different climates often show unique growth responses to temperature, reflecting temperature adaptation. Yet, whether populations from different climates differ in physiological temperature acclimation remains unclear. Here, we test whether populations from differing thermal environments exhibit different growth responses to temperature and differences in temperature acclimation of leaf respiration. We grew tropical and subtropical populations of two mangrove species (Avicennia germinans and Rhizophora mangle) under ambient and experimentally warmed conditions in a common garden at the species' northern range limit. We quantified growth and temperature responses of leaf respiration (R) at seven time points over ~10 months. Warming increased productivity of tropical populations more than subtropical populations, reflecting a higher temperature optimum for growth. In both species, R measured at 25 °C declined as seasonal temperatures increased, demonstrating thermal acclimation. Contrary to our expectations, acclimation of R was consistent across populations and temperature treatments. However, populations differed in adjusting the temperature sensitivity of R (Q10) to seasonal temperatures. Following a freeze event, tropical Avicennia showed greater freeze damage than subtropical Avicennia, while both Rhizophora populations appeared equally susceptible. We found evidence of temperature adaptation at the whole-plant scale but little evidence for population differences in thermal acclimation of leaf physiology. Studies that examine potential costs and benefits of thermal acclimation in an evolutionary context may provide new insights into limits of thermal acclimation.
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Affiliation(s)
- Jeff Chieppa
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
- College of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA
| | - Ilka C Feller
- Smithsonian Environmental Research Center, Edgewater, MD 21037, USA
| | - Kylie Harris
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
| | - Susannah Dorrance
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
| | - Matthew A Sturchio
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
| | - Eve Gray
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith New South Wales, Australia
| | - Michael J Aspinwall
- Department of Biology, University of North Florida, Jacksonville, FL 32224, USA
- College of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA
- Formation Environmental LLC, 1631 Alhambra Blvd, Suite 220, Sacramento, CA 95816, USA
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12
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Castillejo MA, Pascual J, Jorrín-Novo JV, Balbuena TS. Proteomics research in forest trees: A 2012-2022 update. FRONTIERS IN PLANT SCIENCE 2023; 14:1130665. [PMID: 37089649 PMCID: PMC10114611 DOI: 10.3389/fpls.2023.1130665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/14/2023] [Indexed: 05/03/2023]
Abstract
This review is a compilation of proteomic studies on forest tree species published in the last decade (2012-2022), mostly focused on the most investigated species, including Eucalyptus, Pinus, and Quercus. Improvements in equipment, platforms, and methods in addition to the increasing availability of genomic data have favored the biological knowledge of these species at the molecular, organismal, and community levels. Integration of proteomics with physiological, biochemical and other large-scale omics in the direction of the Systems Biology, will provide a comprehensive understanding of different biological processes, from growth and development to responses to biotic and abiotic stresses. As main issue we envisage that proteomics in long-living plants will thrive light on the plant responses and resilience to global climate change, contributing to climate mitigation strategies and molecular breeding programs. Proteomics not only will provide a molecular knowledge of the mechanisms of resilience to either biotic or abiotic stresses, but also will allow the identification on key gene products and its interaction. Proteomics research has also a translational character being applied to the characterization of the variability and biodiversity, as well as to wood and non-wood derived products, traceability, allergen and bioactive peptides identification, among others. Even thought, the full potential of proteomics is far from being fully exploited in forest tree research, with PTMs and interactomics being reserved to plant model systems. The most outstanding achievements in forest tree proteomics in the last decade as well as prospects are discussed.
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Affiliation(s)
- María Angeles Castillejo
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
- *Correspondence: María Angeles Castillejo,
| | - Jesús Pascual
- Plant Physiology, Department of Organisms and Systems Biology, University of Oviedo, Oviedo, Spain
- University Institute of Biotechnology of Asturias, University of Oviedo, Oviedo, Spain
| | - Jesus V. Jorrín-Novo
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
| | - Tiago Santana Balbuena
- Department of Agricultural, Livestock and Environmental Biotechnology, School of Agriculture and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo, Brazil
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13
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Ahrens CW, Watson‐Lazowski A, Huang G, Tissue DT, Rymer PD. The roles of divergent and parallel molecular evolution contributing to thermal adaptive strategies in trees. PLANT, CELL & ENVIRONMENT 2022; 45:3476-3491. [PMID: 36151708 PMCID: PMC9828096 DOI: 10.1111/pce.14449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Local adaptation is a driver of biological diversity, and species may develop analogous (parallel evolution) or alternative (divergent evolution) solutions to similar ecological challenges. We expect these adaptive solutions would culminate in both phenotypic and genotypic signals. Using two Eucalyptus species (Eucalyptus grandis and Eucalyptus tereticornis) with overlapping distributions grown under contrasting 'local' temperature conditions to investigate the independent contribution of adaptation and plasticity at molecular, physiological and morphological levels. The link between gene expression and traits markedly differed between species. Divergent evolution was the dominant pattern driving adaptation (91% of all significant genes); but overlapping gene (homologous) responses were dependent on the determining factor (plastic, adaptive or genotype by environment interaction). Ninety-eight percent of the plastic homologs were similarly regulated, while 50% of the adaptive homologs and 100% of the interaction homologs were antagonistical. Parallel evolution for the adaptive effect in homologous genes was greater than expected but not in favour of divergent evolution. Heat shock proteins for E. grandis were almost entirely driven by adaptation, and plasticity in E. tereticornis. These results suggest divergent molecular evolutionary solutions dominated the adaptive mechanisms among species, even in similar ecological circumstances. Suggesting that tree species with overlapping distributions are unlikely to equally persist in the future.
