13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee

Plants experience physiological and metabolic changes in response to water deficit during critical stages, such as fruiting. In coffee, the allocation of fresh assimilates and interplay between leaf orientation, leaf age, and carbon changes are unknown. Understanding these strategies would reveal ho...

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Main Authors: Janice Nakamya, Jonas Van Laere, Roel Merckx, Rebecca Hood-Nowtny, Gerd Dercon
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Plant Science
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Online Access:https://www.frontiersin.org/articles/10.3389/fpls.2025.1618182/full
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author Janice Nakamya
Janice Nakamya
Jonas Van Laere
Roel Merckx
Rebecca Hood-Nowtny
Gerd Dercon
author_facet Janice Nakamya
Janice Nakamya
Jonas Van Laere
Roel Merckx
Rebecca Hood-Nowtny
Gerd Dercon
author_sort Janice Nakamya
collection DOAJ
description Plants experience physiological and metabolic changes in response to water deficit during critical stages, such as fruiting. In coffee, the allocation of fresh assimilates and interplay between leaf orientation, leaf age, and carbon changes are unknown. Understanding these strategies would reveal how coffee plants enhance their survival and productivity under water scarcity. Four-year-old Venecia Arabica coffee clones under water stress were pulse labelled with 13C-CO2 in a greenhouse. Three hours after labelling, leaf punches from young and old leaf pairs were collected at 10, 11, 12, and 13 days of water deficit (50% pot capacity/PC). These were analysed to assess 13C enrichment in relation to carbon assimilation and leaf carbon changes over time. Water deficit significantly decreased carbon assimilation by 20-52% compared to well-watered plants, especially in young leaves (p< 0.05). In addition, old leaves on the sun-exposed side performed better in terms of carbon assimilation than those on the shaded side; however, the orientation effect was not evident under stress. At harvest, approximately 15 days of water deficit, carbon allocation exhibited a marked decline, particularly in young leaves. The plants prioritised the allocation of newly assimilated carbon to roots and shoots, and to a lesser extent, to the fruits to support survival, storage, and production. Notably, carbon redistribution resulted in elevated levels of starch and sugar in fruits (by 33% and 51%, respectively), shoots, and roots, accompanied by a reduction in foliar sugar and cellulose contents in young leaves. These findings highlight the complex survival strategies employed by coffee plants, demonstrating their capacity to optimise resource allocation to storage organs and the potential of old leaves in response to drought. The results offer valuable guidance for coffee breeding programs aimed at enhancing the resilience of Coffea arabica to climate-induced water scarcity.
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spelling doaj-art-2a3ece5ba1094eaea76f1d93e8a20f8a2025-08-20T03:34:16ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2025-08-011610.3389/fpls.2025.1618182161818213C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffeeJanice Nakamya0Janice Nakamya1Jonas Van Laere2Roel Merckx3Rebecca Hood-Nowtny4Gerd Dercon5Soil and Water Management & Crop Nutrition Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Seibersdorf, AustriaInstitute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences Vienna, Vienna, AustriaSenckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, GermanyDivision of Soil and Water Management, Faculty of Bioscience Engineering, KU Leuven, BelgiumInstitute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences Vienna, Vienna, AustriaSoil and Water Management & Crop Nutrition Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Seibersdorf, AustriaPlants experience physiological and metabolic changes in response to water deficit during critical stages, such as fruiting. In coffee, the allocation of fresh assimilates and interplay between leaf orientation, leaf age, and carbon changes are unknown. Understanding these strategies would reveal how coffee plants enhance their survival and productivity under water scarcity. Four-year-old Venecia Arabica coffee clones under water stress were pulse labelled with 13C-CO2 in a greenhouse. Three hours after labelling, leaf punches from young and old leaf pairs were collected at 10, 11, 12, and 13 days of water deficit (50% pot capacity/PC). These were analysed to assess 13C enrichment in relation to carbon assimilation and leaf carbon changes over time. Water deficit significantly decreased carbon assimilation by 20-52% compared to well-watered plants, especially in young leaves (p< 0.05). In addition, old leaves on the sun-exposed side performed better in terms of carbon assimilation than those on the shaded side; however, the orientation effect was not evident under stress. At harvest, approximately 15 days of water deficit, carbon allocation exhibited a marked decline, particularly in young leaves. The plants prioritised the allocation of newly assimilated carbon to roots and shoots, and to a lesser extent, to the fruits to support survival, storage, and production. Notably, carbon redistribution resulted in elevated levels of starch and sugar in fruits (by 33% and 51%, respectively), shoots, and roots, accompanied by a reduction in foliar sugar and cellulose contents in young leaves. These findings highlight the complex survival strategies employed by coffee plants, demonstrating their capacity to optimise resource allocation to storage organs and the potential of old leaves in response to drought. The results offer valuable guidance for coffee breeding programs aimed at enhancing the resilience of Coffea arabica to climate-induced water scarcity.https://www.frontiersin.org/articles/10.3389/fpls.2025.1618182/fullcarbon distributiondrought stressassimilation13CexcessCoffea arabica L
spellingShingle Janice Nakamya
Janice Nakamya
Jonas Van Laere
Roel Merckx
Rebecca Hood-Nowtny
Gerd Dercon
13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
Frontiers in Plant Science
carbon distribution
drought stress
assimilation
13Cexcess
Coffea arabica L
title 13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
title_full 13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
title_fullStr 13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
title_full_unstemmed 13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
title_short 13C-CO2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
title_sort 13c co2 pulse labelling evaluation of water deficit on leaf carbon dynamics and whole plant allocation in fruiting coffee
topic carbon distribution
drought stress
assimilation
13Cexcess
Coffea arabica L
url https://www.frontiersin.org/articles/10.3389/fpls.2025.1618182/full
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