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Hussin SA, Ali SH, Lotfy ME, El-Samad EHA, Eid MA, Abd-Elkader AM, Eisa SS. Morpho-physiological mechanisms of two different quinoa ecotypes to resist salt stress. BMC PLANT BIOLOGY 2023; 23:374. [PMID: 37518180 PMCID: PMC10388498 DOI: 10.1186/s12870-023-04342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/10/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte showing various mechanisms of salt resistance among different ecotype cultivars. This study aimed to determine salt resistance limits for a Peruvian sea level ecotype "Hualhuas" and a Bolivian salar ecotype "Real" and elucidate individual mechanisms conferring differences in salt resistance between these cultivars. The plants were grown in sandy soil and irrigated with various saline solutions concentrations (0, 100, 200, 300, 400, and 500 mM NaCl) under controlled conditions. RESULTS High salinity treatment (500 mM NaCl) reduced the plant growth by 80% and 87% in Hualhuas and Real cultivars, respectively. EC50 (water salinity which reduces the maximum yield by 50%) was at a salinity of 300 mM NaCl for Hualhuas and between 100 and 200 mM NaCl for Real plants. Both cultivars were able to lower the osmotic potential of all organs due to substantial Na+ accumulation. However, Hualhuas plants exhibited distinctly lower Na+ contents and consequently a higher K+/Na+ ratio compared to Real plants, suggesting a more efficient control mechanism for Na+ loading and better K+ retention in Hualhuas plants. Net CO2 assimilation rates (Anet) were reduced, being only 22.4% and 36.2% of the control values in Hualhuas and Real, respectively, at the highest salt concentration. At this salinity level, Hualhuas plants showed lower stomatal conductance (gs) and transpiration rates (E), but higher photosynthetic water use efficiency (PWUE), indicative of an efficient control mechanism over the whole gas-exchange machinery. CONCLUSION These results reveal that Hualhuas is a promising candidate in terms of salt resistance and biomass production compared to Real.
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Affiliation(s)
- Sayed A Hussin
- Agricultural Botany Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt.
| | - Safwat Hassan Ali
- Agricultural Biochemistry Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt
| | - Muhammad E Lotfy
- Agricultural Botany Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt
| | - Emad H Abd El-Samad
- Vegetable Research Department, Agricultural & Biological Research Institute, National Research Centre, 33 El-Buhouth St, Dokki, 12622, Giza, Egypt
| | - Mohamed A Eid
- Soil Science Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt
| | - Ali M Abd-Elkader
- Agricultural Botany Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt
| | - Sayed Said Eisa
- Agricultural Botany Department, Faculty of Agriculture, Ain Shams University, Hadayek Shubra 11241, P.O. Box 68, Cairo, Egypt.
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Rademacher T, Fonti P, LeMoine JM, Fonti MV, Basler D, Chen Y, Friend AD, Seyednasrollah B, Eckes-Shephard AH, Richardson AD. Manipulating phloem transport affects wood formation but not local nonstructural carbon reserves in an evergreen conifer. PLANT, CELL & ENVIRONMENT 2021; 44:2506-2521. [PMID: 34043242 DOI: 10.1111/pce.14117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
How variations in carbon supply affect wood formation remains poorly understood in particular in mature forest trees. To elucidate how carbon supply affects carbon allocation and wood formation, we attempted to manipulate carbon supply to the cambial region by phloem girdling and compression during the mid- and late-growing season and measured effects on structural development, CO2 efflux and nonstructural carbon reserves in stems of mature white pines. Wood formation and stem CO2 efflux varied with a location relative to treatment (i.e., above or below the restriction). We observed up to twice as many tracheids formed above versus below the treatment after the phloem transport manipulation, whereas the cell-wall area decreased only slightly below the treatments, and cell size did not change relative to the control. Nonstructural carbon reserves in the xylem, needles and roots were largely unaffected by the treatments. Our results suggest that low and high carbon supply affects wood formation, primarily through a strong effect on cell proliferation, and respiration, but local nonstructural carbon concentrations appear to be maintained homeostatically. This contrasts with reports of decoupling of source activity and wood formation at the whole-tree or ecosystem level, highlighting the need to better understand organ-specific responses, within-tree feedbacks, as well as phenological and ontogenetic effects on sink-source dynamics.
