Supplemental
Figure I: Spectra of blue (thin continuous line) and red light (thin dashed line) used to induce
photosynthetic oxygen evolution in leaves of the A. thaliana tt3 mutant. Blue or red
fluorescence excitation light was provided by a UV-A-PAM (thin dotted line) and Mini-PAM
(dash-dotted line) fluorometer. Additionally, the summarized absorbance spectrum of the
violaxanthin cycle pigments (V-cycle, thick continuous line) is shown. Single spectra of
violaxanthin, antheraxanthin and zeaxanthin in 75% acetone were recorded during HPLC
analysis with a photodiode array-detector.
Figure II: Content of polyphenolics in leaf samples of the tt3 and tt5 mutant, which prior to
the HPLC analysis were used for the measurements of chlorophyll fluorescence excitation
spectra (Figure 1). Plants were acclimated to low light conditions (LL, PPFD of 50 µmol m-2
s-1) or to high light (HL, 420 µmol m-2 s-1). Hydroxycinnamic acids and flavonols were
identified on the basis of their online absorbance spectra during HPLC analysis. Leaf contents
of the compounds are sums of their respective derivatives and are expressed as sinapic acid,
kaempferol and quercetin equivalents according to the calibration of the HPLC with pure
substances. Flavonols were below detection limit in LL grown leaves and the tt5 mutant.
Significant differences of the contents of sinapic acid derivatives are indicated by letters based
on the results of a One-way ANOVA in combination with a Tukey’s multiple comparison test.
Means of n = 5-6, + SD