Fig. 1: Plasma membrane (PM) H⁺-ATPase regulates ammonium (NH₄⁺) uptake in rice.

a ¹⁵NH₄⁺ absorption rate in wild-type (WT) rice. To determine ¹⁵NH₄⁺ absorption rates, rice seedlings were incubated in 2 mM ¹⁵NH₄⁺ solution with 5 μM fusicoccin (FC) for 30 min under dark or illuminated conditions. b Average transpiration rates of rice leaves under dark and illuminated conditions over 30 min. Small circles in a, b represent data points for individual experiments; three biological replicates were analysed for each treatment. Columns and error bars in a, b represent the means ± standard errors (SEs; n = 3). Differences were evaluated using the two-tailed Student’s t test (*P < 0.05; ***P < 0.005; n.s., not significant). The exact P values are 0.0018 (mock in dark vs. FC in dark), 0.0025 (mock in dark vs. mock in light), 0.0143 (mock in light vs. FC in light) and 0.0016 (FC in dark vs. FC in light) for (a); 0.8194 (mock in dark vs. FC in dark), 0.0006 (mock in dark vs. mock in light), 0.0851 (mock in light vs. FC in light), and 4.27 × 10⁻⁵ (FC in dark vs. FC in light) for (b). n.s. Not significant.