title: Editing of plastid RNA in Arabidopsis thaliana ecotypes.
abstract: Post-transcriptional maturation of plastid-encoded mRNAs from land plants includes editing by making cytidine to uridine alterations at highly specific positions; this usually restores codon identities for conserved amino acids that are important for the proper function of the affected proteins. In contrast to the rather constant number of editing sites their location varies greatly, even between closely related taxa. Here, we experimentally determined the specific pattern of editing sites (the editotype) of the plastid genome of Arabidopsis thaliana ecotype Columbia (Col-0). Based on phylogenetic analyses of plastid open reading frames, we identified 28 editing sites. Two editing events in the genes matK and ndhB seem to have evolved late during the evolution of flowering plants. Strikingly, they are embedded in almost identical sequence elements and seem to be phylogenetically co-processed. This suggests that the two sites are recognized by the same trans-factor, which could help to explain the hitherto enigmatic gain of editing sites in evolution. In order to trace variations in editotype at the subspecies level we examined two other A. thaliana accessions, Cape Verde Islands (Cvi-0) and Wassilewskija (Ws-2), for the Col-0 editing sites. Both Cvi-0 and Ws-2 possess and process the whole set of editing sites as determined in Col-0, but the consequences of RNA editing differ at one position between the ecotypes.
authors.affiliation: Department für Biologie I der Ludwig-Maximilians-Universität München, Bereich Botanik, Menzingerstr. 67, 80638 München, Germany. tillich@staff.uni-marburg.de
authors.forename: Michael
authors.initials: M
authors.lastname: Tillich
authors.forename: Helena T
authors.initials: HT
authors.lastname: Funk
authors.forename: Christian
authors.initials: C
authors.lastname: Schmitz-Linneweber
authors.forename: Peter
authors.initials: P
authors.lastname: Poltnigg
authors.forename: Bartolomé
authors.initials: B
authors.lastname: Sabater
authors.forename: Mercedes
authors.initials: M
authors.lastname: Martin
authors.forename: Rainer M
authors.initials: RM
authors.lastname: Maier
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D008969:Molecular Sequence Data; D018087:Plastids / Q000235:genetics*; D017393:RNA Editing; D018749:RNA, Plant / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant