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Compound-specific δ15N composition of free amino acids in moss as indicators of atmospheric nitrogen sources.
- Source :
- Scientific Reports; 9/25/2018, Vol. 8 Issue 1, p1-1, 1p
- Publication Year :
- 2018
-
Abstract
- Haplocladium microphyllum moss samples were collected in Nanchang, China. Free amino acid (FAA) concentrations and N isotope compositions (δ<superscript>15</superscript>N<subscript>FAA</subscript>) in the samples were determined and compared with the bulk N concentrations and δ<superscript>15</superscript>N<subscript>bulk</subscript> values. The aim was to determine whether δ<superscript>15</superscript>N<subscript>FAA</subscript> values in moss (which are very variable) indicate the sources of atmospheric N. The δ<superscript>15</superscript>N<subscript>FAA</subscript> values among individual FAA varied widely (from −19.3‰ to +16.1‰), possibly because of the different sources of N and isotope fractionation in amino acids metabolic pathways. Total <superscript>15</superscript>N-enrichment for the individual FAAs was equal to total <superscript>15</superscript>N-depletion relative to δ<superscript>15</superscript>N<subscript>bulk</subscript>. The concentration-weighted mean δ<superscript>15</superscript>N value for total FAAs (TFAA) (δ<superscript>15</superscript>N<subscript>TFAA</subscript>) was −3.1‰ ± 3.2‰, which was similar to δ<superscript>15</superscript>N<subscript>bulk</subscript> (−4.0‰ ± 2.9‰). We concluded that a N isotope balance occurred during amino acid metabolism and that little isotope disparity occurred between the concentration-weighted TFAA and bulk N. We concluded that δ<superscript>15</superscript>N<subscript>TFAA</subscript> ≈ δ<superscript>15</superscript>N<subscript>bulk</subscript> ≈ δ<superscript>15</superscript>N<subscript>source</subscript>. The mean δ<superscript>15</superscript>N<subscript>alanine</subscript> (−4.1‰), δ<superscript>15</superscript>N<subscript>glutamate</subscript> (−4.2‰), and δ<superscript>15</superscript>N<subscript>lysine</subscript> (−4.0‰) were similar to the mean δ<superscript>15</superscript>N<subscript>bulk</subscript>, which we attributed to little isotope fractionation occurring during their in situ the metabolic pathways. This suggests that δ<superscript>15</superscript>N<subscript>alanine</subscript>, δ<superscript>15</superscript>N<subscript>glutamate</subscript>, and δ<superscript>15</superscript>N<subscript>lysine</subscript> in moss can be used to indicate the sources of atmospheric N deposition. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20452322
- Volume :
- 8
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Scientific Reports
- Publication Type :
- Academic Journal
- Accession number :
- 131975856
- Full Text :
- https://doi.org/10.1038/s41598-018-32531-x