Fig. 5.

Evolution of the FRK class through the plant kingdom. All species analyzed are represented. The green star shows the first appearance of a FRK-like gene in the genome of A. trichopoda. Because of the challenging task of genome sequence assembly in Gymnosperms, it cannot be determined with certainty if the first FRK-like gene appeared before or after Angiospermae diversification. The red star shows the loss of the FRK class in monocots while the yellow stars refer to the expansion and emergence of new FRK groups. Numbers refer to FRK groups (1 to 4) found in each species