201
|
Brito P, Grams TE, Matysssek R, Jimenez MS, Gonzalez-Rodríguez AM, Oberhuber W, Wieser G. Increased water use efficiency does not prevent growth decline of Pinus canariensis in a semi-arid treeline ecotone in Tenerife, Canary Islands (Spain). ANNALS OF FOREST SCIENCE 2016; 73:741-749. [PMID: 27482149 PMCID: PMC4961253 DOI: 10.1007/s13595-016-0562-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/17/2016] [Indexed: 05/19/2023]
Abstract
KEY MESSAGE Intrinsic water-use efficiency of Pinus canariensis (Sweet ex Spreng.) growing at a semi-arid treeline has increased during the past 37 years. Tree-ring width by contrast has declined, likely caused by reduced stomatal conductance due to increasing aridity. CONTEXT Rising atmospheric CO2 concentration (Ca ) has been related to tree growth enhancement accompanied by increasing intrinsic water-use-efficiency (iWUE). Nevertheless, the extent of rising Ca on long-term changes in iWUE and growth has remained poorly understood to date in Mediterranean treeline ecosystems. AIMS This study aimed to examine radial growth and physiological responses of P. canariensis in relation to rising Ca and increasing aridity at treeline in Tenerife, Canary Islands, Spain. METHODS We evaluated temporal changes in secondary growth (tree-ring width; TRW) and tree ring stable C isotope signature for assessing iWUE from 1975 through 2011. RESULTS Precipitation was the main factor controlling secondary growth. Over the last 36 years P. canariensis showed a decline in TRW at enhanced iWUE, likely caused by reduced stomatal conductance due to increasing aridity. CONCLUSION Our results indicate that increasing aridity has overridden the potential CO2 fertilization on tree growth of P. canariensis at its upper distribution limit.
Collapse
Affiliation(s)
- Patricia Brito
- Department of Botany, Ecology and Plant Physiology, Universidad de
La Laguna (ULL), C/Astrofísico Francisco Sánchez s/n, E-38207 La
Laguna, Tenerife, Spain
| | - Thorsten E.E. Grams
- Ecophysiology of Plants, Department of Ecology and Ecosystem
Management, Technische Universität München, Von-Carlowitz-Platz 2,
85354 Freising, Germany
| | - Rainer Matysssek
- Ecophysiology of Plants, Department of Ecology and Ecosystem
Management, Technische Universität München, Von-Carlowitz-Platz 2,
85354 Freising, Germany
| | - Maria S. Jimenez
- Department of Botany, Ecology and Plant Physiology, Universidad de
La Laguna (ULL), C/Astrofísico Francisco Sánchez s/n, E-38207 La
Laguna, Tenerife, Spain
| | - Agueda M. Gonzalez-Rodríguez
- Department of Botany, Ecology and Plant Physiology, Universidad de
La Laguna (ULL), C/Astrofísico Francisco Sánchez s/n, E-38207 La
Laguna, Tenerife, Spain
| | - Walter Oberhuber
- Institute of Botany, Leopold-Franzens-Universität Innsbruck,
Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Gerhard Wieser
- Department of Alpine Timberline Ecophysiology, Federal Research and
Training Centre for Forests, Natural Hazards and Landscape (BFW), Rennweg 1, A-6020
Innsbruck, Austria
- Gerhard Wieser
| |
Collapse
|
202
|
Phillips CA, O'Connell TC. Fecal carbon and nitrogen isotopic analysis as an indicator of diet in Kanyawara chimpanzees, Kibale National Park, Uganda. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:685-697. [DOI: 10.1002/ajpa.23073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/28/2016] [Accepted: 08/04/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Caroline A. Phillips
- Evolutionary Studies Institute, University of the WitwatersrandWits2050 South Africa
- Department of Archaeology and AnthropologyMcDonald Institute of Archaeological Research, University of CambridgeDowning StreetCambridge CB2 3ER England
| | - Tamsin C. O'Connell
- Department of Archaeology and AnthropologyMcDonald Institute of Archaeological Research, University of CambridgeDowning StreetCambridge CB2 3ER England
| |
Collapse
|
203
|
Hellmann C, Werner C, Oldeland J. A Spatially Explicit Dual-Isotope Approach to Map Regions of Plant-Plant Interaction after Exotic Plant Invasion. PLoS One 2016; 11:e0159403. [PMID: 27462988 PMCID: PMC4963087 DOI: 10.1371/journal.pone.0159403] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/02/2016] [Indexed: 11/19/2022] Open
Abstract
Understanding interactions between native and invasive plant species in field settings and quantifying the impact of invaders in heterogeneous native ecosystems requires resolving the spatial scale on which these processes take place. Therefore, functional tracers are needed that enable resolving the alterations induced by exotic plant invasion in contrast to natural variation in a spatially explicit way. 15N isoscapes, i.e., spatially referenced representations of stable nitrogen isotopic signatures, have recently provided such a tracer. However, different processes, e.g. water, nitrogen or carbon cycles, may be affected at different spatial scales. Thus multi-isotope studies, by using different functional tracers, can potentially return a more integrated picture of invader impact. This is particularly true when isoscapes are submitted to statistical methods suitable to find homogeneous subgroups in multivariate data such as cluster analysis. Here, we used model-based clustering of spatially explicit foliar δ15N and δ13C isoscapes together with N concentration of a native indicator species, Corema album, to map regions of influence in a Portuguese dune ecosystem invaded by the N2-fixing Acacia longifolia. Cluster analysis identified regions with pronounced alterations in N budget and water use efficiency in the native species, with a more than twofold increase in foliar N, and δ13C and δ15N enrichment of up to 2‰ and 8‰ closer to the invader, respectively. Furthermore, clusters of multiple functional tracers indicated a spatial shift from facilitation through N addition in the proximity of the invader to competition for resources other than N in close contact. Finding homogeneous subgroups in multi-isotope data by means of model-based cluster analysis provided an effective tool for detecting spatial structure in processes affecting plant physiology and performance. The proposed method can give an objective measure of the spatial extent of influence of plant-plant interactions, thus improving our understanding of spatial pattern and interactions in plant communities.
Collapse
Affiliation(s)
- Christine Hellmann
- Experimental and Systems Ecology, University of Bielefeld, Bielefeld, Germany
- Ecosystem Physiology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Christiane Werner
- Ecosystem Physiology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Jens Oldeland
- Biodiversity, Evolution and Ecology of Plants, Biocentre Klein Flottbek and Botanical Garden, University of Hamburg, Hamburg, Germany
| |
Collapse
|
204
|
Lightfoot E, Przelomska N, Craven M, O Connell TC, He L, Hunt HV, Jones MK. Intraspecific carbon and nitrogen isotopic variability in foxtail millet (Setaria italica). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1475-1487. [PMID: 27321835 DOI: 10.1002/rcm.7583] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Isotopic palaeodietary studies generally focus on bone collagen from human and/or animal remains. While plant remains are rarely analysed, it is known that plant isotope values can vary as a result of numerous factors, including soil conditions, the environment and type of plant. The millets were important food crops in prehistoric Eurasia, yet little is known about the isotopic differences within millet species. METHODS Here we compare the stable isotope ratios within and between Setaria italica plants grown in a controlled environment chamber. Using homogenised samples, we compare carbon isotope ratios of leaves and grains, and nitrogen isotope ratios of grains, from 29 accessions of Setaria italica. RESULTS We find significant isotopic variability within single leaves and panicles, and between leaves and panicles within the same plant, which must be considered when undertaking plant isotope studies. We find that the leaves and grains from the different accessions have a ca 2‰ range in δ(13) C values, while the nitrogen isotope values in the grains have a ca 6‰ range. We also find an average offset of 0.9‰ between leaves and grains in their δ(13) C values. CONCLUSIONS The variation found is large enough to have archaeological implications and within- and between-plant isotope variability should be considered in isotope studies. The range in δ(15) N values is particularly significant as it is larger than the typical values quoted for a trophic level enrichment, and as such may lead to erroneous interpretations of the amount of animal protein in human or animal diets. It is therefore necessary to account for the variability in plant stable isotope values during palaeodietary reconstructions. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Emma Lightfoot
- McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge, CB2 3ER, UK
| | - Natalia Przelomska
- Department of Archaeology and Anthropology, University of Cambridge, Downing Street, Cambridge, CB2 3DZ, UK
| | - Martha Craven
- Department of Archaeology and Anthropology, University of Cambridge, Downing Street, Cambridge, CB2 3DZ, UK
| | - Tamsin C O Connell
- Department of Archaeology and Anthropology, University of Cambridge, Downing Street, Cambridge, CB2 3DZ, UK
| | - Lu He
- College of Agriculture, Shanxi Agricultural University, Taigu, 030801, China
| | - Harriet V Hunt
- McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge, CB2 3ER, UK
| | - Martin K Jones
- Department of Archaeology and Anthropology, University of Cambridge, Downing Street, Cambridge, CB2 3DZ, UK
| |
Collapse
|
205
|
von Holstein ICC, Makarewicz CA. Geographical variability in northern European sheep wool isotopic composition (δ(13) C, δ(15) N, δ(2) H values). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1423-1434. [PMID: 27197035 DOI: 10.1002/rcm.7578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/31/2016] [Accepted: 04/02/2016] [Indexed: 06/05/2023]
Abstract
RATIONALE Light stable isotopic analysis of herbivore proteinaceous tissues (hair, muscle, milk) is critical for authenticating the point of origin of finished agricultural or industrial products in both ancient and modern economies. This study examined the distribution of light stable isotopes in herbivores in northern Europe (Iceland to Finland), which is expected to depend on regional-level environmental inputs (precipitation, temperature) and local variables (vegetation type, fodder type, soil type). METHODS Sheep wool was obtained from animals managed using traditional methods and located across a gradient of northern European environments. Defatted whole-year samples were analysed by isotope ratio mass spectrometry (IRMS) for carbon (δ(13) C values), nitrogen (δ(15) N values) and un-exchangeable hydrogen (δ(2) H values) isotopic composition. RESULTS Wool δ(13) C, δ(15) N and δ(2) H values showed the same correlations to local mean annual precipitation and temperature as were expected for graze plants. Wool δ(2) H values were correlated with local modelled meteoric water δ(2) H values, mediated by plant solid tissue and leaf water fractionations. Cluster analysis distinguished wool from Sweden and the Baltic region from more western material. Local variation in vegetation or soil type did not disrupt dependence on climatic variables but did affect geospatial discrimination. CONCLUSIONS Wool isotopic composition in northern Europe is controlled by the effects of local precipitation and temperature on graze plant inputs, and is only weakly affected by pasture type. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
| | - Cheryl A Makarewicz
- Institut für Ur- und Frühgeschichte, Christian-Albrechts-Universität, D-24098, Kiel, Germany
| |
Collapse
|
206
|
Wieser G, Oberhuber W, Gruber A, Leo M, Matyssek R, Grams TEE. Stable Water Use Efficiency under Climate Change of Three Sympatric Conifer Species at the Alpine Treeline. FRONTIERS IN PLANT SCIENCE 2016; 7:799. [PMID: 27375653 PMCID: PMC4894875 DOI: 10.3389/fpls.2016.00799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/22/2016] [Indexed: 05/23/2023]
Abstract
The ability of treeline associated conifers in the Central Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined tree ring stable carbon and oxygen isotope ratios of Pinus cembra, Picea abies, and Larix decidua trees from 1975 to 2010. Stable isotope ratios were compared with leaf level gas exchange measurements carried out in situ between 1979 and 2007. Results indicate that tree ring derived intrinsic water-use efficiency (iWUE) of P. cembra, P. abies and L. decidua remained constant during the last 36 years despite climate warming and rising atmospheric CO2. Temporal patterns in Δ(13)C and Δ(18)O mirrored leaf level gas exchange assessments, suggesting parallel increases of CO2-fixation and stomatal conductance of treeline conifer species. As at the study site soil water availability was not a limiting factor iWUE remained largely stable throughout the study period. The stability in iWUE was accompanied by an increase in basal area increment (BAI) suggesting that treeline trees benefit from both recent climate warming and CO2 fertilization. Finally, our results suggest that iWUE may not change species composition at treeline in the Austrian Alps due to similar ecophysiological responses to climatic changes of the three sympatric study species.