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Affiliation(s)
- Collin W. Ahrens
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
- School of Biotechnology and Biomolecular SciencesUniversity of New South WalesSydneyNew South WalesAustralia
- Research Centre for Ecosystem ResilienceRoyal Botanic Gardens and Domain TrustSydneyNew South WalesAustralia
| | - Alexander Watson‐Lazowski
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
- John Innes CentreNorwich Research ParkNorwichUK
| | - Guomin Huang
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
| | - David T. Tissue
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
- Global Centre for Land‐Based Innovation, Hawkesbury CampusWestern Sydney UniversityRichmondNew South WalesAustralia
| | - Paul D. Rymer
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
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14
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Posch BC, Hammer J, Atkin OK, Bramley H, Ruan YL, Trethowan R, Coast O. Wheat photosystem II heat tolerance responds dynamically to short- and long-term warming. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:erac039. [PMID: 35604885 PMCID: PMC9127437 DOI: 10.1093/jxb/erac039] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 05/10/2023]
Abstract
Wheat photosynthetic heat tolerance can be characterized using minimal chlorophyll fluorescence to quantify the critical temperature (Tcrit) above which incipient damage to the photosynthetic machinery occurs. We investigated intraspecies variation and plasticity of wheat Tcrit under elevated temperature in field and controlled-environment experiments, and assessed whether intraspecies variation mirrored interspecific patterns of global heat tolerance. In the field, wheat Tcrit varied diurnally-declining from noon through to sunrise-and increased with phenological development. Under controlled conditions, heat stress (36 °C) drove a rapid (within 2 h) rise in Tcrit that peaked after 3-4 d. The peak in Tcrit indicated an upper limit to PSII heat tolerance. A global dataset [comprising 183 Triticum and wild wheat (Aegilops) species] generated from the current study and a systematic literature review showed that wheat leaf Tcrit varied by up to 20 °C (roughly two-thirds of reported global plant interspecies variation). However, unlike global patterns of interspecies Tcrit variation that have been linked to latitude of genotype origin, intraspecific variation in wheat Tcrit was unrelated to that. Overall, the observed genotypic variation and plasticity of wheat Tcrit suggest that this trait could be useful in high-throughput phenotyping of wheat photosynthetic heat tolerance.
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Affiliation(s)
- Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Julia Hammer
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
- Department of Biology, The University of Western Ontario, 1151 Richmond St, N6A 3K7, London, Canada
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Helen Bramley
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW 2390, Australia
| | - Yong-Ling Ruan
- Australia-China Research Centre for Crop Improvement and School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Richard Trethowan
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW 2390, Australia
- School of Life and Environmental Sciences, Plant Breeding Institute, Sydney Institute of Agriculture, The University of Sydney, Cobbitty, NSW 2570, Australia
| | - Onoriode Coast
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
- School of Environmental and Rural Sciences, University of New England, Armidale, NSW 2351, Australia
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15
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Bendall ER, Bedward M, Boer M, Clarke H, Collins L, Leigh A, Bradstock RA. Growth enhancements of elevated atmospheric [CO
2
] are reduced under drought‐like conditions in temperate eucalypts. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- E. R. Bendall
- University of Wollongong Centre for Environmental Risk Management of Bushfires Northfields Avenue Wollongong New South Wales Australia 2522
| | - M. Bedward
- University of Wollongong Centre for Environmental Risk Management of Bushfires Northfields Avenue Wollongong New South Wales Australia 2522
| | - M. Boer
- Hawkesbury Institute for the Environment Western Sydney University Richmond New South Wales Australia
| | - H. Clarke
- University of Wollongong Centre for Environmental Risk Management of Bushfires Northfields Avenue Wollongong New South Wales Australia 2522
- Hawkesbury Institute for the Environment Western Sydney University Richmond New South Wales Australia
| | - L. Collins
- La Trobe University Department of Ecology Environment & Evolution Bundoora Victoria 3086 Australia
- Arthur Rylah Institute for Environmental Research Department of Environment, Land, Water and Planning Heidelberg Victoria 3084 Australia
- Pacific Forestry Centre Canadian Forest Service Natural Resources Canada 506 Burnside Road West Victoria BC V8Z 1M5 Canada
| | - A. Leigh
- University of Technology Sydney School of Life Sciences Broadway New South Wales Australia
| | - R. A. Bradstock
- University of Wollongong Centre for Environmental Risk Management of Bushfires Northfields Avenue Wollongong New South Wales Australia 2522
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16
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Maccagni A, Willi Y. Niche breadth and elevational range size: a comparative study on Middle-European Brassicaceae species. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210005. [PMID: 35067087 PMCID: PMC8784931 DOI: 10.1098/rstb.2021.0005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 09/30/2021] [Indexed: 01/26/2023] Open
Abstract
High-elevation species are predicted to have larger elevational ranges compared with species of lower elevations. The reasoning is that temperature variability is greater at higher elevation, selecting for wider niche breadth and more plastic genotypes. We used macroevolutionary comparisons involving 90 Brassicaceae species of the central Alps to test for associations among median elevation of occurrence, elevational range size and thermal variability over space and time on the one hand, and their associations with performance breadth or trait plasticity on the other hand. Performance breadth and trait plasticity were estimated by raising replicate plants per species under three temperature treatments (mild, recurrent frost, recurrent heat). Against prediction, we found that mid-elevation species had the largest elevational ranges, and their ranges were associated with increased spatial thermal variability. Nevertheless, variability in the thermal regime was positively associated neither with niche breadth nor with plasticity. Evidence for adaptive constraints was limited to a trade-off between acclimation-based increases in frost and heat resistance, and phylogenetic niche conservatism for median elevation of occurrence and temporal thermal variability. Results suggest that large elevational range size is associated with divergent adaptation within species, but not with more niche breadth or trait plasticity. This article is part of the theme issue 'Species' ranges in the face of changing environments (part I)'.
