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1.
We evaluated diurnal and seasonal patterns of carbon isotope composition of leaf dark-respired CO2 ( δ 13 Cl ) in the C3 perennial shrub velvet mesquite ( Prosopis velutina ) across flood plain and upland savanna ecosystems in the south-western USA. δ 13 Cl of darkened leaves increased to maximum values late during daytime periods and declined gradually over night-time periods to minimum values at pre-dawn. The magnitude of the diurnal shift in δ 13 Cl was strongly influenced by seasonal and habitat-related differences in soil water availability and leaf surface vapour pressure deficit. δ 13 Cl and the cumulative flux-weighted δ 13 C value of photosynthates were positively correlated, suggesting that progressive 13 C enrichment of the CO2 evolved by darkened leaves during the daytime mainly resulted from short-term changes in photosynthetic 13 C discrimination and associated shifts in the δ 13 C signature of primary respiratory substrates. The 13 C enrichment of dark-respired CO2 relative to photosynthates across habitats and seasons was 4 to 6‰ at the end of the daytime period (1800 h), but progressively declined to 0‰ by pre-dawn (0300 h). The origin of night-time and daytime variations in δ 13 Cl is discussed in terms of the carbon source(s) feeding respiration and the drought-induced changes in carbon metabolism. 相似文献
2.
Four ecotypes of Phragmites australis from different habitats in northwest China were examined to compare their photosynthetic characteristics. In a swamp ecotype, the Δ 13 C value of leaf materials was −34.0‰, and bundle sheath cells contained a small amount of organelles and round-shaped chloroplasts, as being similar to typical C3 plants. In a dune ecotype, the Δ 13 C value was −20.9‰ and bundle sheath cells contained oval-shaped chloroplasts with poorly-developed grana. In light and heavy salt meadow ecotypes, Δ 13 C values were −30.6‰ and −35.6‰, respectively. The shape of bundle sheath chloroplasts in the light salt meadow ecotype was intermediate between those of the swamp and dune ecotypes. Abundance of bundle sheath organelles in the heavy salt meadow ecotype was intermediate. The swamp ecotype had photosynthetic enzyme activities typical of C3 type plants, whereas the dune ecotype had an increased activity of phosphoenolpyruvate carboxylase (PEPC), a key C4 enzyme, and a decreased ribulose 1,5-bisphosphate carboxylase (Rubisco) activity. The light salt meadow and heavy salt meadow ecotypes had substantial activities of PEPC, which indicates potential for C4 photosynthesis. These data suggest that this species evolved the C3 -like ecotype in swamp environments and the C4 -like C3 -C4 intermediate in dune desert environments, and C3 -like C3 -C4 intermediates in salt environments. 相似文献
3.
M. DURANCEAU J. GHASHGHAIE F. BADECK E. DELEENS & G. CORNIC 《Plant, cell & environment》1999,22(5):515-523
The variations in δ 13 C in both leaf carbohydrates (starch and sucrose) and CO2 respired in the dark from the cotyledonary leaves of Phaseolus vulgaris L. were investigated during a progressive drought. As expected, sucrose and starch became heavier (enriched in 13 C) with decreasing stomatal conductance and decreasing p i / p a during the first half (15 d) of the dehydration cycle. Thereafter, when stomata remained closed and leaf net photosynthesis was near zero, the tendency was reversed: the carbohydrates became lighter (depleted in 13 C). This may be explained by increased p i / p a but other possible explanations are also discussed. Interestingly, the variations in δ 13 C of CO2 respired in the dark were correlated with those of sucrose for both well-watered and dehydrated plants. A linear relationship was obtained between δ 13 C of CO2 respired in the dark and sucrose, respired CO2 always being enriched in 13 C compared with sucrose by ≈ 6‰. The whole leaf organic matter was depleted in 13 C compared with leaf carbohydrates by at least 1‰. These results suggest that: (i) a discrimination by ≈ 6‰ occurs during dark respiration processes releasing 13 C-enriched CO2 ; and that (ii) this leads to 13 C depletion in the remaining leaf material. 相似文献
4.
