Fig. 2.

The phylogenetic tree and evolutionary roadmap of LHC proteins. (A). Phylogenetic tree of LHC-like subfamily. (B). Phylogenetic tree of FCP subfamily. The detailed information of A and B is provided in Figs. S5 and S6, respectively. (C and D). Structural diagrams of members of LHC-like and FCP subfamilies. (E). Evolutionary roadmap of LHC genes. The arrows indicate endosymbiotic relationships. Cyanobacteria evolved into plastids in three major groups: red algae, glaucophytes, and green algae through primary endosymbiosis. Green algae produce plastids in chlorarachniophytes via secondary endosymbiosis. Red algae generate cryptophyte plastids through secondary endosymbiosis. Cryptophytes produce plastids in haptophytes and stramenopiles through tertiary endosymbiosis. Haptophytes produce plastids in dinoflagellates through quaternary endosymbiosis. The arrows denote the direction of endosymbiotic events. The color of the arrows corresponds to distinct endosymbiotic origins: blue for cyanobacteria, green for green algae, purple for rhodophytes, light blue for cryptophytes, and orange for haptophytes. Thick lines denote major lineages: dark/light green, green lineage; gray, glaucophyte lineage; red/orange, red lineage.