Fig. 3: osa1 mutant plants exhibit lower N uptake and decreased C content.

a Phenotypes of WT and osa1 plants (scale = 10 cm). b Root and shoot dry weights of WT plants and osa1 mutants. c Relative expression levels of OSA1 in the roots and leaves of WT plants and osa1 mutants. d Relative PM H⁺-ATPase protein levels in the roots and leaves of WT plants and osa1 mutants. e ATP hydrolytic activity of PM H⁺-ATPase in WT plants and osa1 mutants. f ¹⁵NH₄⁺ absorption rates in the roots of WT plants and osa1 mutants under different NH₄⁺ concentrations. The ¹⁵NH₄⁺ absorption rate was determined after seedlings were incubated with 0.5–8 mM ¹⁵NH₄⁺ for 5 min. g, h Total N and C levels in roots and leaves of WT plants and osa1 mutants. 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.