FIGURE 6.

FIP1 regulates the expression of CIPK8 and CIPK23 and affects seedling nitrate content in the presence of nitrate. RNA was extracted from seedlings grown for 7 days with various sources of nitrogen [(NH₄)₂Suc, KNO₃, or NH₄NO₃ media]. The expression levels of CIPK8 (A) and CIPK23 (B) in the fip1 mutant, determined using qPCR. The expression levels of CIPK8 (C) and CIPK23 (D) in the cpsf30 mutant, determined using qPCR. Error bars represent the SD of the biological replicates (n = 4). (E) Nitrate content in the CIPK23 overexpression line (CIPK23-OE) grown in ½ MS medium for 7 days. Error bars represent the SD of the biological replicates (n = 5). Asterisks and different letters indicate significant differences to the WT (p < 0.05, U-test).