Collapse
Affiliation(s)
- Gerhard Wieser
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Walter Oberhuber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Andreas Gruber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Marco Leo
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Rainer Matyssek
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| | - Thorsten Erhard Edgar Grams
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| |
Collapse
|
207
|
Brillante L, Mathieu O, Lévêque J, Bois B. Ecophysiological Modeling of Grapevine Water Stress in Burgundy Terroirs by a Machine-Learning Approach. FRONTIERS IN PLANT SCIENCE 2016; 7:796. [PMID: 27375651 PMCID: PMC4894889 DOI: 10.3389/fpls.2016.00796] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/22/2016] [Indexed: 05/21/2023]
Abstract
In a climate change scenario, successful modeling of the relationships between plant-soil-meteorology is crucial for a sustainable agricultural production, especially for perennial crops. Grapevines (Vitis vinifera L. cv Chardonnay) located in eight experimental plots (Burgundy, France) along a hillslope were monitored weekly for 3 years for leaf water potentials, both at predawn (Ψpd) and at midday (Ψstem). The water stress experienced by grapevine was modeled as a function of meteorological data (minimum and maximum temperature, rainfall) and soil characteristics (soil texture, gravel content, slope) by a gradient boosting machine. Model performance was assessed by comparison with carbon isotope discrimination (δ(13)C) of grape sugars at harvest and by the use of a test-set. The developed models reached outstanding prediction performance (RMSE < 0.08 MPa for Ψstem and < 0.06 MPa for Ψpd), comparable to measurement accuracy. Model predictions at a daily time step improved correlation with δ(13)C data, respect to the observed trend at a weekly time scale. The role of each predictor in these models was described in order to understand how temperature, rainfall, soil texture, gravel content and slope affect the grapevine water status in the studied context. This work proposes a straight-forward strategy to simulate plant water stress in field condition, at a local scale; to investigate ecological relationships in the vineyard and adapt cultural practices to future conditions.
Collapse
Affiliation(s)
- Luca Brillante
- Viticulture Research Center, Council for Agricultural Research and EconomicsConegliano, Italy
- UMR CNRS/uB 6282 Biogéosciences, Université de BourgogneDijon, France
| | - Olivier Mathieu
- UMR CNRS/uB 6282 Biogéosciences, Université de BourgogneDijon, France
| | - Jean Lévêque
- UMR CNRS/uB 6282 Biogéosciences, Université de BourgogneDijon, France
| | - Benjamin Bois
- UMR CNRS/uB 6282 Biogéosciences, Université de BourgogneDijon, France
- Institut Universitaire de la Vigne et du Vin “Jules Guyot,” Université de BourgogneDijon, France
| |
Collapse
|
208
|
Ellsworth PZ, Cousins AB. Carbon isotopes and water use efficiency in C4 plants. CURRENT OPINION IN PLANT BIOLOGY 2016; 31:155-61. [PMID: 27155062 DOI: 10.1016/j.pbi.2016.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/07/2016] [Accepted: 04/14/2016] [Indexed: 05/13/2023]
Abstract
Drought is a major agricultural problem worldwide. Therefore, selection for increased water use efficiency (WUE) in food and biofuel crop species will be an important trait in plant breeding programs. The leaf carbon isotopic composition (δ(13)Cleaf) has been suggested to serve as a rapid and effective high throughput phenotyping method for WUE in both C3 and C4 species. This is because WUE, leaf carbon discrimination (Δ(13)Cleaf), and δ(13)Cleaf are correlated through their relationships with intercellular to ambient CO2 partial pressures (Ci/Ca). However, in C4 plants, changing environmental conditions may influence photosynthetic efficiency (bundle-sheath leakiness) and post-photosynthetic fractionation that will potentially alter the relationship between δ(13)Cleaf and Ci/Ca. Here we discuss how these factors influence the relationship between δ(13)Cleaf and WUE, and the potential of using δ(13)Cleaf as a meaningful proxy for WUE.
Collapse
Affiliation(s)
| | - Asaph B Cousins
- Washington State University, Pullman, WA 99163, United States.
| |
Collapse
|
209
|
Bellasio C, Beerling DJ, Griffiths H. An Excel tool for deriving key photosynthetic parameters from combined gas exchange and chlorophyll fluorescence: theory and practice. PLANT, CELL & ENVIRONMENT 2016; 39:1180-97. [PMID: 25923517 DOI: 10.1111/pce.12560] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/10/2015] [Accepted: 02/25/2015] [Indexed: 05/23/2023]
Abstract
Combined photosynthetic gas exchange and modulated fluorometres are widely used to evaluate physiological characteristics associated with phenotypic and genotypic variation, whether in response to genetic manipulation or resource limitation in natural vegetation or crops. After describing relatively simple experimental procedures, we present the theoretical background to the derivation of photosynthetic parameters, and provide a freely available Excel-based fitting tool (EFT) that will be of use to specialists and non-specialists alike. We use data acquired in concurrent variable fluorescence-gas exchange experiments, where A/Ci and light-response curves have been measured under ambient and low oxygen. From these data, the EFT derives light respiration, initial PSII (photosystem II) photochemical yield, initial quantum yield for CO2 fixation, fraction of incident light harvested by PSII, initial quantum yield for electron transport, electron transport rate, rate of photorespiration, stomatal limitation, Rubisco (ribulose 1·5-bisphosphate carboxylase/oxygenase) rate of carboxylation and oxygenation, Rubisco specificity factor, mesophyll conductance to CO2 diffusion, light and CO2 compensation point, Rubisco apparent Michaelis-Menten constant, and Rubisco CO2 -saturated carboxylation rate. As an example, a complete analysis of gas exchange data on tobacco plants is provided. We also discuss potential measurement problems and pitfalls, and suggest how such empirical data could subsequently be used to parameterize predictive photosynthetic models.
Collapse
Affiliation(s)
- Chandra Bellasio
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - David J Beerling
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| |
Collapse
|
210
|
Bellasio C, Beerling DJ, Griffiths H. Deriving C4 photosynthetic parameters from combined gas exchange and chlorophyll fluorescence using an Excel tool: theory and practice. PLANT, CELL & ENVIRONMENT 2016; 39:1164-79. [PMID: 26286697 DOI: 10.1111/pce.12626] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/06/2015] [Indexed: 05/27/2023]
Abstract
The higher photosynthetic potential of C4 plants has led to extensive research over the past 50 years, including C4 -dominated natural biomes, crops such as maize, or for evaluating the transfer of C4 traits into C3 lineages. Photosynthetic gas exchange can be measured in air or in a 2% Oxygen mixture using readily available commercial gas exchange and modulated PSII fluorescence systems. Interpretation of these data, however, requires an understanding (or the development) of various modelling approaches, which limit the use by non-specialists. In this paper we present an accessible summary of the theory behind the analysis and derivation of C4 photosynthetic parameters, and provide a freely available Excel Fitting Tool (EFT), making rigorous C4 data analysis accessible to a broader audience. Outputs include those defining C4 photochemical and biochemical efficiency, the rate of photorespiration, bundle sheath conductance to CO2 diffusion and the in vivo biochemical constants for PEP carboxylase. The EFT compares several methodological variants proposed by different investigators, allowing users to choose the level of complexity required to interpret data. We provide a complete analysis of gas exchange data on maize (as a model C4 organism and key global crop) to illustrate the approaches, their analysis and interpretation. © 2015 John Wiley & Sons Ltd.
Collapse
Affiliation(s)
- Chandra Bellasio
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - David J Beerling
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| |
Collapse
|
211
|
Holtum JA, Hancock LP, Edwards EJ, Crisp MD, Crayn DM, Sage R, Winter K. Australia lacks stem succulents but is it depauperate in plants with crassulacean acid metabolism (CAM)? CURRENT OPINION IN PLANT BIOLOGY 2016; 31:109-117. [PMID: 27088716 DOI: 10.1016/j.pbi.2016.03.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 03/22/2016] [Accepted: 03/28/2016] [Indexed: 06/05/2023]
Abstract
In the flora of Australia, the driest vegetated continent, crassulacean acid metabolism (CAM), the most water-use efficient form of photosynthesis, is documented in only 0.6% of native species. Most are epiphytes and only seven terrestrial. However, much of Australia is unsurveyed, and carbon isotope signature, commonly used to assess photosynthetic pathway diversity, does not distinguish between plants with low-levels of CAM and C3 plants. We provide the first census of CAM for the Australian flora and suggest that the real frequency of CAM in the flora is double that currently known, with the number of terrestrial CAM species probably 10-fold greater. Still unresolved is the question why the large stem-succulent life - form is absent from the native Australian flora even though exotic large cacti have successfully invaded and established in Australia.
Collapse
Affiliation(s)
- Joseph Am Holtum
- Terrestrial Ecosystems and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville 4811, Queensland, Australia; Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Panama.
| | - Lillian P Hancock
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA
| | - Michael D Crisp
- Research School of Biology, Australian National University, Canberra 2601, ACT, Australia
| | - Darren M Crayn
- Australian Tropical Herbarium, James Cook University, PO Box 6811, Cairns 4870, Queensland, Australia
| | - Rowan Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Canada
| | - Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Panama
| |
Collapse
|
212
|
León‐Sánchez L, Nicolás E, Nortes PA, Maestre FT, Querejeta JI. Photosynthesis and growth reduction with warming are driven by nonstomatal limitations in a Mediterranean semi-arid shrub. Ecol Evol 2016; 6:2725-38. [PMID: 27066247 PMCID: PMC4798828 DOI: 10.1002/ece3.2074] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/08/2016] [Accepted: 02/12/2016] [Indexed: 11/15/2022] Open
Abstract
Whereas warming enhances plant nutrient status and photosynthesis in most terrestrial ecosystems, dryland vegetation is vulnerable to the likely increases in evapotranspiration and reductions in soil moisture caused by elevated temperatures. Any warming-induced declines in plant primary production and cover in drylands would increase erosion, land degradation, and desertification. We conducted a four-year manipulative experiment in a semi-arid Mediterranean ecosystem to evaluate the impacts of a ~2°C warming on the photosynthesis, transpiration, leaf nutrient status, chlorophyll content, isotopic composition, biomass growth, and postsummer survival of the native shrub Helianthemum squamatum. We predicted that warmed plants would show reduced photosynthetic activity and growth, primarily due to the greater stomatal limitation imposed by faster and more severe soil drying under warming. On average, warming reduced net photosynthetic rates by 36% across the study period. Despite this strong response, warming did not affect stomatal conductance and transpiration. The reduction of peak photosynthetic rates with warming was more pronounced in a drought year than in years with near-average rainfall (75% and 25-40% reductions relative to controls, respectively), with no indications of photosynthetic acclimation to warming through time. Warmed plants had lower leaf N and P contents, δ (13)C, and sparser and smaller leaves than control plants. Warming reduced shoot dry mass production by 31%. However, warmed plants were able to cope with large reductions in net photosynthesis, leaf area, and shoot biomass production without changes in postsummer survival rates. Our findings highlight the key role of nonstomatal factors (biochemical and/or nutritional) in reducing net carbon assimilation rates and growth under warming, which has important implications for projections of plant carbon balance under the warmer and drier climatic scenario predicted for drylands worldwide. Projected climate warming over the coming decades could reduce net primary production by about one-third in semi-arid gypsum shrublands dominated by H. squamatum.
