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Yu YZ, Liu HT, Yang F, Li L, Schäufele R, Tcherkez G, Schnyder H, Gong XY. δ13C of bulk organic matter and cellulose reveal post-photosynthetic fractionation during ontogeny in C4 grass leaves. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1451-1464. [PMID: 37943576 DOI: 10.1093/jxb/erad445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
The 13C isotope composition (δ13C) of leaf dry matter is a useful tool for physiological and ecological studies. However, how post-photosynthetic fractionation associated with respiration and carbon export influences δ13C remains uncertain. We investigated the effects of post-photosynthetic fractionation on δ13C of mature leaves of Cleistogenes squarrosa, a perennial C4 grass, in controlled experiments with different levels of vapour pressure deficit and nitrogen supply. With increasing leaf age class, the 12C/13C fractionation of leaf organic matter relative to the δ13C of atmosphere CO2 (ΔDM) increased while that of cellulose (Δcel) was almost constant. The divergence between ΔDM and Δcel increased with leaf age class, with a maximum value of 1.6‰, indicating the accumulation of post-photosynthetic fractionation. Applying a new mass balance model that accounts for respiration and export of photosynthates, we found an apparent 12C/13C fractionation associated with carbon export of -0.5‰ to -1.0‰. Different ΔDM among leaves, pseudostems, daughter tillers, and roots indicate that post-photosynthetic fractionation happens at the whole-plant level. Compared with ΔDM of old leaves, ΔDM of young leaves and Δcel are more reliable proxies for predicting physiological parameters due to the lower sensitivity to post-photosynthetic fractionation and the similar sensitivity in responses to environmental changes.
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Affiliation(s)
- Yong Zhi Yu
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Hai Tao Liu
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- College of Resources and Environment, Henan Agricultural University, Zhengzhou 450046, China
| | - Fang Yang
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- College of Resources and Environment, Jilin Agricultural University, Changchun 130117, China
| | - Lei Li
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Rudi Schäufele
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
| | - Guillaume Tcherkez
- Research School of Biology, ANU Joint College of Science, Australian National University, Canberra ACT 0200, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, 42 rue Georges Morel, 49070 Beaucouzé, France
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
| | - Xiao Ying Gong
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, D-85354 Freising, Germany
- Fujian Provincial Key Laboratory for Plant Eco-physiology, Fuzhou, China
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Responses of Carbon Isotope Composition of Common C3 and C4 Plants to Climatic Factors in Temperate Grasslands. SUSTAINABILITY 2022. [DOI: 10.3390/su14127311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Investigating relationships between climatic factors and plant δ13C of both C3 and C4 plants simultaneously is critical for accurately predicting the effects of climate change on plant ecophysiology and ecosystem functioning and reconstructing past vegetation and climate conditions. We selected common C3 and C4 plants in temperate grasslands in Inner Mongolia, China, i.e., Stipa spp., Carex spp., Leymus chinensis and Cleistogenes spp., and investigated the relationships between climatic factors and plant δ13C of each genus/species. The results showed that precipitation, especially growing season precipitation (GSP), was the dominant factor affecting plant δ13C in this region. For C3 plants, there were significantly negative relationships between precipitation and plant δ13C. For C4 plants, plant δ13C of Cleistogenes spp. firstly increased, then decreased with precipitation at a breakpoint GSP 204.84 mm. Our findings emphasize that C4 plant δ13C is sensitive to precipitation, but responses are species-specific and environment-specific, and suggest that C4 plant δ13C can be used as a proxy for water use efficiency (WUE), but care should be taken in evaluating WUE. Moreover, our findings provide basic information for accurately predicting the effects of climate change on ecosystem structure and function and reconstructing past vegetation and climate conditions from bulk materials in arid and semiarid regions.
