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Effect of elevated CO 2 on carbon partitioning in young Quercus ilex L. during resprouting
Author(s) -
Aranjuelo Iker,
PintóMarijuan Marta,
Avice Jean Christophe,
Fleck Isabel
Publication year - 2011
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.4715
Subject(s) - chemistry , photosynthesis , shoot , sink (geography) , acclimatization , dry matter , biomass partitioning , carbon sink , botany , organic matter , nitrogen , horticulture , ecology , biology , climate change , biochemistry , cartography , organic chemistry , geography
Stored carbon (C) represents a very important C pool with residence times of years to decades in tree organic matter. With the objective of understanding C assimilation, partitioning and remobilization in 2‐year‐old Quercus ilex L., those trees were exposed for 7 months to different [CO 2 ] (elevated: 700 µmol mol −1 ; and ambient: 350 µmol mol −1 CO 2 ). The 13 C‐isotopic composition of the ambient CO 2 (ca. −12.8‰) was modified (to ca. −19.2‰) under the elevated CO 2 conditions in order to analyze C allocation and partitioning before aerial biomass excision, and during the following regrowth (resprouting). Although after 7 months of growth under elevated [CO 2 ], Q. ilex plants increased dry matter production, the absence of significant differences in photosynthetic activity suggests that such an increase was lower than expected. Nitrogen availability was not involved in photosynthetic acclimation. The removal of aboveground organs did not enable the balance between C availability and C requirements to be achieved. The isotopic characterization revealed that before the cutting, C partitioning to the stem (main C sink) prevented leaf C accumulation. During regrowth the roots were the organ with more of the labelled C. Furthermore, developing leaves had more C sink strength than shoots during this period. After the cutting, the amount of C delivered from the root to the development of aboveground organs exceeded the requirements of leaves, with the consequent carbohydrate accumulation. These findings demonstrate that, despite having a new C sink, the responsiveness of those resprouts under elevated [CO 2 ] conditions will be strongly conditioned by the plant's capacity to use the extra C present in leaves through its allocation to other organs (roots) and processes (respiration). Copyright © 2011 John Wiley & Sons, Ltd.