Collapse
Affiliation(s)
- Lupe León‐Sánchez
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC)Campus Universitario de EspinardoPO Box 164E‐30100MurciaSpain
| | - Emilio Nicolás
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC)Campus Universitario de EspinardoPO Box 164E‐30100MurciaSpain
| | - Pedro A. Nortes
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC)Campus Universitario de EspinardoPO Box 164E‐30100MurciaSpain
| | - Fernando T. Maestre
- Biodiversity and Conservation UnitDepartment of Biology and GeologyUniversidad Rey Juan CarlosMóstoles28933MadridSpain
| | - José I. Querejeta
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC)Campus Universitario de EspinardoPO Box 164E‐30100MurciaSpain
| |
Collapse
|
213
|
Adams MA, Turnbull TL, Sprent JI, Buchmann N. Legumes are different: Leaf nitrogen, photosynthesis, and water use efficiency. Proc Natl Acad Sci U S A 2016; 113:4098-103. [PMID: 27035971 PMCID: PMC4839396 DOI: 10.1073/pnas.1523936113] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Using robust, pairwise comparisons and a global dataset, we show that nitrogen concentration per unit leaf mass for nitrogen-fixing plants (N2FP; mainly legumes plus some actinorhizal species) in nonagricultural ecosystems is universally greater (43-100%) than that for other plants (OP). This difference is maintained across Koppen climate zones and growth forms and strongest in the wet tropics and within deciduous angiosperms. N2FP mostly show a similar advantage over OP in nitrogen per leaf area (Narea), even in arid climates, despite diazotrophy being sensitive to drought. We also show that, for most N2FP, carbon fixation by photosynthesis (Asat) and stomatal conductance (gs) are not related to Narea-in distinct challenge to current theories that place the leaf nitrogen-Asat relationship at the center of explanations of plant fitness and competitive ability. Among N2FP, only forbs displayed an Narea-gs relationship similar to that for OP, whereas intrinsic water use efficiency (WUEi; Asat/gs) was positively related to Narea for woody N2FP. Enhanced foliar nitrogen (relative to OP) contributes strongly to other evolutionarily advantageous attributes of legumes, such as seed nitrogen and herbivore defense. These alternate explanations of clear differences in leaf N between N2FP and OP have significant implications (e.g., for global models of carbon fluxes based on relationships between leaf N and Asat). Combined, greater WUE and leaf nitrogen-in a variety of forms-enhance fitness and survival of genomes of N2FP, particularly in arid and semiarid climates.
Collapse
Affiliation(s)
- Mark Andrew Adams
- Centre for Carbon Water and Food, Faculty of Agriculture and Environment, University of Sydney, Brownlow Hill, 2570 NSW, Australia;
| | - Tarryn L Turnbull
- Centre for Carbon Water and Food, Faculty of Agriculture and Environment, University of Sydney, Brownlow Hill, 2570 NSW, Australia
| | - Janet I Sprent
- Plant Sciences, University of Dundee at James Hutton Institute, Dundee DD2 5DA, Scotland
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zürich, 8092 Zurich, Switzerland
| |
Collapse
|
214
|
Lauterbach M, van der Merwe PDW, Keßler L, Pirie MD, Bellstedt DU, Kadereit G. Evolution of leaf anatomy in arid environments – A case study in southern African Tetraena and Roepera (Zygophyllaceae). Mol Phylogenet Evol 2016; 97:129-144. [DOI: 10.1016/j.ympev.2016.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/28/2022]
|
215
|
Jennings KA, Guerrieri R, Vadeboncoeur MA, Asbjornsen H. Response of Quercus velutina growth and water use efficiency to climate variability and nitrogen fertilization in a temperate deciduous forest in the northeastern USA. TREE PHYSIOLOGY 2016; 36:428-443. [PMID: 26917704 DOI: 10.1093/treephys/tpw003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/06/2016] [Indexed: 06/05/2023]
Abstract
Nitrogen (N) deposition and changing climate patterns in the northeastern USA can influence forest productivity through effects on plant nutrient relations and water use. This study evaluates the combined effects of N fertilization, climate and rising atmospheric CO2on tree growth and ecophysiology in a temperate deciduous forest. Tree ring widths and stable carbon (δ(13)C) and oxygen (δ(18)O) isotopes were used to assess tree growth (basal area increment, BAI) and intrinsic water use efficiency (iWUE) ofQuercus velutinaLamb., the dominant tree species in a 20+ year N fertilization experiment at Harvard Forest (MA, USA). We found that fertilized trees exhibited a pronounced and sustained growth enhancement relative to control trees, with the low- and high-N treatments responding similarly. All treatments exhibited improved iWUE over the study period (1984-2011). Intrinsic water use efficiency trends in the control trees were primarily driven by changes in stomatal conductance, while a stimulation in photosynthesis, supported by an increase in foliar %N, contributed to enhancing iWUE in fertilized trees. All treatments were predominantly influenced by growing season vapor pressure deficit (VPD), with BAI responding most strongly to early season VPD and iWUE responding most strongly to late season VPD. Nitrogen fertilization increasedQ. velutinasensitivity to July temperature and precipitation. Combined, these results suggest that ambient N deposition in N-limited northeastern US forests has enhanced tree growth over the past 30 years, while rising ambient CO2has improved iWUE, with N fertilization and CO2having synergistic effects on iWUE.
Collapse
Affiliation(s)
- Katie A Jennings
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA
| | - Rossella Guerrieri
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA
| | | | - Heidi Asbjornsen
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA Department of Natural Resources and the Environment and Earth Systems Research Center, University of New Hampshire, 114 James Hall, Durham, NH 03824, USA
| |
Collapse
|
216
|
Cotton JM, Cerling TE, Hoppe KA, Mosier TM, Still CJ. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum. SCIENCE ADVANCES 2016; 2:e1501346. [PMID: 27051865 PMCID: PMC4820366 DOI: 10.1126/sciadv.1501346] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/09/2016] [Indexed: 06/01/2023]
Abstract
The spread of C4 grasses in the late Neogene is one of the most important ecological transitions of the Cenozoic, but the primary driver of this global expansion is widely debated. We use the stable carbon isotopic composition (δ(13)C) of bison and mammoth tissues as a proxy for the relative abundance of C3 and C4 vegetation in their grazing habitat to determine climatic and atmospheric CO2 controls on C4 grass distributions from the Last Glacial Maximum (LGM) to the present. We predict the spatial variability of grass δ(13)C in North America using a mean of three different methods of classification and regression tree (CART) machine learning techniques and nine climatic variables. We show that growing season precipitation and temperature are the strongest predictors of all single climate variables. We apply this CART analysis to high-resolution gridded climate data and Coupled Model Intercomparison Project (CMIP5) mean paleoclimate model outputs to produce predictive isotope landscape models ("isoscapes") for the current, mid-Holocene, and LGM average δ(13)C of grass-dominated areas across North America. From the LGM to the present, C4 grass abundances substantially increased in the Great Plains despite concurrent increases in atmospheric CO2. These results suggest that changes in growing season precipitation rather than atmospheric CO2 were critically important in the Neogene expansion of C4 grasses.
Collapse
Affiliation(s)
- Jennifer M. Cotton
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97330, USA
- Department of Geological Sciences, California State University, Northridge, Northridge, CA 91330, USA
| | - Thure E. Cerling
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA
| | - Kathryn A. Hoppe
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA
- Department of Geology, Green River Community College, Auburn, WA 98092, USA
| | - Thomas M. Mosier
- School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University, Corvallis, OR 97330, USA
| | - Christopher J. Still
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97330, USA
| |
Collapse
|
217
|
Benomar L, Lamhamedi MS, Rainville A, Beaulieu J, Bousquet J, Margolis HA. Genetic Adaptation vs. Ecophysiological Plasticity of Photosynthetic-Related Traits in Young Picea glauca Trees along a Regional Climatic Gradient. FRONTIERS IN PLANT SCIENCE 2016; 7:48. [PMID: 26870067 PMCID: PMC4737914 DOI: 10.3389/fpls.2016.00048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 01/12/2016] [Indexed: 05/23/2023]
Abstract
Assisted population migration (APM) is the intentional movement of populations within a species range to sites where future environmental conditions are projected to be more conducive to growth. APM has been proposed as a proactive adaptation strategy to maintain forest productivity and to reduce the vulnerability of forest ecosystems to projected climate change. The validity of such a strategy will depend on the adaptation capacity of populations, which can partially be evaluated by the ecophysiological response of different genetic sources along a climatic gradient. This adaptation capacity results from the compromise between (i) the degree of genetic adaptation of seed sources to their environment of origin and (ii) the phenotypic plasticity of functional trait which can make it possible for transferred seed sources to positively respond to new growing conditions. We examined phenotypic variation in morphophysiological traits of six seed sources of white spruce (Picea glauca [Moench] Voss) along a regional climatic gradient in Québec, Canada. Seedlings from the seed sources were planted at three forest sites representing a mean annual temperature (MAT) gradient of 2.2°C. During the second growing season, we measured height growth (H2014) and traits related to resources use efficiency and photosynthetic rate (A max). All functional traits showed an adaptive response to the climatic gradient. Traits such as H2014, A max, stomatal conductance (g s ), the ratio of mesophyll to stomatal conductance, water use efficiency, and photosynthetic nitrogen-use efficiency showed significant variation in both physiological plasticity due to the planting site and seed source variation related to local genetic adaptation. However, the amplitude of seed source variation was much less than that related to plantation sites in the area investigated. The six seed sources showed a similar level of physiological plasticity. H2014, A max and g s , but not carboxylation capacity (V cmax), were correlated and decreased with a reduction of the average temperature of the growing season at seed origin. The clinal variation in H2014 and A max appeared to be driven by CO2 conductance. The presence of locally adapted functional traits suggests that the use of APM may have advantages for optimizing seed source productivity in future local climates.