Guoan Wang Jiamao Han Liping Zhou Xiaogang Xiong Zhenhai Wu 《Physiologia plantarum》2005,125(1):74-81
Carbon isotope ratio of leaf dry matter, δ 13 C, was measured on species occurring within Baiyin desert community, consisting of valley, slope and ridge microhabitats, and within Shandan desert community, consisting of Gobi desert and seasonal flooded creek microhabitats, in Northwest China. δ 13 C of C3 species increased with a decrease in soil water availability, suggesting that water-use efficiency (WUE) increased with decreasing soil moisture, whereas for all C4 species, δ 13 C tended to decrease with decreasing soil water availability, suggesting that WUE also increased with decreasing soil moisture. Above results indicated that water-use pattern was conservative under drought for C4 and C3 plants. In this present study, C4 species' occurrences within different microhabitats were investigated and C4 plants were observed to be absent and/or scarce within relatively lower soil moisture microhabitats, whereas they occurred and/or even had a high abundance within relatively higher soil moisture microhabitats, suggesting limited moisture available was a key factor of limiting C4 distribution in arid region of Northwest China. 相似文献
5.
Abstract. In the marine environment, the range of values of carbon isotope fractionation between particulate tissue of phytoplankton and inorganic carbon can be more than 20‰ (− 35‰ < δ13 C < − 14‰). This review considers the influence of seawater temperature, lipid content of phytoplanktonic cells, kinetic fractionation, and carbon pathway on δ13 C values observed at sea.
In order to study the contribution of carboxylases (RUBISCO and the β-carboxylases phosphoenolpyruvate carboxylase, phosphoenoplpyruvate carboxykinase and pyruvate carboxylase) to variations of particulate δ13 C values at sea, we present results obtained simultenously on carboxylase activities and δ13 C in various environmental conditions. The lowest δ13 C values are clearly associated with predominance of ribulose-1.5-bisphosphate carboxylase activity, but it was more difficult to explain the high δ13 C values. Different hypotheses are discussed. 相似文献
In order to study the contribution of carboxylases (RUBISCO and the β-carboxylases phosphoenolpyruvate carboxylase, phosphoenoplpyruvate carboxykinase and pyruvate carboxylase) to variations of particulate δ
6.
BEHZAD MORTAZAVI MAUREEN H. CONTE JEFFREY P. CHANTON MATTHEW C. SMITH J. C. WEBER JASMINE CRUMSEY & JALEH GHASHGHAIE 《Plant, cell & environment》2009,32(10):1310-1323
Isotopic labelling experiments were conducted to assess relationships among 13 C of recently assimilated carbon ( δC A ), foliage respiration ( δC F ), soluble carbohydrate ( δC SC ), leaf waxes ( δC LW ) and bulk organic matter ( δC OM ). Slash pine, sweetgum and maize were grown under 13 C depleted CO2 to label biomass and then placed under ambient conditions to monitor the loss of label. In pine and sweetgum, δC F of labelled plants (∼−44 and −35‰, respectively) rapidly approached control values but remained depleted by ∼4–6‰ after 3–4 months. For these tree species, no or minimal label was lost from δC SC , δC LW and δC OM during the observation periods. δC F and δC SC of labelled maize plants rapidly changed and were indistinguishable from controls after 1 month, while δC LW and δC OM more slowly approached control values and remained depleted by 2–6‰. Changes in δC F in slash pine and sweetgum fit a two-pool exponential model, with the fast turnover metabolic pool (∼3–4 d half-life) constituting only 1–2% of the total. In maize, change in δC F fits a single pool model with a half-life of 6.4 d. The 13 C of foliage respiration and biochemical pools reflect temporally integrated values of δC A , with change in isotopic composition dampened by the size of metabolic carbon reserves and turnover rates. 相似文献
7.
It has been suggested previously that Japanese larch ( Larix kaempferi ) exhibits characteristics of C4 photosynthesis. To further evaluate this suggestion, stable carbon isotope ratios were determined for leaf and bark tissue of Larix gmelini, L. kaempferi, L. laricina, L. Iyallii, L. occidentalis , and L. sibirica. All δ13 C values were more negative than –22‰. Short-term labeling with 14 CO2 showed that phosphoglyceric acid and other phosphorylated compounds were the first products of photosynthesis in L. sibirica. Both of these results strongly suggest that the initial fixation of atmospheric CO2 in these six Larix species is accomplished solely via the C3 photosynthetic pathway. 相似文献
8.
