The effect of drought on C and N stable isotopes in different fractions of leaves, stems and roots of sensitive and tolerant beech ecotypes

Abstract

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 δ δ 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 δ δ 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 δ δ δ 13 C also tended to be increased by drought, but this effect was not statistically significant. For both δ δ δ δ 13 C and δ δ δ δ 15 N, enrichment was observed from the site of uptake/ source to the site of use/sink. A gradient for δ δ δ

Age-related nutrient content and carbon isotope composition in the leaves and branches of Quercus aquifolioides along an altitudinal gradient

“…We also observed that there is a consistent trend of more negative d 13 C values in leaves when compared to branches. Similar patterns have been observed in a range of other studies (Terwilliger et al 2001;Scartazza et al 2004;Brandes et al 2006;Peuke et al 2006). On one hand, this may be a result of a higher lipid content in the membrane-rich chloroplasts, as it has been reported that lipids are depleted in 13 C compared with organic matter, acids, sugars and respired CO 2 (Hobbie and Werner 2004).…”

Nutritional quality and yield of onion as affected by different application methods and doses of humic substances

“…In agreement with those findings, the fact that plants fertilized with HS were less depleted in 13 C, highlighted that those plants had lower transpiration rates. δ 13 C has been frequently described as an integrator of stomatal opening, transpiration and photosynthetic performance of several crops (Araus et al, 2003;Peuke et al, 2006;Yousfi et al, 2010Yousfi et al, , 2012. In agreement with those studies, the fact that plants fertilized with HS showed fewer reductions in 13 C at final harvest reveals that stomatal opening in those plants was lower, with the consequent diminishment in transpiration and photosynthetic rates.…”

Water use of winter cereals under well-watered and drought-stressed conditions

“…water deficit resulted in higher WUE values (Peuke et al 2006). The present results, however, show that this correlation cannot be demonstrated when drought occurs during the later phases of development.…”