Identification of RNA editing sites in chloroplast transcripts of Phalaenopsis aphrodite and comparative analysis with those of other seed plants.

RNA editing sites were systematically examined for the transcripts of 74 known protein-coding genes in the chloroplasts of Phalaenopsis aphrodite. A total of 44 editing sites were identified in 24 transcripts, the highest reported in seed plants. In addition, 21 editing sites are unique to the Phalaenopsis orchid as compared with other seed plants. All editing is C-to-U conversion, and 42 editing sites bring about the changes in amino acids. One of the remaining two editing sites occurs in the transcripts of the ndhB pseudogene, and another in the 5'-untranslated region of psbH transcripts.