1
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Mulero G, Jiang D, Bonfil DJ, Helman D. Use of thermal imaging and the photochemical reflectance index (PRI) to detect wheat response to elevated CO 2 and drought. PLANT, CELL & ENVIRONMENT 2023; 46:76-92. [PMID: 36289576 PMCID: PMC10098568 DOI: 10.1111/pce.14472] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/05/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
The spectral-based photochemical reflectance index (PRI) and leaf surface temperature (Tleaf ) derived from thermal imaging are two indicative metrics of plant functioning. The relationship of PRI with radiation-use efficiency (RUE) and Tleaf with leaf transpiration could be leveraged to monitor crop photosynthesis and water use from space. Yet, it is unclear how such relationships will change under future high carbon dioxide concentrations ([CO2 ]) and drought. Here we established an [CO2 ] enrichment experiment in which three wheat genotypes were grown at ambient (400 ppm) and elevated (550 ppm) [CO2 ] and exposed to well-watered and drought conditions in two glasshouse rooms in two replicates. Leaf transpiration (Tr ) and latent heat flux (LE) were derived to assess evaporative cooling, and RUE was calculated from assimilation and radiation measurements on several dates along the season. Simultaneous hyperspectral and thermal images were taken at~ $\unicode{x0007E}$ 1.5 m from the plants to derive PRI and the temperature difference between the leaf and its surrounding air (∆ $\unicode{x02206}$ Tleaf-air ). We found significant PRI and RUE and∆ $\unicode{x02206}$ Tleaf-air and Tr correlations, with no significant differences among the genotypes. A PRI-RUE decoupling was observed under drought at ambient [CO2 ] but not at elevated [CO2 ], likely due to changes in photorespiration. For a LE range of 350 W m-2 , the ΔTleaf-air range was~ $\unicode{x0007E}$ 10°C at ambient [CO2 ] and only~ $\unicode{x0007E}$ 4°C at elevated [CO2 ]. Thicker leaves in plants grown at elevated [CO2 ] suggest higher leaf water content and consequently more efficient thermoregulation at high [CO2 ] conditions. In general, Tleaf was maintained closer to the ambient temperature at elevated [CO2 ], even under drought. PRI, RUE, ΔTleaf -air , and Tr decreased linearly with canopy depth, displaying a single PRI-RUE and ΔTleaf -air Tr model through the canopy layers. Our study shows the utility of these sensing metrics in detecting wheat responses to future environmental changes.
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Affiliation(s)
- Gabriel Mulero
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
| | - Duo Jiang
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
| | - David J. Bonfil
- Department of Vegetable and Field Crop ResearchAgricultural Research Organization, Gilat Research CenterGilatIsrael
| | - David Helman
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
- The Advanced School for Environmental StudiesThe Hebrew University of JerusalemJerusalemIsrael
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2
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Jiang D, Mulero G, Bonfil DJ, Helman D. Early or late? The role of genotype phenology in determining wheat response to drought under future high atmospheric CO 2 levels. PLANT, CELL & ENVIRONMENT 2022; 45:3445-3461. [PMID: 36098352 PMCID: PMC9828765 DOI: 10.1111/pce.14430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 08/29/2022] [Indexed: 06/01/2023]
Abstract
The combination of a future rise in atmospheric carbon dioxide concentration ([CO2 ]) and drought will significantly impact wheat production and quality. Genotype phenology is likely to play an essential role in such an effect. Yet, its response to elevated [CO2 ] and drought has not been studied before. Here we conducted a temperature-controlled glasshouse [CO2 ] enrichment experiment in which two wheat cultivars with differing maturity timings and life cycle lengths were grown under ambient (aCO2 approximately 400 μmol mol-1 ) and elevated (eCO2 approximately 550 μmol mol-1 ) [CO2 ]. The two cultivars, bred under dry and warm Mediterranean conditions, were well-watered or exposed to drought at 40% pot holding capacity. We aimed to explore water × [CO2 ] × genotype interaction in terms of phenology, physiology, and agronomic trait response. Our results show that eCO2 had a significant effect on plants grown under drought. eCO2 boosted the booting stage of the late-maturing genotype (cv. Ruta), thereby prolonging its booting-to-anthesis period by approximately 3 days (p < 0.05) while unaffecting the phenological timing of the early-maturing genotype (cv. Zahir). The prolonged period resulted in a much higher carbon assimilation rate, particularly during pre-anthesis (+87% for Ruta vs. +22% for Zahir under eCO2 ). Surprisingly, there was no eCO2 effect on transpiration rate and grain protein content in both cultivars and under both water conditions. The higher photosynthesis (and transpiration efficiency) of Ruta was not translated into higher aboveground biomass or grain yield, whereas both cultivars showed a similar increase of approximately 20% in these two traits at eCO2 under drought. Overall, Zahir, the cultivar that responded the least to eCO2, had a more efficient source-to-sink balance with a lower sink limitation than Ruta. The complex water × [CO2 ] × genotype interaction found in this study implies that future projections should account for multifactor interactive effects in modeling wheat response to future climate.
