Ultrastructure and chemistry of Clarkia elegans leaf wax: A comparative study with brassica leaf waxes

1976 ◽  
Vol 6 (6) ◽  
pp. 353-360 ◽  
Author(s):  
Grace M. Hunt ◽  
P.J. Holloway ◽  
E.A. Baker
Keyword(s):  
Comparative Study ◽  
Leaf Wax ◽  
Leaf Waxes

Comparative study on epicuticular leaf waxes of Araucaria araucana, Agathis robusta and Wollemia nobilis (Araucariaceae)

2008 ◽  
Vol 56 (8) ◽  
pp. 644 ◽  
Author(s):  
Simona Dragota ◽  
Markus Riederer
Keyword(s):  
Chemical Composition ◽  
Comparative Study ◽  
Chemical Compositions ◽  
Cuticular Waxes ◽  
Leaf Waxes ◽  
Leaf Surfaces ◽  
Epicuticular Wax Crystals ◽  
Araucaria Araucana ◽  
Main Components ◽  
Wax Crystals

The present study describes fine structure and chemical composition of the epicuticular leaf waxes of three Araucariaceae species. The leaf surfaces of samples from greenhouse-grown juvenile trees of Araucaria araucana K.Koch and Agathis robusta F.Muell. were investigated by scanning electron microscopy (SEM) and compared with data for a young greenhouse-grown Wollemia nobilis W.G.Jones, K.D.Hill & J.M.Allen cutting characterised earlier. The chemical compositions of the epicuticular waxes selectively removed from the adaxial and abaxial leaf surfaces of A. araucana, A. robusta and W. nobilis were studied by gas chromatography combined with mass spectroscopy (GC–MS). The main components of the leaf cuticular waxes of A. araucana, A. robusta and W. nobilis are members of the following three major compound classes: n-alkanes, secondary alcohols and alkane diols. It was shown earlier that the latter two classes contribute to the formation of the tubular epicuticular-wax crystals on the leaf surfaces. The present comparative study also revealed differences in the crystalline microstructure and chemical composition of the epicuticular leaf waxes among the three species.

scholarly journals Leaf waxes in litter and topsoils along a European transect

2016 ◽  
Author(s):  
Imke Schäfer ◽  
Verena Lanny ◽  
Jörg Franke ◽  
Timothy I. Eglinton ◽  
Michael Zech ◽  
...  
Keyword(s):  
Chain Length ◽  
Deciduous Forest ◽  
Soil Depth ◽  
Large Species ◽  
Alkanoic Acid ◽  
Climate Conditions ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Forest Sites ◽  
Alkanoic Acids

Abstract. Lipid biomarkers are increasingly used to reconstruct past environmental and climate conditions. Leaf wax derived long chain n-alkanes and n-alkanoic acids may have great potential for reconstructing past changes in vegetation, but the factors that affect the leaf wax distribution in fresh plant material, as well as in soils and sediments are not yet fully understood and need further research. We systematically investigated the influence of vegetation and soil depth on leaf waxes in litter and topsoils along a European transect. Our deciduous forest sites are often dominated by the n-C27 alkane and n-C28 alkanoic acid. Conifers produce few n-alkanes, but show high abundances of the C24 n-alkanoic acid. Grasslands are characterized by relatively high amounts of C31 and C33 n-alkanes and C32 and C34 n-alkanoic acids. Chain length ratios thus may allow to distinguish between different vegetation types, but caution must be exercised given the large species-specific variability of chain length patterns. An updated endmember model with a new n-alkane ratio is provided to illustrate, and tentatively account for, degradation effects on n-alkanes.

scholarly journals Heritability of the structures and 13C fractionation in tomato leaf wax alkanes: a genetic model system to inform paleoenvironmental reconstructions

2017 ◽  
Author(s):  
Amanda L.D. Bender ◽  
Daniel H. Chitwood ◽  
Alexander S. Bradley
Keyword(s):  
Plant Communities ◽  
Genetic Model ◽  
Average Chain Length ◽  
Implicit Assumption ◽  
Tomato Cultivar ◽  
Environmental Variance ◽  
Leaf Wax ◽  
Tomato Species ◽  
Leaf Waxes ◽  
Paleoclimate Proxy

AbstractLeaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of the n-alkane paleoclimate proxy is modulated by the extent to which genetic as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2 H of waxes though rainwater and the δ13C of leaf waxes by changing plant communities (i.e., C3 versus C4 input). Here we test the assumption of little genetic control over 5 C variation of leaf wax by presenting the results of an experimental greenhouse growth study in which we estimate the role of genetic variability on structural and isotopic leaf wax traits in a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. We found that the leaves of S. pennellii, a wild desert tomato relative, produces significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions; we introduce a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2–1.4%o over n-alkanes. By modeling our results from the ILs, we report the broad-sense heritability values (H2) of leaf wax traits to describe the degree to which genetic variation contributes to variation of these traits. Individual carbon isotope values of alkanes are of low heritability (H2 = 0.13–0.19), suggesting that δ13C of leaf waxes from this study are strongly influenced by environmental variance, which supports the interpretation that variation in the 5 C of wax compounds recorded in sediments reflects paleohydrological changes. Average chain length (ACL) values of n-alkanes are of intermediate heritability (H2 = 0.30), suggesting that ACL values are strongly influenced by genetic cues.

scholarly journals Leaf waxes in litter and topsoils along a European transect

SOIL ◽  
2016 ◽  
Vol 2 (4) ◽  
pp. 551-564 ◽  
Author(s):  
Imke K. Schäfer ◽  
Verena Lanny ◽  
Jörg Franke ◽  
Timothy I. Eglinton ◽  
Michael Zech ◽  
...  
Keyword(s):  
Chain Length ◽  
Deciduous Forest ◽  
Soil Depth ◽  
Large Species ◽  
Alkanoic Acid ◽  
Climate Conditions ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Forest Sites ◽  
Alkanoic Acids

Abstract. Lipid biomarkers are increasingly used to reconstruct past environmental and climate conditions. Leaf-wax-derived long-chain n-alkanes and n-alkanoic acids may have great potential for reconstructing past changes in vegetation, but the factors that affect the leaf wax distribution in fresh plant material, as well as in soils and sediments, are not yet fully understood and need further research. We systematically investigated the influence of vegetation and soil depth on leaf waxes in litter and topsoils along a European transect. The deciduous forest sites are often dominated by the n-C27 alkane and n-C28 alkanoic acid. Conifers produce few n-alkanes but show high abundances of the C24 n-alkanoic acid. Grasslands are characterized by relatively high amounts of C31 and C33 n-alkanes and C32 and C34 n-alkanoic acids. Chain length ratios thus may allow for distinguishing between different vegetation types, but caution must be exercised given the large species-specific variability in chain length patterns. An updated endmember model with the new n-alkane ratio (n-C31 + n-C33) / (n-C27 + n-C31 + n-C33) is provided to illustrate, and tentatively account for, degradation effects on n-alkanes.

scholarly journals Distinguishing between old and modern permafrost sources in the northeast Siberian land–shelf system with compound-specific <i>δ</i><sup>2</sup>H analysis

2017 ◽  
Vol 11 (4) ◽  
pp. 1879-1895 ◽  
Author(s):  
Jorien E. Vonk ◽  
Tommaso Tesi ◽  
Lisa Bröder ◽  
Henry Holmstrand ◽  
Gustaf Hugelius ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Quantitative Measure ◽  
The Arctic ◽  
Near Surface ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Shelf Slope ◽  
Siberian Arctic ◽  
Long Chain ◽  
Ice Complex

Abstract. Pleistocene ice complex permafrost deposits contain roughly a quarter of the organic carbon (OC) stored in permafrost (PF) terrain. When permafrost thaws, its OC is remobilized into the (aquatic) environment where it is available for degradation, transport or burial. Aquatic or coastal environments contain sedimentary reservoirs that can serve as archives of past climatic change. As permafrost thaw is increasing throughout the Arctic, these reservoirs are important locations to assess the fate of remobilized permafrost OC.We here present compound-specific deuterium (δ2H) analysis on leaf waxes as a tool to distinguish between OC released from thawing Pleistocene permafrost (ice complex deposits; ICD) and from thawing Holocene permafrost (from near-surface soils). Bulk geochemistry (%OC; δ13C; %total nitrogen, TN) was analyzed as well as the concentrations and δ2H signatures of long-chain n-alkanes (C21 to C33) and mid- to long-chain n-alkanoic acids (C16 to C30) extracted from both ICD-PF samples (n =  9) and modern vegetation and O-horizon (topsoil-PF) samples (n =  9) from across the northeast Siberian Arctic. Results show that these topsoil-PF samples have higher %OC, higher OC ∕ TN values and more depleted δ13C-OC values than ICD-PF samples, suggesting that these former samples trace a fresher soil and/or vegetation source. Whereas the two investigated sources differ on the bulk geochemical level, they are, however, virtually indistinguishable when using leaf wax concentrations and ratios. However, on the molecular isotope level, leaf wax biomarker δ2H values are statistically different between topsoil PF and ICD PF. For example, the mean δ2H value of C29 n-alkane was −246 ± 13 ‰ (mean ± SD) for topsoil PF and −280 ± 12 ‰ for ICD PF. With a dynamic isotopic range (difference between two sources) of 34 to 50 ‰; the isotopic fingerprints of individual, abundant, biomarker molecules from leaf waxes can thus serve as endmembers to distinguish between these two sources. We tested this molecular δ2H tracer along with another source-distinguishing approach, dual-carbon (δ13C–Δ14C) isotope composition of bulk OC, for a surface sediment transect in the Laptev Sea. Results show that general offshore patterns along the shelf-slope transect are similar, but the source apportionment between the approaches vary, which may highlight the advantages of either. This study indicates that the application of δ2H leaf wax values has potential to serve as a complementary quantitative measure of the source and differential fate of OC thawed out from different permafrost compartments.

