A Rice Dual-localized Pentatricopeptide Repeat Protein is involved in Organellar RNA Editing with MORFs

Abstract

Flowering plants engage in diverse RNA editing events in mitochondrion and chloroplast on post-transcriptional process. Although several PPRs and MORFs were identified as RNA editing factors, the underlying mechanism of PPRs and the cooperation among them are still obscure. Here, we identified a rice dual-localized PPR mutant Ospgl1. Loss-of-function of OsPGLl resulted in defect of chloroplast RNA editing at ndhD-878 and mitochondrial RNA editing at ccmFc-543, which can be restored via complementary validation. Despite the synonymous editing on ccmFc-543, loss of editing at ndhD-878 caused failure of conversion from serine to leucine, leading to the dysfunction of chloroplast and defective in photosynthetic complex, further studies demonstrated OsPGL1 directly bound to both two transcripts. The interaction between three MORFs (MORF2/8/9) and OsPGL1 were confirmed in vitro and in vivo, implied OsPGL1 functioned on RNA editing via an editosome. It also suggested MORFs assisted and contributed to the flexible PPR-RNA recognition model during RNA editing through the cooperation with PPRs. These results provide new insight into the relationship between RNA editing and plant development on chloroplast.\n\nHighlightWe firstly characterized a dual-localized PPR protein which is required for RNA editing in mitochondrion and chloroplast simultaneously. OsPGL1 binds to two distinguish target transcripts directly and cooperated with MORFs.