Fig. 1. Acetate needs to be metabolized to inhibit LHCSR3 accumulation.

WT, icl, icl-C and dum11 strains were acclimated for 16 h in LL (15 µmol photons m⁻² s⁻¹) in HSM; sparged with air (labelled as “air”); sparged with air and supplemented with 10 mM sodium acetate (labelled as “acet”); sparged with air enriched with 5% CO₂ (labelled as “CO₂”). After sampling for the LL conditions, light intensity was increased to 600 µmol photons m⁻² s⁻¹ (HL); samples were taken 1 h (RNA) or 4 h (protein) after exposure to HL. a, c. Accumulation of LHCSR3 mRNA at the indicated conditions normalized to WT LL ctrl (n = 3 biological samples, mean ± s.d.). The p-values for the comparisons of acetate and CO₂ conditions to air are based on ANOVA Dunnett’s multiple comparisons test of log10 transformed mRNA data as indicated in the graphs (*P < 0.005, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns, not significant). Exact p-values can be found at the Source Data file. b, d. Immunoblot analyses of LHCSR3 and ATPB (loading control) under the indicated conditions. Representative datasets of experiments repeated three times.