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Liu Z, Baoyin T, Sun J, Minggagud H, Li X. Plant sizes mediate mowing-induced changes in nutrient stoichiometry and allocation of a perennial grass in semi-arid grassland. Ecol Evol 2018; 8:3109-3118. [PMID: 29607010 PMCID: PMC5869294 DOI: 10.1002/ece3.3866] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 11/12/2022] Open
Abstract
While mowing‐induced changes in plant traits and their effects on ecosystem functioning in semi‐arid grassland are well studied, the relations between plant size and nutrient strategies are largely unknown. Mowing may drive the shifts of plant nutrient limitation and allocation. Here, we evaluated the changes in nutrient stoichiometry and allocation with variations in sizes of Leymus chinensis, the dominant plant species in Inner Mongolia grassland, to various mowing frequencies in a 17‐yr controlled experiment. Affected by mowing, the concentrations of nitrogen (N), phosphorus (P), and carbon (C) in leaves and stems were significantly increased, negatively correlating with plant sizes. Moreover, we found significant trade‐offs between the concentrations and accumulation of N, P, and C in plant tissues. The N:P ratios of L. chinensis aboveground biomass, linearly correlating with plant size, significantly decreased with increased mowing frequencies. The ratios of C:N and C:P of L. chinensis individuals were positively correlated with plant size, showing an exponential pattern. With increased mowing frequencies, L. chinensis size was correlated with the allocation ratios of leaves to stems of N, P, and C by the tendencies of negative parabola, positive, and negative linear. The results of structure equation modeling showed that the N, P, and C allocations were co‐regulated by biomass allocation and nutrient concentration ratios of leaves to stems. In summary, we found a significant decoupling effect between plant traits and nutrient strategies along mowing frequencies. Our results reveal a mechanism for how long‐term mowing‐induced changes in concentrations, accumulations, ecological stoichiometry, and allocations of key elements are mediated by the variations in plant sizes of perennial rhizome grass.
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Affiliation(s)
- Zhiying Liu
- Key Laboratory of Grassland Ecology School of Ecology and Environment Inner Mongolia University Hohhot China
| | - Taogetao Baoyin
- Key Laboratory of Grassland Ecology School of Ecology and Environment Inner Mongolia University Hohhot China
| | - Juan Sun
- College of Animal Science and Technology Qingdao Agricultural University Qingdao China
| | - Hugjiltu Minggagud
- Key Laboratory of Grassland Ecology School of Ecology and Environment Inner Mongolia University Hohhot China
| | - Xiliang Li
- Key Laboratory of Grassland Ecology and Restoration of Ministry of Agriculture National Forage Improvement Center Institute of Grassland Research Chinese Academy of Agricultural Sciences Hohhot China
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Yang H, Yu Q, Sheng WP, Li SG, Tian J. Determination of leaf carbon isotope discrimination in C4 plants under variable N and water supply. Sci Rep 2017; 7:351. [PMID: 28336951 PMCID: PMC5428480 DOI: 10.1038/s41598-017-00498-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 03/02/2017] [Indexed: 11/09/2022] Open
Abstract
Understanding the mechanisms underlying variations in carbon isotope discrimination (Δ) in C4 plants is critical for predicting the C3/C4 ratio in C3/C4 mixed grassland. The value of Δ is determined by bundle sheath leakiness (Ф) and the ratio of intercellular to ambient CO2 concentration (C i /C a ). Leaf nitrogen concentration (N leaf ) is considered a driver of Δ in C4 plants. However, little is known about how N leaf affects Ф and C i /C a , and subsequently Δ. Here leaf carbon isotope composition, N leaf , Ф, and leaf gas exchange were measured in Cleistogenes squarrosa, a dominant C4 species in the Inner Mongolia grassland. Δ remained relatively stable under variable N and water supply. Higher N supply and lower water supply increased N leaf , stimulated photosynthesis and further decreased C i /C a . High N supply increased Ф, which responded weakly to water supply. N leaf exerted similar effects on C i /C a and on Ф in the field and pot experiments. Pooling all the data, N leaf explained 73% of the variation in C i /C a . Overall, both Ф and C i /C a determined Δ; however, the contribution of Ф was stronger. N leaf influenced Δ primarily though C i /C a , rather than Ф. Ф should be considered in estimating Δ of C4 endmember.
