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The effect of drought on C and N stable isotopes in different fractions of leaves, stems and roots of sensitive and tolerant beech ecotypes
Author(s) -
PEUKE A. D.,
GESSLER A.,
RENNENBERG H.
Publication year - 2006
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2005.01452.x
Subject(s) - beech , delta , starch , ecotype , chemistry , botany , δ13c , horticulture , aqueous solution , stable isotope ratio , biology , food science , physics , quantum mechanics , engineering , aerospace engineering
Beech seedlings from 11 German climatic provenances were exposed to a realistically timed drought treatment in a greenhouse experiment. The stable isotope composition of carbon (C) and nitrogen (N) was analysed in pooled bulk material of roots, stems and leaves, as well as in the aqueous extracts and starch fractions. The δ 13 C values increased in bulk samples (BS) of roots, stems and leaves by drought, although no leaf growth occurred during the experimental period. A clear drought effect on δ 13 C in aqueous extracts was detected in leaves. In aqueous extracts of stems and roots as well as in starch fractions of all organs, abundance of δ 13 C also tended to be increased by drought, but this effect was not statistically significant. For both δ 13 C and δ 15 N, enrichment was observed from the site of uptake/source to the site of use/sink. A gradient for δ 13 C in all fractions from leaves (−29.49, −28.89 and −27.85‰) to stems (−28.81, −27.48 and −26.98‰) and to roots (−27.60, −26.37 and −26.48‰) was detected in BS, aqueous extracts and starch, respectively. An opposite gradient for δ 15 N was found in BS: 1.59‰, 1.84‰ and 3.05‰ in roots, stems and leaves, respectively. δ 15 N was neither affected by drought in the BS nor in aqueous extracts, but an effect of provenance was observed. Particularly in roots and stems, drought‐sensitive provenances showed the strongest shifts in δ 13 C induced by drought and the lowest δ 15 N values. In the present experiment, δ 13 C values were more affected by the environmental factor drought, while δ 15 N values were more affected by the genetic factor provenance.