Evolutionary studies of the bHLH transcription factors belonging to MBW complex: their role in seed development.

The ancestral function of these genes appears to be flavonoid biosynthesis and the conservation of TT8 expression patterns in the innermost layer of the seed coat in angiosperms suggests that their function in postzygotic barriers may also be conserved. Moreover, the literature review and the results of the present study suggest a sophisticated association, linking the mechanisms of action of these genes to the cross-communication activity between the different tissues of the seed. Thus, it provides avenues to study the mechanisms of action of TT8, in the postzygotic triploid block, which is crucial since it impacts seed development in unbalanced crosses.