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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.
| | - Qiang Yu
- National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Wen-Ping Sheng
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Sheng-Gong Li
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jing Tian
- Key Laboratory of Ecosystem Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
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Gong XY, Schäufele R, Schnyder H. Bundle-sheath leakiness and intrinsic water use efficiency of a perennial C4 grass are increased at high vapour pressure deficit during growth. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:321-333. [PMID: 27864539 PMCID: PMC5853292 DOI: 10.1093/jxb/erw417] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/20/2016] [Indexed: 05/05/2023]
Abstract
Bundle-sheath leakiness (ϕ) is a key parameter of the CO2-concentrating mechanism of C4 photosynthesis and is related to leaf-level intrinsic water use efficiency (WUEi). This work studied short-term dynamic responses of ϕ to alterations of atmospheric CO2 concentration in Cleistogenes squarrosa, a perennial grass, grown at high (1.6 kPa) or low (0.6 kPa) vapour pressure deficit (VPD) combined with high or low N supply in controlled environment experiments. ϕ was determined by concurrent measurements of photosynthetic gas exchange and on-line carbon isotope discrimination, using a new protocol. Growth at high VPD led to an increase of ϕ by 0.13 and a concurrent increase of WUEi by 14%, with similar effects at both N levels. ϕ responded dynamically to intercellular CO2 concentration (C i), increasing with C i Across treatments, ϕ was negatively correlated to the ratio of CO2 saturated assimilation rate to carboxylation efficiency (a proxy of the relative activities of Rubisco and phosphoenolpyruvate carboxylase) indicating that the long-term environmental effect on ϕ was related to the balance between C3 and C4 cycles. Our study revealed considerable dynamic and long-term variation in ϕ of C. squarrosa, suggesting that ϕ should be determined when carbon isotope discrimination is used to assess WUEi Also, the data indicate a trade-off between WUEi and energetic efficiency in C. squarrosa.
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Affiliation(s)
- Xiao Ying Gong
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
| | - Rudi Schäufele
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
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Liu HT, Gong XY, Schäufele R, Yang F, Hirl RT, Schmidt A, Schnyder H. Nitrogen fertilization and δ 18 O of CO 2 have no effect on 18 O-enrichment of leaf water and cellulose in Cleistogenes squarrosa (C 4 ) - is VPD the sole control? PLANT, CELL & ENVIRONMENT 2016; 39:2701-2712. [PMID: 27576868 DOI: 10.1111/pce.12824] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 06/06/2023]
Abstract
The oxygen isotope composition of cellulose (δ18 OCel ) archives hydrological and physiological information. Here, we assess previously unexplored direct and interactive effects of the δ18 O of CO2 (δ18 OCO2 ), nitrogen (N) fertilizer supply and vapour pressure deficit (VPD) on δ18 OCel , 18 O-enrichment of leaf water (Δ18 OLW ) and cellulose (Δ18 OCel ) relative to source water, and pex px , the proportion of oxygen in cellulose that exchanged with unenriched water at the site of cellulose synthesis, in a C4 grass (Cleistogenes squarrosa). δ18 OCO2 and N supply, and their interactions with VPD, had no effect on δ18 OCel , Δ18 OLW , Δ18 OCel and pex px . Δ18 OCel and Δ18 OLW increased with VPD, while pex px decreased. That VPD-effect on pex px was supported by sensitivity tests to variation of Δ18 OLW and the equilibrium fractionation factor between carbonyl oxygen and water. N supply altered growth and morphological features, but not 18 O relations; conversely, VPD had no effect on growth or morphology, but controlled 18 O relations. The work implies that reconstructions of VPD from Δ18 OCel would overestimate amplitudes of VPD variation, at least in this species, if the VPD-effect on pex px is ignored. Progress in understanding the relationship between Δ18 OLW and Δ18 OCel will require separate investigations of pex and px and of their responses to environmental conditions.
