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Retta MA, Yin X, Ho QT, Watté R, Berghuijs HNC, Verboven P, Saeys W, Cano FJ, Ghannoum O, Struik PC, Nicolaï BM. The role of chloroplast movement in C4 photosynthesis: A theoretical analysis using a 3-D reaction-diffusion model for maize. J Exp Bot 2023:7135625. [PMID: 37083863 PMCID: PMC10400148 DOI: 10.1093/jxb/erad138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Indexed: 05/03/2023]
Abstract
Chloroplasts movement within mesophyll (M) cells in C4 plants is hypothesized to enhance the CO2 concentrating mechanism (CCM), but this is difficult to verify experimentally. A three-dimensional (3-D) leaf model can help analyze how chloroplast movement influences the operation of CCM. The first volumetric reaction-diffusion model of C4 photosynthesis that incorporates: detailed 3-D leaf anatomy, light propagation, ATP and NADPH production and CO2, O2 and bicarbonate concentration driven by diffusional and assimilation/emission processes, was developed and implemented for maize leaves to simulate various chloroplast movement scenarios within M cells : the movement of all M chloroplasts towards bundle-sheath (BS) cells (aggregative movement) and movement of only those of interveinal M cells towards BS cells (avoidance movement). Light absorbed by bundle-sheath (BS) chloroplasts relative to M chloroplasts increased in both cases. Avoidance movement decreased light absorption by M chloroplasts considerably. Consequently, total ATP and NADPH production and net photosynthesis rate increased for aggregative movement and decreased for avoidance movement case compared to the default case of no chloroplast movement at high light intensities. Leakiness increased in both chloroplast movement scenarios due to the imbalance in energy production and demand in M and BS cells. These results suggest the need to design strategies for coordinated increases in electron transport and Rubisco activities for an efficient CCM at very high light intensities.
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Affiliation(s)
- M A Retta
- KU Leuven, MeBioS division, Willem de Croylaan 42, B-3001, Leuven, Belgium
- Centre for Crop Systems Analysis, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - X Yin
- Centre for Crop Systems Analysis, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - Q T Ho
- Institute of Marine Research, Nordnesgaten 50, NO-5005 Bergen, P.O. Box 1870, Nordnes, Norway
| | - R Watté
- KU Leuven, MeBioS division, Willem de Croylaan 42, B-3001, Leuven, Belgium
| | - H N C Berghuijs
- Plant Production Systems group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - P Verboven
- KU Leuven, MeBioS division, Willem de Croylaan 42, B-3001, Leuven, Belgium
| | - W Saeys
- KU Leuven, MeBioS division, Willem de Croylaan 42, B-3001, Leuven, Belgium
| | - F J Cano
- Centro de Investigación Forestal (CIFOR), Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Carretera de la Coruña Km 7.5, 28040, Madrid, Spain
- ARC Centre of Excellence for Translational Photosynthesis, Hawkesbury Institute for the Environment, University of Western Sydney, Hawkesbury campus, Locked Bag 1797, Penrith 2751, NSW, Australia
| | - O Ghannoum
- ARC Centre of Excellence for Translational Photosynthesis, Hawkesbury Institute for the Environment, University of Western Sydney, Hawkesbury campus, Locked Bag 1797, Penrith 2751, NSW, Australia
| | - P C Struik
- Centre for Crop Systems Analysis, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - B M Nicolaï
- KU Leuven, MeBioS division, Willem de Croylaan 42, B-3001, Leuven, Belgium
- Flanders Center of Postharvest Technology, Willem de Croylaan 42, B-3001, Leuven, Belgium
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Crous KY, Campany C, Lopez R, Cano FJ, Ellsworth DS. Canopy position affects photosynthesis and anatomy in mature Eucalyptus trees in elevated CO2. Tree Physiol 2020; 41:tpaa117. [PMID: 32918811 DOI: 10.1093/treephys/tpaa117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/26/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Leaves are exposed to different light conditions according to their canopy position, resulting in structural and anatomical differences with consequences for carbon uptake. While these structure-function relationships have been thoroughly explored in dense forest canopies, such gradients may be diminished in open canopies, and they are often ignored in ecosystem models. We tested within-canopy differences in photosynthetic properties and structural traits in leaves in a mature Eucalyptus tereticornis canopy exposed to long-term elevated CO2 for up to three years. We explored these traits in relation to anatomical variation and diffusive processes for CO2 (i.e., stomatal conductance, gs and mesophyll conductance, gm) in both upper and lower portions of the canopy receiving ambient and elevated CO2. While shade