Fig. 4. The effect of elevated CO₂ on the expression of N metabolism-related genes and NO₃^- uptake is mediated by DNR1-OsARFs module.

Extent of OsARF6 and OsARF17-mediated ChIP-qPCR enrichment (relative to Input) of TGTCTC-containing promoter fragments from OsNRT1.1B (a, b) and OsNIA2 (c, d) under ambient CO₂ (aCO₂) and elevated CO₂ (eCO₂) conditions. Data are mean ± s.e.m. (n = 3 biological replicates). P-values were generated from two-sided Student’s t tests. OsARF6 and OsARF17 activate OsNRT1.1B (e) and OsNIA2 (f) promoter-LUC fusion constructs in transient transactivation assays. The LUC/REN activity obtained from a co-transfection with an empty effector construct and indicated reporter constructs under ambient CO₂ (aCO₂) was set to 1. Root mRNA abundances of OsNRT1.1B (g) and OsNRT2.3a (h) relative to ZH11 pAct::DNR1-Flag under aCO₂ (set to 1). i, j Shoot mRNA abundances of OsNPF2.4 (i) and OsNIA2 (g) relative to ZH11 pAct::DNR1-Flag under aCO₂ (set to 1). k Root ¹⁵NO₃^- uptake rate of OsARF6 and OsARF17 overexpression lines in the ZH11 pAct::DNR1-Flag background grown under aCO₂ and elevated CO₂ (eCO₂) conditions, respectively. e–k Data are mean ± s.e.m. (n = 3 biological replicates). P-values were generated from two-way ANOVA. Different letters indicate significant differences among treatments (P < 0.05). Source data are provided as a Source Data file.