A Remarkable New Leaf Type With Unusual Photosynthetic Tissue in a Central Asiatic Genus of Chenopodiaceae 总被引:7,自引:0,他引:7
Abstract: From the hygrohalophyte Borszczowia aralocaspica Bunge (Chenopodiaceae), a new leaf type with 1-layered chlorenchyma is described as "borszczovoid" and compared with other leaf types in subfamily Salsoloideae. The chlorenchyma is suspected to represent a unique C4 type. Evidence is cited from anatomical studies and documented by micrographs and Carbon isotope determinations (ä13 C values). The 1-layered photosynthetic tissue combines all essential anatomical characters of a 2-layered chlorenchyma of regular C4 plants and is in intimate contact with concentrically arranged peripheral bundles. The ä13 C values are − 13.03 ‰ from young stems and − 13.78 ‰ from leaves. The results are discussed in the anatomical, physiological and taxonomic framework. In addition, from distantly-related Suaeda species of section Conosperma the conospermoid leaf type is re-described. It is characterized by typical palisade and Kranz layers and differs from the C4 suaedoid type by an external water-storaging hypodermis and an arrangement of Kranz cells reminiscent of the atriplicoid type from subfamily Chenopodioideae. From eight other species of Chenopodiaceae ä13 C values are given for the first time. 相似文献
9.
The antiquity of the use of seaweed to feed domestic animals was investigated through carbon ( δ 13 C) and oxygen ( δ 18 O) isotope analysis of tooth enamel bioapatite. The analysis was performed on sheep and cattle teeth from two Neolithic sites in Orkney (Scotland). At the Knap of Howar, c . 3600 bc , carbon isotopes reflect grazing on terrestrial plants throughout the year for both sheep and cattle, with no contribution of seaweed to their diet. At the Holm of Papa Westray North (HPWN), c . 3000 bc , significant contribution of seaweed to the sheep diet during winter is indicated by bioapatite δ 13 C values as high as −5.7‰, far outside of the range of values expected for the feeding on terrestrial C3 plants, and δ 18 O values higher than expected during winter, possibly caused by ingestion of oceanic water with seaweed. Ingestion of seaweed by sheep at HPWN might have been necessitated by severe reduction of pastures during winter. Results suggest that sheep ingested fresh seaweed rather than dry fodder, perhaps directly on the shore as sheep do nowadays on North Ronaldsay. A significant difference between the two populations is the exclusive reliance on seaweed by the North Ronaldsay sheep, which have developed physiological adaptations to this diet. Contribution of seaweed to the sheep winter diet at HPWN might have been a first step towards this adaptation. 相似文献
10.
A. KOHZU T. YOSHIOKA T. ANDO M. TAKAHASHI K. KOBA & E. WADA 《The New phytologist》1999,144(2):323-330
The natural abundance of 13 C and 15 N was measured in basidiocarps of at least 115 species in 88 genera of ectomycorrhizal, wood-decomposing and litter-decomposing fungi from Japan and Malaysia. The natural abundance of 13 C and 15 N was also measured in leaves, litter, soil and wood from three different sites. 15 N and 13 C were enriched in ectomycorrhizal and wood-decomposing fungi, respectively, relative to their substrates. Ectomycorrhizal and wood-decomposing fungi could be distinguished on the basis of their δ13 C and δ15 N signatures. Although there was high variability in the isotopic composition of fungi, the following isotope- enrichment factors (ε, mean±SD) of the fungi relative to substrates were observed:
εectomycorrhizal fungi/litter = 6.1±0.4‰15 N
εectomycorrhizal fungi/wood = 1.4±0.8‰13 C
εwood-decomposing fungi/wood = −0.6±0.7‰15 N
εwood-decomposing fungi/wood = 3.5±0.9‰13 C
The basis of isotope fractionation in C metabolism from wood to wood-decomposing fungus is discussed. 相似文献
ε
ε
ε
ε
The basis of isotope fractionation in C metabolism from wood to wood-decomposing fungus is discussed. 相似文献
11.