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Affiliation(s)
- Alessio Maccagni
- Plant Ecology and Evolution, Department of Environmental Sciences, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
- Botanical Garden of the Canton Ticino, Brissago Islands, P.O. 245, 6614 Brissago, Switzerland
| | - Yvonne Willi
- Plant Ecology and Evolution, Department of Environmental Sciences, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
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17
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Aspinwall MJ, Chieppa J, Gray E, Golden-Ebanks M, Davidson L. Warming impacts on photosynthetic processes in dominant plant species in a subtropical forest. PHYSIOLOGIA PLANTARUM 2022; 174:e13654. [PMID: 35233781 DOI: 10.1111/ppl.13654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/20/2022] [Indexed: 05/21/2023]
Abstract
Climate warming could shift some subtropical regions to a tropical climate in the next 30 years. Yet, climate warming impacts on subtropical species and ecosystems remain unclear. We conducted a passive warming experiment in a subtropical forest in Florida, USA, to determine warming impacts on four species differing in their climatic distribution, growth form, and functional type: Serenoa repens (palm), Andropogon glomeratus (C4 grass), Pinus palustris (needled evergreen tree), and Quercus laevis (broadleaved deciduous tree). We hypothesized that warming would have neutral-positive effects on photosynthetic processes in monocot species with warmer climatic distributions or adaptations to warmer temperatures, but negative effects on photosynthesis in tree species. We also hypothesized that periods of low soil moisture would alter photosynthetic responses to warming. In both monocot species, warming had no significant effect on net photosynthesis (A) or stomatal conductance (gs ) measured at prevailing temperatures, or photosynthetic capacity measured at a common temperature. In P. palustris, warming reduced A (-15%) and gs (-28%), and caused small reductions in Rubisco carboxylation and RuBP regeneration. Warming had little effect on photosynthetic processes in Q. laevis. Interestingly, A. glomeratus showed little sensitivity to reduced soil moisture, and all C3 species reduced A and gs as soil moisture declined and did so consistently across temperature treatments. In subtropical forests of the southeastern US, we conclude that climate warming may have neutral or slightly positive effects on the performance of grasses and broadleaved species but negative effects on P. palustris seedlings, foreshadowing possible changes in community and ecosystem properties.
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Affiliation(s)
- Michael J Aspinwall
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
| | - Jeff Chieppa
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
| | - Eve Gray
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
| | | | - Lynsae Davidson
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
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18
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Marchin RM, Backes D, Ossola A, Leishman MR, Tjoelker MG, Ellsworth DS. Extreme heat increases stomatal conductance and drought-induced mortality risk in vulnerable plant species. GLOBAL CHANGE BIOLOGY 2022; 28:1133-1146. [PMID: 34741566 PMCID: PMC9299030 DOI: 10.1111/gcb.15976] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/12/2021] [Accepted: 10/27/2021] [Indexed: 05/29/2023]
Abstract
Tree mortality during global-change-type drought is usually attributed to xylem dysfunction, but as climate change increases the frequency of extreme heat events, it is necessary to better understand the interactive role of heat stress. We hypothesized that some drought-stressed plants paradoxically open stomata in heatwaves to prevent leaves from critically overheating. We experimentally imposed heat (>40°C) and drought stress onto 20 broadleaf evergreen tree/shrub species in a glasshouse study. Most well-watered plants avoided lethal overheating, but drought exacerbated thermal damage during heatwaves. Thermal safety margins (TSM) quantifying the difference between leaf surface temperature and leaf critical temperature, where photosynthesis is disrupted, identified species vulnerability to heatwaves. Several mechanisms contributed to high heat tolerance and avoidance of damaging leaf temperatures-small leaf size, low leaf osmotic potential, high leaf mass per area (i.e., thick, dense leaves), high transpirational capacity, and access to water. Water-stressed plants had smaller TSM, greater crown dieback, and a fundamentally different stomatal heatwave response relative to well-watered plants. On average, well-watered plants closed stomata and decreased stomatal conductance (gs ) during the heatwave, but droughted plants did not. Plant species with low gs , either due to isohydric stomatal behavior under water deficit or inherently low transpirational capacity, opened stomata and increased gs under high temperatures. The current paradigm maintains that stomata close before hydraulic thresholds are surpassed, but our results suggest that isohydric species may dramatically increase gs (over sixfold increases) even past their leaf turgor loss point. By actively increasing water loss at high temperatures, plants can be driven toward mortality thresholds more rapidly than has been previously recognized. The inclusion of TSM and responses to heat stress could improve our ability to predict the vulnerability of different tree species to future droughts.
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Affiliation(s)
- Renée M. Marchin
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Diana Backes
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Alessandro Ossola
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Michelle R. Leishman
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Mark G. Tjoelker
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - David S. Ellsworth
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
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19
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Filipe JC, Rymer PD, Byrne M, Hardy G, Mazanec R, Ahrens CW. Signatures of natural selection in a foundation tree along Mediterranean climatic gradients. Mol Ecol 2022; 31:1735-1752. [PMID: 35038378 PMCID: PMC9305101 DOI: 10.1111/mec.16351] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/04/2022] [Accepted: 01/10/2022] [Indexed: 11/30/2022]
Abstract
Temperature and precipitation regimes are rapidly changing, resulting in forest dieback and extinction events, particularly in Mediterranean‐type climates (MTC). Forest management that enhance forests’ resilience is urgently required, however adaptation to climates in heterogeneous landscapes with multiple selection pressures is complex. For widespread trees in MTC we hypothesized that: patterns of local adaptation are associated with climate; precipitation is a stronger factor of adaptation than temperature; functionally related genes show similar signatures of adaptation; and adaptive variants are independently sorting across the landscape. We sampled 28 populations across the geographic distribution of Eucalyptus marginata (jarrah), in South‐west Western Australia, and obtained 13,534 independent single nucleotide polymorphic (SNP) markers across the genome. Three genotype‐association analyses that employ different ways of correcting population structure were used to identify putatively adapted SNPs associated with independent climate variables. While overall levels of population differentiation were low (FST = 0.04), environmental association analyses found a total of 2336 unique SNPs associated with temperature and precipitation variables, with 1440 SNPs annotated to genic regions. Considerable allelic turnover was identified for SNPs associated with temperature seasonality and mean precipitation of the warmest quarter, suggesting that both temperature and precipitation are important factors in adaptation. SNPs with similar gene functions had analogous allelic turnover along climate gradients, while SNPs among temperature and precipitation variables had uncorrelated patterns of adaptation. These contrasting patterns provide evidence that there may be standing genomic variation adapted to current climate gradients, providing the basis for adaptive management strategies to bolster forest resilience in the future.