Collapse
Affiliation(s)
- Lahcen Benomar
- Faculté de Foresterie, de Géographie et de Géomatique, Centre D'étude de la Forêt, Université LavalQuebec, QC, Canada
| | - Mohammed S. Lamhamedi
- Direction de la Recherche Forestière, Ministère des Forêts, de la Faune et des ParcsQuebec, QC, Canada
| | - André Rainville
- Direction de la Recherche Forestière, Ministère des Forêts, de la Faune et des ParcsQuebec, QC, Canada
| | - Jean Beaulieu
- Faculté de Foresterie, de Géographie et de Géomatique, Centre D'étude de la Forêt, Université LavalQuebec, QC, Canada
| | - Jean Bousquet
- Faculté de Foresterie, de Géographie et de Géomatique, Centre D'étude de la Forêt, Université LavalQuebec, QC, Canada
| | - Hank A. Margolis
- Faculté de Foresterie, de Géographie et de Géomatique, Centre D'étude de la Forêt, Université LavalQuebec, QC, Canada
| |
Collapse
|
218
|
Voelker SL, Brooks JR, Meinzer FC, Anderson R, Bader MKF, Battipaglia G, Becklin KM, Beerling D, Bert D, Betancourt JL, Dawson TE, Domec JC, Guyette RP, Körner C, Leavitt SW, Linder S, Marshall JD, Mildner M, Ogée J, Panyushkina I, Plumpton HJ, Pregitzer KS, Saurer M, Smith AR, Siegwolf RTW, Stambaugh MC, Talhelm AF, Tardif JC, Van de Water PK, Ward JK, Wingate L. A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2 : evidence from carbon isotope discrimination in paleo and CO2 enrichment studies. GLOBAL CHANGE BIOLOGY 2016; 22:889-902. [PMID: 26391334 DOI: 10.1111/gcb.13102] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/24/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
Rising atmospheric [CO2 ], ca , is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water, and nutrient cycling of forests. Researchers have proposed various strategies for stomatal regulation of leaf gas-exchange that include maintaining a constant leaf internal [CO2 ], ci , a constant drawdown in CO2 (ca - ci ), and a constant ci /ca . These strategies can result in drastically different consequences for leaf gas-exchange. The accuracy of Earth systems models depends in part on assumptions about generalizable patterns in leaf gas-exchange responses to varying ca . The concept of optimal stomatal behavior, exemplified by woody plants shifting along a continuum of these strategies, provides a unifying framework for understanding leaf gas-exchange responses to ca . To assess leaf gas-exchange regulation strategies, we analyzed patterns in ci inferred from studies reporting C stable isotope ratios (δ(13) C) or photosynthetic discrimination (∆) in woody angiosperms and gymnosperms that grew across a range of ca spanning at least 100 ppm. Our results suggest that much of the ca -induced changes in ci /ca occurred across ca spanning 200 to 400 ppm. These patterns imply that ca - ci will eventually approach a constant level at high ca because assimilation rates will reach a maximum and stomatal conductance of each species should be constrained to some minimum level. These analyses are not consistent with canalization toward any single strategy, particularly maintaining a constant ci . Rather, the results are consistent with the existence of a broadly conserved pattern of stomatal optimization in woody angiosperms and gymnosperms. This results in trees being profligate water users at low ca , when additional water loss is small for each unit of C gain, and increasingly water-conservative at high ca , when photosystems are saturated and water loss is large for each unit C gain.
Collapse
Affiliation(s)
- Steven L Voelker
- Department of Forest Ecosystems & Society, Oregon State University, Corvallis, OR, 97331, USA
| | - J Renée Brooks
- Western Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR, 97333, USA
| | - Frederick C Meinzer
- U.S.D.A. Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Rebecca Anderson
- Jack Baskin Engineering, University of California Santa Cruz, Santa Cruz, CA, 95604, USA
| | - Martin K-F Bader
- New Zealand Forest Research Institute (SCION), Te Papa Tipu Innovation Park, 20 Sala Street, 3046, Rotorua, New Zealand
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Second University of Naples, 81100, Caserta, Italy
- Ecole Pratique des Hautes Etudes, Centre for Bio-Archaeology and Ecology, Institut de Botanique, University of Montpellier 2, Montpellier, F-34090, France
| | - Katie M Becklin
- Department of Ecology and Evolutionary Biology, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
| | - David Beerling
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Didier Bert
- UMR1202 BIOGECO, INRA, F-33610, Cestas, France
- UMR 1202 BIOGECO, University of Bordeaux, F-33615, Pessac, France
| | - Julio L Betancourt
- National Research Program, Water Mission Area, U.S. Geological Survey, Mail Stop 430, 12201 Sunrise Valley Drive, Reston, VA, 20192, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California Berkeley, 1105 Valley Life Science Bldg #3140, Berkeley, CA, 94720, USA
| | - Jean-Christophe Domec
- Bordeaux Sciences Agro, UMR ISPA 1391, INRA, 33175, Gradignan, France
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708, USA
| | - Richard P Guyette
- Department of Forestry, University of Missouri, 203 ABNR Building, Columbia, MO, 65211, USA
| | - Christian Körner
- Institute of Botany, University of Basel, Schonbeinstrasse 6, CH-4056, Basel, Switzerland
| | | | - Sune Linder
- Laboratory for Tree-Ring Research, University of Arizona, 1215 E. Lowell St., Tucson, AZ, 85721-0045, USA
| | - John D Marshall
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, PO Box 49, SE-230 53, Alnarp, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Manuel Mildner
- Institute of Botany, University of Basel, Schonbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Jérôme Ogée
- Bordeaux Sciences Agro, UMR ISPA 1391, INRA, 33175, Gradignan, France
- UMR1391 ISPA, INRA, 33140, Villenave d'Ornon, France
| | - Irina Panyushkina
- Laboratory for Tree-Ring Research, University of Arizona, 1215 E. Lowell St., Tucson, AZ, 85721-0045, USA
| | | | - Kurt S Pregitzer
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844, USA
| | | | - Andrew R Smith
- School of the Environment, Natural Resources and Geography, Bangor University, Gwynedd, LL57 2UW, UK
| | | | - Michael C Stambaugh
- Department of Forestry, University of Missouri, 203 ABNR Building, Columbia, MO, 65211, USA
| | - Alan F Talhelm
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844, USA
| | - Jacques C Tardif
- Centre for Forest Interdisciplinary Research (C-FIR), University of Winnipeg, 515 Avenue Portage, Winnipeg, MB, Canada, R3B 2E9
| | - Peter K Van de Water
- Department of Earth & Environmental Sciences, California State University, Fresno, 2576 E. San Ramon Ave., Mail Stop ST-24, Fresno, CA, 93740, USA
| | - Joy K Ward
- Department of Ecology and Evolutionary Biology, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
| | - Lisa Wingate
- Bordeaux Sciences Agro, UMR ISPA 1391, INRA, 33175, Gradignan, France
- UMR1391 ISPA, INRA, 33140, Villenave d'Ornon, France
| |
Collapse
|
219
|
The interaction of biotic and abiotic factors at multiple spatial scales affects the variability of CO2 fluxes in polar environments. Polar Biol 2015. [DOI: 10.1007/s00300-015-1883-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
220
|
Mattiello L, Riaño-Pachón DM, Martins MCM, da Cruz LP, Bassi D, Marchiori PER, Ribeiro RV, Labate MTV, Labate CA, Menossi M. Physiological and transcriptional analyses of developmental stages along sugarcane leaf. BMC PLANT BIOLOGY 2015; 15:300. [PMID: 26714767 PMCID: PMC4696237 DOI: 10.1186/s12870-015-0694-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/17/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND Sugarcane is one of the major crops worldwide. It is cultivated in over 100 countries on 22 million ha. The complex genetic architecture and the lack of a complete genomic sequence in sugarcane hamper the adoption of molecular approaches to study its physiology and to develop new varieties. Investments on the development of new sugarcane varieties have been made to maximize sucrose yield, a trait dependent on photosynthetic capacity. However, detailed studies on sugarcane leaves are scarce. In this work, we report the first molecular and physiological characterization of events taking place along a leaf developmental gradient in sugarcane. RESULTS Photosynthetic response to CO2 indicated divergence in photosynthetic capacity based on PEPcase activity, corroborated by activity quantification (both in vivo and in vitro) and distinct levels of carbon discrimination on different segments along leaf length. Additionally, leaf segments had contrasting amount of chlorophyll, nitrogen and sugars. RNA-Seq data indicated a plethora of biochemical pathways differentially expressed along the leaf. Some transcription factors families were enriched on each segment and their putative functions corroborate with the distinct developmental stages. Several genes with higher expression in the middle segment, the one with the highest photosynthetic rates, were identified and their role in sugarcane productivity is discussed. Interestingly, sugarcane leaf segments had a different transcriptional behavior compared to previously published data from maize. CONCLUSION This is the first report of leaf developmental analysis in sugarcane. Our data on sugarcane is another source of information for further studies aiming to understand and/or improve C4 photosynthesis. The segments used in this work were distinct in their physiological status allowing deeper molecular analysis. Although limited in some aspects, the comparison to maize indicates that all data acquired on one C4 species cannot always be easily extrapolated to other species. However, our data indicates that some transcriptional factors were segment-specific and the sugarcane leaf undergoes through the process of suberizarion, photosynthesis establishment and senescence.
Collapse
Affiliation(s)
- Lucia Mattiello
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
- Laboratório de Genoma Funcional, Instituto de Biologia, Universidade Estadual de Campinas Campinas, Caixa Postal 6109, Campinas, 13083-862, SP, Brazil.
| | - Diego Mauricio Riaño-Pachón
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Marina Camara Mattos Martins
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Larissa Prado da Cruz
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Denis Bassi
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, 13083-970, Campinas, SP, Brazil.
| | - Paulo Eduardo Ribeiro Marchiori
- Laboratório de Fisiologia de Plantas "Coaracy M. Franco", Centro de Pesquisa e Desenvolvimento em Ecofisiologia e Biofísica, Instituto Agronômico, Caixa Postal 28, Campinas, 13020-902, SP, Brazil.
| | - Rafael Vasconcelos Ribeiro
- Departamento de Biologia de Plantas, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, 13083-970, SP, Brazil.
| | - Mônica T Veneziano Labate
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, Universidade de São Paulo, Caixa Postal 83, Piracicaba, 13400-970, SP, Brazil.
| | - Carlos Alberto Labate
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, Universidade de São Paulo, Caixa Postal 83, Piracicaba, 13400-970, SP, Brazil.
| | - Marcelo Menossi
- Laboratório de Genoma Funcional, Instituto de Biologia, Universidade Estadual de Campinas Campinas, Caixa Postal 6109, Campinas, 13083-862, SP, Brazil.
| |
Collapse
|
221
|
Yang H, He N, He Y, Li S, Shi P, Zhang X. Stable Water Use Efficiency of Tibetan Alpine Meadows in Past Half Century: Evidence from Wool δ13C Values. PLoS One 2015; 10:e0144752. [PMID: 26660306 PMCID: PMC4676705 DOI: 10.1371/journal.pone.0144752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 11/23/2015] [Indexed: 11/18/2022] Open
Abstract
Understanding the influences of climatic changes on water use efficiency (WUE) of Tibetan alpine meadows is important for predicting their long-term net primary productivity (NPP) because they are considered very sensitive to climate change. Here, we collected wool materials produced from 1962 to 2010 and investigated the long-term WUE of an alpine meadow in Tibet on basis of the carbon isotope values of vegetation (δ13Cveg). The values of δ13Cveg decreased by 1.34‰ during 1962-2010, similar to changes in δ13C values of atmospheric CO2. Carbon isotope discrimination was highly variable and no trend was apparent in the past half century. Intrinsic water use efficiency (Wi) increased by 18 μmol·mol-1 (approximately 23.5%) during 1962-2010 because the increase in the intercellular CO2 concentration (46 μmol·mol-1) was less than that in the atmospheric CO2 concentration (Ca, 73 μmol·mol-1). In addition, Wi increased significantly with increasing growing season temperature and Ca. However, effective water use efficiency (We) remained relatively stable, because of increasing vapor pressure deficit. Ca, precipitation, and growing season temperature collectively explained 45% of the variation of We. Our findings indicate that the We of alpine meadows in the Tibetan Plateau remained relatively stable by physiological adjustment to elevated Ca and growing season temperature. These findings improve our understanding and the capacity to predict NPP of these ecosystems under global change scenarios.