resulted in 13% lower leaf mass per area ratio (MA) in lower versus upper canopy leaves, there was no relationship between leaf Nmass and canopy gap fraction. Both maximum carboxylation capacity (Vcmax) and maximum electron transport (Jmax) were ~ 18% lower in shaded leaves and were also reduced by ~ 22% with leaf aging. In mature leaves, we found no canopy differences for gm or gs, despite anatomical differences in MA, leaf thickness and mean mesophyll thickness between canopy positions. There was a positive relationship between net photosynthesis and gm or gs in mature leaves. Mesophyll conductance was negatively correlated with mean parenchyma length, suggesting that long palisade cells may contribute to a longer CO2 diffusional pathway and more resistance to CO2 transfer to chloroplasts. Few other relationships between gm and anatomical variables were found in mature leaves, which may be due to the open crown of Eucalyptus. Consideration of shade effects and leaf-age dependent responses to photosynthetic capacity and mesophyll conductance are critical to improve canopy photosynthesis models and will improve understanding of long-term responses to elevated CO2 in tree canopies.
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Affiliation(s)
- K Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - C Campany
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
- Department of Biology, Shepherd University, P.O. Box 5000, Shepherdstown, West Virginia, 25443, USA
| | - R Lopez
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - F J Cano
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - D S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
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Earles JM, Buckley TN, Brodersen CR, Busch FA, Cano FJ, Choat B, Evans JR, Farquhar GD, Harwood R, Huynh M, John GP, Miller ML, Rockwell FE, Sack L, Scoffoni C, Struik PC, Wu A, Yin X, Barbour MM. Embracing 3D Complexity in Leaf Carbon-Water Exchange. Trends Plant Sci 2019; 24:15-24. [PMID: 30309727 DOI: 10.1016/j.tplants.2018.09.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/06/2018] [Accepted: 09/11/2018] [Indexed: 06/08/2023]
Abstract
Leaves are a nexus for the exchange of water, carbon, and energy between terrestrial plants and the atmosphere. Research in recent decades has highlighted the critical importance of the underlying biophysical and anatomical determinants of CO2 and H2O transport, but a quantitative understanding of how detailed 3D leaf anatomy mediates within-leaf transport has been hindered by the lack of a consensus framework for analyzing or simulating transport and its spatial and temporal dynamics realistically, and by the difficulty of measuring within-leaf transport at the appropriate scales. We discuss how recent technological advancements now make a spatially explicit 3D leaf analysis possible, through new imaging and modeling tools that will allow us to address long-standing questions related to plant carbon-water exchange.
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Affiliation(s)
- J Mason Earles
- School of Forestry & Environmental Studies, Yale University, New Haven, CT 06511, USA; Equal contribution
| | - Thomas N Buckley
- Department of Plant Sciences, University of California Davis, CA 95916, USA; Equal contribution
| | - Craig R Brodersen
- School of Forestry & Environmental Studies, Yale University, New Haven, CT 06511, USA
| | - Florian A Busch
- Research School of Biology, Australian National University, Action, ACT 0200, Australia
| | - F Javier Cano
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW 2753, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW 2753, Australia
| | - John R Evans
- Research School of Biology, Australian National University, Action, ACT 0200, Australia
| | - Graham D Farquhar
- Research School of Biology, Australian National University, Action, ACT 0200, Australia
| | | | - Minh Huynh
- University of Sydney, Sydney, NSW 2006, Australia
| | - Grace P John
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, CA 90095, USA
| | - Megan L Miller
- College of Natural Resources, University of Idaho, Moscow, ID 83844, USA
| | - Fulton E Rockwell
- Department of Organism and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, CA 90095, USA
| | - Christine Scoffoni
- Department of Biological Sciences, California State University Los Angeles, CA 90032, USA
| | - Paul C Struik
- Department of Plant Sciences, Wageningen University, Centre for Crop Systems Analysis, 6700 AK Wageningen, The Netherlands
| | - Alex Wu
- Centre for Plant Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xinyou Yin
- Department of Plant Sciences, Wageningen University, Centre for Crop Systems Analysis, 6700 AK Wageningen, The Netherlands
| | - Margaret M Barbour
- University of Sydney, Sydney, NSW 2006, Australia; www.sydney.edu.au/science/people/margaret.barbour.
