C-to-U RNA editing events are prevalent in land plant organelles. Specificity of these events is mediated by PPR proteins, which recognize and bind RNA sequences via their PPR motifs. I performed RNA-seq on two mutant Arabidopsis lines to identify mitochondrial editing events mediated by the PPR proteins AT1G13410 (MEF134) and BIR1 (AT3G61170) respectively. Restoration of editing at these sites was confirmed in mutants complemented by Agrobacterium floral dip transformation. MEF134 is required for editing of nad5-553 and nad3-352. BIR1 is required for editing of the nad1-493, nad4-403, nad7-698 and ccmFN2-356 sites.