Figure 1

Phosphothreonine-immunoblot of thylakoid proteins isolated from Arabidopsis leaves after four different treatments: Control (Ctr), Cold/Light (C/L), Dark (D) and Cold/Dark (C/D). Below the immunoblot, 77 K fluorescence emission ratios (F732/F685 ± S.D.) of thylakoids from differentially treated plants are given. F732 stands for the fluorescence peak at 732 nm representing the emission from PSI and F685 for the fluorescence peak at 685 nm from PSII. Differences in F732/F685 ratios are related to reversible phosphorylation of the light-harvesting chl a/b proteins (LHCII) and their attachment with PSI (phosphorylated, high ratio) and PSII (non-phosphorylated, low ratio). P-CP43, P-D2, P-D1 denote the phosphorylated proteins of PSII core, P-LHCII denote the LHCII phosphoproteins.