Fig. 5: Engineering of the Os1900 promoter provided a continuum of alleles with different fertilization responses.
a Profile of three double-strand break sites and three expected deletion mutations. b Schematic view of the Os1900 promoter target for 19 guide RNAs (gRNAs), where three gRNAs represent one construction. The target promoter region was 5 kb upstream of the translation start position (ATG). c Sequencing of Os1900 promoter deletion mutants (M1–M9) among T1 plants. (–) indicates deletions; (+) indicates insertions. d Potential fertilizer-related cis-regulatory elements (CREs) related to combinations of N, P-fertilizer in the Os1900 promoter were scanned using the PlantPAN3.0 program at a relative profile score threshold of 99%. Black triangles: CREs related to P; Pink triangles: CREs related to N; Red star marks: P1BSs. e Overlapping evolutionally conserved CREs of Os1900 (showed in d) with other MAX1-like genes (Os900, Os1400, Os5100). f Os1900 gene expression of various Os1900 promoter mutants to different fertilizer concentrations, n = 3,4 biologically independent samples. Means of M1–M9 were compared with the corresponding gene expression in WT in four conditions, respectively. 50 ppm 0 h and 1 h: TDS is 50 ppm and 245 ppm, respectively; 30 ppm 0 h and 1 h: TDS is 30 ppm and 245 ppm, respectively. Cultivation conditions and sampling time were the same with Fig. 5b. (*FDR < 0.05; **FDR < 0.01. FDR values, see Supplementary Data 4). Error bars indicate SD, Significance value is from Student’s t-test (two-tailed).