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Affiliation(s)
- J C Filipe
- Centre for Terrestrial Ecosystem Science and Sustainability, Harry Butler Institute, Murdoch University
| | - P D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University
| | - M Byrne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions
| | - G Hardy
- Centre for Terrestrial Ecosystem Science and Sustainability, Harry Butler Institute, Murdoch University
| | - R Mazanec
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions
| | - C W Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University
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20
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Tarvainen L, Wittemann M, Mujawamariya M, Manishimwe A, Zibera E, Ntirugulirwa B, Ract C, Manzi OJL, Andersson MX, Spetea C, Nsabimana D, Wallin G, Uddling J. Handling the heat - photosynthetic thermal stress in tropical trees. THE NEW PHYTOLOGIST 2022; 233:236-250. [PMID: 34655491 DOI: 10.1111/nph.17809] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/09/2021] [Indexed: 06/13/2023]
Abstract
Warming climate increases the risk for harmful leaf temperatures in terrestrial plants, causing heat stress and loss of productivity. The heat sensitivity may be particularly high in equatorial tropical tree species adapted to a thermally stable climate. Thermal thresholds of the photosynthetic system of sun-exposed leaves were investigated in three tropical montane tree species native to Rwanda with different growth and water use strategies (Harungana montana, Syzygium guineense and Entandrophragma exselsum). Measurements of chlorophyll fluorescence, leaf gas exchange, morphology, chemistry and temperature were made at three common gardens along an elevation/temperature gradient. Heat tolerance acclimated to maximum leaf temperature (Tleaf ) across the species. At the warmest sites, the thermal threshold for normal function of photosystem II was exceeded in the species with the highest Tleaf despite their higher heat tolerance. This was not the case in the species with the highest transpiration rates and lowest Tleaf . The results point to two differently effective strategies for managing thermal stress: tolerance through physiological adjustment of leaf osmolality and thylakoid membrane lipid composition, or avoidance through morphological adaptation and transpiratory cooling. More severe photosynthetic heat stress in low-transpiring montane climax species may result in a competitive disadvantage compared to high-transpiring pioneer species with more efficient leaf cooling.
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Affiliation(s)
- Lasse Tarvainen
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Maria Wittemann
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Myriam Mujawamariya
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Aloysie Manishimwe
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Etienne Zibera
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Bonaventure Ntirugulirwa
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
- Rwanda Agriculture and Animal Development Board, PO Box 5016, Kigali, Rwanda
| | - Claire Ract
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Olivier J L Manzi
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Mats X Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Donat Nsabimana
- School of Forestry and Biodiversity and Biological Sciences, University of Rwanda, Busogo, Rwanda
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
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21
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Sturchio MA, Chieppa J, Chapman SK, Canas G, Aspinwall MJ. Temperature acclimation of leaf respiration differs between marsh and mangrove vegetation in a coastal wetland ecotone. GLOBAL CHANGE BIOLOGY 2022; 28:612-629. [PMID: 34653300 DOI: 10.1111/gcb.15938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/04/2021] [Indexed: 05/21/2023]
Abstract
Temperature acclimation of leaf respiration (R) is an important determinant of ecosystem responses to temperature and the magnitude of temperature-CO2 feedbacks as climate warms. Yet, the extent to which temperature acclimation of R exhibits a common pattern across different growth conditions, ecosystems, and plant functional types remains unclear. Here, we measured the short-term temperature response of R at six time points over a 10-month period in two coastal wetland species (Avicennia germinans [C3 mangrove] and Spartina alterniflora [C4 marsh grass]) growing under ambient and experimentally warmed temperatures at two sites in a marsh-mangrove ecotone. Leaf nitrogen (N) was determined on a subsample of leaves to explore potential coupling of R and N. We hypothesized that both species would reduce R at 25°C (R25 ) and the short-term temperature sensitivity of R (Q10 ) as air temperature (Tair ) increased across seasons, but the decline would be stronger in Avicennia than in Spartina. For each species, we hypothesized that seasonal temperature acclimation of R would be equivalent in plants grown under ambient and warmed temperatures, demonstrating convergent acclimation. Surprisingly, Avicennia generally increased R25 with increasing growth temperature, although the Q10 declined as seasonal temperatures increased and did so consistently across sites and treatments. Weak temperature acclimation resulted in reduced homeostasis of R in Avicennia. Spartina reduced R25 and the Q10 as seasonal temperatures increased. In Spartina, seasonal temperature acclimation was largely consistent across sites and treatments resulting in greater respiratory homeostasis. We conclude that co-occurring coastal wetland species may show contrasting patterns of respiratory temperature acclimation. Nonetheless, leaf N scaled positively with R25 in both species, highlighting the importance of leaf N in predicting respiratory capacity across a range of growth temperatures. The patterns of respiratory temperature acclimation shown here may improve the predictions of temperature controls of CO2 fluxes in coastal wetlands.
