Fig. 5: Duplication and preferential retention of BIAs biosynthetic genes.

a Schematic of the evolutionary history of plant BIA biosynthetic genes. Here specifically showed the duplication and retention pattern of the functional clade. The lowest branch represents the other clade of these ancient duplications, and the lineage names were determined by the species in these corresponding clades. Solid lines in different colors represent these lineages retained homologous genes, while gray dashed lines indicate those lineages that lost the duplicated genes. b Prediction of putative functional BIA biosynthetic genes. Evidence from phylogenetic clustering, key residues conservation, and experimental validation were used to predict BIA biosynthetic genes. Note, the previously identified CNMT gene in N. nucifera⁹ is not in the same clade of functional orthologs in other species. Enzymes involved in the shared-upstream biosynthetic pathway of BIAs were shown with red bold font. Microsynteny comparisons of syntenic blocks where CYP80B/NMCH (c), CNMT (d), 6OMT (e) located on. BIA biosynthetic genes in magnoliids and early-diverging eudicots exhibited an obvious syntenic relationship. Rectangles represent annotated genes, while directions differentiated with blue and green. Solid red lines linked the syntenic BIA biosynthesis genes. Dashed black lines linked the orthologous regions where the lost BIA genes located on. Species are abbreviated as: S. polyrhiza, Spol; A. tatarinowii, Atat; A. manshuriensis, Aman; S. henryi, Sahe; Piper nigrum, Pnig; C. kanehirae, Ckan; L. chinense, Lchi; Arabidopsis thaliana, Atha; Vitis vinifera, Vvin; Papaver somniferum, Psom; Coptis chinensis, Cchi; Nymphaea colorata, Ncol; A. trichopoda, Atri.