Abstract. Changes in crassulacean acid metabolism (CAM) in the leaves of Bryophyllum daigremontianum were studied comparatively under closely controlled (phytotron) and semi-natural (greenhouse) conditions utilizing measurements of natural carbon isotope composition (δ13 C) of the total leaf matter. Abrupt transfer of plants from long days to short days resulted in an overall increase of CAM in mature leaves (no. 3 from the apex and older) and thus in a higher CAM level for the whole plant. Study during the course of a year in semi-natural conditions showed that a progressive increase in length of day and day night temperature differences (February ← June) activated CAM but only a passage to short days (June ← October) produced the maximum CAM. Under the experimental conditions employed, the maximum shift from the C3 -type to the C4 -type of metabolism was observed in plants subjected to semi-natural progressive variations in the environment, i.e. the δ13 C values indicated that for plants in the greenhouse the total carbon flow entering the cells was mediated by phosphoenolpyruvate carboxylase activity. 相似文献
12.
Abstract: Over 60 Salsola species of Chenopodiaceae from South Africa were studied for their photosynthesis type, using δ13 C analysis and light microscopy of leaf anatomy. These species cover about 70 % of the total list of Southern African Salsola species and grow naturally in South and Southwest African desert regions. All species are shrubby forms and belong to the single subsection Caroxylon. Only C4 photosynthesis was found in the Salsola species determined with 13 C/12 C carbon isotope discrimination values that ranged from - 11.04 to - 14.03 % (PDB), plus the presence of a Kranz type assimilation tissue anatomy. The apparent absence of C3 in Salsola in South and Southwest Africa and the known presence of C3 and C3 - C4 intermediate photosynthesis in Caroxylon, Salsola species in Asia strongly indicate that the genus Salsola originated in Asia and later migrated to South Africa. 相似文献
13.
Correlations Between Foliar Stable Carbon Isotope Composition and Environmental Factors in Desert Plant Reaumuria soongorica (Pall.) Maxim. 总被引:2,自引:0,他引:2
Jian-Ying MA Tuo CHEN Wei-Ya QIANG Gang WANG 《植物学报(英文版)》2005,47(9):1065-1073
Leaves of 407 individuals of Reaumuria soongorica (Pall.) Maxim. collected from the major distribution areas were measured to investigate the distribution characteristics of the stable carbon isotope in this desert plant, as well as correlations between δ^13C values and environmental factors. Results showed that δ^13C values in R. soongorica ranged from -22.77‰ to -29.85‰ and that the mean δ^13C value (-26.52‰) was higher than a previously reported δ^13C value for a different desert ecosystem. This indicates that R. soongorica belongs to the C3 photosynthetic pathway and has higher water use efficiency than other species. The correlations between δ^13C values and environmental factors demonstrated that the foliar δ^13C values in R. soongorica increased significantly with decreasing mean annual precipitation and mean relative humidity, and decreased with decreasing duration of sunshine and evaporation. The spatial distribution trend of δ^13C values in R. soongorica was not obvious and there was no significant correlation between the δ^13C values and mean annual temperature. We conclude that different distribution trends in δ^13C values for R. soongorica were likely caused by stomatal limitation rather than by nutrient-related changes in photosynthetic efficiency and that precipitation played an important role in the wide distribution range of R. soongorica. This pattern of δ^13C values for R. soongorica reinforced that it is a super-xerophil in terms of its adaptive strategies to a desert environment. 相似文献
14.
The diet of African hippopotamids can be documented through δ 13 C analyses of enamel and other tissues. Analysis of a 10-million-year sequence of hippopotamids in and near the Lake Turkana Basin of northern Kenya shows that hippos have included a substantial fraction of C3 vegetation in their diets since the late Miocene when C4 vegetation first appears in hippo diet as a measurable fraction. The C4 component of vegetation becomes dominant (>50%) by Upper Burgi time ( c . 2 million years ago) but does not reach 100% for all individuals. It is therefore not unexpected that the δ 13 C values of modern hippopotamids show a higher fraction of dietary C3 biomass than has been estimated from traditional observations. Analysis of δ 18 O of hippos from different stratigraphic levels shows no systematic trend over time; the average value for fossil hippos over the last 10 million years is similar to that of modern hippos from the Omo River system. 相似文献
15.