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Affiliation(s)
- Matthew A Sturchio
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
| | - Jeff Chieppa
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
| | - Samantha K Chapman
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, Villanova, Pennsylvania, USA
| | - Gabriela Canas
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
| | - Michael J Aspinwall
- Department of Biology, University of North Florida, Jacksonville, Florida, USA
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
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22
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Ahrens CW, Challis A, Byrne M, Leigh A, Nicotra AB, Tissue D, Rymer P. Repeated extreme heatwaves result in higher leaf thermal tolerances and greater safety margins. THE NEW PHYTOLOGIST 2021; 232:1212-1225. [PMID: 34292598 DOI: 10.1111/nph.17640] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
The frequency and severity of heatwave events are increasing, exposing species to conditions beyond their physiological limits. Species respond to heatwaves in different ways, however it remains unclear if plants have the adaptive capacity to successfully respond to hotter and more frequent heatwaves. We exposed eight tree populations from two climate regions grown under cool and warm temperatures to repeated heatwave events of moderate (40°C) and extreme (46°C) severity to assess adaptive capacity to heatwaves. Leaf damage and maximum quantum efficiency of photosystem II (Fv /Fm ) were significantly impacted by heatwave severity and growth temperatures, respectively; populations from a warm-origin avoided damage under moderate heatwaves compared to those from a cool-origin, indicating a degree of local adaptation. We found that plasticity to heatwave severity and repeated heatwaves contributed to enhanced thermal tolerance and lower leaf temperatures, leading to greater thermal safety margins (thermal tolerance minus leaf temperature) in a second heatwave. Notably, while we show that adaptation and physiological plasticity are important factors affecting plant adaptive capacity to thermal stress, plasticity of thermal tolerances and thermal safety margins provides the opportunity for trees to persist among fluctuating heatwave exposures.
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Affiliation(s)
- Collin W Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Margaret Byrne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, Locked Bag 104, Bentley, WA, 6983, Australia
| | - Andrea Leigh
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Adrienne B Nicotra
- Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Paul Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
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Shay JE, Pennington LK, Mandussi Montiel-Molina JA, Toews DJ, Hendrickson BT, Sexton JP. Rules of Plant Species Ranges: Applications for Conservation Strategies. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.700962] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Earth is changing rapidly and so are many plant species’ ranges. Here, we synthesize eco-evolutionary patterns found in plant range studies and how knowledge of species ranges can inform our understanding of species conservation in the face of global change. We discuss whether general biogeographic “rules” are reliable and how they can be used to develop adaptive conservation strategies of native plant species across their ranges. Rules considered include (1) factors that set species range limits and promote range shifts; (2) the impact of biotic interactions on species range limits; (3) patterns of abundance and adaptive properties across species ranges; (4) patterns of gene flow and their implications for genetic rescue, and (5) the relationship between range size and conservation risk. We conclude by summarizing and evaluating potential species range rules to inform future conservation and management decisions. We also outline areas of research to better understand the adaptive capacity of plants under environmental change and the properties that govern species ranges. We advise conservationists to extend their work to specifically consider peripheral and novel populations, with a particular emphasis on small ranges. Finally, we call for a global effort to identify, synthesize, and analyze prevailing patterns or rules in ecology to help speed conservation efforts.
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Breshears DD, Fontaine JB, Ruthrof KX, Field JP, Feng X, Burger JR, Law DJ, Kala J, Hardy GESJ. Underappreciated plant vulnerabilities to heat waves. THE NEW PHYTOLOGIST 2021; 231:32-39. [PMID: 33728638 DOI: 10.1111/nph.17348] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
With climate change, heat waves are becoming increasingly frequent, intense and broader in spatial extent. However, while the lethal effects of heat waves on humans are well documented, the impacts on flora are less well understood, perhaps except for crops. We summarize recent findings related to heat wave impacts including: sublethal and lethal effects at leaf and plant scales, secondary ecosystem effects, and more complex impacts such as increased heat wave frequency across all seasons, and interactions with other disturbances. We propose generalizable practical trials to quantify the critical bounding conditions of vulnerability to heat waves. Collectively, plant vulnerabilities to heat waves appear to be underappreciated and understudied, particularly with respect to understanding heat wave driven plant die-off and ecosystem tipping points.
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Affiliation(s)
- David D Breshears
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Joseph B Fontaine
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia
| | - Katinka X Ruthrof
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Kensington, WA, 6151, Australia
| | - Jason P Field
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA
| | - Xiao Feng
- Department of Geography, Florida State University, Tallahassee, FL, 32306, USA
| | - Joseph R Burger
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
- Arizona Institutes for Resilience, University of Arizona, Tucson, AZ, 85721, USA
| | - Darin J Law
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA
| | - Jatin Kala
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia
- Centre for Climate-Impacted Terrestrial Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA, Australia
| | - Giles E St J Hardy
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia
- Centre for Climate-Impacted Terrestrial Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA, Australia
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25
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Wang R, He N, Li S, Xu L, Li M. Spatial variation and mechanisms of leaf water content in grassland plants at the biome scale: evidence from three comparative transects. Sci Rep 2021; 11:9281. [PMID: 33927280 PMCID: PMC8084930 DOI: 10.1038/s41598-021-88678-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 04/12/2021] [Indexed: 11/19/2022] Open
Abstract
Leaf water content (LWC) has important physiological and ecological significance for plant growth. However, it is still unclear how LWC varies over large spatial scale and with plant adaptation strategies. Here, we measured the LWC of 1365 grassland plants, along three comparative precipitation transects from meadow to desert on the Mongolia Plateau (MP), Loess Plateau, and Tibetan Plateau, respectively, to explore its spatial variation and the underlying mechanisms that determine this variation. The LWC data were normally distributed with an average value of 0.66 g g−1. LWC was not significantly different among the three plateaus, but it differed significantly among different plant life forms. Spatially, LWC in the three plateaus all decreased and then increased from meadow to desert grassland along a precipitation gradient. Unexpectedly, climate and genetic evolution only explained a small proportion of the spatial variation of LWC in all plateaus, and LWC was only weakly correlated with precipitation in the water-limited MP. Overall, the lasso variation in LWC with precipitation in all plateaus represented an underlying trade-off between structural investment and water income in plants, for better survival in various environments. In brief, plants should invest less to thrive in a humid environment (meadow), increase more investment to keep a relatively stable LWC in a drying environment, and have high investment to hold higher LWC in a dry environment (desert). Combined, these results indicate that LWC should be an important variable in future studies of large-scale trait variations.
