Coordinated regulation of carbon and nitrogen assimilation confers drought tolerance in maize (Zea mays L.)

(A)LY66 has greater drought tolerance and recovery than LY99 through coordinating regulation of C and N assimilation. Up- (red) and down-regulated (green) genes encoding C/N metabolism-responsive enzymes in LY66 when compared to LY99 under drought stress. (B) Auxin might participate in coordinating regulation of C and N assimilation and drought tolerance. Rubp: Ribulose-1,5-disphosphate; PGA: 3-phosphoglycerate; GAP: Glyceraldehyde 3-phosphate; TP: Triose phosphate; ADPG: Adenosine diphosphate glucose; Gln: Glutamine; Glu: Glutamate; NO3−: Nitrate; NO2−: Nitrite; NH4+: Ammonia; LHCa: PS-I light harvesting complex subunit; LHCb: PS-II light harvesting complex subunit; PSBA: Chlorophyll binding protein D1; PSBD: Chlorophyll binding protein D2; Rubp: Ribulose bisphosphate carboxylase; GAP: Glyceraldehyde phosphate dehydrogenase; SPS: Sucrose phosphate synthase; AGP: ADP glucose pyrophosphorylase; GBSS: Granule-bound starch synthase; SBE: Starch branching enzyme; SS: Starch synthase; INV: Invertase; SuSy: Sucrose synthase; NR: Nitrate reductase; NiR: Nitrite reductase; AMT: Ammonium transporter protein; GS: Glutamine synthetase; GDH: Glutamate dehydrogenase.