Christopher H. House Victoria J. Orphan Kendra A. Turk Burt Thomas Annelie Pernthaler Jennifer M. Vrentas Samantha B. Joye 《Environmental microbiology》2009,11(9):2207-2215
To assess and study the heterogeneity of δ13 C values for seep microorganisms of the Eel River Basin, we studied two principally different sample sets: sediments from push cores and artificial surfaces colonized over a 14 month in situ incubation. In a single sediment core, the δ13 C compositions of methane seep-associated microorganisms were measured and the relative activity of several metabolisms was determined using radiotracers. We observed a large range of archaeal δ13 C values (> 50‰) in this microbial community. The δ13 C of ANME-1 rods ranged from −24‰ to −87‰. The δ13 C of ANME-2 sarcina ranged from −18‰ to −75‰. Initial measurements of shell aggregates were as heavy as −19.5‰ with none observed to be lighter than −57‰. Subsequent measurements on shell aggregates trended lighter reaching values as 13 C-depleted as −73‰. The observed isotopic trends found for mixed aggregates were similar to those found for shell aggregates in that the initial measurements were often enriched and the subsequent analyses were more 13 C-depleted (with values as light as −56‰). The isotopic heterogeneity and trends observed within taxonomic groups suggest that ANME-1 and ANME-2 sarcina are capable of both methanogenesis and methanotrophy. In situ microbial growth was investigated by incubating a series of slides and silicon (Si) wafers for 14 months in seep sediment. The experiment showed ubiquitous growth of bacterial filaments (mean δ13 C = −38 ± 3‰), suggesting that this bacterial morphotype was capable of rapid colonization and growth. 相似文献
16.
Using stable isotopes to determine soil carbon input differences under ambient and elevated atmospheric CO2 conditions 总被引:1,自引:0,他引:1
JENNIFER NITSCHELM REAS LÜSCHER UELI HARTWIG & CHRIS VAN KESSEL 《Global Change Biology》1997,3(5):411-416
Quantitative estimates of soil C input under ambient (35 Pa) and elevated (60 Pa) CO2 -partial pressure (pCO2 ) were determined in a Free-Air Carbon dioxide Enrichment (FACE) experiment. To facilitate 13 C-tracing, Trifolium repens L. was grown in a soil with an initial δ13 C distinct by at least 5‰ from the δ13 C of T. repens grown under ambient or elevated pCO2 . A shift in δ13 C of the soil organic C was detected after one growing season. Calculated new soil C inputs in soil under ambient and elevated pCO2 were 2 and 3 t ha–1 , respectively. Our findings suggest that under elevated CO2 conditions, soil C sequestration may be altered by changes in plant biomass production and quality. 相似文献
17.
Elevated pyruvate,orthophosphate dikinase (PPDK) activity alters carbon metabolism in C3 transgenic potatoes with a C4 maize PPDK gene 总被引:1,自引:0,他引:1
Ken Ishimaru Yasunobu Ohkawa Teruo Ishige Dennis J. Tobias Ryu Ohsugi 《Physiologia plantarum》1998,103(3):340-346
Changes in carbon metabolism and δ13 C value of transgenic potato plants with a maize pyruvate,orthophosphate dikinase (PPDK; EC 2.7.9.1) gene are reported. PPDK catalyzes the formation of phospho enol pyruvate (PEP), the initial acceptor of CO2 in the C4 photosynthetic pathway. PPDK activities in the leases of transgenic potatoes were up to 5.4‐fold higher than those of control potato plants (wild‐type and treated control plants). In the transgenic potato plants, PPDK activity in leaves was negatively correlated with pyruvate content (r2 = 0.81), and was positively correlated with malate content (r2 = 0.88). A significant increase in the δ13 C value was observed in the transgenic potato plants, suggesting a certain contribution of PEP carboxylase as the initial acceptor of atmospheric CO2 . These data suggest that elevated PPDK activity may alter carbon metabolism and lead to a partial operation of C4 ‐type carbon metabolism. However, since parameters associated with CO2 gas exchange were not affected, the altered carbon metabolism had only a small effect on the total photosynthetic characteristics of the transgenic plants. 相似文献
18.
