Fig. 4

The micro-collinearity analysis reveals the history of segmental duplication of chr. 8, which gives rise to a duplicated AG locus in cjaND. a The syntenic analysis of chr. 8 based orthologous gene-pairs. The gray and colored curves indicate the syntenic pairs of genes. The gene labels on the top are conserved genes associated with AG in ancestors of eudicots. The rectangle on the bottom indicates the chr.8 and the black shading areas indicate the syntenic blocks containing the two AG paralogs, within which the conserved two GDSL genes and NIP1 genes are found. b The representative genomic structure of the syntenic block containing AG genes, and only genes with orthologous pairs are shown. The length of arrow shapes is on scale with the length of gene model. The scale of intergenic region is ten times that of the gene coding region; the interrupted line indicates the length is longer than 1 Mb, and the details of gene locations are in the Supplementary Table S13. c The distribution of Ks values of syntenic gene-pairs in chr.8, and the top bin of Ks values is between 0.44 and 0.51. d–e Relative expression level of AG copies of C. japonica. CjAG1 (d) and CjAG2 (e) display similar expression patterns in single (cjaND) and doubled flowers (C. japonica “JINPANLIZHI”). SE, sepal; PE, petal; STA, stamen; CA, carpel; P-OUT, outer petal; P-IN, inner petal