Figure 4
Proposed scheme of transcriptome changes to the central carbon metabolism in D. tertiolecta upon nitrogen depletion.
Arrows represent potential carbon fluxes. Enzymes are in bold italics. Blue arrows represent reducing power (NADPH) and red arrows represent acetyl-CoA. Black boxes denote pathway names. A recently proposed C4-like carbon-concentrating mechanism (CCM) in microalgae78,79,80,81 is shown to depict an alternative route for carbon assimilation. Neutral lipid droplets found in microalgae consist mostly of triacylglycerols (TAGs), formed by combining FAs and glycerol. Legend: ACCase, acetyl-CoA carboxylase; ACD, acyl-CoA dehydrogenase; ACL, ATP-citrate lyase; ACS, acyl-CoA synthetase; AGPP, ADP-glucose pyrophosphorylase; AMY, amylase; CA, carbonic anhydrase; DGAT, diacylglycerol acyltransferase; DHAP, dihydroxyacetone phosphate; F1,6 P, fructose 1,6-bisphosphate; F6P, fructose 6-phosphate; FAT, fatty acyl-acyl carrier protein (ACP) thioesterase; G1P, glucose 1-phosphate; G6P, glucose 6-phosphate; G6PDH: G6P dehydrogenase, GAP, glyceraldehyde 3-phosphate; GPAT, glycerol-3-phosphate acyltransferase; GPDH, glycerol-3-phosphate dehydrogenase; MAL, malate; MDH, malate dehydrogenase; MME: NADP-malic enzyme; OAA, oxaloacetate; PDC, pyruvate dehydrogenase complex; PEP, phosphoenolpyruvate; PEPC, PEP carboxylase; PK, pyruvate kinase; Ru5P, ribulose 5-phosphate; Ru1,5BP, ribulose 1,5-bisphosphate; RuBisCO, Ru1,5BP carboxylase/oxygenase; TPT, triose phosphate translocator; 3-PGA, 3-phosphoglycerate; 6PGDH, 6-phosphogluconate dehydrogenase. Please refer to Supplementary Information for abbreviations of genes involved in starch synthesis and photosynthesis and antenna proteins.
