Natural 13C distribution in oil palm (Elaeis guineensis Jacq.) and consequences for allocation pattern |
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Authors: | Emmanuelle Lamade Guillaume Tcherkez Nuzul Hijri Darlan Rosario Lobato Rodrigues Chantal Fresneau Caroline Mauve Marlène Lamothe‐Sibold Diana Sketriené Jaleh Ghashghaie |
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Institution: | 1. UPR34 Performance of Perennial Cropping Systems, CIRAD‐PERSYST, Montpellier, France;2. Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, Australian Capital Territory, Australia;3. Indonesian Oil Palm Research Institute, IOPRI, Medan, North Sumatra, Indonesia;4. Embrapa Amazonia Ocidental, Manaus, Brazil;5. ESE, Université Paris‐Sud, Orsay cedex, France;6. Plateforme Métabolisme‐Métabolome, Université Paris‐Sud, Orsay cedex, France |
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Abstract: | Oil palm has now become one of the most important crops, palm oil representing nearly 25% of global plant oil consumption. Many studies have thus addressed oil palm ecophysiology and photosynthesis‐based models of carbon allocation have been used. However, there is a lack of experimental data on carbon fixation and redistribution within palm trees, and important C‐sinks have not been fully characterized yet. Here, we carried out extensive measurement of natural 13C‐abundance (δ13C) in oil palm tissues, including fruits at different maturation stages. We find a 13C‐enrichment in heterotrophic organs compared to mature leaves, with roots being the most 13C‐enriched. The δ13C in fruits decreased during maturation, reflecting the accumulation in 13C‐depleted lipids. We further used observed δ13C values to compute plausible carbon fluxes using a steady‐state model of 13C‐distribution including metabolic isotope effects (12v/13v). The results suggest that fruits represent a major respiratory loss (≈39% of total tree respiration) and that sink organs such as fruits are fed by sucrose from leaves. That is, glucose appears to be a quantitatively important compound in palm tissues, but computations indicate that it is involved in dynamic starch metabolism rather that C‐exchange between organs. |
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Keywords: | carbon allocation isotope composition oleosynthesis cost respiratory losses 13C/12C fractionation |
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