Fig. 6: Natural variation in OsMYB8 promoter confers DFOT divergence in japonica and indica.

a Haplotype analysis of OsMYB8 promoter in the 3513 rice germplasms. Nucleotide variations in the 2-kb promoter of OsMYB8 were shown. b Distribution frequency of the three OsMYB8 haplotypes in diverse Asian cultivated rice accession. The haplotype with the largest number was highlighted in red. c Nucleotide diversity (π) of a 100-kb genomic region surrounding OsMYB8 in the indica (Ind), temperate japonica (TeJ) and O. rufipogon (Ruf). The regions (Chr1: 25,590,725–25,592,725) between two black vertical lines indicates the position of OsMYB8 promoter. d F_ST values of TeJ_Ind, Ruf_TeJ, and Ruf_Ind in a 100-kb genomic region surrounding OsMYB8. The region (Chr1: 25,590,725–25,592,725) between two black vertical lines indicates the position of OsMYB8 promoter. e The DFOT of the rice accessions with Hap1 and Hap2 in May 2022 in Guangzhou. (n = 30 accessions). f Relative expression levels of OsMYB8 in lodicules of the rice accessions with Hap1 and Hap2, respectively. (n = 10 accessions). g JA-Ile content in TFB and ZH11 lodicules at 9:00 am. (n = 3 biological replicates). h Transient dual-luciferase assays showing the transcriptional activity of pOsMYB8^Hap1 and pOsMYB8^Hap2 in rice protoplasts. (n = 3 technical replicates). The values in f–h are shown as mean ± SEM. Significance is evaluated by the two-sided Student’s t-test, and P values are indicated. i Relative expression levels of OsMYB8 in lodicules of ZH11, OsMYB8^TF/Osmyb8^ZH transgenic lines and the Osmyb8^ZH mutant. Values are mean ± SEM. (n = 3 biological replicates). Letters above the bars indicate significant differences (P < 0.05), as evaluated by one-way ANOVA with Tukey’s multiple comparisons test. j Comparison of panicles in ZH11, OsMYB8^TF/Osmyb8^ZH transgenic lines and the Osmyb8^ZH mutant at 11:30 am in October 2022 in Guangzhou. Scale bars, 1 cm. k Number of opened florets in ZH11, OsMYB8^TF/Osmyb8^ZH transgenic lines, and the Osmyb8^ZH mutant at different time points of the day in October 2022 in Guangzhou. Values are mean ± SEM. (n = 10 panicles). Source data are provided as a Source Data file.