Identification and comparative genomics of OVATE Family Members from Gramineae uncovers sequence and structural diversity, evolutionary trends, and insights into functional features

Ovate Family Proteins (OFPs) are plant-specific, transcriptional repressors characterized by the presence of an OVATE domain. The OFP gene family has been analysed only from a handful of species, and functionally characterized from even fewer plants. Members of Gramineae have been subject of several investigations, and now has complete genome sequence for several species. Such analyses revealed diversity in genome size, ploidy and chromosome number. However, there exists a gap in cataloguing the complete compendium of OFP family across Gramineae. In the present study, we therefore identified and catalogued homologs of OFPs across ten Gramineae members to analyse gene and protein structure and properties, evolutionary relationship, expression pattern, and predict interacting partners. A positive correlation was found between genome-size and OFP family size, with Triticum genome harbouring the maximum number; most of the Gramineae OFPs are intronless. Comparative analysis revealed variation in gene sizes, protein physico-chemical properties and structures including motifs. Phylogenetic reconstruction reflected homolog-based clustering. Expression analysis in Oryza revealed spatio-temporal variation with maximum expression in reproductive tissues. Prediction of interactome showed homeobox domain containing proteins as major interacting partners. The study thus form foundation for future functional analysis of role of OFPs in regulating economically important traits.