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Affiliation(s)
- Ruomeng Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Nianpeng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China. .,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China. .,Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, 130024, China.
| | - Shenggong Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China. .,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Li Xu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China
| | - Mingxu Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China
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Roy J, Rineau F, De Boeck HJ, Nijs I, Pütz T, Abiven S, Arnone JA, Barton CVM, Beenaerts N, Brüggemann N, Dainese M, Domisch T, Eisenhauer N, Garré S, Gebler A, Ghirardo A, Jasoni RL, Kowalchuk G, Landais D, Larsen SH, Leemans V, Le Galliard J, Longdoz B, Massol F, Mikkelsen TN, Niedrist G, Piel C, Ravel O, Sauze J, Schmidt A, Schnitzler J, Teixeira LH, Tjoelker MG, Weisser WW, Winkler B, Milcu A. Ecotrons: Powerful and versatile ecosystem analysers for ecology, agronomy and environmental science. GLOBAL CHANGE BIOLOGY 2021; 27:1387-1407. [PMID: 33274502 PMCID: PMC7986626 DOI: 10.1111/gcb.15471] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 05/08/2023]
Abstract
Ecosystems integrity and services are threatened by anthropogenic global changes. Mitigating and adapting to these changes require knowledge of ecosystem functioning in the expected novel environments, informed in large part through experimentation and modelling. This paper describes 13 advanced controlled environment facilities for experimental ecosystem studies, herein termed ecotrons, open to the international community. Ecotrons enable simulation of a wide range of natural environmental conditions in replicated and independent experimental units while measuring various ecosystem processes. This capacity to realistically control ecosystem environments is used to emulate a variety of climatic scenarios and soil conditions, in natural sunlight or through broad-spectrum lighting. The use of large ecosystem samples, intact or reconstructed, minimizes border effects and increases biological and physical complexity. Measurements of concentrations of greenhouse trace gases as well as their net exchange between the ecosystem and the atmosphere are performed in most ecotrons, often quasi continuously. The flow of matter is often tracked with the use of stable isotope tracers of carbon and other elements. Equipment is available for measurements of soil water status as well as root and canopy growth. The experiments ran so far emphasize the diversity of the hosted research. Half of them concern global changes, often with a manipulation of more than one driver. About a quarter deal with the impact of biodiversity loss on ecosystem functioning and one quarter with ecosystem or plant physiology. We discuss how the methodology for environmental simulation and process measurements, especially in soil, can be improved and stress the need to establish stronger links with modelling in future projects. These developments will enable further improvements in mechanistic understanding and predictive capacity of ecotron research which will play, in complementarity with field experimentation and monitoring, a crucial role in exploring the ecosystem consequences of environmental changes.
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27
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Geange SR, Arnold PA, Catling AA, Coast O, Cook AM, Gowland KM, Leigh A, Notarnicola RF, Posch BC, Venn SE, Zhu L, Nicotra AB. The thermal tolerance of photosynthetic tissues: a global systematic review and agenda for future research. THE NEW PHYTOLOGIST 2021; 229:2497-2513. [PMID: 33124040 DOI: 10.1111/nph.17052] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/25/2020] [Indexed: 05/09/2023]
Abstract
Understanding plant thermal tolerance is fundamental to predicting impacts of extreme temperature events that are increasing in frequency and intensity across the globe. Extremes, not averages, drive species evolution, determine survival and increase crop performance. To better prioritize agricultural and natural systems research, it is crucial to evaluate how researchers are assessing the capacity of plants to tolerate extreme events. We conducted a systematic review to determine how plant thermal tolerance research is distributed across wild and domesticated plants, growth forms and biomes, and to identify crucial knowledge gaps. Our review shows that most thermal tolerance research examines cold tolerance of cultivated species; c. 5% of articles consider both heat and cold tolerance. Plants of extreme environments are understudied, and techniques widely applied in cultivated systems are largely unused in natural systems. Lastly, we find that lack of standardized methods and metrics compromises the potential for mechanistic insight. Our review provides an entry point for those new to the methods used in plant thermal tolerance research and bridges often disparate ecological and agricultural perspectives for the more experienced. We present a considered agenda of thermal tolerance research priorities to stimulate efficient, reliable and repeatable research across the spectrum of plant thermal tolerance.
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Affiliation(s)
- Sonya R Geange
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
- Department of Biological Sciences, University of Bergen, Bergen, 5008, Norway
- Bjerknes Centre for Climate Research, University of Bergen, Bergen, 5008, Norway
| | - Pieter A Arnold
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Alexandra A Catling
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
- School of Biological Sciences, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - Onoriode Coast
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent,, ME4 4TB, UK
| | - Alicia M Cook
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Kelli M Gowland
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Andrea Leigh
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, 2007, Australia
| | - Rocco F Notarnicola
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Bradley C Posch
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Susanna E Venn
- School of Life and Environmental Sciences, Deakin University, Melbourne, Vic., 3125, Australia
| | - Lingling Zhu
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Adrienne B Nicotra
- Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
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28
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Notarnicola RF, Nicotra AB, Kruuk LEB, Arnold PA. Tolerance of Warmer Temperatures Does Not Confer Resilience to Heatwaves in an Alpine Herb. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.615119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Climate change is generating both sustained trends in average temperatures and higher frequency and intensity of extreme events. This poses a serious threat to biodiversity, especially in vulnerable environments, like alpine systems. Phenotypic plasticity is considered to be an adaptive mechanism to cope with climate change in situ, yet studies of the plastic responses of alpine plants to high temperature stress are scarce. Future weather extremes will occur against a background of warmer temperatures, but we do not know whether acclimation to warmer average temperatures confers tolerance to extreme heatwaves. Nor do we know whether populations on an elevational gradient differ in their tolerance or plasticity in response to warming and heatwave events. We investigated the responses of a suite of functional traits of an endemic Australian alpine herb, Wahlenbergia ceracea, to combinations of predicted future (warmer) temperatures and (relative) heatwaves. We also tested whether responses differed between high- vs. low-elevation populations. When grown under warmer temperatures, W. ceracea plants showed signs of acclimation by means of higher thermal tolerance (Tcrit, T50, and Tmax). They also invested more in flower production, despite showing a concurrent reduction in photosynthetic efficiency (Fv/Fm) and suppression of seed production. Heatwaves reduced both photosynthetic efficiency and longevity. However, we found no evidence that acclimation to warmer temperatures conferred tolerance of the photosynthetic machinery to heatwaves. Instead, when exposed to heatwaves following warmer growth temperatures, plants had lower photosynthetic efficiency and underwent a severe reduction in seed production. High- and low-elevation populations and families exhibited limited genetic variation in trait means and plasticity in response to temperature. We conclude that W. ceracea shows some capacity to acclimate to warming conditions but there is no evidence that tolerance of warmer temperatures confers any resilience to heatwaves.