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Affiliation(s)
- Duo Jiang
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
| | - Gabriel Mulero
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
| | - David J. Bonfil
- Department of Vegetable and Field Crop Research, Agricultural Research OrganizationGilat Research CenterGilatIsrael
| | - David Helman
- Department of Soil & Water Sciences, Institute of Environmental Sciences, The Robert H. Smith Faculty of Agriculture, Food and EnvironmentThe Hebrew University of JerusalemRehovotIsrael
- The Advanced School for Environmental StudiesThe Hebrew University of JerusalemJerusalemIsrael
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3
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Six decades of warming and drought in the world's top wheat-producing countries offset the benefits of rising CO 2 to yield. Sci Rep 2022; 12:7921. [PMID: 35562577 PMCID: PMC9106749 DOI: 10.1038/s41598-022-11423-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 04/14/2022] [Indexed: 11/09/2022] Open
Abstract
Future atmospheric carbon-dioxide concentration ([CO2]) rise is expected to increase the grain yield of C3 crops like wheat even higher under drought. This expectation is based on small-scale experiments and model simulations based on such observations. However, this combined effect has never been confirmed through actual observations at the nationwide or regional scale. We present the first evidence that warming and drought in the world's leading wheat-producing countries offset the benefits of increasing [CO2] to wheat yield in the last six decades. Using country-level wheat yield census observations, [CO2] records, and gridded climate data in a statistical model based on a well-established methodology, we show that a [CO2] rise of ~ 98 μmol mol-1 increased the yield by 7% in the area of the top-twelve wheat-producing countries, while warming of 1.2 °C and water depletion of ~ 29 mm m-2 reduced the wheat grain yield by ~ 3% and ~ 1%, respectively, in the last six decades (1961-2019). Our statistical model corroborated the beneficial effect of [CO2] but contrasted the expected increase of grain yield under drought. Moreover, the increase in [CO2] barely offsets the adverse impacts of warming and drought in countries like Germany and France, with a net yield loss of 3.1% and no gain, respectively, at the end of the sampling period relative to the 1961-1965 baseline. In China and the wheat-growing areas of the former Soviet Union-two of the three largest wheat-producing regions-yields were ~ 5.5% less than expected from current [CO2] levels. Our results suggest shifting our efforts towards more experimental studies set in currently warm and dry areas and combining these with statistical and numerical modeling to improve our understanding of future impacts of a warmer and drier world with higher [CO2].
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4
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Liu S, Zhuang Q. Leaf
13
C data constrain the uncertainty of the carbon dynamics of temperate forest ecosystems. Ecosphere 2021. [DOI: 10.1002/ecs2.3741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Shaoqing Liu
- Department of Earth, Atmospheric and Planetary Sciences Purdue University West Lafayette Indiana USA
- Department of Environmental and Earth Sciences University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Qianlai Zhuang
- Department of Earth, Atmospheric and Planetary Sciences Purdue University West Lafayette Indiana USA
- Department of Agronomy Purdue University West Lafayette Indiana USA
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5
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Marcos-Barbero EL, Pérez P, Martínez-Carrasco R, Arellano JB, Morcuende R. Screening for Higher Grain Yield and Biomass among Sixty Bread Wheat Genotypes Grown under Elevated CO 2 and High-Temperature Conditions. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10081596. [PMID: 34451641 PMCID: PMC8401911 DOI: 10.3390/plants10081596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 06/01/2023]
Abstract
Global warming will inevitably affect crop development and productivity, increasing uncertainty regarding food production. The exploitation of genotypic variability can be a promising approach for selecting improved crop varieties that can counteract the adverse effects of future climate change. We investigated the natural variation in yield performance under combined elevated CO2 and high-temperature conditions in a set of 60 bread wheat genotypes (59 of the 8TH HTWSN CIMMYT collection and Gazul). Plant height, biomass production, yield components and phenological traits were assessed. Large variations in the selected traits were observed across genotypes. The CIMMYT genotypes showed higher biomass and grain yield when compared to Gazul, indicating that the former performed better than the latter under the studied environmental conditions. Principal component and hierarchical clustering analyses revealed that the 60 wheat genotypes employed different strategies to achieve final grain yield, highlighting that the genotypes that can preferentially increase grain and ear numbers per plant will display better yield responses under combined elevated levels of CO2 and temperature. This study demonstrates the success of the breeding programs under warmer temperatures and the plants' capacity to respond to the concurrence of certain environmental factors, opening new opportunities for the selection of widely adapted climate-resilient wheat genotypes.
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6
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Miao Y, Cai Y, Wu H, Wang D. Diurnal and Seasonal Variations in the Photosynthetic Characteristics and the Gas Exchange Simulations of Two Rice Cultivars Grown at Ambient and Elevated CO 2. FRONTIERS IN PLANT SCIENCE 2021; 12:651606. [PMID: 33889167 PMCID: PMC8056013 DOI: 10.3389/fpls.2021.651606] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 03/12/2021] [Indexed: 05/02/2023]
Abstract
Investigating the diurnal and seasonal variations of plant photosynthetic performance under future atmospheric CO2 conditions is essential for understanding plant adaptation to global change and for estimating parameters of ecophysiological models. In this study, diurnal changes of net photosynthetic rate (Anet), stomatal conductance (gs), and photochemical efficiency of PSII (Fv'/F m ') were measured in two rice cultivars grown in the open-top-chambers at ambient (∼450 μmol mol-1) and elevated (∼650 μmol mol-1) CO2 concentration [(CO2)] throughout the growing season for 2 years. The results showed that elevated (CO2) greatly increased Anet, especially at jointing stage. This stimulation was acclimated with the advance of growing season and was not affected by either stomatal limitations or Rubisco activity. Model parameters in photosynthesis model (Vcmax, Jmax, and Rd) and two stomatal conductance models (m and g1) varied across growing stages and m and g1 also varied across (CO2) treatments and cultivars, which led to more accurate photosynthesis and stomatal conductance simulations when using these cultivar-, CO2-, and stage- specific parameters. The results in the study suggested that further research is still needed to investigate the dominant factors contributing to the acclimation of photosynthetic capacity under future elevated CO2 conditions. The study also highlighted the need of investigating the impact of other environmental, such as nitrogen and O3, and non-environmental factors, such as additional rice cultivars, on the variations of these parameters in photosynthesis and stomatal conductance models and their further impacts on simulations in large scale carbon and water cycles.
