Fig. 2: OSA1 overexpression promotes nitrogen (N) and carbon (C) uptake in rice.

a Phenotypes of 4-week-old WT and OSA1-overexpressing (ox) plants. b Dry weights of WT and OSA1-ox plants. c Relative OSA1 expression levels in WT and OSA1-ox plants. d Relative PM H⁺-ATPase protein levels in WT and OSA1-ox plants. e Hydrolytic activity of PM H⁺-ATPase in WT and OSA1-ox plants. f ¹⁵NH₄⁺ absorption rates in the roots of WT and OSA1-ox plants under different NH₄⁺ concentrations. To determine ¹⁵NH₄⁺ absorption rates, seedlings were incubated with 0.5–8 mM ¹⁵NH₄⁺ for 5 min to reflect the net uptake rate. g, h Total N and C levels in WT and OSA1-ox plants. Plants were grown hydroponically in a greenhouse for 4 weeks. Small circles in b–h represent data points for individual experiments; three biological replicates were analysed for each treatment. Values in b–h are presented as the means ±  SEs (n = 3). Differences were evaluated using the two-tailed Student’s t test (*P < 0.05; **P < 0.01). The exact P values are provided in the Source Data file.