LHCI association preserves PSI activity under high light conditions. PSI-LHCI complex was treated with high light (1000 μE at 4°C). In (A) PSI-LHCI WT Chl bleaching (red circles) is reported together with the P700 content, determined from the P700+ absorption at 435 nm (black squares). In (B) Chl bleaching (blue diamonds) and P700 content (green triangles) are reported for the experiments performed with PSI particles purified from ΔLhca4 plants. Data from WT are also reported for comparison (red and black for Chl bleaching and PSI activity respectively). Inset: comparison of decrease of P700 content in WT vs. ΔLhca4 plants. All data are the result of at least 3 experimental repetitions, for each P700 measurement three independent samples were pooled together. SD is also reported.