Analysis of chloroplast RNA editing sites in phalaenopsis aphrodite

RNA editing sites were systematically examined for the transcripts of 74 known protein-coding genes in the chloroplasts of P. aphrodite. A total of 44 editing sites were identified in 24 transcripts, the highest number reported in seed plants to date. In addition, 21 editing sites were unique to Phalaenopsis as compared to other seed plants. All editing was C-to-U conversion, and 42 editing sites caused the change in amino acids. One of the remaining two editing sites occurred in transcripts of the ndhB pseudogene, and another in the 5' untranslated region of psbH transcripts. However, RNA editing did not restore the continuous open reading frame in the frameshifted ndh genes, further confirming that they are pseudogenes.