Two Consequential Whole-Genome Triplications and The Formation Of The Solanaceae Genome

Comparison of tomato genome to grape genome revealed a eudicot-common triplication and a more recent triplication. The later one is shared by tomato and potato, but not other asteroid plants well-characterized so far, including monkey flower, sunflower, and lettuce. This recent triplication is estimated to have occurred at 71(+/-19.4) mya based on Ks between paralogous genes produced the event, which was overlapped with KT extinction, which was inferred to kill the majority of plants and animals, including dinosaurs. We also shows that the divergence of lamiid-campanulid, two main asteroid lineages, and rosid-asterid are all near the occurrence of the aforementioned triplication common to major eudicots, suggesting that the hexaploidization was responsible for the formation of major eudicot lineages in a short time of several million years, which at least partially explained the mystery of the explosion of angiosperm plants on earth. By using the asterid and rosid genomes, we constructed the ancestral genomes of eudicots, the most comprehensive one so far, and that of Solanaceae.