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@ARTICLE{Zhu:1044993,
      author       = {Zhu, Jianjun and Hirl, Regina T. and Baca Cabrera, Juan C.
                      and Schäufele, Rudi and Schnyder, Hans},
      title        = {{A}ssessing and avoiding {C} isotopic contamination
                      artefacts in mesocosm-scale 13{CO}2/12{CO}2 labelling
                      systems: from biomass components to purified carbohydrates
                      and dark respiration},
      journal      = {Plant methods},
      volume       = {21},
      number       = {1},
      issn         = {1746-4811},
      address      = {London},
      publisher    = {BioMed Central},
      reportid     = {FZJ-2025-03477},
      pages        = {111},
      year         = {2025},
      abstract     = {Quantitative understanding of plant carbon (C) metabolism
                      by 13CO2/12CO2-labelling studies requires absence (or
                      knowledge) of C-isotopic contamination artefacts during
                      tracer application and sample processing. Surprisingly, this
                      concern has not been addressed systematically and
                      comprehensively yet is especially crucial in experiments at
                      different atmospheric CO2 concentrations ([CO2]), when
                      experimental protocols require frequent access to the
                      labelling chambers. Here, we used a plant growth
                      chamber-based 13CO2/12CO2 gas exchange-facility to address
                      this topic. The facility comprised four independent units,
                      with two chambers routinely operated in parallel under
                      identical conditions except for the isotopic composition of
                      CO2 supplied to them (δ13CCO2 −43.5‰ versus −5.6‰).
                      In this setup, dδ13CX (the measurements-based
                      δ13C-difference between matching samples X collected from
                      the parallel chambers) is expected to equal dδ13CRef (the
                      predictable, non-contaminated δ13C-difference ), if
                      sample-C is completely derived from the contrasting CO2
                      sources. Accordingly, contamination (fcontam) was determined
                      as fcontam = 1– dδ13CX/dδ13CRef in this experimental
                      setup. Determinations were made for biomass fractions,
                      water-soluble carbohydrate (WSC) components and dark
                      respiration of Lolium perenne (perennial ryegrass) stands
                      following growth for ∼9 weeks at 200, 400 or 800 µmol
                      mol− 1 CO2, with a terminal two weeks-long period of
                      extensive experimental disturbance of the chambers.},
      cin          = {IBG-3},
      ddc          = {570},
      cid          = {I:(DE-Juel1)IBG-3-20101118},
      pnm          = {2173 - Agro-biogeosystems: controls, feedbacks and impact
                      (POF4-217)},
      pid          = {G:(DE-HGF)POF4-2173},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {40790535},
      UT           = {WOS:001548547400001},
      doi          = {10.1186/s13007-025-01431-3},
      url          = {https://juser.fz-juelich.de/record/1044993},
}