Fig. 2: OsNLP4^indica introgression improves yield and NUE in japonica rice.

a Phenotypes of the XS134 and NILs (NIL-1, NIL-2) plants grown in hydroponic media supplemented with different nitrate concentrations for 18 days. Scale bar = 2.0 cm. b Biomass of the plants under different nitrate conditions, as shown in (a). c Growth phenotype at the maturing stage of representative XS134, NIL-1, and NIL-2 plants grown in vermiculite pots and provided with different nitrate concentrations. Images of four-month-old plants were taken. LN: 1 mM KNO₃, HN: 5 mM KNO₃. Scale bar = 8.0 cm. d Images of total grains per plant for XS134, NIL-1, and NIL-2 under different nitrate conditions, as shown in c. Scale bar = 2.0 cm. e Growth phenotype of representative XS134, NIL-1, and NIL-2 at maturing stage in the field under different N conditions (Changxing, Zhejiang province, China). LN: 90 kg urea/ha, NN: 180 kg urea/ha, HN: 360 kg urea/ha. Scale bar = 8.0 cm. f Images of total grains per plant for XS134, NIL-1, and NIL-2 under different N conditions as shown in (e). Scale bar = 1.0 cm.Tiller number per plant (g), actual yield per plot (h), and NUE (i) of XS134, NIL-1, and NIL-2 in the field under different N conditions as shown in (e). Grain yield per plot (j), and NUE (k) of XS134, NIL-1, and NIL-2 in the large-scale field under different N conditions (Lingshui, Hainan province, China). Each plot is 66 m². LN: 75 kg urea/ha, HN: 150 kg urea/ha (local routine N application levels). The values are the means ± SDs (n = 16 plants for b and g, n = 4 replicates, 80 plants per replicate for h and i, n = 4 replicates, 1700 plants per replicate for j and k. The different letters above the bars denote significant differences (P < 0.05) according to a two-sided Duncan’s multiple range test. Source data are provided as a Source Data file.