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Affiliation(s)
- Tim Rademacher
- School of Informatics, Computing, and Cyber Security, Northern Arizona University, Flagstaff, Arizona, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Patrick Fonti
- Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - James M LeMoine
- School of Informatics, Computing, and Cyber Security, Northern Arizona University, Flagstaff, Arizona, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | - Marina V Fonti
- Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Institute of Ecology and Geography, Siberian Federal University, Krasnoyarsk, Russian Federation
| | - David Basler
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Yizhao Chen
- Department of Geography, University of Cambridge, Cambridge, UK
| | - Andrew D Friend
- Department of Geography, University of Cambridge, Cambridge, UK
| | - Bijan Seyednasrollah
- School of Informatics, Computing, and Cyber Security, Northern Arizona University, Flagstaff, Arizona, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | | | - Andrew D Richardson
- School of Informatics, Computing, and Cyber Security, Northern Arizona University, Flagstaff, Arizona, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
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Aluko OO, Li C, Wang Q, Liu H. Sucrose Utilization for Improved Crop Yields: A Review Article. Int J Mol Sci 2021; 22:4704. [PMID: 33946791 PMCID: PMC8124652 DOI: 10.3390/ijms22094704] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/14/2021] [Accepted: 04/17/2021] [Indexed: 12/13/2022] Open
Abstract
Photosynthetic carbon converted to sucrose is vital for plant growth. Sucrose acts as a signaling molecule and a primary energy source that coordinates the source and sink development. Alteration in source-sink balance halts the physiological and developmental processes of plants, since plant growth is mostly triggered when the primary assimilates in the source leaf balance with the metabolic needs of the heterotrophic sinks. To measure up with the sink organ's metabolic needs, the improvement of photosynthetic carbon to synthesis sucrose, its remobilization, and utilization at the sink level becomes imperative. However, environmental cues that influence sucrose balance within these plant organs, limiting positive yield prospects, have also been a rising issue over the past few decades. Thus, this review discusses strategies to improve photosynthetic carbon assimilation, the pathways actively involved in the transport of sucrose from source to sink organs, and their utilization at the sink organ. We further emphasize the impact of various environmental cues on sucrose transport and utilization, and the strategic yield improvement approaches under such conditions.
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Affiliation(s)
- Oluwaseun Olayemi Aluko
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (O.O.A.); (C.L.)
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Chuanzong Li
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (O.O.A.); (C.L.)
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Qian Wang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (O.O.A.); (C.L.)
| | - Haobao Liu
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; (O.O.A.); (C.L.)
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Zheng Y, Li F, Hao L, Yu J, Guo L, Zhou H, Ma C, Zhang X, Xu M. Elevated CO 2 concentration induces photosynthetic down-regulation with changes in leaf structure, non-structural carbohydrates and nitrogen content of soybean. BMC PLANT BIOLOGY 2019; 19:255. [PMID: 31195963 PMCID: PMC6567668 DOI: 10.1186/s12870-019-1788-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 04/18/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND Understanding the mechanisms of crops in response to elevated CO2 concentrations is pivotal to estimating the impacts of climate change on the global agricultural production. Based on earlier results of the "doubling-CO2 concentration" experiments, many current climate models may overestimate the CO2 fertilization effect on crops, and meanwhile, underestimate the potential impacts of future climate change on global agriculture ecosystem when the atmospheric CO2 concentration goes beyond the optimal levels for crop growth. RESULTS This study examined the photosynthetic response of soybean (Glycine max (L.) Merr.) to elevated CO2 concentration associated with changes in leaf structure, non-structural carbohydrates and nitrogen content with environmental growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, 1200, 1400, 1600 ppm. We found CO2-induced down-regulation of leaf photosynthesis as evidenced by the consistently declined leaf net photosynthetic rate (An) with elevated CO2 concentrations. This down-regulation of leaf photosynthesis was evident in biochemical and photochemical processes since the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) were dramatically decreased at higher CO2 concentrations exceeding their optimal values of about 600 ppm and 400 ppm, respectively. Moreover, the down-regulation of leaf photosynthesis at high CO2 concentration was partially attributed to the reduced stomatal conductance (Gs) as demonstrated by the declines in stomatal density and stomatal area as well as the changes in the spatial distribution pattern of stomata. In addition, the smaller total mesophyll size (palisade and spongy tissues) and the lower nitrogen availability may also contribute to the down-regulation of leaf photosynthesis when soybean subjected to high CO2 concentration environment. CONCLUSIONS Down-regulation of leaf photosynthesis associated with the changes in stomatal traits, mesophyll tissue size, non-structural carbohydrates, and nitrogen availability of soybean in response to future high atmospheric CO2 concentration and climate change.