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Affiliation(s)
- Hai Tao Liu
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Xiao Ying Gong
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Rudi Schäufele
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Fang Yang
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Regina Theresia Hirl
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Anja Schmidt
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354, Freising, Germany
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Liu Y, Li Y, Zhang L, Xu X, Niu H. Effects of sampling method on foliar δ (13)C of Leymus chinensis at different scales. Ecol Evol 2015; 5:1068-75. [PMID: 25798224 PMCID: PMC4364821 DOI: 10.1002/ece3.1401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 12/15/2014] [Indexed: 12/03/2022] Open
Abstract
Stable carbon isotope composition (δ (13)C) usually shows a negative relationship with precipitation at a large scale. We hypothesized that sampling method affects foliar δ (13)C and its response pattern to precipitation. We selected 11 sites along a precipitation gradient in Inner Mongolia and collected leaves of Leymus chinensis with five or six replications repeatedly in each site from 2009 to 2011. Additionally, we collected leaves of L. chinensis separately from two types of grassland (grazed and fenced) in 2011. Foliar δ (13)C values of all samples were measured. We compared the patterns that foliar δ (13)C to precipitation among different years or different sample sizes, the differences of foliar δ (13)C between grazed and fenced grassland. Whether actual annual precipitation (AAP) or mean annual precipitation (MAP), it was strongly correlated with foliar δ (13)C every year. Significant difference was found between the slopes of foliar δ (13)C to AAP and MAP every year, among the slopes of foliar δ (13)C to AAP from 2009 to 2011. The more samples used at each site the lower and convergent P-values of the linear regression test between foliar δ (13)C and precipitation. Furthermore, there was significant lower foliar δ (13)C value in presence of grazed type than fenced type grassland. These findings provide evidence that there is significant effect of sampling method to foliar δ (13)C and its response pattern to precipitation of L. chinensis. Our results have valuable implications in methodology for future field sampling studies.
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Affiliation(s)
- Yanjie Liu
- College of Resources and Environment, University of Chinese Academy of Sciences19-A Yuquan Road, Beijing 100049, China
- Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10D-78457 Konstanz, Germany
| | - Yan Li
- Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10D-78457 Konstanz, Germany
| | - Lirong Zhang
- College of Resources and Environment, University of Chinese Academy of Sciences19-A Yuquan Road, Beijing 100049, China
| | - Xingliang Xu
- Key Laboratory and Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of SciencesNO.11-A Datun Road, Beijing, 100101, China
| | - Haishan Niu
- College of Resources and Environment, University of Chinese Academy of Sciences19-A Yuquan Road, Beijing 100049, China
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Braun A, Schneider S, Auerswald K, Bellof G, Schnyder H. Forward modeling of fluctuating dietary 13C signals to validate 13C turnover models of milk and milk components from a diet-switch experiment. PLoS One 2014; 8:e85235. [PMID: 24392000 PMCID: PMC3877384 DOI: 10.1371/journal.pone.0085235] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 12/01/2013] [Indexed: 12/05/2022] Open
Abstract
Isotopic variation of food stuffs propagates through trophic systems. But, this variation is dampened in each trophic step, due to buffering effects of metabolic and storage pools. Thus, understanding of isotopic variation in trophic systems requires knowledge of isotopic turnover. In animals, turnover is usually quantified in diet-switch experiments in controlled conditions. Such experiments usually involve changes in diet chemical composition, which may affect turnover. Furthermore, it is uncertain if diet-switch based turnover models are applicable under conditions with randomly fluctuating dietary input signals. Here, we investigate if turnover information derived from diet-switch experiments with dairy cows can predict the isotopic composition of metabolic products (milk, milk components and feces) under natural fluctuations of dietary isotope and chemical composition. First, a diet-switch from a C3-grass/maize diet to a pure C3-grass diet was used to quantify carbon turnover in whole milk, lactose, casein, milk fat and feces. Data were analyzed with a compartmental mixed effects model, which allowed for multiple pools and intra-population variability, and included a delay between feed ingestion and first tracer appearance in outputs. The delay for milk components and whole milk was ∼12 h, and that of feces ∼20 h. The half-life (t½) for carbon in the feces was 9 h, while lactose, casein and milk fat had a t½ of 10, 18 and 19 h. The 13C kinetics of whole milk revealed two pools, a fast pool with a t½ of 10 h (likely representing lactose), and a slower pool with a t½ of 21 h (likely including casein and milk fat). The diet-switch based turnover information provided a precise prediction (RMSE ∼0.2 ‰) of the natural 13C fluctuations in outputs during a 30 days-long period when cows ingested a pure C3 grass with naturally fluctuating isotope composition.
