Fig. 2.

Phylogenetic analysis of TRB proteins. (A) Simplified evolution of the main Viridiplantae lineages with known TRB proteins. One TRB protein evolved initially in Streptophyta in Klebsormidiophyceae, then diversified to three similar homologues in Mosses and Lycophyta and several diverse homologues in seed plants, with five members in A. thaliana from Brassicaceae. The evolutionary tree was adopted from Rensing 2020 and Cheng et al. 2019. (B) ML phylogenetic tree of TRB proteins. Twenty-seven species were included in 83 sequences with 465 bp in the final data set. Only one species from the family was selected for the final analysis. The ML likelihood is -24,356.573420. The numbers below branches indicate bootstrap support values > 50%. Four major groups are shown in the phylogenetic tree: TRB_A for Streptophyte algae, Lycophyta and Bryophyta; TRB_B including AtTRB4 and AtTRB5 for Embryophyta; TRB_C for Embryophyta with AtTRB1 and the nested TRB_D encompassing AtTRB2 and AtTRB3. Motifs are ranked and ordered by the highest probability of occurrence. Fifteen most probable motifs are depicted. For sequence and sequence conservation information, see Supplementary Fig. 1. For a list of species, see Supplementary Table 3