Collapse
Affiliation(s)
- Hao Yang
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Nianpeng He
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yongtao He
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shenggong Li
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Peili Shi
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xianzhou Zhang
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
222
|
Liu Y, Zhang L, Xu X, Niu H. Understanding the wide geographic range of a clonal perennial grass: plasticity versus local adaptation. AOB PLANTS 2015; 8:plv141. [PMID: 26644341 PMCID: PMC4705351 DOI: 10.1093/aobpla/plv141] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/18/2015] [Indexed: 05/10/2023]
Abstract
Both phenotypic plasticity and local adaptation may allow widely distributed plant species to either acclimate or adapt to environmental heterogeneity. Given the typically low genetic variation of clonal plants across their habitats, phenotypic plasticity may be the primary adaptive strategy allowing them to thrive across a wide range of habitats. In this study, the mechanism supporting the widespread distribution of the clonal plant Leymus chinensis was determined, i.e. phenotypic plasticity or local specialization in water use efficiency (WUE; reflected by foliar δ(13)C). To test whether plasticity is required for the species to thrive in different habitats, samples were collected across its distribution in the Mongolian steppe, and a controlled watering experiment was conducted with two populations at two different sites. Five populations were also transplanted from different sites into a control environment, and the foliar δ(13)C was compared between the control and original habitats, to test for local specialization in WUE. Results demonstrated decreased foliar δ(13)C with increasing precipitation during controlled watering experiments, with divergent responses between the two populations assessed. Change in foliar δ(13)C (-3.69 ‰) due to water addition was comparable to fluctuations of foliar δ(13)C observed in situ (-4.83 ‰). Foliar δ(13)C differed by -0.91 ‰ between two transplanted populations; however, this difference was not apparent between the two populations when growing in their original habitats. Findings provide evidence that local adaptation affects foliar δ(13)C much less than phenotypic plasticity. Thus, plasticity in WUE is more important than local adaptation in allowing the clonal plant L. chinensis to occupy a wide range of habitats in the Mongolian steppe.
Collapse
Affiliation(s)
- Yanjie Liu
- College of Resources and Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, Konstanz D-78457, Germany
| | - Lirong Zhang
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research of Chinese Academy of Sciences, No. 16 Lincui Road, Beijing 100101, China
| | - Xingliang Xu
- Key Laboratory and Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, No. 11A Datun Road, Beijing 100101, China
| | - Haishan Niu
- College of Resources and Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
| |
Collapse
|
223
|
Xu M, Wang G, Li X, Cai X, Li X, Christie P, Zhang J. The key factor limiting plant growth in cold and humid alpine areas also plays a dominant role in plant carbon isotope discrimination. FRONTIERS IN PLANT SCIENCE 2015; 6:961. [PMID: 26579188 PMCID: PMC4630956 DOI: 10.3389/fpls.2015.00961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/21/2015] [Indexed: 06/05/2023]
Abstract
Many environmental factors affect carbon isotope discrimination in plants, yet the predominant factor influencing this process is generally assumed to be the key growth-limiting factor. However, to our knowledge this hypothesis has not been confirmed. We therefore determined the carbon isotope composition (δ(13)C) of plants growing in two cold and humid mountain regions where temperature is considered to be the key growth-limiting factor. Mean annual temperature (MAT) showed a significant impact on variation in carbon isotope discrimination value (Δ) irrespective of study area or plant functional type with either partial correlation or regression analysis, but the correlation between Δ and soil water content (SWC) was usually not significant. In multiple stepwise regression analysis, MAT was either the first or the only variable selected into the prediction model of Δ against MAT and SWC, indicating that the effect of temperature on carbon isotope discrimination was predominant. The results therefore provide evidence that the key growth-limiting factor is also crucial for plant carbon isotope discrimination. Changes in leaf morphology, water viscosity and carboxylation efficiency with temperature may be responsible for the observed positive correlation between Δ and temperature.
Collapse
Affiliation(s)
- Meng Xu
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Guoan Wang
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Xiaoliang Li
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Xiaobu Cai
- Tibet Agricultural and Animal Husbandry College, Tibet UniversityLinzhi, China
| | - Xiaolin Li
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Peter Christie
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| | - Junling Zhang
- College of Resources and Environmental Sciences, China Agricultural UniversityBeijing, China
| |
Collapse
|
224
|
Kanpanon N, Kasemsap P, Thaler P, Kositsup B, Gay F, Lacote R, Epron D. Carbon isotope composition of latex does not reflect temporal variations of photosynthetic carbon isotope discrimination in rubber trees (Hevea brasiliensis). TREE PHYSIOLOGY 2015; 35:1166-1175. [PMID: 26358051 DOI: 10.1093/treephys/tpv070] [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: 01/31/2015] [Accepted: 07/03/2015] [Indexed: 06/05/2023]
Abstract
Latex, the cytoplasm of laticiferous cells localized in the inner bark of rubber trees (Hevea brasiliensis Müll. Arg.), is collected by tapping the bark. Following tapping, latex flows out of the trunk and is regenerated, whereas in untapped trees, there is no natural exudation. It is still unknown whether the carbohydrates used for latex regeneration in tapped trees is coming from recent photosynthates or from stored carbohydrates, and in the former case, it is expected that latex carbon isotope composition of tapped trees will vary seasonally, whereas latex isotope composition of untapped trees will be more stable. Temporal variations of carbon isotope composition of trunk latex (δ(13)C-L), leaf soluble compounds (δ(13)C-S) and bulk leaf material (δ(13)C-B) collected from tapped and untapped 20-year-old trees were compared. A marked difference in δ(13)C-L was observed between tapped and untapped trees whatever the season. Trunk latex from tapped trees was more depleted (1.6‰ on average) with more variable δ(13)C values than those of untapped trees. δ(13)C-L was higher and more stable across seasons than δ(13)C-S and δ(13)C-B, with a maximum seasonal difference of 0.7‰ for tapped trees and 0.3‰ for untapped trees. δ(13)C-B was lower in tapped than in untapped trees, increasing from August (middle of the rainy season) to April (end of the dry season). Differences in δ(13)C-L and δ(13)C-B between tapped and untapped trees indicated that tapping affects the metabolism of both laticiferous cells and leaves. The lack of correlation between δ(13)C-L and δ(13)C-S suggests that recent photosynthates are mixed in the large pool of stored carbohydrates that are involved in latex regeneration after tapping.
Collapse
Affiliation(s)
- Nicha Kanpanon
- Department of Horticulture, Faculty of Agriculture, Kasetsart University, 10900 Bangkok, Thailand Ecologie et Ecophysiologie Forestières, Faculté des Sciences, Université de Lorraine, UMR 1137, F-54506 Vandoeuvre-les-Nancy, France Ecologie et Ecophysiologie Forestières, Centre de Nancy - Lorraine, INRA, UMR 1137, F-54280 Champenoux, France
| | - Poonpipope Kasemsap
- Department of Horticulture, Faculty of Agriculture, Kasetsart University, 10900 Bangkok, Thailand
| | - Philippe Thaler
- CIRAD, UMR Eco&Sols, F-34060 Montpellier, France Hevea Research Platform in Partnership, Kasetsart University, Centre of Thai-French Cooperation on Higher Education and Research, 10900 Bangkok, Thailand
| | - Boonthida Kositsup
- Department of Botany, Faculty of Science, Chulalongkorn University, 10330 Bangkok, Thailand
| | - Frédéric Gay
- CIRAD, UMR Eco&Sols, F-34060 Montpellier, France Hevea Research Platform in Partnership, Kasetsart University, Centre of Thai-French Cooperation on Higher Education and Research, 10900 Bangkok, Thailand
| | - Régis Lacote
- Hevea Research Platform in Partnership, Kasetsart University, Centre of Thai-French Cooperation on Higher Education and Research, 10900 Bangkok, Thailand CIRAD, UPR Tree Crop-Based Systems, F-34000 Montpellier, France
| | - Daniel Epron
- Ecologie et Ecophysiologie Forestières, Faculté des Sciences, Université de Lorraine, UMR 1137, F-54506 Vandoeuvre-les-Nancy, France Ecologie et Ecophysiologie Forestières, Centre de Nancy - Lorraine, INRA, UMR 1137, F-54280 Champenoux, France CIRAD, UMR Eco&Sols, F-34060 Montpellier, France
| |
Collapse
|
225
|
Winter K, Holtum JAM, Smith JAC. Crassulacean acid metabolism: a continuous or discrete trait? THE NEW PHYTOLOGIST 2015; 208:73-8. [PMID: 25975197 DOI: 10.1111/nph.13446] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/22/2015] [Indexed: 05/27/2023]
Abstract
The key components of crassulacean acid metabolism (CAM) - nocturnal fixation of atmospheric CO2 and its processing via Rubisco in the subsequent light period - are now reasonably well understood in terms of the biochemical reactions defining this water-saving mode of carbon assimilation. Phenotypically, however, the degree to which plants engage in the CAM cycle relative to regular C3 photosynthesis is highly variable. Depending upon species, ontogeny and environment, the contribution of nocturnal CO2 fixation to 24-h carbon gain can range continuously from close to 0% to 100%. Nevertheless, not all possible combinations of light and dark CO2 fixation appear equally common. Large-scale surveys of carbon-isotope ratios typically show a strongly bimodal frequency distribution, with relatively few intermediate values. Recent research has revealed that many species capable of low-level CAM activity are nested within the peak of C3 -type isotope signatures. While questions remain concerning the adaptive significance of dark CO2 fixation in such species, plants with low-level CAM should prove valuable models for investigating the discrete changes in genetic architecture and gene expression that have enabled the evolutionary transition from C3 to CAM.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Joseph A M Holtum
- Centre for Tropical Biodiversity and Climate Change, James Cook University, Townsville, QLD, 4811, Australia
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| |
Collapse
|
226
|
Manzaneda AJ, Rey PJ, Anderson JT, Raskin E, Weiss-Lehman C, Mitchell-Olds T. Natural variation, differentiation, and genetic trade-offs of ecophysiological traits in response to water limitation in Brachypodium distachyon and its descendent allotetraploid B. hybridum (Poaceae). Evolution 2015; 69:2689-704. [PMID: 26377138 DOI: 10.1111/evo.12776] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 07/02/2015] [Accepted: 08/25/2015] [Indexed: 11/30/2022]
Abstract
Differences in tolerance to water stress may underlie ecological divergence of closely related ploidy lineages. However, the mechanistic basis of physiological variation governing ecogeographical cytotype segregation is not well understood. Here, using Brachypodium distachyon and its derived allotetraploid B. hybridum as model, we test the hypothesis that, for heteroploid annuals, ecological divergence of polyploids in drier environments is based on trait differentiation enabling drought escape. We demonstrate that under water limitation allotetraploids maintain higher photosynthesis and stomatal conductance and show earlier flowering than diploids, concordant with a drought-escape strategy to cope with water stress. Increased heterozygosity and greater genetic variability and plasticity of polyploids could confer a superior adaptive capability. Consistent with these predictions, we document (1) greater standing within-population genetic variation in water-use efficiency (WUE) and flowering time in allotetraploids, and (2) the existence of (nonlinear) environmental clines in physiology across allotetraploid populations. Increased gas exchange and diminished WUE occurred at the driest end of the gradient, consistent with a drought-escape strategy. Finally, we found that allotetraploids showed weaker genetic correlations than diploids congruous with the expectation of relaxed pleiotropic constraints in polyploids. Our results suggest evolutionary divergence of ecophysiological traits in each ploidy lineage.
