Exogenous sugar addition can exacerbate root carbon limitation in trees
© 2025 The Author(s). New Phytologist © 2025 New Phytologist Foundation.
| Publié dans: | The New phytologist. - 1979. - (2025) vom: 21. Mai |
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| Auteur principal: | |
| Autres auteurs: | , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2025
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article carbon allocation carbon balance carbon isotopes carbon starvation defoliation exogenous sugar leaf gas exchange leaf senescence |
| Résumé: | © 2025 The Author(s). New Phytologist © 2025 New Phytologist Foundation. In most tree species, roots serve as major carbon (C) sinks, where C is depleted first when C assimilation is limited. Recent methodological advancements in sugar infusion allow for a better understanding of physiological processes alleviating root C limitation. We conducted a glasshouse experiment with maple (Acer pseudoplatanus L.) and pine (Pinus sylvestris L.) saplings that underwent defoliation followed by either slow, fast, or no 13C-labeled glucose infusion. We measured photosynthetic parameters, nonstructural carbohydrate (NSC) concentrations, and δ13C in cellulose of leaves, twigs, and fine roots, as well as the isotopic composition of dark-respired CO2. Sugar infusion induced photosynthetic downregulation and leaf senescence in maple but not in pine. Leaf photosynthesis was negatively correlated with leaf NSC concentration in maple. These responses exacerbated root C limitation in maple. Conversely, pine maintained stable photosynthetic rates and needle NSC concentrations across treatments, showing the potential of sugar infusion to mitigate root C limitation. Our study suggests that exogenous sugar supply reduces the root C availability when it impairs a plant's photosynthetic performance. Species-specific differences influence infused sugar transport and overall source-sink responses. Alleviating C limitation in roots via exogenous sugar addition is feasible only if photosynthesis is not impeded |
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| Description: | Date Revised 22.05.2025 published: Print-Electronic Citation Status Publisher |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.70231 |