Quantification of carbon (C) fluxes in mycorrhizal plants is one of the important yet little explored tasks of mycorrhizal physiology and ecology. 13CO2 pulse-chase labelling experiments are increasingly being used to track the fate of C in these plant-microbial symbioses. Nevertheless, continuous monitoring of both the below- and aboveground CO2 emissions remains a challenge, although it is necessary to establish the full C budget of mycorrhizal plants. Here, a novel CO2 collection system is presented which allows assessment of gaseous CO2 emissions (including isotopic composition of their C) from both belowground and shoot compartments. This system then is used to quantify the allocation of recently fixed C in mycorrhizal versus nonmycorrhizal Medicago truncatula plants with comparable biomass and mineral nutrition. Using this system, we confirmed substantially greater belowground C drain in mycorrhizal versus nonmycorrhizal plants, with the belowground CO2 emissions showing large variation because of fluctuating environmental conditions in the glasshouse. Based on the assembled 13C budget, the C allocation to the mycorrhizal fungus was between 2.3% (increased 13C allocation to mycorrhizal substrate) and 2.9% (reduction of 13C allocation to mycorrhizal shoots) of the plant gross photosynthetic production. Although the C allocation to shoot respiration (measured during one night only) did not differ between the mycorrhizal and nonmycorrhizal plants under our experimental conditions, it presented a substantial part (∼10%) of the plant C budget, comparable to the amount of CO2 released belowground. These results advocate quantification of both above- and belowground CO2 emissions in future studies.

Faculty of Science Department of Botany Charles University Prague Benátská 2 128 01 Prague 2 Czech Republic

Institute of Botany Academy of Sciences of the Czech Republic Zámek 1 252 43 Průhonice Czech Republic

Laboratory of Fungal Biology Institute of Microbiology Academy of Sciences of the Czech Republic Vídeňská 1083 14220 Prague 4 Czech Republic

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New Phytol. 2006;172(3):544-53 PubMed

FEMS Microbiol Ecol. 2010 Apr;72(1):125-31 PubMed

Front Plant Sci. 2015 Feb 13;6:65 PubMed

New Phytol. 2009;182(1):188-99 PubMed

Mycorrhiza. 2011 Nov;21(8):689-702 PubMed

Tree Physiol. 1996 Nov-Dec;16(11_12):1023-1029 PubMed

Plant Physiol. 1993 Mar;101(3):1063-1071 PubMed

Glob Chang Biol. 2013 Feb;19(2):621-36 PubMed

Trends Plant Sci. 2008 Nov;13(11):583-8 PubMed

Appl Microbiol Biotechnol. 2013 May;97(10):4639-49 PubMed

Mycorrhiza. 2007 May;17(3):223-34 PubMed

Trends Ecol Evol. 1995 Oct;10(10):407-11 PubMed

Ecol Lett. 2008 Mar;11(3):296-310 PubMed

New Phytol. 2014 Jul;203(2):646-56 PubMed

Front Plant Sci. 2016 Jun 06;7:782 PubMed

FEMS Microbiol Ecol. 2003 Jul 1;45(2):181-7 PubMed

Science. 1981 Jul 24;213(4506):473-4 PubMed

Plant Physiol. 1999 Jun;120(2):587-98 PubMed

New Phytol. 2006;171(1):159-70 PubMed

Ecol Evol. 2016 May 30;6(13):4332-46 PubMed

New Phytol. 2006;172(1):3-6 PubMed

Plant Cell Environ. 2012 Apr;35(4):819-28 PubMed

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