Fig. 5: Low CO₂ levels can trigger qE and CCM genes in the absence of light.

WT, cia5 and cia5-C cells were bubbled with air overnight in darkness; next day air bubbling was either maintained or replaced by CO₂-limited-air bubbling in the darkness or in the presence of 600 µmol photons m⁻² s⁻¹ light. Sampling was performed after 1 h (RNA) or 4 h (protein). a mRNA accumulation of LHCSR3.1 (qE gene) and CAH4, LCIA, LCI1 (CCM genes) in WT, cia5 and cia5-C. Data were normalized to WT air dark; (n = 3 biological samples, mean ± s.d.). The p-values for the comparisons of WT with cia5 and cia5 with cia5-C 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 Immunoblot analyses of LHCSR3 and ATPB (loading control) under the indicated conditions. Representative dataset of experiment repeated three times. c Immunoblot analyses of LHCSR3 and ATPB (loading control) of WT samples presented in b. Above the immunoblot shown are the amount of protein loaded per lane and the quantification of LHCSR3 protein accumulation (calculated as LHCSR3 /ATPB ratio) normalized to the air dark conditions. Representative dataset of experiment repeated three times.