RNA editing of the barley (Hordeum vulgare) mitochondrial ATP synthase subunit 9.

The barley (Hordeum vulgare) FO-ATP synthase subunit 9 (atp9) was isolated from the mitochondrial DNA. Two copies of atp9 are present in barley mitochondria and 2 major transcripts of 2.7 kb and 1.2 kb were detected on RNA blots. RNA editing as C-to-U conversion occurs in barley atp9 in seven positions. Five of these seven positions lead to an amino acid change whereas two conversions are silent. The editing positions of barley were found to be identical to those of wheat. Whereas in wheat, Oenothera and Petunia all the atp9 transcripts were fully edited, 24% of the barley cDNA clones were partially edited as compared to 10% partially edited clones in wheat.