1C-04 Evolution of pentatricopeptide repeat gene family in angiosperms

Pentatricopeptide repeats (PPR) are a eukaryotic gene family that had intriguingly expanded their family size by 50-100 times during higher plant evolution. From the recent functional genomic studies, almost all of the plant PPR proteins are found to localized in chloroplast or mitochondria, and they are involved in versatile post-transcriptional RNA modification processes such as RNA cleavage, editing, stabilization and translation. In this study we have characterized the evolution of the mitochondrial Restorer of fertility PPR (Rf-PPR) genes, the class of PPR genes that had counter-evolved against higher plant specific cytoplasmic male sterility (CMS). CMS is a mitochondrially-inherited male sterility phenomenon that is often observed in natural population, and it is also an important crop trait utilized for F1 hybrid breeding. In this presentation, insights of how evolutional selective constraints acting upon Rf-PPR genes can be related to plant sexual expression through CMS will be discussed. This study also highlighted the amino acid residues responsible for RNA-recognition, from the position specific selection pattern of the PPR motifs in Rf-PPR genes.