Fig. 6: Non-photochemical quenching (NPQ) amplitude and endogenous PsbS levels.

a Induction and relaxation kinetics of NPQ measured in the WT, koLhcb4, Lhcb4.1-only, and Lhcb8-only lines under actinic light (1280 μmol of photons m⁻² s⁻¹) followed by recovery in the dark (biological replicates ≥ 5). b Correlation between protein amount and the NPQ parameter (recorded during the light phase and calculated as the integral between minute 0 and minute 8 of the NPQ function). The levels of Lhcb4, Lhcb4_H242L, and Lhcb8 were estimated in T2 segregating populations via immunodecoration with specific antibodies and plotted against the recorded NPQ value. A quadratic function described the relationship. The WT Lhcb4 protein level was normalized to 1. c Quantification of PsbS levels by densitometric analysis of immunoblots incubated with α-PsbS antibody. Data are shown as mean ± standard deviation of n = 3 biological replicates. The statistical significance was determined by a one-way ANOVA test followed by the Tukey’s test and depicted with lower-case letters (P-value ≤ 0.05).