Extended Data Fig. 4: Evolutionary tree of the RADIALIS family genes in angiosperms.

a, Phylogenetic tree of RADIALIS-like genes from representative eudicot species. We selected outgroup genes in the Arabidopsis thaliana genome (RAD1 and RAD3 clades), based on the previous study on clustering of RADIALIS-like genes (Gao et al. 2017). RADIALIS from Antirrhinum majus, which was originally identified as the RADIALIS gene, and DkRAD and DkRAD2 (from D. kaki) were indicated in green and red, respectively. They were nested into the same clade, the RAD2, with significant statistic support (bootstrap value = 0.93). b, Phylogenetic tree of RADIALIS-like genes within the RAD2 clade, with the genes from various angiosperms species (homology e-value < 1e⁻³⁰), using CCA1-like genes from A. thaliana as the outgroup. Although this clade was thought to be basically monophyletic, each lineage underwent frequent duplications. DkRAD and DkRAD2 were also derived from a lineage-specific duplication. c, Expression patterns of the two RADIALIS-like genes, DkRAD and DkRAD2, in hexaploid D. kaki and diploid D.lotus. DkRAD expression was not detectable in diploid D. lotus, or in stage 3 in D.kaki, but it was expressed in stage 2 flowers of D. kaki. DkRAD2 exhibited AH-specific upregulation in D. kaki (as evidenced by the fact that belongs to Clst 4, Fig. 1f) and was expressed at some level in all samples examined, including diploid D. lotus.