Figure 1.

Scheme of localization of the pathways of carbon, nitrate, and sulfate assimilation in exemplary C₃ and C₄ plants. Schematic localization of key enzymes of (A) CO₂, (B) nitrate, and (C) sulfate assimilation in mesophyll cells (MC) and bundle sheath cells (BS) of representative species for C₃ and C₄ monocots and dicots was compiled from the literature described in the manuscript. MC, mesophyll cells; BS, bundle sheath cells; PEPC, phosphoenolpyruvate carboxylase; ME, malic enzyme; PCK, phosphoenolpyruvate carboxykinase; NR, nitrate reductase; NiR, nitrite reductase, GS, glutamine synthetase; GOGAT, glutamate synthase; ATPS, ATP sulfurylase; APS, adenosine 5´-phosphosulfate; APR, APS reductase; SiR, sulfite reductase; OASTL, O-acetylserine (thiol)lyase.