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Affiliation(s)
| | | | | | - Dan Wang
- Department of Ecology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China
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7
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Tcherkez G, Ben Mariem S, Larraya L, García-Mina JM, Zamarreño AM, Paradela A, Cui J, Badeck FW, Meza D, Rizza F, Bunce J, Han X, Tausz-Posch S, Cattivelli L, Fangmeier A, Aranjuelo I. Elevated CO2 has concurrent effects on leaf and grain metabolism but minimal effects on yield in wheat. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5990-6003. [PMID: 32687190 PMCID: PMC7751139 DOI: 10.1093/jxb/eraa330] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/14/2020] [Indexed: 05/21/2023]
Abstract
While the general effect of CO2 enrichment on photosynthesis, stomatal conductance, N content, and yield has been documented, there is still some uncertainty as to whether there are interactive effects between CO2 enrichment and other factors, such as temperature, geographical location, water availability, and cultivar. In addition, the metabolic coordination between leaves and grains, which is crucial for crop responsiveness to elevated CO2, has never been examined closely. Here, we address these two aspects by multi-level analyses of data from several free-air CO2 enrichment experiments conducted in five different countries. There was little effect of elevated CO2 on yield (except in the USA), likely due to photosynthetic capacity acclimation, as reflected by protein profiles. In addition, there was a significant decrease in leaf amino acids (threonine) and macroelements (e.g. K) at elevated CO2, while other elements, such as Mg or S, increased. Despite the non-significant effect of CO2 enrichment on yield, grains appeared to be significantly depleted in N (as expected), but also in threonine, the S-containing amino acid methionine, and Mg. Overall, our results suggest a strong detrimental effect of CO2 enrichment on nutrient availability and remobilization from leaves to grains.
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Affiliation(s)
- Guillaume Tcherkez
- Research School of Biology, ANU Joint College of Sciences, Australian National University, Canberra Australia
- Institut de Recherche en Horticulture et Semences, INRA d’Angers, Université d’Angers, Structure Fédérative de Recherche QUASAV, Beaucouzé, France
| | - Sinda Ben Mariem
- AgroBiotechnology Institute (IdAB), CSIC-Government of Navarre, Mutilva, Spain
| | - Luis Larraya
- Institute for Multidisciplinary Applied Biology, Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, Pamplona, Spain
| | - Jose M García-Mina
- Facultades de Ciencias y Farmacia y Nutrición, Grupo de Biología y Química Agrícola (Departamento de Biología Ambiental), Universidad de Navarra, Pamplona, Spain
| | - Angel M Zamarreño
- Facultades de Ciencias y Farmacia y Nutrición, Grupo de Biología y Química Agrícola (Departamento de Biología Ambiental), Universidad de Navarra, Pamplona, Spain
| | | | - Jing Cui
- Research School of Biology, ANU Joint College of Sciences, Australian National University, Canberra Australia
| | - Franz-Werner Badeck
- CREA Research Centre for Genomics and Bioinformatics, Fiorenzuola d’Arda, Italy
| | - Diego Meza
- Institute of Landscape and Plant Ecology, University of Hohenheim, Stuttgart, Germany
| | - Fulvia Rizza
- CREA Research Centre for Genomics and Bioinformatics, Fiorenzuola d’Arda, Italy
| | - James Bunce
- Adaptive Cropping Systems Lab, Beltsville Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, Beltsville, MD, USA
| | - Xue Han
- Institute of Environment and sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (IEDA, CAAS), Beijing, China
| | - Sabine Tausz-Posch
- Department of Agriculture, Science and the Environment, School of Health, Medical and Applied Sciences, CQUniversity Australia, Kawana, QLD, Australia
| | - Luigi Cattivelli
- CREA Research Centre for Genomics and Bioinformatics, Fiorenzuola d’Arda, Italy
| | - Andreas Fangmeier
- Institute of Landscape and Plant Ecology, University of Hohenheim, Stuttgart, Germany
| | - Iker Aranjuelo
- AgroBiotechnology Institute (IdAB), CSIC-Government of Navarre, Mutilva, Spain
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8
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Dingkuhn M, Luquet D, Fabre D, Muller B, Yin X, Paul MJ. The case for improving crop carbon sink strength or plasticity for a CO 2-rich future. CURRENT OPINION IN PLANT BIOLOGY 2020; 56:259-272. [PMID: 32682621 DOI: 10.1016/j.pbi.2020.05.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/13/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
Atmospheric CO2 concentration [CO2] has increased from 260 to 280μmolmol-1 (level during crop domestication up to the industrial revolution) to currently 400 and will reach 550μmolmol-1 by 2050. C3 crops are expected to benefit from elevated [CO2] (e-CO2) thanks to photosynthesis responsiveness to [CO2] but this may require greater sink capacity. We review recent literature on crop e-CO2 responses, related source-sink interactions, how abiotic stresses potentially interact, and prospects to improve e-CO2 response via breeding or genetic engineering. Several lines of evidence suggest that e-CO2 responsiveness is related either to sink intrinsic capacity or adaptive plasticity, for example, involving enhanced branching. Wild relatives and old cultivars mostly showed lower photosynthetic rates, less downward acclimation of photosynthesis to e-CO2 and responded strongly to e-CO2 due to greater phenotypic plasticity. While reverting to such archaic traits would be an inappropriate strategy for breeding, we argue that substantial enhancement of vegetative sink vigor, inflorescence size and/or number and root sinks will be necessary to fully benefit from e-CO2. Potential ideotype features based on enhanced sinks are discussed. The generic 'feast-famine' sugar signaling pathway may be suited to engineer sink strength tissue-specifically and stage-specifically and help validate ideotype concepts. Finally, we argue that models better accounting for acclimation to e-CO2 are needed to predict which trait combinations should be targeted by breeders for a CO2-rich world.
