Interspecific variation in bulk tissue, fatty acid and monosaccharide delta(13)C values of leaves from a mesotrophic grassland plant community.
The leaves of 37 grass, herb, shrub and tree species were collected from a mesotrophic grassland to assess natural variability in bulk, fatty acid and monosaccharide delta(13)C values of leaves from one plant community. The leaf tissue mean bulk delta(13)C value was -29.3 per thousand. No significant differences between tissue bulk delta(13)C values with life form were determined (P=0.40). On average, C(16:0), C(18:2) and C(18:3) constituted 89% of leaf tissue total fatty acids, whose delta(13)C values were depleted compared to whole leaf tissues. A general interspecific (between different species) trend for fatty acids delta(13)C values was observed, i.e. delta(13)C(16:0)<delta(13)C(18:2)<delta(13)C(18:3), although these values ranged widely between species, e.g. C(16:0) (-34.7 per thousand, Alisma plantago-aquatica; -44.0 per thousand, Leucanthemum vulgare), C(18:2) (-33.3 per thousand, Acer campestre; -44.2 per thousand, L. vulgare;) and C(18:3) (-34.3 per thousand, Bellis perennis; -41.8 per thousand, Plantago lanceolata). Average relative abundances of leaf monosaccharides arabinose, xylose, mannose, galactose and glucose were 12%, 13%, 5%, 12% and 54%, respectively. Mean delta(13)C values of these monosaccharides were -26.6 per thousand (arabinose), -27.2 per thousand (xylose), -30.9 per thousand (mannose), -30.0 per thousand (galactose) and -29.0 per thousand (glucose). The general relationship between individual monosaccharide delta(13)C values, delta(13)C(arabinose)>delta(13)C(xylose)>delta(13)C(glucose)>delta(13)C(galactose), was consistently observed. Therefore, we have shown (i) diversity in compound-specific delta(13)C values contributing to leaf bulk delta(13)C values; (ii) interspecific variability between bulk and compound-specific delta(13)C values of leaves of individual grassland species, and (iii) trends between individual fatty acid and monosaccharide delta(13)C values common to leaves of all species within one plant community.
Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry, Cantocks Close, Bristol, UK.
Jennifer A J
JA
Dungait
Gordon
G
Docherty
Vanessa
V
Straker
Richard P
RP
Evershed
D002247:Carbon Isotopes; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D009005:Monosaccharides / Q000737:chemistry* / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D006109:Poaceae / Q000737:chemistry* / Q000378:metabolism*
D002247:Carbon Isotopes; D005227:Fatty Acids; D009005:Monosaccharides