Fig. S4.

Transcript levels quantified by qRT-PCR under changing CO₂ conditions. Transcript levels of CGHR genes were measured in P. tricornutum cells grown under high-CO₂ (open bar), atmospheric air (gray bar), or very-low-CO₂ (closed bar) conditions with continuous illumination. Transcript levels were normalized to the transcript levels of the gapC2 gene. Data represent the mean ± SD of three separate experiments. The transcript level of Pt43232 under the high-CO₂ condition was 3.1-fold higher than for air-grown cells. Respective Pt43234 and Pt32401 transcript levels were 5.4-fold and 120-fold higher, under the air-grown condition compared with the transcript levels of 1% CO₂-grown cells. The transcript level of Pt32401 was more significantly responsive to low CO₂ than the other CGHR factors, and the accumulation level of Pt32401 under the air-grown condition was higher than the other CGHR factors. Under the very-low-CO₂ condition, the Pt43234 and Pt32401 transcript levels were reduced significantly.