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Cano FJ, López R, Warren CR. Implications of the mesophyll conductance to CO2 for photosynthesis and water-use efficiency during long-term water stress and recovery in two contrasting Eucalyptus species. Plant Cell Environ 2014; 37:2470-90. [PMID: 24635724 DOI: 10.1111/pce.12325] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 05/26/2023]
Abstract
Water stress (WS) slows growth and photosynthesis (A(n)), but most knowledge comes from short-time studies that do not account for longer term acclimation processes that are especially relevant in tree species. Using two Eucalyptus species that contrast in drought tolerance, we induced moderate and severe water deficits by withholding water until stomatal conductance (g(sw)) decreased to two pre-defined values for 24 d, WS was maintained at the target g(sw) for 29 d and then plants were re-watered. Additionally, we developed new equations to simulate the effect on mesophyll conductance (g(m)) of accounting for the resistance to refixation of CO(2). The diffusive limitations to CO(2), dominated by the stomata, were the most important constraints to A(n). Full recovery of A(n) was reached after re-watering, characterized by quick recovery of gm and even higher biochemical capacity, in contrast to the slower recovery of g(sw). The acclimation to long-term WS led to decreased mesophyll and biochemical limitations, in contrast to studies in which stress was imposed more rapidly. Finally, we provide evidence that higher gm under WS contributes to higher intrinsic water-use efficiency (iWUE) and reduces the leaf oxidative stress, highlighting the importance of gm as a target for breeding/genetic engineering.
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Affiliation(s)
- F Javier Cano
- Unidad Docente de Anatomía, Fisiología y Genética Forestal, E.T.S.I. Montes, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
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Cano FJ, Sánchez-Gómez D, Rodríguez-Calcerrada J, Warren CR, Gil L, Aranda I. Effects of drought on mesophyll conductance and photosynthetic limitations at different tree canopy layers. Plant Cell Environ 2013; 36:1961-80. [PMID: 23527762 DOI: 10.1111/pce.12103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 03/12/2013] [Accepted: 03/14/2013] [Indexed: 05/24/2023]
Abstract
In recent years, many studies have focused on the limiting role of mesophyll conductance (gm ) to photosynthesis (An ) under water stress, but no studies have examined the effect of drought on gm through the forest canopy. We investigated limitations to An on leaves at different heights in a mixed adult stand of sessile oak (Quercus petraea) and beech (Fagus sylvatica) trees during a moderately dry summer. Moderate drought decreased An of top and lowest beech canopy leaves much more than in leaves located in the mid canopy; whereas in oak, An of the lower canopy was decreased more than in sunlit leaves. The decrease of An was probably not due to leaf-level biochemistry given that VCmax was generally unaffected by drought. The reduction in An was instead associated with reduction in stomatal and mesophyll conductances. Drought-induced increases in stomatal limitations were largest in leaves from the top canopy, whereas drought-induced increases in mesophyll limitations were largest in leaves from the lowest canopy. Sensitivity analysis highlighted the need to decompose the canopy into different leaf layers and to incorporate the limitation imposed by gm when assessing the impact of drought on the gas exchange of tree canopies.
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Affiliation(s)
- F Javier Cano
- Unidad Docente de Anatomía, Fisiología y Genética Forestal, E.T.S.I. Montes, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
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Abstract
Studies of water stress commonly examine either gas exchange or leaf metabolites, and many fail to quantify the concentration of CO₂ in the chloroplasts (C(c)). We redress these limitations by quantifying C(c) from discrimination against ¹³CO₂ and using gas chromatography-mass spectrometry (GC-MS) for leaf metabolite profiling. Five Eucalyptus and two Acacia species from semi-arid to mesic habitats were subjected to a 2 month water stress treatment (Ψ(pre-dawn) = -1.7 to -2.3 MPa). Carbohydrates dominated the leaf metabolite profiles of species from dry areas, whereas organic acids dominated the metabolite profiles of species from wet areas. Water stress caused large decreases in photosynthesis and C(c), increases in 17-33 metabolites and decreases in 0-9 metabolites. In most species, fructose, glucose and sucrose made major contributions to osmotic adjustment. In Acacia, significant osmotic adjustment was also caused by increases in pinitol, pipecolic acid and trans-4-hydroxypipecolic acid. There were also increases in low-abundance metabolites (e.g. proline and erythritol), and metabolites that are indicative of stress-induced changes in metabolism [e.g. γ-aminobutyric acid (GABA) shunt, photorespiration, phenylpropanoid pathway]. The response of gas exchange to water stress and rewatering is rather consistent among species originating from mesic to semi-arid habitats, and the general response of metabolites to water stress is rather similar, although the specific metabolites involved may vary.
