PPR2263, a DYW-Subgroup Pentatricopeptide Repeat Protein, Is Required for Mitochondrial nad5 and cob Transcript Editing, Mitochondrion Biogenesis, and Maize Growth

• Published in: The Plant cell 2012-02, Vol.24 (2), p.676-691
• Main Authors: Sosso, Davide, Mbelo, Sylvie, Vernoud, Vanessa, Gendrot, Ghislaine, Dedieu, Annick, Chambrier, Pierre, Dauzat, Myriam, Heurtevin, Laure, Guyon, Virginie, Takenaka, Mizuki, Rogowsky, Peter M.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Arabidopsis - genetics; Arabidopsis - growth & development; Chloroplasts; Chloroplasts - enzymology; Corn; Cytochromes b - genetics; Development Biology; Flowering plants; Gene Expression Regulation, Plant; Life Sciences; Microscopy, Electron, Transmission; Mitochondria; Mitochondria - enzymology; Mitochondria - ultrastructure; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Molecular Sequence Data; Mutagenesis, Insertional; NADH Dehydrogenase - genetics; Oxidoreductases - metabolism; Phenotype; Phenotypes; Plant cells; Plant growth; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Proteins; RNA; RNA Editing; RNA, Plant - genetics; Seedlings; Seeds - growth & development; Sexual maturity; Vegetal Biology; Zea mays - genetics; Zea mays - growth & development; Zea mays - metabolism
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.111.091074

RNA editing plays an important role in organelle gene expression in various organisms, including flowering plants, changing the nucleotide information at precise sites. Here, we present evidence that the maize (Zea mays) nuclear gene Pentatricopeptide repeat 2263 (PPR2263) encoding a DYW domain-containing PPR protein is required for RNA editing in the mitochondrial NADH dehydrogenase5 (nad5) and cytochrome b (cob) transcripts at the nad5-1550 and cob-908 sites, respectively. Its putative ortholog, MITOCHONDRIAL EDITING FACTOR29, fulfills the same role in Arabidopsis thaliana. Both the maize and the Arabidopsis proteins show preferential localization to mitochondria but are also detected in chloroplasts. In maize, the corresponding ppr2263 mutation causes growth defects in kernels and seedlings. Embryo and endosperm growth are reduced, leading to the production of small but viable kernels. Mutant plants have narrower and shorter leaves, exhibit a strong delay in flowering time, and generally do not reach sexual maturity. Whereas mutant chloroplasts do not have major defects, mutant mitochondris lack complex III and are characterized by a compromised ultrastructure, increased transcript levels, and the induction of alternative oxidase. The results suggest that mitochondrial RNA editing at the cob-908 site is necessary for mitochondrion biogenesis, cell division, and plant growth in maize.