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29
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Zhu L, Bloomfield KJ, Asao S, Tjoelker MG, Egerton JJG, Hayes L, Weerasinghe LK, Creek D, Griffin KL, Hurry V, Liddell M, Meir P, Turnbull MH, Atkin OK. Acclimation of leaf respiration temperature responses across thermally contrasting biomes. THE NEW PHYTOLOGIST 2021; 229:1312-1325. [PMID: 32931621 DOI: 10.1111/nph.16929] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Short-term temperature response curves of leaf dark respiration (R-T) provide insights into a critical process that influences plant net carbon exchange. This includes how respiratory traits acclimate to sustained changes in the environment. Our study analysed 860 high-resolution R-T (10-70°C range) curves for: (a) 62 evergreen species measured in two contrasting seasons across several field sites/biomes; and (b) 21 species (subset of those sampled in the field) grown in glasshouses at 20°C : 15°C, 25°C : 20°C and 30°C : 25°C, day : night. In the field, across all sites/seasons, variations in R25 (measured at 25°C) and the leaf T where R reached its maximum (Tmax ) were explained by growth T (mean air-T of 30-d before measurement), solar irradiance and vapour pressure deficit, with growth T having the strongest influence. R25 decreased and Tmax increased with rising growth T across all sites and seasons with the single exception of winter at the cool-temperate rainforest site where irradiance was low. The glasshouse study confirmed that R25 and Tmax thermally acclimated. Collectively, the results suggest: (1) thermal acclimation of leaf R is common in most biomes; and (2) the high T threshold of respiration dynamically adjusts upward when plants are challenged with warmer and hotter climates.
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Affiliation(s)
- Lingling Zhu
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Keith J Bloomfield
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Shinichi Asao
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - John J G Egerton
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Building 116, Canberra, ACT, 2601, Australia
| | - Lucy Hayes
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
| | - Lasantha K Weerasinghe
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
- Faculty of Agriculture, University of Peradeniya, Peradeniya, 20400, Sri Lanka
| | - Danielle Creek
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
- INRAE Univ. Clermont-Auvergne, PIAF, Clermont-Ferrand, 63000, France
| | - Kevin L Griffin
- Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, 10964, USA
| | - Vaughan Hurry
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 84, Sweden
| | - Michael Liddell
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Qld, 4878, Australia
| | - Patrick Meir
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
| | - Matthew H Turnbull
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
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30
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Birami B, Nägele T, Gattmann M, Preisler Y, Gast A, Arneth A, Ruehr NK. Hot drought reduces the effects of elevated CO 2 on tree water-use efficiency and carbon metabolism. THE NEW PHYTOLOGIST 2020; 226:1607-1621. [PMID: 32017113 DOI: 10.1111/nph.16471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/28/2020] [Indexed: 05/15/2023]
Abstract
Trees are increasingly exposed to hot droughts due to CO2 -induced climate change. However, the direct role of [CO2 ] in altering tree physiological responses to drought and heat stress remains ambiguous. Pinus halepensis (Aleppo pine) trees were grown from seed under ambient (421 ppm) or elevated (867 ppm) [CO2 ]. The 1.5-yr-old trees, either well watered or drought treated for 1 month, were transferred to separate gas-exchange chambers and the temperature gradually increased from 25°C to 40°C over a 10 d period. Continuous whole-tree shoot and root gas-exchange measurements were supplemented by primary metabolite analysis. Elevated [CO2 ] reduced tree water loss, reflected in lower stomatal conductance, resulting in a higher water-use efficiency throughout amplifying heat stress. Net carbon uptake declined strongly, driven by increases in respiration peaking earlier in the well-watered (31-32°C) than drought (33-34°C) treatments unaffected by growth [CO2 ]. Further, drought altered the primary metabolome, whereas the metabolic response to [CO2 ] was subtle and mainly reflected in enhanced root protein stability. The impact of elevated [CO2 ] on tree stress responses was modest and largely vanished with progressing heat and drought. We therefore conclude that increases in atmospheric [CO2 ] cannot counterbalance the impacts of hot drought extremes in Aleppo pine.