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Affiliation(s)
| | | | - Denis Fabre
- CIRAD, UMR 108 AGAP, F-34398 Montpellier, France
| | - Bertrand Muller
- INRAE, UMR 759 LEPSE, Institut de Biologie Intégrative des Plantes, F-34060 Montpellier, France
| | - Xinyou Yin
- Centre for Crop Systems Analysis, Dept. Plant Sciences, Wageningen University & Research, Wageningen, The Netherlands
| | - Matthew J Paul
- Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
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9
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Bourgault M, Webber HA, Chenu K, O'Leary GJ, Gaiser T, Siebert S, Dreccer F, Huth N, Fitzgerald GJ, Tausz M, Ewert F. Early vigour in wheat: Could it lead to more severe terminal drought stress under elevated atmospheric [CO 2 ] and semi-arid conditions? GLOBAL CHANGE BIOLOGY 2020; 26:4079-4093. [PMID: 32320514 DOI: 10.1111/gcb.15128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/19/2020] [Indexed: 06/11/2023]
Abstract
Early vigour in wheat is a trait that has received attention for its benefits reducing evaporation from the soil surface early in the season. However, with the growth enhancement common to crops grown under elevated atmospheric CO2 concentrations (e[CO2 ]), there is a risk that too much early growth might deplete soil water and lead to more severe terminal drought stress in environments where production relies on stored soil water content. If this is the case, the incorporation of such a trait in wheat breeding programmes might have unintended negative consequences in the future, especially in dry years. We used selected data from cultivars with proven expression of high and low early vigour from the Australian Grains Free Air CO2 Enrichment (AGFACE) facility, and complemented this analysis with simulation results from two crop growth models which differ in the modelling of leaf area development and crop water use. Grain yield responses to e[CO2 ] were lower in the high early vigour group compared to the low early vigour group, and although these differences were not significant, they were corroborated by simulation model results. However, the simulated lower response with high early vigour lines was not caused by an earlier or greater depletion of soil water under e[CO2 ] and the mechanisms responsible appear to be related to an earlier saturation of the radiation intercepted. Whether this is the case in the field needs to be further investigated. In addition, there was some evidence that the timing of the drought stress during crop growth influenced the effect of e[CO2 ] regardless of the early vigour trait. There is a need for FACE investigations of the value of traits for drought adaptation to be conducted under more severe drought conditions and variable timing of drought stress, a risky but necessary endeavour.
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Affiliation(s)
- Maryse Bourgault
- Northern Agricultural Research Center, Montana State University, Havre, MT, USA
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Creswick, Vic., Australia
| | - Heidi A Webber
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Bonn, Germany
- Leibniz Centre for Agricultural Landscape Research (ZALF), Brandenburg, Germany
| | - Karine Chenu
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), University of Queensland, Toowoomba, Qld, Australia
| | - Garry J O'Leary
- Agriculture Victoria, Grains Innovation Park, Horsham, Vic., Australia
| | - Thomas Gaiser
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Bonn, Germany
| | - Stefan Siebert
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Bonn, Germany
- Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Fernanda Dreccer
- CSIRO Agriculture and Food, Cooper Laboratory, University of Queensland, Gatton, Qld, Australia
| | - Neil Huth
- CSIRO Agriculture and Food, Toowoomba, Qld, Australia
| | - Glenn J Fitzgerald
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Creswick, Vic., Australia
- Agriculture Victoria, Grains Innovation Park, Horsham, Vic., Australia
| | - Michael Tausz
- Department of Agriculture, Science and the Environment, CQ University, Norman Gardens, Qld, Australia
| | - Frank Ewert
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Bonn, Germany
- Leibniz Centre for Agricultural Landscape Research (ZALF), Brandenburg, Germany
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10
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Tausz-Posch S, Tausz M, Bourgault M. Elevated [CO 2 ] effects on crops: Advances in understanding acclimation, nitrogen dynamics and interactions with drought and other organisms. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22 Suppl 1:38-51. [PMID: 30945436 DOI: 10.1111/plb.12994] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/01/2019] [Indexed: 05/13/2023]
Abstract
Future rapid increases in atmospheric CO2 concentration [CO2 ] are expected, with values likely to reach ~550 ppm by mid-century. This implies that every terrestrial plant will be exposed to nearly 40% more of one of the key resources determining plant growth. In this review we highlight selected areas of plant interactions with elevated [CO2 ] (e[CO2 ]), where recently published experiments challenge long-held, simplified views. Focusing on crops, especially in more extreme and variable growing conditions, we highlight uncertainties associated with four specific areas. (1) While it is long known that photosynthesis can acclimate to e[CO2 ], such acclimation is not consistently observed in field experiments. The influence of sink-source relations and nitrogen (N) limitation on acclimation is investigated and current knowledge about whether stomatal function or mesophyll conductance (gm ) acclimate independently is summarised. (2) We show how the response of N uptake to e[CO2 ] is highly variable, even for one cultivar grown within the same field site, and how decreases in N concentrations ([N]) are observed consistently. Potential mechanisms contributing to [N] decreases under e[CO2 ] are discussed and proposed solutions are addressed. (3) Based on recent results from crop field experiments in highly variable, non-irrigated, water-limited environments, we challenge the previous opinion that the relative CO2 effect is larger under drier environmental conditions. (4) Finally, we summarise how changes in growth and nutrient concentrations due to e[CO2 ] will influence relationships between crops and weeds, herbivores and pathogens in agricultural systems.
