Natural 13C distribution in oil palm (Elaeis guineensis Jacq.) and consequences for allocation pattern. (16th October 2015)

• Record Type: Journal Article
• Authors: Lamade, Emmanuelle; Tcherkez, Guillaume; Darlan, Nuzul Hijri; Rodrigues, Rosario Lobato; Fresneau, Chantal; Mauve, Caroline; Lamothe‐Sibold, Marlène; Sketriené, Diana; Ghashghaie, Jaleh
• Is Part Of: Plant, cell and environment. Volume 39:Number 1(2016)
• Page Start: 199
• Page End: 212
• Publication Date: 2015-10-16
• Subjects: carbon allocation -- isotope composition -- oleosynthesis cost -- respiratory losses -- 13C/12C fractionation; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12606
• Languages: English
• ISSNs: 0140-7791

Abstract

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 13 C‐abundance ( δ 13 C) in oil palm tissues, including fruits at different maturation stages. We find a 13 C‐enrichment in heterotrophic organs compared to mature leaves, with roots being the most 13 C‐enriched. The δ 13 C in fruits decreased during maturation, reflecting the accumulation in 13 C‐depleted lipids. We further used observed δ 13 C values to compute plausible carbon fluxes using a steady‐state model of 13 C‐distribution including metabolic isotope effects ( 12 v / 13 v ). 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. Abstract : This paper describes a new model for oil palm carbon fluxes and allocation based on 13 C natural abundance. It is shown that respiratory costs in fruits are larger than that commonly assumed using models based simple biomass distribution. It also suggests that sucrose is the main circulating sugar for fruit filling and leaf development while glucose content and isotope composition mostly reflect starch metabolism.