Variation in root-zone CO2 concentration modifies isotopic fractionation of carbon and nitrogen in tomato seedlings
• The contribution to the carbon budget and growth by root acquisition of inorganic carbon and the influence that this has on NO 3 - and NH 4 + uptake and assimilation has not been adequately quantified. • The influence of varying root-zone CO 2 concentrations on tissue δ 13 C and δ 15 N was used...
| Publié dans: | The New phytologist. - 1979. - 157(2003), 1 vom: 25. Jan., Seite 45-54 |
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| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2003
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Lycopersicon esculentum (tomato) anaplerotic discrimination isotope phosphoenolpyruvate carboxylase δ13C δ15N |
| Résumé: | • The contribution to the carbon budget and growth by root acquisition of inorganic carbon and the influence that this has on NO 3 - and NH 4 + uptake and assimilation has not been adequately quantified. • The influence of varying root-zone CO 2 concentrations on tissue δ 13 C and δ 15 N was used to estimate the contribution to the carbon budget of root-assimilated carbon in tomato ( Lycopersicon esculentum ) seedlings. • Biomass accumulation was greater at 0.5% and 1% (v/v) root-zone CO 2 in NO 3 - and NH 4 + -fed plants than with 0% root-zone CO 2 . The plant δ 13 C values were not altered by 1% CO 2 with δ 13 C = -29.00‰, but they were increased when supplied with 1% CO 2 with δ 13 C = -10.91‰. The δ 15 N values of NO 3 - -fed plants were unchanged by variation in root-zone CO 2 concentration. In NH 4 + -fed plants the δ 15 N values were c. 1.5‰ higher at 1% CO 2 . • Changes in δ 13 C values with increased CO 2 concentration (δ 13 C = -10.91‰) were ascribed to root incorporation of CO 2 . Less than 5% of carbon was derived from root dark fixation and thus cannot explain increases in growth on a mass basis. Reduced discrimination with NH 4 + nutrition at 1% CO 2 could be related to increased exudation of NH 4 + and organic nitrogen and also reduced uptake |
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| Description: | Date Revised 20.04.2021 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1046/j.1469-8137.2003.00650.x |