342 344 346 348 350

magnetic field, mT

10 µg Chl

10 µg Chl+ 1 mM NaN3

10 µg Chl in 50% D2O

Singlet oxygen detection by EPR spectroscopy using TEMPD as spin probe.

Shown are typical spectra recorded after 2 min illumination with red light at 500 µmol quanta m-2 s-1. The samples contained 10 µg/ml pure chlorophyll a and b (Chl a/b = 3). Chl was dissolved in methanol and measurements were performed in a buffer containing 0.3 M sorbitol, 50 mM KCl, 5 mM MgCl2, 25 mM HEPES pH 7.6. If indicated, azide was added, or water was replaced by 50% D2O.

Suppl. Fig. 1

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2 min light + FeEDTA

no FeEDTA

dark

magnetic field, mT

Spin trapping with 4-POBN/EtOH.Thylakoids from flag leaves of Lomerit from the 14th of June 2014 were chosen.

10 µg Chl ml-1 were illuminated for 2 min with red light (RG 630) at 500 µmol quanta m-2s-1. The spin trapping assay contained50 mM 4-POBN, 4% ethanol and 50 µM FeEDTA, when indicated.

Suppl. Fig. 2

335 340 345 350 355 360

+ SOD

+ MV

magnetic field, mT

Spin trapping with DEPMPO.Thylakoids from flag leaves of Lomerit from the 14th of June 2014 were chosen.

40 µg Chl ml-1 were illuminated for 2 min with red light (RG 630) at 500 µmol quanta m-2s-1. The spin trapping assay contained10 mM DEPMPO, 1 mM DPTA in 0.3 M sorbitol, 20 mM HEPES (pH 7.6).When indicated, 50 U SOD or 100 µM methylviologen (MV) were added.

Suppl. Fig. 3

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magnetic field, mT

no inhibtor

+ DCMU

+ DNP-INT

Spin trapping with 4-POBN/EtOH, effect of inhibitorsThylakoids from flag leaves of Lomerit from the 14th of June 2014 were chosen.

10 µg Chl ml-1 were illuminated for 2 min with red light (RG 630) at 500 µmol quanta m-2s-1. The spin trapping assay contained50 mM 4-POBN, 4% ethanol, 50 µM FeEDTA, 10 µM DCMU and100 µM DNP-INT, when indicated.

Suppl. Fig. 4

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magnetic field, mT

ROS detection by spin trapping EPR using 4-POBN/EtOH as spin trap.

Thylakoids (10 µg Chl)

Pure chlorophyll (10 µg Chl)

Shown are the signals of the typical 4-POBN/α-hydroxyethyl adducts recorded after 2 min illumination with red light (RG 630) at 500 µmol quanta m-2 s-1. The samples contained thylakoid membranes (10 µg Chl/ml) or pure chlorophyll (10 µg Chl/ml Chl a/b = 3). Chl was desolved in methanol and measurements were performed in a buffer containing 0.3 M sorbitol, 50 mM KCl, 5 mM MgCl2, 25 mM HEPES pH 7.6

Suppl. Fig. 5