scholarly journals Distinguishing between old and modern permafrost sources with compound-specific δ<sup>2</sup>H analysis

2017 ◽  
Author(s):  
Jorien E. Vonk ◽  
Tommaso Tesi ◽  
Lisa Bröder ◽  
Henry Holmstrand ◽  
Gustaf Hugelius ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Quantitative Measure ◽  
The Arctic ◽  
Near Surface ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Shelf Slope ◽  
Alkanoic Acids ◽  
Long Chain ◽  
Ice Complex

Abstract. Pleistocene ice complex permafrost deposits contain roughly a quarter of the organic carbon (OC) stored in permafrost terrain. When permafrost thaws, its OC is remobilized into the (aquatic) environment where it is available for degradation, transport or burial. Aquatic or coastal environments contain sedimentary reservoirs that can serve as archives of past climatic change. As permafrost thaw is increasing throughout the Arctic, these reservoirs are important locations to assess the fate of remobilized permafrost OC. We here present compound-specific deuterium (δ2H) analysis on leaf waxes as a tool to distinguish between OC released from thawing Pleistocene permafrost (Ice Complex Deposits; ICD) and from thawing Holocene permafrost (from near-surface soils). Bulk geochemistry (%OC, δ13C, %total nitrogen; TN) was analyzed as well as the concentrations and δ2H signatures of long-chain n-alkanes (C21 to C33) and mid/long-chain n-alkanoic acids (C16 to C30) extracted from both ICD-PF samples (n = 9) and modern vegetation/O-horizon (Topsoil-PF) samples (n = 9) from across the northeast Siberian Arctic. Results show that these Topsoil-PF samples have higher %OC, higher OC/TN values, and more depleted δ13C-OC values than ICD-PF samples, suggesting that these former samples trace a fresher soil and/or vegetation source. Median concentrations of high-molecular weight n-alkanes (sum of C25-C27-C29-C31) were 210 ± 350 µg/gOC (median ± IQR) for Topsoil-PF and 250 ± 81 µg/gOC for ICD-PF samples. Long-chain n-alkanoic acids (sum of C22-C24-C26-C28) were more abundant than long-chain n-alkanes, both in Topsoil-PF samples (4700 ± 3400 µg/gOC) and in ICD samples (6630 ± 3500 µg/gOC). Whereas the two investigated sources differ on the bulk geochemical level, they are, however, virtually indistinguishable when using leaf wax concentrations and ratios. However, on the molecular-isotope level, leaf wax biomarker δ2H values are statistically different between Topsoil-PF and ICD-PF. The mean δ2H value of C29 n-alkane was −246 ± 13 ‰ (mean ± stdev) for Topsoil-PF and −280 ± 12 ‰ for ICD-PF, whereas the C31 n-alkane was −247 ± 23 ‰ for Topsoil-PF and −297 ± 15 ‰ for ICD-PF. The C28 n-alkanoic acid δ2H value was −220 ± 15 ‰ for Topsoil-PF and −267 ± 16 ‰ for ICD-PF. With a dynamic isotopic range (difference between two sources) of 34 to 50 ‰, the isotopic fingerprints of individual, abundant, biomarker molecules from leaf waxes can thus serve as end-members to distinguish between these two sources. We tested this molecular δ2H tracer along with another source-distinguishing approach, dual-carbon (δ13C-δ14C) isotope composition of bulk OC, for a surface sediment transect in the Laptev Sea. Results show that general offshore patterns along the shelf-slope transect are similar, but the source apportionment between the approaches vary, which may highlight the advantages of either. The δ2H molecular approach has the advantage that it circumvents uncertainties related to a marine end-member, yet the δ13C-δ14C approach has the advantage that it represents the bulk OC fraction thereby avoiding issues related to the molecular-bulk upscaling challenge. This study indicates that the application of δ2H leaf wax values has potential to serve as a complementary quantitative measure of the source and differential fate of OC thawed out from different permafrost compartments.