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Affiliation(s)
- Yunpu Zheng
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Fei Li
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Lihua Hao
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Jingjin Yu
- School of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, 210095 People’s Republic of China
| | - Lili Guo
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Haoran Zhou
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Chao Ma
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Xixi Zhang
- School of Water Conservancy and Hydropower, Hebei University of Engineering, Handan, 056038 China
| | - Ming Xu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, College of Environment and Planning, Henan University, Kaifeng, 475004 China
- Center for Remote Sensing and Spatial Analysis, Department of Ecology, Evolution and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 USA
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Huang J, Hammerbacher A, Weinhold A, Reichelt M, Gleixner G, Behrendt T, van Dam NM, Sala A, Gershenzon J, Trumbore S, Hartmann H. Eyes on the future - evidence for trade-offs between growth, storage and defense in Norway spruce. THE NEW PHYTOLOGIST 2019; 222:144-158. [PMID: 30289558 DOI: 10.1111/nph.15522] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/28/2018] [Indexed: 05/20/2023]
Abstract
Carbon (C) allocation plays a central role in tree responses to environmental changes. Yet, fundamental questions remain about how trees allocate C to different sinks, for example, growth vs storage and defense. In order to elucidate allocation priorities, we manipulated the whole-tree C balance by modifying atmospheric CO2 concentrations [CO2 ] to create two distinct gradients of declining C availability, and compared how C was allocated among fluxes (respiration and volatile monoterpenes) and biomass C pools (total biomass, nonstructural carbohydrates (NSC) and secondary metabolites (SM)) in well-watered Norway spruce (Picea abies) saplings. Continuous isotope labelling was used to trace the fate of newly-assimilated C. Reducing [CO2 ] to 120 ppm caused an aboveground C compensation point (i.e. net C balance was zero) and resulted in decreases in growth and respiration. By contrast, soluble sugars and SM remained relatively constant in aboveground young organs and were partially maintained with a constant allocation of newly-assimilated C, even at expense of root death from C exhaustion. We conclude that spruce trees have a conservative allocation strategy under source limitation: growth and respiration can be downregulated to maintain 'operational' concentrations of NSC while investing newly-assimilated C into future survival by producing SM.
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Affiliation(s)
- Jianbei Huang
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Almuth Hammerbacher
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, 0028, Pretoria, South Africa
| | - Alexander Weinhold
- German Centre for Integrative Biodiversity Research, Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Michael Reichelt
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Gerd Gleixner
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Thomas Behrendt
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Nicole M van Dam
- German Centre for Integrative Biodiversity Research, Deutscher Platz 5e, 04103, Leipzig, Germany
- Institute of Biodiversity, Friedrich Schiller University, Dornburger-Str. 159, 07743, Jena, Germany
| | - Anna Sala
- Division of Biological Sciences, The University of Montana, Missoula, MT, 59812, USA
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Susan Trumbore
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
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Hussin S, Geissler N, El-Far MMM, Koyro HW. Effects of salinity and short-term elevated atmospheric CO 2 on the chemical equilibrium between CO 2 fixation and photosynthetic electron transport of Stevia rebaudiana Bertoni. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017. [PMID: 28645057 DOI: 10.1016/j.plaphy.2017.06.017] [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] [Indexed: 05/14/2023]
Abstract
The effect of water salinity on plant growth and photosynthetic traits of Stevia rebaudiana was investigated to determine its level and mechanisms of salinity tolerance. It was also attempted to assess how short-term elevated CO2 concentration would influence the boundaries and mechanisms of its photosynthetic capacity. The plants were grown in gravel/hydroponic system under controlled greenhouse conditions and irrigated with four different salinity levels (0, 25, 50 and 100 mol m-3NaCl). Low salinity did not significantly alter the plant fresh weight, which was substantially decreased by 67% at high salinity treatment. Salinity tolerance threshold was reached at 50 mol m-3 NaCl while C50 was between 50 and 100 mol m-3 NaCl, indicating that S. rebaudiana is a moderate salt tolerant species. Salt-induced growth reduction was apparently linked to a significant decline of about 47% in the photosynthetic rates (Anet) at high salinity treatment, leading consequently to a disequilibrium between CO2-assimilation and electron transport rates (indicated by enhanced ETRmax/Agross ratio). Elevated atmospheric CO2 enhanced CO2 assimilation rates by 65% and 80% for control and high-salt-stressed plants respectively, likely due to significant increases in intercellular CO2 concentration (indicated by enhanced Ci/Ca). The priority for Stevia under elevated atmospheric CO2 was not to save water but to maximize photosynthesis so that the PWUE was progressively improved and the threat of oxidative stress was diminished (decline in ETRmax/Agross). The results imply that elevated CO2 level could ameliorate some of the detrimental effects of salinity, conferring higher tolerance and survival of S. rebaudiana, a highlydesired feature with the forthcoming era of global changes.