Collapse
Affiliation(s)
- Antonio J Manzaneda
- Departamento Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Paraje las Lagunillas s/n, 23071, Jaén, Spain. .,Institute for Genome Sciences and Policy, Department of Biology, Duke University, P.O. Box 90338, Durham, North Carolina, 27708.
| | - Pedro J Rey
- Departamento Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Paraje las Lagunillas s/n, 23071, Jaén, Spain
| | - Jill T Anderson
- Department of Genetics, University of Georgia, Athens, Georgia, 30602
| | - Evan Raskin
- Institute for Genome Sciences and Policy, Department of Biology, Duke University, P.O. Box 90338, Durham, North Carolina, 27708
| | - Christopher Weiss-Lehman
- Department of Ecology and Evolutionary Biology, Biofrontiers Institute, University of Colorado, Boulder, Colarado, 80309
| | - Thomas Mitchell-Olds
- Institute for Genome Sciences and Policy, Department of Biology, Duke University, P.O. Box 90338, Durham, North Carolina, 27708
| |
Collapse
|
227
|
Weston DJ, Timm CM, Walker AP, Gu L, Muchero W, Schmutz J, Shaw AJ, Tuskan GA, Warren JM, Wullschleger SD. Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function. PLANT, CELL & ENVIRONMENT 2015; 38:1737-1751. [PMID: 25266403 DOI: 10.1111/pce.12458] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 06/03/2023]
Abstract
Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics.
Collapse
Affiliation(s)
- David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Collin M Timm
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Lianhong Gu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeremy Schmutz
- Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
- HudsonAlpha Institute of Biotechnology, Huntsville, AL, 35806, USA
| | - A Jonathan Shaw
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Stan D Wullschleger
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| |
Collapse
|
228
|
Leverkus AB, Castro J, Delgado-Capel MJ, Molinas-González C, Pulgar M, Marañón-Jiménez S, Delgado-Huertas A, Querejeta JI. Restoring for the present or restoring for the future: enhanced performance of two sympatric oaks (Quercus ilex
and Quercus pyrenaica
) above the current forest limit. Restor Ecol 2015. [DOI: 10.1111/rec.12259] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexandro B. Leverkus
- Departamento de Ecología, Facultad de Ciencias; Universidad de Granada; E-18071, Granada Spain
| | - Jorge Castro
- Departamento de Ecología, Facultad de Ciencias; Universidad de Granada; E-18071, Granada Spain
| | - Manuel J. Delgado-Capel
- Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR; Unidad de Investigación de Biogeoquímica de Isótopos Estables; E-18100 Granada Spain
| | - Carlos Molinas-González
- Departamento de Ecología, Facultad de Ciencias; Universidad de Granada; E-18071, Granada Spain
| | - Manuel Pulgar
- Departamento de Biología Animal, Vegetal y Ecología, Área de Ecología, Facultad de Ciencias Experimentales; Universidad de Jaén; E-23071 Jaén Spain
| | - Sara Marañón-Jiménez
- Department Hydrosystemmodellierung; Helmholtz-Zentrum für Umweltforschung GmbH-UFZ; Permoserstraße 15 D-04318 Leipzig Germany
| | - Antonio Delgado-Huertas
- Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR; Unidad de Investigación de Biogeoquímica de Isótopos Estables; E-18100 Granada Spain
| | - José I. Querejeta
- Departamento de Conservación de Suelo y Agua, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC); Campus Universitario de Espinardo; PO Box 164 E-30100 Murcia Spain
| |
Collapse
|
229
|
Wegener F, Beyschlag W, Werner C. Dynamic carbon allocation into source and sink tissues determine within-plant differences in carbon isotope ratios. FUNCTIONAL PLANT BIOLOGY : FPB 2015; 42:620-629. [PMID: 32480706 DOI: 10.1071/fp14152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 03/10/2015] [Indexed: 05/28/2023]
Abstract
Organs of C3 plants differ in their C isotopic signature (δ13C). In general, leaves are 13C-depleted relative to other organs. To investigate the development of spatial δ13C patterns, we induced different C allocation strategies by reducing light and nutrient availability for 12 months in the Mediterranean shrub Halimium halimifolium L. We measured morphological and physiological traits and the spatial δ13C variation among seven tissue classes during the experiment. A reduction of light (Low-L treatment) increased aboveground C allocation, plant height and specific leaf area. Reduced nutrient availability (Low-N treatment) enhanced C allocation into fine roots and reduced the spatial δ13C variation. In contrast, control and Low-L plants with high C allocation in new leaves showed a high δ13C variation within the plant (up to 2.5‰). The spatial δ13C variation was significantly correlated with the proportion of second-generation leaves from whole-plant biomass (R2=0.46). According to our results, isotope fractionation in dark respiration can influence the C isotope composition of plant tissues but cannot explain the entire spatial pattern seen. Our study indicates a foliar depletion in 13C during leaf development combined with export of relatively 13C-enriched C by mature source leaves as an important reason for the observed spatial δ13C pattern.
Collapse
Affiliation(s)
- Frederik Wegener
- AgroEcosystem Research, BAYCEER, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Wolfram Beyschlag
- Experimental and Systems Ecology, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Christiane Werner
- AgroEcosystem Research, BAYCEER, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| |
Collapse
|
230
|
Rasheed F, Dreyer E, Richard B, Brignolas F, Brendel O, Le Thiec D. Vapour pressure deficit during growth has little impact on genotypic differences of transpiration efficiency at leaf and whole-plant level: an example from Populus nigra L. PLANT, CELL & ENVIRONMENT 2015; 38:670-84. [PMID: 25099629 DOI: 10.1111/pce.12423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 07/23/2014] [Accepted: 07/27/2014] [Indexed: 05/02/2023]
Abstract
Poplar genotypes differ in transpiration efficiency (TE) at leaf and whole-plant level under similar conditions. We tested whether atmospheric vapour pressure deficit (VPD) affected TE to the same extent across genotypes. Six Populus nigra genotypes were grown under two VPD. We recorded (1) (13)C content in soluble sugars; (2) (18)O enrichment in leaf water; (3) leaf-level gas exchange; and (4) whole-plant biomass accumulation and water use. Whole-plant and intrinsic leaf TE and (13)C content in soluble sugars differed significantly among genotypes. Stomatal conductance contributed more to these differences than net CO2 assimilation rate. VPD increased water use and reduced whole-plant TE. It increased intrinsic leaf-level TE due to a decline in stomatal conductance. It also promoted higher (18)O enrichment in leaf water. VPD had no genotype-specific effect. We detected a deviation in the relationship between (13)C in leaf sugars and (13)C predicted from gas exchange and the standard discrimination model. This may be partly due to genotypic differences in mesophyll conductance, and to its lack of sensitivity to VPD. Leaf-level (13)C discrimination was a powerful predictor of the genetic variability of whole-plant TE irrespective of VPD during growth.
Collapse
Affiliation(s)
- Fahad Rasheed
- INRA, UMR 1137 Ecologie et Ecophysiologie Forestières, F-54280, Champenoux, France; University of Agriculture, Department of Forestry, Range Management & Wildlife, 38000, Faisalabad, Pakistan; Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Faculté des Sciences, F-54500, Vandoeuvre-lès-Nancy, France; INRA, EA 1207, Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, Orléans, F-45067, France
| | | | | | | | | | | |
Collapse
|
231
|
Hussain MI, Reigosa MJ. Characterization of xanthophyll pigments, photosynthetic performance, photon energy dissipation, reactive oxygen species generation and carbon isotope discrimination during artemisinin-induced stress in Arabidopsis thaliana. PLoS One 2015; 10:e0114826. [PMID: 25635811 PMCID: PMC4312038 DOI: 10.1371/journal.pone.0114826] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 11/14/2014] [Indexed: 01/03/2023] Open
Abstract
Artemisinin, a potent antimalarial drug, is phytotoxic to many crops and weeds. The effects of artemisinin on stress markers, including fluorescence parameters, photosystem II photochemistry, photon energy dissipation, lipid peroxidation, reactive oxygen species generation and carbon isotope discrimination in Arabidopsis thaliana were studied. Arabidopsis ecotype Columbia (Col-0) seedlings were grown in perlite and watered with 50% Hoagland nutrient solution. Adult plants of Arabidopsis were treated with artemisinin at 0, 40, 80, 160 μM for one week. Artemisinin, in the range 40-160 μM, decreased the fresh biomass, chl a, b and leaf mineral contents. Photosynthetic efficiency, yield and electron transport rate in Arabidopsis were also reduced following exposure to 80 and 160 μM artemisinin. The ΦNPQ and NPQ were less than control. Artemisinin treatment caused an increase in root oxidizability and lipid peroxidation (MDA contents) of Arabidopsis. Calcium and nitrogen contents decreased after 80 and 160 μM artemisinin treatment compared to control. δ13C values were less negative following treatment with artemisinin as compared to the control. Artemisinin also decreased leaf protein contents in Arabidopsis. Taken together, these data suggest that artemisinin inhibits many physiological and biochemical processes in Arabidopsis.
Collapse
Affiliation(s)
- M. Iftikhar Hussain
- Department of Plant Biology and Soil Science, University of Vigo, Campus Lagoas-Marcosende, 36310—Vigo, Spain
- International Center for Biosaline Agriculture (ICBA), P.O. Box 14660, Dubai, U.A.E
| | - Manuel J. Reigosa
- Department of Plant Biology and Soil Science, University of Vigo, Campus Lagoas-Marcosende, 36310—Vigo, Spain
| |
Collapse
|
232
|
Verlinden MS, Fichot R, Broeckx LS, Vanholme B, Boerjan W, Ceulemans R. Carbon isotope compositions (δ(13) C) of leaf, wood and holocellulose differ among genotypes of poplar and between previous land uses in a short-rotation biomass plantation. PLANT, CELL & ENVIRONMENT 2015; 38:144-156. [PMID: 24906162 DOI: 10.1111/pce.12383] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 06/03/2023]
Abstract
The efficiency of water use to produce biomass is a key trait in designing sustainable bioenergy-devoted systems. We characterized variations in the carbon isotope composition (δ(13) C) of leaves, current year wood and holocellulose (as proxies for water use efficiency, WUE) among six poplar genotypes in a short-rotation plantation. Values of δ(13) Cwood and δ(13) Cholocellulose were tightly and positively correlated, but the offset varied significantly among genotypes (0.79-1.01‰). Leaf phenology was strongly correlated with δ(13) C, and genotypes with a longer growing season showed a higher WUE. In contrast, traits related to growth and carbon uptake were poorly linked to δ(13) C. Trees growing on former pasture with higher N-availability displayed higher δ(13) C as compared with trees growing on former cropland. The positive relationships between δ(13) Cleaf and leaf N suggested that spatial variations in WUE over the plantation were mainly driven by an N-related effect on photosynthetic capacities. The very coherent genotype ranking obtained with δ(13) C in the different tree compartments has some practical outreach. Because WUE remains largely uncoupled from growth in poplar plantations, there is potential to identify genotypes with satisfactory growth and higher WUE.
