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@INPROCEEDINGS{Schmidt:856671,
      author       = {Schmidt, Lilian and Junker, Laura and Büchsenschütz, Jana
                      and Wiese-Klinkenberg, Anika and Zinkernagel, Jana},
      title        = {{A}pplicability and limitations of multiparametric
                      fluorescence measurements to assess pigment concentrations
                      in leafy vegetables},
      reportid     = {FZJ-2018-06033},
      year         = {2018},
      abstract     = {There is growing interest to monitor plant stress
                      responses, developmental processes and concentrations of
                      health-promoting pigments in vegetables by non-destructive
                      measurements. One device for non-invasive monitoring of
                      plant performance and quantification of pigment
                      concentrations in vegetables is the portable fluorescence
                      sensor Multiplex® (Force-A, Orsay Cedex, France). Here,
                      plant pigment concentrations are estimated based on
                      vegetation indices derived from multiparametric fluorescence
                      measurements. This method is increasingly used to monitor
                      stress-related changes in plant pigments and flavonoids in
                      horticultural experiments, but there is little evidence for
                      an exact quantification of these leaf compounds. In this
                      study, we assessed the applicability, but also limitations
                      of the Multiplex® sensor in monitoring of plant stress
                      responses and quantification of pigment concentrations in
                      leaves of vegetable crops. We conducted two studies: First,
                      we investigated changes in leaf metabolism of tomato plants
                      subjected to nitrogen deficiency, and linked fluorometric
                      measurements using the Multiplex® with biochemical analyses
                      of foliar pigment and flavonoid concentrations. Second, we
                      tested if fluorometric measurements using the Multiplex®
                      are useful for predicting pigment concentrations of leafy
                      vegetables. Here, we correlate biochemically assessed
                      concentrations of chlorophylls in spinach and anthocyanins
                      in red cabbage to non-invasive quantification derived from
                      Multiplex® data. In order to measure samples with varying
                      pigment concentrations, spinach as well as red cabbage
                      plants were grown in the field either supplied with $50\%$
                      or $100\%$ of the recommended nitrogen supply. For both
                      experiments, fluorometric measurements with the Multiplex®
                      were performed on leaves. Immediately after, leaf samples
                      were frozen for biochemical analysis of pigment content.
                      Preliminary results show that measurements with the
                      Multiplex® represent the onset of stress-related changes in
                      leaf metabolism of tomato plants subjected to nitrogen
                      deficiency well. Nevertheless, there was high variation in
                      the quantification of pigment content of leaves and
                      vegetables by biochemical and fluorometric analyses. In
                      consequence, the correlations between pigment concentrations
                      assessed by biochemical analysis and Multiplex®
                      measurements were rather weak. We conclude that the
                      Multiplex® sensor can be of advantage in monitoring of
                      plant development and stress responses, but is of limited
                      use for non-invasive quantification of the concentration of
                      foliar pigment concentrations in leafy vegetables.},
      month         = {Feb},
      date          = {2018-02-28},
      organization  = {52. DGG $\&$ BHGL Jahrestagung,
                       Geisenheim (Germany), 28 Feb 2018 - 2
                       Mar 2018},
      subtyp        = {After Call},
      cin          = {IBG-2},
      cid          = {I:(DE-Juel1)IBG-2-20101118},
      pnm          = {582 - Plant Science (POF3-582)},
      pid          = {G:(DE-HGF)POF3-582},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/856671},
}