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Affiliation(s)
- S Tausz-Posch
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - M Tausz
- School of Biosciences, University of Birmingham, Birmingham, UK
- Department of Agriculture, Science and the Environment, CQUniversity Australia, Rockhampton, QLD, Australia
| | - M Bourgault
- Northern Agricultural Research Center, Montana State University, Havre, MT, USA
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11
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Wang H, Zhou G, Jiang Y, Shi Y, Xu Z. Effects of elevated CO
2
on
Stipa baicalensis
photosynthesis depend on precipitation and growth phase. Ecol Res 2019. [DOI: 10.1111/1440-1703.12044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Hui Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany Chinese Academy of Sciences Beijing China
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China
| | - Guangsheng Zhou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany Chinese Academy of Sciences Beijing China
- Chinese Academy of Meteorological Sciences Institute Of Ecological Environment and Agrometeorology, Beijing China
| | - Yanling Jiang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany Chinese Academy of Sciences Beijing China
| | - Yaohui Shi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany Chinese Academy of Sciences Beijing China
| | - Zhenzhu Xu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany Chinese Academy of Sciences Beijing China
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12
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Leakey ADB, Ferguson JN, Pignon CP, Wu A, Jin Z, Hammer GL, Lobell DB. Water Use Efficiency as a Constraint and Target for Improving the Resilience and Productivity of C 3 and C 4 Crops. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:781-808. [PMID: 31035829 DOI: 10.1146/annurev-arplant-042817-040305] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The ratio of plant carbon gain to water use, known as water use efficiency (WUE), has long been recognized as a key constraint on crop production and an important target for crop improvement. WUE is a physiologically and genetically complex trait that can be defined at a range of scales. Many component traits directly influence WUE, including photosynthesis, stomatal and mesophyll conductances, and canopy structure. Interactions of carbon and water relations with diverse aspects of the environment and crop development also modulate WUE. As a consequence, enhancing WUE by breeding or biotechnology has proven challenging but not impossible. This review aims to synthesize new knowledge of WUE arising from advances in phenotyping, modeling, physiology, genetics, and molecular biology in the context of classical theoretical principles. In addition, we discuss how rising atmospheric CO2 concentration has created and will continue to create opportunities for enhancing WUE by modifying the trade-off between photosynthesis and transpiration.
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Affiliation(s)
- Andrew D B Leakey
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA;
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - John N Ferguson
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Charles P Pignon
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA;
| | - Alex Wu
- Centre for Crop Science and Centre of Excellence for Translational Photosynthesis, University of Queensland, St. Lucia, Queensland 4069, Australia
| | - Zhenong Jin
- Department of Earth System Science and Center for Food Security and Environment, Stanford University, Stanford, California 94305, USA
| | - Graeme L Hammer
- Centre for Crop Science and Centre of Excellence for Translational Photosynthesis, University of Queensland, St. Lucia, Queensland 4069, Australia
| | - David B Lobell
- Department of Earth System Science and Center for Food Security and Environment, Stanford University, Stanford, California 94305, USA
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Houshmandfar A, Fitzgerald GJ, O'Leary G, Tausz-Posch S, Fletcher A, Tausz M. The relationship between transpiration and nutrient uptake in wheat changes under elevated atmospheric CO 2. PHYSIOLOGIA PLANTARUM 2018; 163:516-529. [PMID: 29205382 DOI: 10.1111/ppl.12676] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/20/2017] [Indexed: 05/26/2023]
Abstract
The impact of elevated [CO2 ] (e[CO2 ]) on crops often includes a decrease in their nutrient concentrations where reduced transpiration-driven mass flow of nutrients has been suggested to play a role. We used two independent approaches, a free-air CO2 enrichment (FACE) experiment in the South Eastern wheat belt of Australia and a simulation study employing the agricultural production systems simulator (APSIM), to show that transpiration (mm) and nutrient uptake (g m-2 ) of nitrogen (N), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg) and manganese (Mn) in wheat are correlated under e[CO2 ], but that nutrient uptake per unit water transpired is higher under e[CO2 ] than under ambient [CO2 ] (a[CO2 ]). This result suggests that transpiration-driven mass flow of nutrients contributes to decreases in nutrient concentrations under e[CO2 ], but cannot solely explain the overall decline.
