Genome-wide identification and functional characterization of CLG family genes reveal likely roles in epidermal development in Arabidopsis.

Key message: We identified a CX₂CX₁₂CPXC motif and 11 CLG genes that regulate epidermal development by interacting with homeodomain leucine-zipper IV family proteins in Arabidopsis. Zinc finger proteins (ZFPs), the key regulators of plant growth and development, can be categorized based on the sequence patterns of zinc finger motifs. Here, by aligning the amino acid sequences of CFL1, AtCFL1, AtCFL2, GIRl, and GIR2, we identified the CX₂CX₁₂CPXC motif in their C-terminus, which differs from all the previously characterized canonical zinc finger motifs. A total of 11 non-canonical ZFPs were identified in Arabidopsis based on the pattern and we named these genes as the CLG family genes (CFL1-like genes). We further established that the family genes are randomly distributed on five chromosomes, containing two conserved motifs and possess various cis-acting elements associated with plant hormones, stress responses and tissue regulation. Moreover, the family genes exhibit a wide range of expression profiles, and all of these proteins have nuclear localization signals. They may affect epidermal development through interactions with homeodomain leucine-zipper IV (HD-ZIP IV) family proteins. Overall, these findings comprehensively characterize CLG family genes and lay a foundation for further elaborating their biological functions in plant growth and development.