Figure 7
Expression levels of key glucose-related and glycolytic genes under different environmental conditions. Expression levels of genes under eight conditions (light/L1, dark/L1, light/HCO3–, dark/ HCO3–, light/Glc, dark/Glc, light/urea, and dark urea, see Materials and methods for details), as compared to the dark/L1 condition. Light exposure induces a significant increase in the expression of the cytosolic fructose bisphosphate aldolase 3 gene (Fba3) encoding the protein that catalyzes the reversible conversion of fructose 1,6-bisphosphate to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. The overexpression is independent of the presence of glucose or bicarbonate in the growth media. Conversely, the expression levels of the two genes corresponding to known glucose transporters in Pt (GLUT1 and GLUT3) appear to be unaffected by light exposure and the presence of organic carbon sources. Fold changes were calculated with respect to the housekeeping gene 18S and were verified with respect to two other housekeeping genes. Results are presented as mean ± SD of three biological and three technical replicates (a total of 9 replicates per gene and condition). *: 0.01 < p < 0.05 when compared to the dark/L1 condition; **: p ≤ 0.01 when compared to the dark/L1 condition.