RNA editing may stabilize membrane-embedded proteins by increasing phydrophobicity: A study of Zanthoxylum piperitum and Z. schinifolium chloroplast NdhG

•C-to-U RNA editing occurs at the ndhG-50 site in two Zanthoxylum species.•This RNA-editing site is partially conserved in dicotyledonous plants (Ser to Leu/Phe).•Many monocots already encode the amino acids resulting from ndhG-50 RNA editing.•RNA editing may increase the hydrophobicity of NdhG for membrane incorporation.•When available, RNA editing should be considered when assessing Ka/Ks values. Most chloroplast genes in Zanthoxylum schinifolium (Korean pepper) and Z. piperitum (Japanese pepper) are subject to neutral or purifying selection (Ka/Ks values