Fig. 2

Ancient evolutionary trajectory of ARF genes in streptophytes. Annotation of auxin response factor genes suggested an early origin and diversification in streptophytic algae. The eight major plant lineages were represented with different colors, solid rounded rectangles indicate presence of ARF genes in corresponding plant lineages, dashed ones suggested absence of data and potential gene losses. Gene groups indicated with an asterisk represented close sister lineages to corresponding angiosperm ARFs. Inferred ancient gene duplications were depicted as golden squares. Group-I and Group-II ARFs was suggested to be derived from the seed plant duplication event