scholarly journals Late Quaternary climate and environmental reconstruction based on leaf wax analyses in the loess sequence of Möhlin, Switzerland

2017 ◽  
Vol 66 (2) ◽  
pp. 91-100
Author(s):  
Lorenz Wüthrich ◽  
Marcel Bliedtner ◽  
Imke Kathrin Schäfer ◽  
Jana Zech ◽  
Fatemeh Shajari ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Late Quaternary ◽  
Marine Isotope Stage ◽  
Environmental Reconstruction ◽  
Moisture Source ◽  
Leaf Wax ◽  
Mis 3 ◽  
Quaternary Climate ◽  
Leaf Waxes ◽  
Long Chain

Abstract. We present the results of leaf wax analyses (long-chain n-alkanes) from the 6.8 m deep loess sequence of Möhlin, Switzerland, spanning the last  ∼  70 kyr. Leaf waxes are well preserved and occur in sufficient amounts only down to 0.4 m and below 1.8 m depth, so no paleoenvironmental reconstructions can be done for marine isotope stage (MIS) 2. Compound-specific δ2Hwax analyses yielded similar values for late MIS 3 compared to the uppermost samples, indicating that various effects (e.g., more negative values due to lower temperatures, more positive values due to an enriched moisture source) cancel each other out. A pronounced  ∼  30 ‰ shift towards more negative values probably reflects more humid conditions before  ∼  32 ka. Radiocarbon dating of the n-alkanes corroborates the stratigraphic integrity of leaf waxes and their potential for dating loess–paleosol sequences (LPS) back to  ∼  30 ka.

Compositions and isotopic differences of iso- and anteiso-alkanes in black mangroves (Avicennia germinans) across a salinity gradient in a subtropical estuary

2016 ◽  
Vol 13 (4) ◽  
pp. 623 ◽  
Author(s):  
Ding He ◽  
Bernd R. T. Simoneit ◽  
Blanca Jara ◽  
Rudolf Jaffé
Keyword(s):  
Environmental Stress ◽  
Salinity Gradient ◽  
Carbon Number ◽  
Dry Weight ◽  
Avicennia Germinans ◽  
Stress Factors ◽  
Chemical Tracers ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Long Chain

Environmental contextMangroves dominate at the interface between land and sea, especially along tropical and subtropical coasts. To gain a better understanding of how mangroves respond to various environmental stress factors, we investigated the use of monomethylalkanes as potential chemical tracers for black mangroves. The application of these chemical tracers could elucidate how black mangroves respond to environmental stress such as sea level rise in mixed mangrove environments. AbstractA series of iso- and anteiso-monomethylalkanes (MMAs) with carbon numbers from C23 to C35 and C14 to C34 respectively were detected in Avicennia germinans. These compounds were present in varying amounts up to 54.1, 1.0 and 3.4µg g–1 dry weight in the leaves, bark and the crustose lichens attached to the bark of A. germinans respectively. These MMAs were not detected in the leaf waxes of Rhizophora mangle and Laguncularia racemosa, but were detected in significantly lower abundances (2–6% of that in A. germinans leaf wax) in the bark and lichen of R. mangle. Significant odd-carbon number distributions and even-carbon number distributions were observed for long chain (C ≥ 25) iso- (maximising at C31) and anteiso-MMAs (maximising at C32) respectively in A. germinans leaf wax. However, no obvious carbon number preferences were detected for bark and lichen. The long chain (LC) iso- and anteiso-MMAs in A. germinans leaf waxes were found to be enriched in 13C by 0.3–4.3 and 0.7–4.2 per mille (‰) compared to the n-alkanes with the same carbon numbers respectively across the salinity gradient of 19.7–32.0 practical salinity units (psu). In comparison, the LC iso- and anteiso-MMAs were found to be more depleted in D by 6.1–55.1 and 7.3–57.0 ‰ compared to the n-alkanes with same carbon numbers respectively. The results imply that A. germinans could be another important source of iso- and anteiso-alkanes in sediments and soils, and that these compounds could potentially be used as biomarkers for this species in mixed mangrove environments.