Collapse
Affiliation(s)
- M S Verlinden
- Department of Biology, Research Group of Plant and Vegetation Ecology, University of Antwerp, Wilrijk, B-2610, Belgium
| | | | | | | | | | | |
Collapse
|
233
|
Llano C, Ugan A. Alternative Interpretations of Intermediate and Positive d13C Isotope Signals in Prehistoric Human Remains from Southern Mendoza, Argentina. CURRENT ANTHROPOLOGY 2014. [DOI: 10.1086/678991] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
234
|
Tholen D, Ethier G, Genty B. Mesophyll conductance with a twist. PLANT, CELL & ENVIRONMENT 2014; 37:2456-2458. [PMID: 24995489 DOI: 10.1111/pce.12401] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 06/28/2014] [Indexed: 06/03/2023]
Affiliation(s)
- Danny Tholen
- Institute of Botany, University of Natural Resources and Life Sciences, Vienna, A-1180, Austria
| | | | | |
Collapse
|
235
|
Flores O, Hérault B, Delcamp M, Garnier É, Gourlet-Fleury S. Functional traits help predict post-disturbance demography of tropical trees. PLoS One 2014; 9:e105022. [PMID: 25226586 PMCID: PMC4165593 DOI: 10.1371/journal.pone.0105022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 07/14/2014] [Indexed: 11/26/2022] Open
Abstract
How tropical tree species respond to disturbance is a central issue of forest ecology, conservation and resource management. We define a hierarchical model to investigate how functional traits measured in control plots relate to the population change rate and to demographic rates for recruitment and mortality after disturbance by logging operations. Population change and demographic rates were quantified on a 12-year period after disturbance and related to seven functional traits measured in control plots. The model was calibrated using a Bayesian Network approach on 53 species surveyed in permanent forest plots (37.5 ha) at Paracou in French Guiana. The network analysis allowed us to highlight both direct and indirect relationships among predictive variables. Overall, 89% of interspecific variability in the population change rate after disturbance were explained by the two demographic rates, the recruitment rate being the most explicative variable. Three direct drivers explained 45% of the variability in recruitment rates, including leaf phosphorus concentration, with a positive effect, and seed size and wood density with negative effects. Mortality rates were explained by interspecific variability in maximum diameter only (25%). Wood density, leaf nitrogen concentration, maximum diameter and seed size were not explained by variables in the analysis and thus appear as independent drivers of post-disturbance demography. Relationships between functional traits and demographic parameters were consistent with results found in undisturbed forests. Functional traits measured in control conditions can thus help predict the fate of tropical tree species after disturbance. Indirect relationships also suggest how different processes interact to mediate species demographic response.
Collapse
Affiliation(s)
- Olivier Flores
- Cirad - Université de La Réunion, UMR PVBMT, 7 chemin de l'IRAT, Saint Pierre, France
| | - Bruno Hérault
- Cirad, UMR Ecologie des Forêts de Guyane, Kourou, France
| | - Matthieu Delcamp
- Cirad, UR B&SEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, Montpellier, France
| | - Éric Garnier
- Centre d'Écologie Fonctionnelle et Évolutive, CNRS – UMR 5175, Montpellier, France
| | - Sylvie Gourlet-Fleury
- Cirad, UR B&SEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, Montpellier, France
| |
Collapse
|
236
|
Gessler A, Ferrio JP, Hommel R, Treydte K, Werner RA, Monson RK. Stable isotopes in tree rings: towards a mechanistic understanding of isotope fractionation and mixing processes from the leaves to the wood. TREE PHYSIOLOGY 2014; 34:796-818. [PMID: 24907466 DOI: 10.1093/treephys/tpu040] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The mechanistic understanding of isotope fractionation processes is increasing but we still lack detailed knowledge of the processes that determine the isotopic composition of the tree-ring archive over the long term. Especially with regard to the path from leaf photosynthate production to wood formation, post-assimilation fractionations/processes might cause at least a partial decoupling between the leaf isotope signals that record processes such as stomatal conductance, transpiration and photosynthesis, and the wood or cellulose signals that are stored in the paleophysiological record. In this review, we start from the rather well understood processes at the leaf level such as photosynthetic carbon isotope fractionation, leaf water evaporative isotope enrichment and the issue of the isotopic composition of inorganic sources (CO2 and H2O), though we focus on the less explored 'downstream' processes related to metabolism and transport. We further summarize the roles of cellulose and lignin as important chemical constituents of wood, and the processes that determine the transfer of photosynthate (sucrose) and associated isotopic signals to wood production. We cover the broad topics of post-carboxylation carbon isotope fractionation and of the exchange of organic oxygen with water within the tree. In two case studies, we assess the transfer of carbon and oxygen isotopic signals from leaves to tree rings. Finally we address the issue of different temporal scales and link isotope fractionation at the shorter time scale for processes in the leaf to the isotopic ratio as recorded across longer time scales of the tree-ring archive.
Collapse
Affiliation(s)
- Arthur Gessler
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany Long-term Forest Ecosystem Research (LWF), Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Juan Pedro Ferrio
- Department of Crop and Forest Science-AGROTECNIO Center, University of Lleida, Avda Rovira Roure 191, 25198 Lleida, Spain
| | - Robert Hommel
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany
| | - Kerstin Treydte
- Research Unit Landscape Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
| | - Russell K Monson
- School of Natural Resources and the Environment and Laboratory for Tree Ring Research, University of Arizona, Tucson, AZ 85721, USA
| |
Collapse
|
237
|
Bellasio C, Griffiths H. Acclimation of C4 metabolism to low light in mature maize leaves could limit energetic losses during progressive shading in a crop canopy. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3725-36. [PMID: 24591058 PMCID: PMC4085954 DOI: 10.1093/jxb/eru052] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
C4 plants have a biochemical carbon-concentrating mechanism that increases CO2 concentration around Rubisco in the bundle sheath. Under low light, the activity of the carbon-concentrating mechanism generally decreases, associated with an increase in leakiness (ϕ), the ratio of CO2 retrodiffusing from the bundle sheath relative to C4 carboxylation. This increase in ϕ had been theoretically associated with a decrease in biochemical operating efficiency (expressed as ATP cost of gross assimilation, ATP/GA) under low light and, because a proportion of canopy photosynthesis is carried out by shaded leaves, potential productivity losses at field scale. Maize plants were grown under light regimes representing the cycle that leaves undergo in the canopy, whereby younger leaves initially developed under high light and were then re-acclimated to low light (600 to 100 μE·m(-2)·s(-1) photosynthetically active radiation) for 3 weeks. Following re-acclimation, leaves reduced rates of light-respiration and reached a status of lower ϕ, effectively optimizing the limited ATP resources available under low photosynthetically active radiation. Direct estimates of respiration in the light, and ATP production rate, allowed an empirical estimate of ATP production rate relative to gross assimilation to be derived. These values were compared to modelled ATP/GA which was predicted using leakiness as the sole proxy for ATP/GA, and, using a novel comprehensive biochemical model, showing that irrespective of whether leaves are acclimated to very low or high light intensity, the biochemical efficiency of the C4 cycle does not decrease at low photosynthetically active radiation.
Collapse
Affiliation(s)
- Chandra Bellasio
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Howard Griffiths
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| |
Collapse
|
238
|
Ubierna N, Farquhar GD. Advances in measurements and models of photosynthetic carbon isotope discrimination in C3 plants. PLANT, CELL & ENVIRONMENT 2014; 37:1494-8. [PMID: 24716900 DOI: 10.1111/pce.12346] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 03/31/2014] [Indexed: 05/08/2023]
Affiliation(s)
- Nerea Ubierna
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
| | | |
Collapse
|
239
|
Winter K, Holtum JAM. Facultative crassulacean acid metabolism (CAM) plants: powerful tools for unravelling the functional elements of CAM photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3425-41. [PMID: 24642847 DOI: 10.1093/jxb/eru063] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Facultative crassulacean acid metabolism (CAM) describes the optional use of CAM photosynthesis, typically under conditions of drought stress, in plants that otherwise employ C3 or C4 photosynthesis. In its cleanest form, the upregulation of CAM is fully reversible upon removal of stress. Reversibility distinguishes facultative CAM from ontogenetically programmed unidirectional C3-to-CAM shifts inherent in constitutive CAM plants. Using mainly measurements of 24h CO2 exchange, defining features of facultative CAM are highlighted in five terrestrial species, Clusia pratensis, Calandrinia polyandra, Mesembryanthemum crystallinum, Portulaca oleracea and Talinum triangulare. For these, we provide detailed chronologies of the shifts between photosynthetic modes and comment on their usefulness as experimental systems. Photosynthetic flexibility is also reviewed in an aquatic CAM plant, Isoetes howellii. Through comparisons of C3 and CAM states in facultative CAM species, many fundamental biochemical principles of the CAM pathway have been uncovered. Facultative CAM species will be of even greater relevance now that new sequencing technologies facilitate the mapping of genomes and tracking of the expression patterns of multiple genes. These technologies and facultative CAM systems, when joined, are expected to contribute in a major way towards our goal of understanding the essence of CAM.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - Joseph A M Holtum
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| |
Collapse
|
240
|
Bellasio C, Burgess SJ, Griffiths H, Hibberd JM. A high throughput gas exchange screen for determining rates of photorespiration or regulation of C4 activity. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3769-79. [PMID: 25006037 PMCID: PMC4085971 DOI: 10.1093/jxb/eru238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Large-scale research programmes seeking to characterize the C4 pathway have a requirement for a simple, high throughput screen that quantifies photorespiratory activity in C3 and C4 model systems. At present, approaches rely on model-fitting to assimilatory responses (A/C i curves, PSII quantum yield) or real-time carbon isotope discrimination, which are complicated and time-consuming. Here we present a method, and the associated theory, to determine the effectiveness of the C4 carboxylation, carbon concentration mechanism (CCM) by assessing the responsiveness of V O/V C, the ratio of RuBisCO oxygenase to carboxylase activity, upon transfer to low O2. This determination compares concurrent gas exchange and pulse-modulated chlorophyll fluorescence under ambient and low O2, using widely available equipment. Run time for the procedure can take as little as 6 minutes if plants are pre-adapted. The responsiveness of V O/V C is derived for typical C3 (tobacco, rice, wheat) and C4 (maize, Miscanthus, cleome) plants, and compared with full C3 and C4 model systems. We also undertake sensitivity analyses to determine the impact of R LIGHT (respiration in the light) and the effectiveness of the light saturating pulse used by fluorescence systems. The results show that the method can readily resolve variations in photorespiratory activity between C3 and C4 plants and could be used to rapidly screen large numbers of mutants or transformants in high throughput studies.
