Hirokazu Tsukaya / The University of Tokyo; National Institutes of Natural Sciences
The land plant-specific ROT FOUR-LIKE/DEVIL (RTFL/DVL) family encodes small peptides and is suggestive of their functions in the regulation of positional cues and polarized cell proliferation of multiple developmental processes in Arabidopsis thaliana. Up to now, no loss-of-function study in this peptide family was reported for its high genetic redundancy.
In this study, we compared whole amino acid sequences of RTFL/DVL members from 22 species among land plants. The result indicated unique evolutionary traits in the RTFL/DVL family. We then analyzed two overexpressors of RTFL/DEVIL members in A. thaliana. Similar phenotypes of the overexpressors suggested a conserved function of RTFL/DVL family among land plants. Meanwhile, some distinct sub-phenotypes could also be, suggestive of their unique sub-functions in each phylogenetic clade.
For the purpose of uncovering the biological function of RTFL/DVL family, a double-RTFL/DVL overexpressor in A. thaliana was constructed and mutated by heavy-ion beam irradiation. Several suppressors showing rescued phenotypes were obtained after screening. Both RTFL genes were confirmed highly expressed in these suppressors, suggestive of the mutation in the downstream of RTFL/DVL signaling pathway. Quantification and comparison of the phenotypes based on several parameters of leaf blade and roots are analyzed among the suppressors. The evolution of RTFL/DVL family will also be discussed in this study.