Compound-specific radiocarbon ages of soil and sedimentary leaf wax biomarkers in an arid high-altitude environment

2021 ◽  
Author(s):  
Bernhard Aichner ◽  
Janet Rethemeyer ◽  
Merle Gierga ◽  
Alexander Stolz ◽  
Monika Mętrak ◽  
...  
Keyword(s):  
High Altitude ◽  
Sediment Core ◽  
Lacustrine Sediments ◽  
Turnover Time ◽  
Soil Samples ◽  
Transport Dynamics ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Age Model ◽  
High Altitude Lake

&lt;p&gt;Compound-specific radiocarbon analysis (CSRA) of leaf waxes has revealed significant lag times before compounds are deposited in marine and lacustrine sediments. No such data so far exist for a cold and arid high altitude lake system, where carbon turnover and biomarker fluxes to sediments are expected to be relatively low. To elucidate transport dynamics of terrestrial leaf waxes in such an environment (MAT: -4&amp;#176;C, MAP &lt;100mm), we determined CSRA-ages of selected long-chain &lt;em&gt;n&lt;/em&gt;-alkanes in surface soil samples (0-10 cm), collected from alpine meadows in the catchment of Lake Karakul (Pamirs, Tajikistan), and in two sections &amp;#160;of a well dated sediment core from the same lake. We aimed to answer the question if there is a potential bias in the interpretation of biomarker records, in case the leaf wax compounds are significantly older than the sediment age-model suggests.&lt;/p&gt;&lt;p&gt;&lt;em&gt;n&lt;/em&gt;C&lt;sub&gt;29&lt;/sub&gt;- and &lt;em&gt;n&lt;/em&gt;C&lt;sub&gt;31&lt;/sub&gt;-alkanes in the soil samples exhibited variable ages, ranging from 105&amp;#177;79 to 2260&amp;#177;155 cal. yrs BP. In the two sediment core samples, three of the four obtained ages for &lt;em&gt;n&lt;/em&gt;C&lt;sub&gt;29&lt;/sub&gt; and &lt;em&gt;n&lt;/em&gt;C&lt;sub&gt;31&lt;/sub&gt; felt on the very lower ends of the 1&amp;#1005;-uncertainty ranges of modelled ages (based on AMS &lt;sup&gt;14&lt;/sup&gt;C&lt;sub&gt;TOC&lt;/sub&gt; and OSL dating results).&lt;/p&gt;&lt;p&gt;The large span of CSRA-ages of soils gives evidence for heterogeneous decomposition and transport conditions in the lake catchment. We hypothesize that compounds with longest pre-aging contributed in lower proportions to the accumulated lake sediments and further suggest that sedimentary leaf waxes represent compounds with intermediate turnover time in soils, for example originating from alluvial plains close to the shores. Overall, the obtained results give evidence that sedimentary leaf wax compounds in this cold and arid high altitude setting are potentially older than the conventional age-model indicates. On the other hand, these findings need to be interpreted in context of the generally large uncertainty ranges of such age-models, which are further influenced by unknown factors for example changes of reservoir effects.&amp;#160;&lt;/p&gt;

scholarly journals DO RADIOCARBON AGES OF PLANT WAX BIOMARKERS AGREE WITH 14C-TOC/OSL-BASED AGE MODELS IN AN ARID HIGH-ALTITUDE LAKE SYSTEM?

Radiocarbon ◽  
2021 ◽  
pp. 1-16
Author(s):  
Bernhard Aichner ◽  
Merle Gierga ◽  
Alexander Stolz ◽  
Monika Mętrak ◽  
Mateusz Wilk ◽  
...  
Keyword(s):  
High Altitude ◽  
Sediment Core ◽  
Turnover Time ◽  
Lake System ◽  
Leaf Wax ◽  
Leaf Waxes ◽  
Age Model ◽  
High Altitude Lake ◽  
Age Range ◽  
Plant Wax

ABSTRACT To elucidate the dynamics of terrestrial leaf waxes in a high-altitude lake system, we performed compound-specific radiocarbon analysis (CSRA) of long-chain n-alkanes in two sediment core sections from Lake Karakul (Pamirs, Tajikistan) and in surface soil samples from the catchment area. We aimed to answer the question whether the n-alkanes are delivered into the lake sediment with substantial delay due to storage in soils, which may cause a potential bias when used as paleoenvironmental proxies. In the surface soils, the CSRA results reveal an age range of n-alkanes from modern to 2278 ± 155 cal BP. In the two sediment core samples, three of the four n-alkane ages fell on the lower ends of the 1σ-uncertainty ranges of modeled ages of the sediments (based on AMS 14C-TOC and OSL dating results). We conclude that sedimentary leaf waxes represent compounds with intermediate turnover time in soils, for example originating from alluvial plains close to the shores. Overall, the results provide evidence that sedimentary leaf wax compounds in this cold and arid setting are potentially older than the conventional age model indicates, but these findings need to be interpreted in context of the generally large uncertainty ranges of such age models.

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