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Affiliation(s)
- Alireza Houshmandfar
- CSIRO Agriculture and Food, Private Bag 5, P.O., Wembley, WA, 6913, Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Creswick, VIC, 3363, Australia
| | - Glenn J Fitzgerald
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Creswick, VIC, 3363, Australia
- Agriculture Victoria, Victoria State Department of Economic Development, Jobs, Transport and Resources, Horsham, 3401, Australia
| | - Garry O'Leary
- Agriculture Victoria, Victoria State Department of Economic Development, Jobs, Transport and Resources, Horsham, 3401, Australia
| | - Sabine Tausz-Posch
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Creswick, VIC, 3363, Australia
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew Fletcher
- CSIRO Agriculture and Food, Private Bag 5, P.O., Wembley, WA, 6913, Australia
| | - Michael Tausz
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Department of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Victoria, 3363, Australia
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14
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Uddin S, Löw M, Parvin S, Fitzgerald GJ, Tausz-Posch S, Armstrong R, O’Leary G, Tausz M. Elevated [CO2] mitigates the effect of surface drought by stimulating root growth to access sub-soil water. PLoS One 2018; 13:e0198928. [PMID: 29902235 PMCID: PMC6002051 DOI: 10.1371/journal.pone.0198928] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/29/2018] [Indexed: 01/26/2023] Open
Abstract
Through stimulation of root growth, increasing atmospheric CO2 concentration ([CO2]) may facilitate access of crops to sub-soil water, which could potentially prolong physiological activity in dryland environments, particularly because crops are more water use efficient under elevated [CO2] (e[CO2]). This study investigated the effect of drought in shallow soil versus sub-soil on agronomic and physiological responses of wheat to e[CO2] in a glasshouse experiment. Wheat (Triticum aestivum L. cv. Yitpi) was grown in split-columns with the top (0-30 cm) and bottom (31-60 cm; 'sub-soil') soil layer hydraulically separated by a wax-coated, root-penetrable layer under ambient [CO2] (a[CO2], ∼400 μmol mol-1) or e[CO2] (∼700 μmol mol-1) [CO2]. Drought was imposed from stem-elongation in either the top or bottom soil layer or both by withholding 33% of the irrigation, resulting in four water treatments (WW, WD, DW, DD; D = drought, W = well-watered, letters denote water treatment in top and bottom soil layer, respectively). Leaf gas exchange was measured weekly from stem-elongation until anthesis. Above-and belowground biomass, grain yield and yield components were evaluated at three developmental stages (stem-elongation, anthesis and maturity). Compared with a[CO2], net assimilation rate was higher and stomatal conductance was lower under e[CO2], resulting in greater intrinsic water use efficiency. Elevated [CO2] stimulated both above- and belowground biomass as well as grain yield, however, this stimulation was greater under well-watered (WW) than drought (DD) throughout the whole soil profile. Imposition of drought in either or both soil layers decreased aboveground biomass and grain yield under both [CO2] compared to the well-watered treatment. However, the greatest 'CO2 fertilisation effect' was observed when drought was imposed in the top soil layer only (DW), and this was associated with e[CO2]-stimulation of root growth especially in the well-watered bottom layer. We suggest that stimulation of belowground biomass under e[CO2] will allow better access to sub-soil water during grain filling period, when additional water is converted into additional yield with high efficiency in Mediterranean-type dryland agro-ecosystems. If sufficient water is available in the sub-soil, e[CO2] may help mitigating the effect of drying surface soil.
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Affiliation(s)
- Shihab Uddin
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Creswick, Victoria, Australia
- Department of Agronomy, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Markus Löw
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Creswick, Victoria, Australia
| | - Shahnaj Parvin
- Department of Agronomy, Bangladesh Agricultural University, Mymensingh, Bangladesh
- School of Ecosystem and Forest Sciences, The University of Melbourne, Creswick, Victoria, Australia
| | - Glenn J. Fitzgerald
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Creswick, Victoria, Australia
- Department of Economic Development, Jobs, Transport and Resources, Horsham, Victoria, Australia
| | - Sabine Tausz-Posch
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Creswick, Victoria, Australia
| | - Roger Armstrong
- Department of Economic Development, Jobs, Transport and Resources, Horsham, Victoria, Australia
- Department of Animal, Plant and Soil Sciences, Centre for AgriBioscience, La Trobe University, Bundoora, Victoria, Australia
| | - Garry O’Leary
- Department of Economic Development, Jobs, Transport and Resources, Horsham, Victoria, Australia
| | - Michael Tausz
- School of Ecosystem and Forest Sciences, The University of Melbourne, Creswick, Victoria, Australia
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15
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Christy B, Tausz-Posch S, Tausz M, Richards R, Rebetzke G, Condon A, McLean T, Fitzgerald G, Bourgault M, O'Leary G. Benefits of increasing transpiration efficiency in wheat under elevated CO 2 for rainfed regions. GLOBAL CHANGE BIOLOGY 2018; 24:1965-1977. [PMID: 29331062 DOI: 10.1111/gcb.14052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
Higher transpiration efficiency (TE) has been proposed as a mechanism to increase crop yields in dry environments where water availability usually limits yield. The application of a coupled radiation and TE simulation model shows wheat yield advantage of a high-TE cultivar (cv. Drysdale) over its almost identical low-TE parent line (Hartog), from about -7 to 558 kg/ha (mean 187 kg/ha) over the rainfed cropping region in Australia (221-1,351 mm annual rainfall), under the present-day climate. The smallest absolute yield response occurred in the more extreme drier and wetter areas of the wheat belt. However, under elevated CO2 conditions, the response of Drysdale was much greater overall, ranging from 51 to 886 kg/ha (mean 284 kg/ha) with the greatest response in the higher rainfall areas. Changes in simulated TE under elevated CO2 conditions are seen across Australia with notable increased areas of higher TE under a drier climate in Western Australia, Queensland and parts of New South Wales and Victoria. This improved efficiency is subtly deceptive, with highest yields not necessarily directly correlated with highest TE. Nevertheless, the advantage of Drysdale over Hartog is clear with the benefit of the trait advantage attributed to TE ranging from 102% to 118% (mean 109%). The potential annual cost-benefits of this increased genetic TE trait across the wheat growing areas of Australia (5 year average of area planted to wheat) totaled AUD 631 MIL (5-year average wheat price of AUD/260 t) with an average of 187 kg/ha under the present climate. The benefit to an individual farmer will depend on location but elevated CO2 raises this nation-wide benefit to AUD 796 MIL in a 2°C warmer climate, slightly lower (AUD 715 MIL) if rainfall is also reduced by 20%.
