Fig. 1: OsNLP4 allelic variations between indica and japonica.

a Conserved single-nucleotide polymorphism (SNP) differentiation between the indica and japonica OsNLP4 proteins. Locations of functional domains are indicated by black bars. Single nucleotide diversities, characterizing the distribution ratio of SNP1 (b), SNP3 (c) and SNP4 (d) from two OsNLP4 haplotypes in 4726 diverse rice accessions (indica: 2759, japonica: 1512, aus: 269, aromatic: 96, intermediate: 90, O. rufipogon: 28, O. glaberrima: 11, O. barthii: 10). e NUE of rice varieties carrying different OsNLP4 haplotypes (Hap-indica, Hap-japonica). All data are from plants grown under normal paddy-field fertilization conditions at Wenjiang in 2023 (Hap-indica, n = 143; Hap-japonica, n = 69). f The chlorate sensitivity of the parental plants Xiushui134 (XS134) and 9311, SSSL95, and XS134^indica-NLP4 (NIL) was tested. Scale bar = 2.0 cm. ¹⁵N uptake assays in XS134 and XS134^indica-NLP4 (NIL-1, NIL-2) plants labeled with ¹⁵N-nitrate (g) and ¹⁵N-ammonium (h). i Total N content of XS134, NIL-1, and NIL-2. Seedlings were grown in modified Kimura B solution (pH 5.8) supplemented with 2 mM KNO₃ for 18 days. j Growth phenotype of representative XS134, NIL-1, and NIL-2 at the maturing stage in the field trial at Hefei in 2022. Scale bar = 8.0 cm. Tiller number per plant (k), actual yield per plot (l), and NUE (m) of XS134, NIL-1, and NIL-2 in the field trial. The values are the means ± SDs (n = 8 replicates, 6 seedlings per replicate for g–i, n = 16 plants for k, n = 16 panicles for l, and n = 4 replicates, 80 plants per replicate for m). The different letters above the bars denote significant differences (P < 0.05) according to a two-side Duncan’s multiple range test for g–i and k-m, and a two-sided Student’s t-test for e. Source data are provided as a Source Data file.