Fig. 1: OsSTP28 locus is associated with tillering response of rice to N supply.

a Phenotype of four parent lines, SAGC-08 (SA), HHZ5-SAL9-Y3-Y1 (HH), BP1976B-2-3-7-TB-1-1 (BP) and PR33282-B-8-1-1-1-1-1(PR), of rice MAGIC population under low nitrogen (LN) or high nitrogen (HN) supply at mature stage. White bars, 20 cm. b Tiller number per plant of four parent varieties under LN or HN supply. Boxes show the first quartile, median, and third quartile; whiskers show the minimum and maximum values. n = 8 individual plants. Different letters indicate significant differences among the treatments (P < 0.05, one-way ANOVA, Tukey’s HSD test). c Pattern diagram of MAGIC population construction by four parents. d Tiller number of 120 MAGIC accessions under LN or HN supply. The dots represent the accessions, lines connect the same accession under LN or HN supply. e Variation of tillering response to N (TRN, the ratio of tiller number between HN and LN). f Manhattan plot for the associations of single nucleic acid polymorphism (SNP) to tiller number under HN on rice whole genome, and the position of 5 candidate genes on rice chromosome 11. Negative log₁₀-transformed P-values from a genome-wide scan were plotted against positions on each of the 12 chromosomes of rice (Oryza sativa L). g TRN and expression response to N (ERN) of OsSTP28. h Correlation between TRN and ERN. The data used for the correlation analyses derived from experiments shown in Fig. 1g. i Natural allelic variation at the promoter region of OsSTP28 in the MAGIC population. The haplotype is referred to as haplotype C (tillering common-response to N, containing 19 lines including SA and BP), and haplotype H (tillering high-response to N, containing 101 lines including HH and PR). Number in yellow or green denotes the number of lines carrying the corresponding allele. j Tiller number of MAGIC lines representing two OsSTP28 haplotypes under LN or HN supply at mature stage. k TRN (HN/LN) of two haplotype lines of MAGIC population. The data used for calculation of TRN derived from experiments shown in Fig. 1j. Significant difference was determined by two-sided Student^’s t-test in d, j and k.