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Affiliation(s)
- Charles R Warren
- School of Biological Sciences, Heydon-Laurence Building A08, University of Sydney, Sydney NSW 2006, Australia.
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Rodríguez-Calcerrada J, Reich PB, Rosenqvist E, Pardos JA, Cano FJ, Aranda I. Leaf physiological versus morphological acclimation to high-light exposure at different stages of foliar development in oak. Tree Physiol 2008; 28:761-771. [PMID: 18316308 DOI: 10.1093/treephys/28.5.761] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigated light acclimation in seedlings of the temperate oak Quercus petraea (Matt.) Liebl. and the co-occurring sub-Mediterranean oak Quercus pyrenaica Willd. Seedlings were raised in a greenhouse for 1 year in either 70 (HL) or 5.3% (LL) of ambient irradiance of full sunlight, and, in the following year, subsets of the LL-grown seedlings were transferred to HL either before leaf flushing (LL-HLBF plants) or after full leaf expansion (LL-HLAF plants). Gas exchange, chlorophyll a fluorescence, nitrogen fractions in photosynthetic components and leaf anatomy were examined in leaves of all seedlings 5 months after plants were moved from LL to HL. Differences between species in the acclimation of LL-grown plants to HL were minor. For LL-grown plants in HL, area-based photosynthetic capacity, maximum rate of carboxylation, maximum rate of electron transport and the effective photochemical quantum yield of photosystem II were comparable to those for plants grown solely in HL. A rapid change in nitrogen distribution among photosynthetic components was observed in LL-HLAF plants, which had the highest photosynthetic nitrogen-use efficiency. Increases in mesophyll thickness and dry mass per unit area governed leaf acclimation in LL-HLBF plants, which tended to have less nitrogen in photosynthetic components and a lower assimilation potential per unit of leaf mass or nitrogen than LL-HLAF plants. The data indicate that the phenological state of seedlings modified the acclimatory response of leaf attributes to increased irradiance. Morphological adaptation of leaves of LL-HLBF plants enhanced photosynthetic capacity per unit leaf area, but not per unit leaf dry mass, whereas substantial redistribution of nitrogen among photosynthetic components in leaves of LL-HLAF plants enhanced both mass- and area-based photosynthetic capacity.
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Affiliation(s)
- J Rodríguez-Calcerrada
- Unidad de Anatomía, Fisiología y Genética Forestal, Escuela Técnica Superior de Ingenieros de Montes, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, Madrid, Spain
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Cano FJ. [Renal transplant and chronic rejection in pediatrics]. Rev Med Chil 1998; 126:96-106. [PMID: 9629760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The rapid advances in immunobiology, pharmacology and molecular biology have made successful renal transplantation the optimal therapeutic modality for adults and children, reaching a near--90% of patient-graft survival among the first years of transplant. But this knowledge also presents clinicians and scientists with difficult challenges, one of the most important remaining is the chronic rejection of the graft. A critical review of the immunobiology, clinical evolution and histopathology of chronic rejection is presented. Immunosuppressive agents with emphasis in their mechanism of action is also detailed.
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Affiliation(s)
- F J Cano
- Unidad de Nefrología Hospital Luis Calvo Mackenna, Faculta de Medicina, Universidad de Chile, Santiago-Chile
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Ceresa S, Cano FJ, Lueg E, Rossel M, Las Heras J. [Intestinal lymphangiectasis secondary to constrictive pericarditis]. Rev Chil Pediatr 1985; 56:462-4. [PMID: 3836450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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