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Affiliation(s)
- Alexander Braun
- Lehrstuhl für Grünlandlehre, Department of Plant Science, Technische Universität München, Freising, Germany
| | - Stephan Schneider
- Fachgebiet Tierernährung, Fakultät Land- und Ernährungswirtschaft, Hochschule Weihenstephan-Triesdorf, Freising, Germany
| | - Karl Auerswald
- Lehrstuhl für Grünlandlehre, Department of Plant Science, Technische Universität München, Freising, Germany
- * E-mail:
| | - Gerhard Bellof
- Fachgebiet Tierernährung, Fakultät Land- und Ernährungswirtschaft, Hochschule Weihenstephan-Triesdorf, Freising, Germany
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Department of Plant Science, Technische Universität München, Freising, Germany
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Auerswald K, Wittmer MHOM, Tungalag R, Bai Y, Schnyder H. Sheep wool δ13C reveals no effect of grazing on the C3/C4 ratio of vegetation in the inner Mongolia-Mongolia border region grasslands. PLoS One 2012; 7:e45552. [PMID: 23029090 PMCID: PMC3459995 DOI: 10.1371/journal.pone.0045552] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 08/23/2012] [Indexed: 11/18/2022] Open
Abstract
We tested whether the abundance of C4 vegetation in grasslands of the Mongolian plateau is influenced by grazing conditions. The analysis exploited the politically originated contrast that exists between Mongolia (low stocking rate, transhumant system) and the district of Inner Mongolia, China (high stocking rate, sedentary system). We estimated the proportion of C4 carbon (PC4) in grazed vegetation from the relative carbon isotope ratio (δ13C) of sheep wool sampled from 298 annual shearings originating from 1996 to 2007. Annual stocking rates varying over time and between the districts of both countries were taken from regional statistics. The PC4 pattern within the 0.7 million km2 sampling area was geostatistically analyzed and related to stocking rates and temperature gradients. For similar climatic conditions, PC4 was the same in both countries. Further, a unique relationship was found between PC4 and July temperature on both sides of the border, which explained 71% of the pattern. Stocking rate and grazing system had no significant influences on present-day C3/C4 abundance ratio. This finding suggests that recent changes in the C3/C4 ratio of these grasslands are mainly a consequence of regional warming, not overgrazing.
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Affiliation(s)
- Karl Auerswald
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, Freising-Weihenstephan, Germany.
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Begcy K, Mariano ED, Gentile A, Lembke CG, Zingaretti SM, Souza GM, Menossi M. A novel stress-induced sugarcane gene confers tolerance to drought, salt and oxidative stress in transgenic tobacco plants. PLoS One 2012; 7:e44697. [PMID: 22984543 PMCID: PMC3439409 DOI: 10.1371/journal.pone.0044697] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 08/09/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Drought is a major abiotic stress that affects crop productivity worldwide. Sugarcane can withstand periods of water scarcity during the final stage of culm maturation, during which sucrose accumulation occurs. Meanwhile, prolonged periods of drought can cause severe plant losses. METHODOLOGY/PRINCIPAL FINDINGS In a previous study, we evaluated the transcriptome of drought-stressed plants to better understand sugarcane responses to drought. Among the up-regulated genes was Scdr1 (sugarcane drought-responsive 1). The aim of the research reported here was to characterize this gene. Scdr1 encodes a putative protein containing 248 amino acids with a large number of proline (19%) and cysteine (13%) residues. Phylogenetic analysis showed that ScDR1is in a clade with homologs from other monocotyledonous plants, separate from those of dicotyledonous plants. The expression of Scdr1 in different varieties of sugarcane plants has not shown a clear association with drought tolerance. CONCLUSIONS/SIGNIFICANCE The overexpression of Scdr1 in transgenic tobacco plants increased their tolerance to drought, salinity and oxidative stress, as demonstrated by increased photosynthesis, water content, biomass, germination rate, chlorophyll content and reduced accumulation of ROS. Physiological parameters, such as transpiration rate (E), net photosynthesis (A), stomatal conductance (gs) and internal leaf CO(2) concentration, were less affected by abiotic stresses in transgenic Scdr1 plants compared with wild-type plants. Overall, our results indicated that Scdr1 conferred tolerance to multiple abiotic stresses, highlighting the potential of this gene for biotechnological applications.
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Affiliation(s)
- Kevin Begcy
- Laboratório de Genoma Funcional, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Eduardo D. Mariano
- Laboratório de Genoma Funcional, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Agustina Gentile
- Laboratório de Genoma Funcional, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Carolina G. Lembke
- Laboratório de Transdução de Sinal, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Sonia Marli Zingaretti
- Unidade de Biotecnologia, Universidade de Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | - Glaucia M. Souza
- Laboratório de Transdução de Sinal, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Marcelo Menossi
- Laboratório de Genoma Funcional, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
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