Fig. 2: LHCSR3 inhibition is driven by CO₂ derived from the metabolism of acetate.

Experiment at LL: a, b mRNA accumulation of LHCSR3 and RHP1 and c concentration of sodium acetate in the growth medium in WT and icl strains. Cells were acclimated overnight at LL (15 µmol photons m⁻² s⁻¹) in HSM sparged with air. At t = 0 cells either continued being sparged with air (labelled “air”); or sparged with air and supplemented with 10 mM sodium acetate (labelled “acet”); or sparged with air enriched with 5% CO₂ (labelled “CO₂”). The addition of acetate or CO₂ is indicated with a green mark on the x-axis. Samples were taken at t = 0, 1 h, 4 h and 8 h. Experiment at HL: d, e mRNA accumulation of LHCSR3 and RHP1 and f concentration of sodium acetate in the growth medium in WT and icl strains. Cells were acclimated overnight at LL (15 µmol photons m⁻² s⁻¹) in HSM sparged with air; at t = 0 light intensity was increased to 600 µmol photons m⁻² s⁻¹. At t = 1 h cells either continued being sparged with air (labelled “air”); or sparged with air and supplemented with 10 mM sodium acetate (labelled “acet”); or bubbled with air enriched with 5% CO₂ (labelled “CO₂”), always at 600 µmol photons m⁻² s⁻¹. The time of addition of acetate or CO₂ is highlighted in green on the x-axis. Samples were taken at t = 0, 1 h, 2 h, 5 h and 9 h. (n = 3 biological samples, mean ± s.d.). The p values for the comparisons of acetate and CO₂ conditions to air (LL; t = 1, 4, 8 h, HL; t = 2, 5, 9 h) 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), following the color-code of the datasets. Exact p-values can be found at the Source Data file. Please note that in some cases the error bars are smaller than the data point symbols.