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Affiliation(s)
- Brendan Christy
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Rutherglen, Vic., Australia
| | - Sabine Tausz-Posch
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | - Michael Tausz
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | | | | | | | - Terry McLean
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Rutherglen, Vic., Australia
| | - Glenn Fitzgerald
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Horsham, Vic., Australia
| | - Maryse Bourgault
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | - Garry O'Leary
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Horsham, Vic., Australia
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16
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Wei Z, Du T, Li X, Fang L, Liu F. Simulation of Stomatal Conductance and Water Use Efficiency of Tomato Leaves Exposed to Different Irrigation Regimes and Air CO 2 Concentrations by a Modified "Ball-Berry" Model. FRONTIERS IN PLANT SCIENCE 2018; 9:445. [PMID: 29686689 PMCID: PMC5900028 DOI: 10.3389/fpls.2018.00445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
Stomatal conductance (gs) and water use efficiency (WUE) of tomato leaves exposed to different irrigation regimes and at ambient CO2 (a[CO2], 400 ppm) and elevated CO2 (e[CO2], 800 ppm) environments were simulated using the "Ball-Berry" model (BB-model). Data obtained from a preliminary experiment (Exp. I) was used for model parameterization, where measurements of leaf gas exchange of potted tomatoes were done during progressive soil drying for 5 days. The measured photosynthetic rate (Pn) was used as an input for the model. Considering the effect of soil water deficits on gs, an equation modifying the slope (m) based on the mean soil water potential (Ψs) in the whole root zone was introduced. Compared to the original BB-model, the modified model showed greater predictability for both gs and WUE of tomato leaves at each [CO2] growth environment. The models were further validated with data obtained from an independent experiment (Exp. II) where plants were subjected to three irrigation regimes: full irrigation (FI), deficit irrigation (DI), and alternative partial root-zone irrigation (PRI) for 40 days at both a[CO2] and e[CO2] environment. The simulation results indicated that gs was independently acclimated to e[CO2] from Pn. The modified BB-model performed better in estimating gs and WUE, especially for PRI strategy at both [CO2] environments. A greater WUE could be seen in plants grown under e[CO2] associated with PRI regime. Conclusively, the modified BB-model was capable of predicting gs and WUE of tomato leaves in various irrigation regimes at both a[CO2] and e[CO2] environments. This study could provide valuable information for better predicting plant WUE adapted to the future water-limited and CO2 enriched environment.
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Affiliation(s)
- Zhenhua Wei
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, China
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Taastrup, Denmark
| | - Taisheng Du
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, China
| | - Xiangnan Li
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Taastrup, Denmark
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Liang Fang
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Taastrup, Denmark
| | - Fulai Liu
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Taastrup, Denmark
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17
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Shimono H, Farquhar G, Brookhouse M, Busch FA, O Grady A, Tausz M, Pinkard EA. Prescreening in large populations as a tool for identifying elevated CO 2-responsive genotypes in plants. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 46:1-14. [PMID: 30939254 DOI: 10.1071/fp18087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/13/2018] [Indexed: 05/21/2023]
Abstract
Elevated atmospheric CO2 concentration (e[CO2]) can stimulate the photosynthesis and productivity of C3 species including food and forest crops. Intraspecific variation in responsiveness to e[CO2] can be exploited to increase productivity under e[CO2]. However, active selection of genotypes to increase productivity under e[CO2] is rarely performed across a wide range of germplasm, because of constraints of space and the cost of CO2 fumigation facilities. If we are to capitalise on recent advances in whole genome sequencing, approaches are required to help overcome these issues of space and cost. Here, we discuss the advantage of applying prescreening as a tool in large genome×e[CO2] experiments, where a surrogate for e[CO2] was used to select cultivars for more detailed analysis under e[CO2] conditions. We discuss why phenotypic prescreening in population-wide screening for e[CO2] responsiveness is necessary, what approaches could be used for prescreening for e[CO2] responsiveness, and how the data can be used to improve genetic selection of high-performing cultivars. We do this within the framework of understanding the strengths and limitations of genotype-phenotype mapping.
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Affiliation(s)
- Hiroyuki Shimono
- Crop Science Laboratory, Faculty of Agriculture, Iwate University, Morioka, 2032162, Japan
| | - Graham Farquhar
- Research School of Biology, Australian National University, Canberra, ACT 2600, Australia
| | - Matthew Brookhouse
- Research School of Biology, Australian National University, Canberra, ACT 2600, Australia
| | - Florian A Busch
- Research School of Biology, Australian National University, Canberra, ACT 2600, Australia
| | | | - Michael Tausz
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, 35203, UK
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18
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Miner GL, Bauerle WL, Baldocchi DD. Estimating the sensitivity of stomatal conductance to photosynthesis: a review. PLANT, CELL & ENVIRONMENT 2017; 40:1214-1238. [PMID: 27925232 DOI: 10.1111/pce.12871] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/17/2016] [Accepted: 11/20/2016] [Indexed: 05/27/2023]
Abstract
A common approach for estimating fluxes of CO2 and water in canopy models is to couple a model of photosynthesis (An ) to a semi-empirical model of stomatal conductance (gs ) such as the widely validated and utilized Ball-Berry (BB) model. This coupling provides an effective way of predicting transpiration at multiple scales. However, the designated value of the slope parameter (m) in the BB model impacts transpiration estimates. There is a lack of consensus regarding how m varies among species or plant functional types (PFTs) or in response to growth conditions. Literature values are highly variable, with inter-species and intra-species variations of >100%, and comparisons are made more difficult because of differences in collection techniques. This paper reviews the various methods used to estimate m and highlights how variations in measurement techniques or the data utilized can influence the resultant m. Additionally, this review summarizes the reported responses of m to [CO2 ] and water stress, collates literature values by PFT and compiles nearly three decades of values into a useful compendium.