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Affiliation(s)
- Sayed Hussin
- Institute of Plant Ecology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany; Agricultural Botany Department, Faculty of Agriculture, Ain Shams University, P.O. Box 68, Hadayek Shubra, 11241 Cairo, Egypt.
| | - Nicole Geissler
- Institute of Plant Ecology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Mervat M M El-Far
- Institute of Plant Ecology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Hans-Werner Koyro
- Institute of Plant Ecology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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Gessler A, Treydte K. The fate and age of carbon - insights into the storage and remobilization dynamics in trees. THE NEW PHYTOLOGIST 2016; 209:1338-1340. [PMID: 26840248 DOI: 10.1111/nph.13863] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Arthur Gessler
- Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
| | - Kerstin Treydte
- Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
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Xu Z, Jiang Y, Zhou G. Response and adaptation of photosynthesis, respiration, and antioxidant systems to elevated CO2 with environmental stress in plants. FRONTIERS IN PLANT SCIENCE 2015; 6:701. [PMID: 26442017 PMCID: PMC4564695 DOI: 10.3389/fpls.2015.00701] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/21/2015] [Indexed: 05/19/2023]
Abstract
It is well known that plant photosynthesis and respiration are two fundamental and crucial physiological processes, while the critical role of the antioxidant system in response to abiotic factors is still a focus point for investigating physiological stress. Although one key metabolic process and its response to climatic change have already been reported and reviewed, an integrative review, including several biological processes at multiple scales, has not been well reported. The current review will present a synthesis focusing on the underlying mechanisms in the responses to elevated CO2 at multiple scales, including molecular, cellular, biochemical, physiological, and individual aspects, particularly, for these biological processes under elevated CO2 with other key abiotic stresses, such as heat, drought, and ozone pollution, as well as nitrogen limitation. The present comprehensive review may add timely and substantial information about the topic in recent studies, while it presents what has been well established in previous reviews. First, an outline of the critical biological processes, and an overview of their roles in environmental regulation, is presented. Second, the research advances with regard to the individual subtopics are reviewed, including the response and adaptation of the photosynthetic capacity, respiration, and antioxidant system to CO2 enrichment alone, and its combination with other climatic change factors. Finally, the potential applications for plant responses at various levels to climate change are discussed. The above issue is currently of crucial concern worldwide, and this review may help in a better understanding of how plants deal with elevated CO2 using other mainstream abiotic factors, including molecular, cellular, biochemical, physiological, and whole individual processes, and the better management of the ecological environment, climate change, and sustainable development.
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Affiliation(s)
- Zhenzhu Xu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Yanling Jiang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Guangsheng Zhou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesBeijing, China
- Chinese Academy of Meteorological SciencesBeijing, China
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Wegener F, Beyschlag W, Werner C. High intraspecific ability to adjust both carbon uptake and allocation under light and nutrient reduction in Halimium halimifolium L. FRONTIERS IN PLANT SCIENCE 2015; 6:609. [PMID: 26300906 PMCID: PMC4528176 DOI: 10.3389/fpls.2015.00609] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 07/23/2015] [Indexed: 05/28/2023]
Abstract
The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. In the present study, we investigated the regulation of C uptake and allocation and their adjustments during plant growth. We induced different allocation strategies in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analyzed allocation parameters as well as morphological and physiological traits for 15 months. Further, we conducted a (13)CO2 pulse-labeling and followed the way of recently assimilated carbon to eight different tissue classes and respiration for 13 days. The plant responses were remarkably distinct in our study, with mainly morphological/physiological adaptions in case of light reduction and adjustment of C allocation in case of nutrient reduction. The transport of recently assimilated C to the root system was enhanced in amount (c. 200%) and velocity under nutrient limited conditions compared to control plants. Despite the 57% light reduction the total biomass production was not affected in the Low L treatment. The plants probably compensated light reduction by an improvement of their ability to fix C. Thus, our results support the concept that photosynthesis is, at least in a medium term perspective, influenced by the C demand of the plant and not exclusively by environmental factors. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C reflux from storage and structural C pools and therefore enhance the fraction of recent assimilates allocated to respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a regulation mechanism for C translocation in plants.
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Affiliation(s)
- Frederik Wegener
- Ecosystem Physiology, University of FreiburgFreiburg, Germany
- AgroEcosystem Research, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of BayreuthBayreuth, Germany
| | - Wolfram Beyschlag
- Experimental and Systems Ecology, University of BielefeldBielefeld, Germany
| | - Christiane Werner
- Ecosystem Physiology, University of FreiburgFreiburg, Germany
- AgroEcosystem Research, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of BayreuthBayreuth, Germany
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