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Affiliation(s)
- Benjamin Birami
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, 82467, Germany
| | - Thomas Nägele
- Department of Biology I, Plant Evolutionary Cell Biology, Ludwig-Maximilian University Munich, Planegg, 82152, Germany
- Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, 1090, Austria
| | - Marielle Gattmann
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, 82467, Germany
| | - Yakir Preisler
- Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Andreas Gast
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, 82467, Germany
| | - Almut Arneth
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, 82467, Germany
| | - Nadine K Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, 82467, Germany
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31
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Zhu L, Cernusak LA, Song X. Dynamic responses of gas exchange and photochemistry to heat interference during drought in wheat and sorghum. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:611-627. [PMID: 32393434 DOI: 10.1071/fp19242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 01/14/2020] [Indexed: 06/11/2023]
Abstract
Drought and heat stress significantly affect crop growth and productivity worldwide. It is unknown how heat interference during drought affects physiological processes dynamically in crops. Here we focussed on gas exchange and photochemistry in wheat and sorghum in response to simulated heat interference via +15°C of temperature during ~2 week drought and re-watering. Results showed that drought decreased net photosynthesis (Anet), stomatal conductance (gs), maximum velocity of ribulose-1, 5-bisphosphate carboxylase/oxygenase carboxylation (Vcmax) and electron transport rate (J) in both wheat and sorghum. Heat interference did not further reduce Anet or gs. Drought increased non-photochemical quenching (Φnpq), whereas heat interference decreased Φnpq. The δ13C of leaf, stem and roots was higher in drought-treated wheat but lower in drought-treated sorghum. The results suggest that (1) even under drought conditions wheat and sorghum increased or maintained gs for transpirational cooling to alleviate negative effects by heat interference; (2) non-photochemical quenching responded differently to drought and heat stress; (3) wheat and sorghum responded in opposing patterns in δ13C. These findings point to the importance of stomatal regulation under heat crossed with drought stress and could provide useful information on development of better strategies to secure crop production for future climate change.
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Affiliation(s)
- Lingling Zhu
- Shenzhen Key Laboratory of Marine Biological Resources and Ecological Environment, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Australia
| | - Xin Song
- Shenzhen Key Laboratory of Marine Biological Resources and Ecological Environment, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; and Corresponding author.
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32
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Diverging Responses of Two Subtropical Tree Species (Schima superba and Cunninghamia lanceolata) to Heat Waves. FORESTS 2020. [DOI: 10.3390/f11050513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The frequency and intensity of heat waves (HWs) has increased in subtropical regions in recent years. The mechanism underlying the HW response of subtropical trees remains unclear. In this study, we conducted an experiment with broad-leaved Schima superba (S. superba) and coniferous Cunninghamia lanceolata (C. lanceolata) seedlings to examine HW (5-day long) effects on stem water transport, leaf water use efficiency (WUE), morphology and growth, and to elucidate differences in the responses of both species. Our results indicated that HWs can significantly reduce hydraulic conductivity in both species. C. lanceolata experienced significant xylem embolism, with the percentage loss of conductivity (PLC) increasing by 40%, while S. superba showed a non-significant increase in PLC (+25%). Furthermore, HW also caused a reduction in photosynthesis rates (An), but transpiration rates (Tr) increased on the 5th day of the HW, together leading to a significant decrease in leaf WUE. From diurnal dynamics, we observed that the HW caused significant decrease of S. superba An only in the morning, but nearly the all day for C. lanceolata. During the morning, with a high vapor pressure deficit (VPD) environment, the HW increased Tr, which contributed a lot to latently cooling the foliage. In comparing the two tree species, we found that HW effects on S. superba were mostly short-term, with leaf senescence but limited or no xylem embolism. The surviving S. superba recovered rapidly, forming new branches and leaves, aided by their extensive root systems. For C. lanceolata, continued seedling growth initially but with subsequent xylem embolism and withering of shoots, led to stunted recovery and regrowth. In conclusion, apart from the direct thermal impacts caused by HW, drought stress was the main cause of significant negative effects on plant water transport and the photosynthetic system. Furthermore, S. superba and C. lanceolata showed clearly different responses to HW, which implies that the response mechanisms of broad-leaved and coniferous tree species to climate change can differ.
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Yichie Y, Hasan MT, Tobias PA, Pascovici D, Goold HD, Van Sluyter SC, Roberts TH, Atwell BJ. Salt-Treated Roots of Oryza australiensis Seedlings are Enriched with Proteins Involved in Energetics and Transport. Proteomics 2019; 19:e1900175. [PMID: 31475433 DOI: 10.1002/pmic.201900175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/05/2019] [Indexed: 11/08/2022]
Abstract
Salinity is a major constraint on rice productivity worldwide. However, mechanisms of salt tolerance in wild rice relatives are unknown. Root microsomal proteins are extracted from two Oryza australiensis accessions contrasting in salt tolerance. Whole roots of 2-week-old seedlings are treated with 80 mM NaCl for 30 days to induce salt stress. Proteins are quantified by tandem mass tags (TMT) and triple-stage Mass Spectrometry. More than 200 differentially expressed proteins between the salt-treated and control samples in the two accessions (p-value <0.05) are found. Gene Ontology (GO) analysis shows that proteins categorized as "metabolic process," "transport," and "transmembrane transporter" are highly responsive to salt treatment. In particular, mitochondrial ATPases and SNARE proteins are more abundant in roots of the salt-tolerant accession and responded strongly when roots are exposed to salinity. mRNA quantification validated the elevated protein abundances of a monosaccharide transporter and an antiporter observed in the salt-tolerant genotype. The importance of the upregulated monosaccharide transporter and a VAMP-like protein by measuring salinity responses of two yeast knockout mutants for genes homologous to those encoding these proteins in rice are confirmed. Potential new mechanisms of salt tolerance in rice, with implications for breeding of elite cultivars are also discussed.
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Affiliation(s)
- Yoav Yichie
- Sydney Institute of Agriculture, University of Sydney, Sydney, Australia
| | - Mafruha T Hasan
- Sydney Institute of Agriculture, University of Sydney, Sydney, Australia
| | - Peri A Tobias
- Sydney Institute of Agriculture, University of Sydney, Sydney, Australia
| | - Dana Pascovici
- Australian Proteome Analysis Facility, Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Hugh D Goold
- NSW Department of Primary Industries, Macquarie University, Sydney, Australia.,Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | | | - Thomas H Roberts
- Sydney Institute of Agriculture, University of Sydney, Sydney, Australia
| | - Brian J Atwell
- Department of Biological Sciences, Macquarie University, Sydney, Australia
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