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Affiliation(s)
- Grace L Miner
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523, USA
| | - William L Bauerle
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523, USA
- Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, CO, 80523, USA
| | - Dennis D Baldocchi
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, 94720, USA
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19
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Schymanski SJ, Or D. Wind increases leaf water use efficiency. PLANT, CELL & ENVIRONMENT 2016; 39:1448-1459. [PMID: 26714739 DOI: 10.1111/pce.12700] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/09/2015] [Accepted: 12/17/2015] [Indexed: 06/05/2023]
Abstract
A widespread perception is that, with increasing wind speed, transpiration from plant leaves increases. However, evidence suggests that increasing wind speed enhances carbon dioxide (CO2 ) uptake while reducing transpiration because of more efficient convective cooling (under high solar radiation loads). We provide theoretical and experimental evidence that leaf water use efficiency (WUE, carbon uptake per water transpired) commonly increases with increasing wind speed, thus improving plants' ability to conserve water during photosynthesis. Our leaf-scale analysis suggests that the observed global decrease in near-surface wind speeds could have reduced WUE at a magnitude similar to the increase in WUE attributed to global rise in atmospheric CO2 concentrations. However, there is indication that the effect of long-term trends in wind speed on leaf gas exchange may be compensated for by the concurrent reduction in mean leaf sizes. These unintuitive feedbacks between wind, leaf size and water use efficiency call for re-evaluation of the role of wind in plant water relations and potential re-interpretation of temporal and geographic trends in leaf sizes.
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Affiliation(s)
| | - Dani Or
- Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
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20
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Bourgault M, James AT, Dreccer MF. Pot size matters revisited: does container size affect the response to elevated CO 2 and our ability to detect genotypic variability in this response in wheat? FUNCTIONAL PLANT BIOLOGY : FPB 2016; 44:52-61. [PMID: 32480546 DOI: 10.1071/fp16047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 07/06/2016] [Indexed: 06/11/2023]
Abstract
Many studies have investigated the effect of elevated CO2 (eCO2) in wheat, although few have evaluated the potential of genotypic variability in the response. Such studies are the next logical step in wheat climate change adaptation research, and they will require the evaluation of large numbers of genotypes. For practical reasons the preliminary studies are most likely to be conducted in controlled environments. There have been concerns that the root restriction related to container-grown plants can influence (1) the response to eCO2, (2) the detection of genotypic variability for various traits of interest, and (3) the ability to find the genotypes most responsive to eCO2. In the present study we evaluated two sizes of container - 1.4L pots and 7.5L columns - side-by side in a glasshouse environment and found that for 14 of 23 traits observed environment effects (ambient CO2, eCO2 or eCO2 and high temperature) were not consistent between plants grown in pots and in columns. More importantly, of the 21 traits showing genotypic variability, only 8 showed consistent genotype differences and rankings across both container types. Statistical analyses conducted separately for plants grown in pots or in columns showed different cultivars as being the most responsive to elevated CO2 and would thus, have led to different conclusions. This study is intended as a message of caution to controlled environment experimenters: using small containers can artificially create conditions that could either hide or overly express genotypic variability in some traits in response to eCO2 compared with what might be expected in larger containers.
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Affiliation(s)
- Maryse Bourgault
- CSIRO Agriculture Flagship, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Qld 4067, Australia
| | - Andrew T James
- CSIRO Agriculture Flagship, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Qld 4067, Australia
| | - M Fernanda Dreccer
- CSIRO Agriculture Flagship, Cooper Laboratory, Warrego Highway, Gatton, Qld 4343, Australia
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21
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Schymanski SJ, Roderick ML, Sivapalan M. Using an optimality model to understand medium and long-term responses of vegetation water use to elevated atmospheric CO2 concentrations. AOB PLANTS 2015; 7:plv060. [PMID: 26019228 PMCID: PMC4497478 DOI: 10.1093/aobpla/plv060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 05/12/2015] [Indexed: 05/29/2023]
Abstract
Vegetation has different adjustable properties for adaptation to its environment. Examples include stomatal conductance at short time scale (minutes), leaf area index and fine root distributions at longer time scales (days-months) and species composition and dominant growth forms at very long time scales (years-decades-centuries). As a result, the overall response of evapotranspiration to changes in environmental forcing may also change at different time scales. The vegetation optimality model simulates optimal adaptation to environmental conditions, based on the assumption that different vegetation properties are optimized to maximize the long-term net carbon profit, allowing for separation of different scales of adaptation, without the need for parametrization with observed responses. This paper discusses model simulations of vegetation responses to today's elevated atmospheric CO2 concentrations (eCO2) at different temporal scales and puts them in context with experimental evidence from free-air CO2 enrichment (FACE) experiments. Without any model tuning or calibration, the model reproduced general trends deduced from FACE experiments, but, contrary to the widespread expectation that eCO2 would generally decrease water use due to its leaf-scale effect on stomatal conductance, our results suggest that eCO2 may lead to unchanged or even increased vegetation water use in water-limited climates, accompanied by an increase in perennial vegetation cover.
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Affiliation(s)
- Stanislaus J Schymanski
- Department of Environmental Systems Science, Swiss Federal Institute of Technology Zurich, Universitätstrasse 16, 8092 Zurich, Switzerland Formerly at: Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Michael L Roderick
- Research School of Earth Sciences and Research School of Biology, Australian National University, Canberra 2601, Australia Australian Research Council Centre of Excellence for Climate System Science, Canberra 2601, Australia
| | - Murugesu Sivapalan
- Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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