% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Wu:838704,
      author       = {Wu, Cheng and Pullinen, Iida and Andres, Stefanie and
                      Kiendler-Scharr, Astrid and Kleist, Einhard and Wahner,
                      Andreas and Wildt, Jürgen and Mentel, Thomas F.},
      title        = {13{C} labelling study of constitutive and stress-induced
                      terpenoide missions from {N}orway spruce and {S}cots pine},
      journal      = {Biogeosciences discussions},
      volume       = {260},
      issn         = {1810-6285},
      address      = {Katlenburg-Lindau [u.a.]},
      publisher    = {Copernicus},
      reportid     = {FZJ-2017-07265},
      pages        = {1 - 29},
      year         = {2017},
      abstract     = {Due to their large source strengths, biogenic volatile
                      organic compounds (BVOCs) are important for atmospheric
                      chemistry. Terpenoids, mainly consisting of isoprene,
                      monoterpenes and sesquiterpenes, are the dominant BVOC
                      class. There are two general mechanisms for their emissions:
                      emissions directly from de novo biosynthesis (de novo
                      emissions) and emissions from organs wherein the terpenoids
                      are stored (pool emissions). While isoprene emissions are
                      pure de novo emissions, the mechanism for monoterpene and
                      sesquiterpene emissions is not always distinct. In
                      particular, conifers have large storage pools and both
                      mechanisms may contribute to the emissions.To obtain more
                      insight into the mechanisms of the terpenoid emissions from
                      Eurasian conifers, we conducted 13CO2 and 13C-glucose
                      labelling studies with Norway spruce (Picea abies L.) and
                      Scots pine (Pinus sylvestris L.). The results from the
                      labelling experiments were further compared to diurnal
                      modulations measured for the emission fluxes of the
                      respective terpenoids, as well as to their release from
                      reservoirs in needles and bark tissue.The comparison allowed
                      the following comprehensive statements for the investigated
                      conifers. Consistent to other studies, we found that
                      constitutive monoterpene emissions mainly originate from
                      storage pools but with compound-specific fractions of de
                      novo emissions. In contrast, stress-induced monoterpene and
                      sesquiterpene emissions are entirely of de novo nature. We
                      also found at least three different carbon sources for
                      monoterpene and sesquiterpene biosynthesis. These sources
                      differ with respect to the timescale after which the
                      recently assimilated carbon reappears in the emitted
                      terpenoids. Carbon directly obtained from assimilated has a
                      short turnover time of few hours, while carbon from other
                      alternative carbon sources has intermediate turnover times
                      of few days and even longer. Terpenoid biosynthesis is not
                      restricted to the presence of light and the carbon for
                      terpenoid biosynthesis can be delivered from the alternative
                      carbon sources. In particular for sesquiterpenes, there can
                      be substantial de novo emissions in darkness reaching up to
                      around $60 \%$ of the daytime emissions. The use of the
                      alternative carbon sources for sesquiterpene synthesis is
                      probably linked to the mevalonic acid (MVA) pathway. The
                      higher the contribution of the MVA pathway to terpenoid
                      synthesis, the higher is the nocturnal de novo emission.In
                      general, the emission mechanisms of monoterpene and
                      sesquiterpene are more complex than assumed so far. Besides
                      pools for terpenoids themselves, there are also pools for
                      terpenoids precursors. Terpenoid synthesis from alternative
                      carbon sources leads to nighttime emissions and hence the
                      amplitude of diurnal modulations of terpenoid emissions may
                      be determined by an overlap of three mechanisms involved:
                      emissions from storage pools, emissions in parallel to CO2
                      uptake and emissions from alternative carbon sources.},
      cin          = {IEK-8},
      ddc          = {570},
      cid          = {I:(DE-Juel1)IEK-8-20101013},
      pnm          = {243 - Tropospheric trace substances and their
                      transformation processes (POF3-243)},
      pid          = {G:(DE-HGF)POF3-243},
      typ          = {PUB:(DE-HGF)16},
      doi          = {10.5194/bg-2017-260},
      url          = {https://juser.fz-juelich.de/record/838704},
}