Andrew P. Vovides John R. Etherington P. Quentin Dresser rew Groenhof Carlos Iglesias Jonathan Flores Ramirez 《Botanical journal of the Linnean Society. Linnean Society of London》2002,138(2):155-162
The cycad Dioon edule Lindl. inhabits a seasonally-dry tropical forest along with associated CAM plants such as bromeliads and cacti. To test the hypothesis that D . edule might also be a CAM plant, diel total-acid fluctuation was measured through the dry to wet seasons of 4 consecutive years on adult D . edule plants in their natural forest habitat in Veracruz, Mexico. Correlations between acid fluctuation index and climatic data, and also soil water potential were determined over this period. Laboratory trials were followed up to estimate diel patterns of CO2 exchange and estimation of δ13 C value. A comparison of stomatal density cm−2 with other C3 , CAM and CAM-facultative plants was made. The diel total titratable-acid fluctuation values, although variable, were found to be consistent and significant for the dry season. Carbon dioxide exchange was found to be typical of C3 plants when hydrated but when the plant was stressed by withholding water, although the leaf remained healthy, there was no significant dark-period CO2 output. Stomatal density was comparable to other CAM and CAM-facultative plants. It was concluded that D. edule is a C3 plant that shows CAM-cycling metabolism when water stressed. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 155–161. 相似文献
19.
Tracing carbon and oxygen isotope signals from newly assimilated sugars in the leaves to the tree-ring archive 总被引:1,自引:0,他引:1
ARTHUR GESSLER ELKE BRANDES NINA BUCHMANN GERHARD HELLE HEINZ RENNENBERG & ROMAIN L. BARNARD 《Plant, cell & environment》2009,32(7):780-795
The analysis of δ 13 C and δ 18 O in tree-ring archives offers retrospective insights into environmental conditions and ecophysiological processes. While photosynthetic carbon isotope discrimination and evaporative oxygen isotope enrichment are well understood, we lack information on how the isotope signal is altered by downstream metabolic processes.
In Pinus sylvestris , we traced the isotopic signals from their origin in the leaf water ( δ18 O) or the newly assimilated carbon ( δ 13 C), via phloem sugars to the tree-ring, over a time-scale that ranges from hours to a growing season.
Seasonally, variable13 C enrichment of sugars related to phloem loading and transport did lead to uncoupling between δ 13 C in the tree-ring, and the c i / c a ratio at the leaf level. In contrast, the oxygen isotope signal was transferred from the leaf water to the tree-ring with an expected enrichment of 27‰, with time-lags of approximately 2 weeks and with a 40% exchange between organic oxygen and xylem water oxygen during cellulose synthesis.
This integrated overview of the fate of carbon and oxygen isotope signals within the model tree species P. sylvestris provides a novel physiological basis for the interpretation of δ13 C and δ 18 O in tree-ring ecology. 相似文献
In Pinus sylvestris , we traced the isotopic signals from their origin in the leaf water ( δ
Seasonally, variable
This integrated overview of the fate of carbon and oxygen isotope signals within the model tree species P. sylvestris provides a novel physiological basis for the interpretation of δ
20.
This study investigated the impact of lipid extraction, CaCO3 removal and of both treatments combined on fish tissue δ13 C, δ15 N and C:N ratio. Furthermore, the suitability of empirical δ13 C lipid normalization and correction models was examined. δ15 N was affected by lipid extraction (increase of up to 1·65‰) and by the combination of both treatments, while acidification alone showed no effect. The observed shift in δ15 N represents a significant bias in trophic level estimates, i.e. lipid-extracted samples are not suitable for δ15 N analysis. C:N and δ13 C were significantly affected by lipid extraction, proportional to initial tissue lipid content. For both variables, rates of change with lipid content (ΔC:N and Δδ13 C) were species specific. All tested lipid normalization and correction models produced biased estimates of fish tissue δ13 C, probably due to a non-representative database and incorrect assumptions and generalizations the models were based on. Improved models need a priori more extensive and detailed studies of the relationships between lipid content, C:N and δ13 C, as well as of the underlying biochemical processes. 相似文献