Collapse
Affiliation(s)
- Chandra Bellasio
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Steven J Burgess
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| |
Collapse
|
241
|
Saffell BJ, Meinzer FC, Voelker SL, Shaw DC, Brooks JR, Lachenbruch B, McKay J. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO(2) assimilation and growth in Douglas-fir. PLANT, CELL & ENVIRONMENT 2014; 37:1536-47. [PMID: 24330052 DOI: 10.1111/pce.12256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/17/2013] [Accepted: 12/04/2013] [Indexed: 05/13/2023]
Abstract
Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years.
Collapse
Affiliation(s)
- Brandy J Saffell
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | | | | | | | | | | | | |
Collapse
|
242
|
Lévesque M, Siegwolf R, Saurer M, Eilmann B, Rigling A. Increased water-use efficiency does not lead to enhanced tree growth under xeric and mesic conditions. THE NEW PHYTOLOGIST 2014; 203:94-109. [PMID: 24635031 DOI: 10.1111/nph.12772] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/20/2014] [Indexed: 06/03/2023]
Abstract
Higher atmospheric CO2 concentrations (c(a)) can under certain conditions increase tree growth by enhancing photosynthesis, resulting in an increase of intrinsic water-use efficiency (i WUE) in trees. However, the magnitude of these effects and their interactions with changing climatic conditions are still poorly understood under xeric and mesic conditions. We combined radial growth analysis with intra- and interannual δ(13)C and δ(18)O measurements to investigate growth and physiological responses of Larix decidua, Picea abies, Pinus sylvestris, Pinus nigra and Pseudotsuga menziesii in relation to rising c(a) and changing climate at a xeric site in the dry inner Alps and at a mesic site in the Swiss lowlands. (i)WUE increased significantly over the last 50 yr by 8-29% and varied depending on species, site water availability, and seasons. Regardless of species and increased (i)WUE, radial growth has significantly declined under xeric conditions, whereas growth has not increased as expected under mesic conditions. Overall, drought-induced stomatal closure has reduced transpiration at the cost of reduced carbon uptake and growth. Our results indicate that, even under mesic conditions, the temperature-induced drought stress has overridden the potential CO2 'fertilization' on tree growth, hence challenging today's predictions of improved forest productivity of temperate forests.
Collapse
Affiliation(s)
- Mathieu Lévesque
- WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Zuercherstrasse 111, CH-8903, Birmensdorf, Switzerland; Swiss Federal Institute of Technology Zurich, Chair of Forest Ecology, CH-8092, Zurich, Switzerland
| | | | | | | | | |
Collapse
|
243
|
Kromdijk J, Ubierna N, Cousins AB, Griffiths H. Bundle-sheath leakiness in C4 photosynthesis: a careful balancing act between CO2 concentration and assimilation. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3443-57. [PMID: 24755278 DOI: 10.1093/jxb/eru157] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Crop species with the C4 photosynthetic pathway are generally characterized by high productivity, especially in environmental conditions favouring photorespiration. In comparison with the ancestral C3 pathway, the biochemical and anatomical modifications of the C4 pathway allow spatial separation of primary carbon acquisition in mesophyll cells and subsequent assimilation in bundle-sheath cells. The CO2-concentrating C4 cycle has to operate in close coordination with CO2 reduction via the Calvin-Benson-Bassham (CBB) cycle in order to keep the C4 pathway energetically efficient. The gradient in CO2 concentration between bundle-sheath and mesophyll cells facilitates diffusive leakage of CO2. This rate of bundle-sheath CO2 leakage relative to the rate of phosphoenolpyruvate carboxylation (termed leakiness) has been used to probe the balance between C4 carbon acquisition and subsequent reduction as a result of environmental perturbations. When doing so, the correct choice of equations to derive leakiness from stable carbon isotope discrimination (Δ(13)C) during gas exchange is critical to avoid biased results. Leakiness responses to photon flux density, either short-term (during measurements) or long-term (during growth and development), can have important implications for C4 performance in understorey light conditions. However, recent reports show leakiness to be subject to considerable acclimation. Additionally, the recent discovery of two decarboxylating C4 cycles operating in parallel in Zea mays suggests that flexibility in the transported C4 acid and associated decarboxylase could also aid in maintaining C4/CBB balance in a changing environment. In this paper, we review improvements in methodology to estimate leakiness, synthesize reports on bundle-sheath leakiness, discuss different interpretations, and highlight areas where future research is necessary.
Collapse
Affiliation(s)
- Johannes Kromdijk
- Institute for Genomic Biology, University of Illinois, 1206W Gregory drive, Urbana, IL 61801, USA
| | - Nerea Ubierna
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, WA99164-4236, USA
| | - Howard Griffiths
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB23EA, UK
| |
Collapse
|
244
|
Marias DE, Meinzer FC, Woodruff DR, Shaw DC, Voelker SL, Brooks JR, Lachenbruch B, Falk K, McKay J. Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree-ring C and O stable isotopes. TREE PHYSIOLOGY 2014; 34:595-607. [PMID: 24973917 DOI: 10.1093/treephys/tpu046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture and photosynthetic gas exchange and can eventually induce tree death. To investigate the long-term (1886-2010) impacts of dwarf mistletoe on the growth and gas exchange characteristics of host western hemlock, we compared the diameter growth and tree-ring cellulose stable carbon (C) and oxygen (O) isotope ratios (δ(13)Ccell, δ(18)Ocell) of heavily infected and uninfected trees. The relative basal area growth of infected trees was significantly greater than that of uninfected trees in 1886-90, but declined more rapidly in infected than uninfected trees through time and became significantly lower in infected than uninfected trees in 2006-10. Infected trees had significantly lower δ(13)Ccell and δ(18)Ocell than uninfected trees. Differences in δ(18)Ocell between infected and uninfected trees were unexpected given that stomatal conductance and environmental variables that were expected to influence the δ(18)O values of leaf water were similar for both groups. However, estimates of mesophyll conductance (gm) were significantly lower and estimates of effective path length for water movement (L) were significantly higher in leaves of infected trees, consistent with their lower values of δ(18)Ocell. This study reconstructs the long-term physiological responses of western hemlock to dwarf mistletoe infection. The long-term diameter growth and δ(13)Ccell trajectories suggested that infected trees were growing faster than uninfected trees prior to becoming infected and subsequently declined in growth and leaf-level photosynthetic capacity compared with uninfected trees as the dwarf mistletoe infection became severe. This study further points to limitations of the dual-isotope approach for identifying sources of variation in δ(13)Ccell and indicates that changes in leaf internal properties such as gm and L that affect δ(18)Ocell must be considered.
Collapse
Affiliation(s)
- Danielle E Marias
- Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331, USA
| | - Frederick C Meinzer
- Pacific Northwest Research Station, USDA Forest Service, Corvallis, OR 97331, USA
| | - David R Woodruff
- Pacific Northwest Research Station, USDA Forest Service, Corvallis, OR 97331, USA
| | - David C Shaw
- Forest Engineering, Resources and Management, Oregon State University, 280 Peavy Hall, Corvallis, OR 97331, USA
| | - Steven L Voelker
- Biology Department, Southern Oregon University, 1250 Siskiyou Blvd, Ashland, OR 97520, USA
| | - J Renée Brooks
- Western Ecology Division, US EPANHEERL, Corvallis, OR 97331, USA
| | - Barbara Lachenbruch
- Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331, USA
| | - Kristen Falk
- Forest Engineering, Resources and Management, Oregon State University, 280 Peavy Hall, Corvallis, OR 97331, USA
| | - Jennifer McKay
- College of Earth, Oceanic, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR 97331, USA
| |
Collapse
|
245
|
Gentsch L, Sturm P, Hammerle A, Siegwolf R, Wingate L, Ogée J, Baur T, Plüss P, Barthel M, Buchmann N, Knohl A. Carbon isotope discrimination during branch photosynthesis of Fagus sylvatica: field measurements using laser spectrometry. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1481-96. [PMID: 24676031 DOI: 10.1093/jxb/eru024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
On-line measurements of photosynthetic carbon isotope discrimination ((13)Δ) under field conditions are sparse. Hence, experimental verification of the natural variability of instantaneous (13)Δ is scarce, although (13)Δ is, explicitly and implicitly, used from leaf to global scales for inferring photosynthetic characteristics. This work presents the first on-line field measurements of (13)Δ of Fagus sylvatica branches, at hourly resolution, using three open branch bags and a laser spectrometer for CO₂ isotopologue measurements (QCLAS-ISO). Data from two August/September field campaigns, in 2009 and 2010, in a temperate forest in Switzerland are shown. Diurnal variability of (13)Δ was substantial, with mean diurnal amplitudes of ~9‰ and maximum diurnal amplitudes of ~20‰. The highest (13)Δ were generally observed during early morning and late afternoon, and the lowest (13)Δ during midday. An assessment of propagated standard deviations of (13)Δ demonstrated that the observed diurnal variation of (13)Δ was not a measurement artefact. Day-to-day variations of (13)Δ were summarized with flux-weighted daily means of (13)Δ, which ranged from 15‰ to 23‰ in 2009 and from 18‰ to 29‰ in 2010, thus displaying a considerable range of 8-11‰. Generally, (13)Δ showed the expected negative relationship with intrinsic water use efficiency. Diurnal and day-to-day variability of (13)Δ was, however, always better predicted by that of net CO₂ assimilation, especially in 2010 when soil moisture was high and vapour pressure deficit was low. Stomatal control of leaf gas exchange, and consequently (13)Δ, could only be identified under drier conditions in 2009.
Collapse
Affiliation(s)
- Lydia Gentsch
- Institute of Agricultural Sciences, ETH Zurich, Universitätsstrasse 2, 8092 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
246
|
Ghashghaie J, Badeck FW. Opposite carbon isotope discrimination during dark respiration in leaves versus roots - a review. THE NEW PHYTOLOGIST 2014; 201:751-769. [PMID: 24251924 DOI: 10.1111/nph.12563] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 09/15/2013] [Indexed: 05/13/2023]
Abstract
In general, leaves are (13) C-depleted compared with all other organs (e.g. roots, stem/trunk and fruits). Different hypotheses are formulated in the literature to explain this difference. One of these states that CO2 respired by leaves in the dark is (13) C-enriched compared with leaf organic matter, while it is (13) C-depleted in the case of root respiration. The opposite respiratory fractionation between leaves and roots was invoked as an explanation for the widespread between-organ isotopic differences. After summarizing the basics of photosynthetic and post-photosynthetic discrimination, we mainly review the recent findings on the isotopic composition of CO2 respired by leaves (autotrophic organs) and roots (heterotrophic organs) compared with respective plant material (i.e. apparent respiratory fractionation) as well as its metabolic origin. The potential impact of such fractionation on the isotopic signal of organic matter (OM) is discussed. Some perspectives for future studies are also proposed .
Collapse
Affiliation(s)
- Jaleh Ghashghaie
- Laboratoire d'Ecologie, Systématique et Evolution (ESE), CNRS UMR8079, Bâtiment 362, Université de Paris-Sud (XI), F-91405, Orsay Cedex, France
| | - Franz W Badeck
- Consiglio per la Ricerca e la sperimentazione in Agricoltura, Genomics research centre (CRA - GPG), Via San Protaso, 302, 29017, Fiorenzuola d'Arda (PC), Italy
- Potsdam Institute for Climate Impact Research (PIK), PF 60 12 03, 14412, Potsdam, Germany
| |
Collapse
|